Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] SBI Bonds Corporate Debt Securities [Member] Total Long-term borrowings Long-term Debt [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Senior Secured Credit Facility Senior Secured Credit Facility [Member] Represents information pertaining to the senior secured credit facility. Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Senior Secured Second Lien Notes Senior Secured Second Lien Notes [Member] Represents information pertaining to the senior secured second lien notes. Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Interest rate Debt Instrument, Interest Rate, Stated Percentage Outstanding Principal Long-term Debt, Gross Discount Debt Instrument, Unamortized Discount Deferred Debt Issuance Cost Debt Issuance Costs, Net Outstanding Borrowings, net Long-term Debt Broker-dealer credit facilities Broker Dealer Credit Facilities [Member] Represents information pertaining to the credit facility entered with broker-dealer subsidiaries. Broker-dealer credit facility on an uncommitted basis Uncommitted Broker Dealer Credit Facility [Member] Represents information pertaining to the credit facility entered with broker-dealer subsidiaries on an uncommitted basis. Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Number of secured credit facilities Number Of Secured Credit Facilities Represents the number of secured credit facilities. Aggregate borrowing Debt Instrument, Unused Borrowing Capacity, Amount Number of borrowing bases Number Of Borrowing Bases The number of borrowing bases for a credit facility. Number of broker-dealer subsidiaries Number of Broker Dealer Subsidiaries of Entity Represents the number of broker-dealer subsidiaries of the entity. Interest rate margin (as a percent) Debt Instrument, Basis Spread on Variable Rate Number of broker-dealer subsidiaries the committed facility is available to Number Of Broker Dealer Subsidiaries Committed Facility Is Available To Number of broker-dealer subsidiaries that the committed facility is available to. Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Commitment fee (as a percent) Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Commitments and Contingencies Disclosure [Abstract] Schedule of minimum rental commitments under non-cancellable leases Schedule Of Future Minimum Rental Payments For Capital And Operating Leases Table Text Block Tabular disclosure of future minimum payments required in the aggregate and for each of the five succeeding fiscal years for capital and operating leases having initial or remaining noncancelable lease terms in excess of one year and the total minimum rentals to be received in the future under noncancelable subleases as of the balance sheet date. Condensed Financial Information Disclosure [Abstract] Condensed Statements of Financial Condition Condensed Financial Statements [Table Text Block] Condensed Statements of Comprehensive Income Condensed Statement of Comprehensive Income [Table Text Block] Condensed Statements of Cash Flows Condensed Cash Flow Statement [Table Text Block] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Short-Term Credit Facilities Short Term Credit Facilities [Member] Represents the information pertaining to the short term credit facility. Short-term Debt [Line Items] Short-term Debt [Line Items] Weighted Average Interest Rate Short-term Debt, Weighted Average Interest Rate, at Point in Time Financing Available Borrowing Outstanding Interest expense Interest Expense, Debt Fair Value Disclosures [Abstract] Summary of fair value measurements measured on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Summary of changes in Level 3 financial instruments measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Summary of netting of certain financial assets and financial liabilities Offsetting Assets and Offsetting Liabilities [Table Text Block] Tabular disclosure of derivative and other financial assets and liabilities that are subject to offsetting, including master netting arrangements. Summary of gross obligations for repurchase agreement and securities borrowed transactions by remaining contractual maturity and class of collateral pledged Schedule Of Remaining Contractual Maturity And Class Of Collateral Pledged [Table Text Block] Tabular disclosure of information by remaining contractual maturity and class of collateral pledges. Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Total Virtu Financial Inc. Stockholders' Equity Parent [Member] Common Stock Common Stock [Member] Treasury Stock Treasury Stock, Common [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Non-Controlling Interest Noncontrolling Interest [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Class A Common Class A [Member] Class C Common Class C [Member] Class D Common Class D [Member] Represents the information pertaining to classification of common stock that has different rights than provided to Class A or B or C shares, representing ownership interest in a corporation. Statement [Line Items] Statement [Line Items] Increase (decrease) in stockholder's/members' equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at beginning period (in shares) Shares, Issued Balance at beginning of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Share based compensation (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Share based compensation Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Repurchase of Class C common stock (in shares) Stock Repurchased During Period, Shares Repurchase of Class C common stock Stock Repurchased During Period, Value Treasury stock purchases (in shares) Treasury Stock, Shares, Acquired Treasury stock purchases Treasury Stock, Value, Acquired, Cost Method Stock option exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock option exercised Stock Issued During Period, Value, Stock Options Exercised Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Foreign exchange translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Distribution from Virtu Financial to non-controlling interest Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Dividends Dividends, Common Stock Issuance of common stock in connection with secondary offering, net of offering costs (in shares) Stock Issued During Period Secondary Offering Shares New Issues Number of new stock issued during the period in a secondary offering. Issuance of common stock in connection with secondary offering, net of offering costs Stock Issued During Period Secondary Offering Value New Issues Equity impact of the value of new stock issued during the period in a secondary public offering. Issuance of Class A common stock (in shares) Stock Issued During Period, Shares, New Issues Issuance of Class A common stock Stock Issued During Period, Value, New Issues Issuance of common stock in connection with employee exchanges (in shares) Stock Issued During Period, Shares, Employee Exchanges Stock Issued During Period, Shares, Employee Exchanges Repurchase of Virtu Financial Units and corresponding number of Class C common stock in connection with secondary offering (in shares) Stock Repurchased During Period, Net Of Offering Costs Adjustment, Shares Stock Repurchased During Period, Net Of Offering Costs Adjustment, Shares Repurchase of Virtu Financial Units and corresponding number of Class C common stock in connection with secondary offering Stock Repurchased During Period, Net Of Offering Costs Adjustment, Value Stock Repurchased During Period, Net Of Offering Costs Adjustment, Value Repurchase of Virtu Financial Units and corresponding number of Class C common stock in connection with employee exchanges (in shares) Common Units Repurchased During Period In Secondary Offering Shares Number of members interests that have been repurchased during the period as part of a secondary offering and have not been retired and are not held in treasury. Issuance of tax receivable agreements in connection with employee exchange Adjustments To Additional Paid In Capital, Increase (Decrease) In Tax Receivable Agreement Adjustments To Additional Paid In Capital, Increase (Decrease) In Tax Receivable Agreement Issuance of tax receivable agreements in connection with secondary offering Adjustments to Additional Paid in Capital Issuance of Tax Receivable Agreements In Connection With Secondary Offering Amount of increase in additional paid in capital (APIC) resulting from issuance of tax receivable agreements in connection with secondary offering. Balance at end of period Balance at end of period (in shares) Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2015 Management Incentive Plan Management Incentive Plan2015 [Member] Represents information pertaining to 2015 Management Incentive Plan. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Exercised (in shares) Forfeited or expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Outstanding at end of period (in shares) Weighted Average Exercise Price Per Share Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Outstanding at end of period (in dollars per share) Weighted Average Remaining Contractual Life Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Weighted Average Remaining Life Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options Exercisable, Number of Options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Options Exercisable, Weighted Average Exercise Price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] BondPoint Bond Point Division And Fixed Income Venue [Member] Represents information related to the Company’s BondPoint division and fixed income venue. Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Held for Sale Discontinued Operations, Held-for-sale [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Total sale proceeds received Proceeds from Divestiture of Businesses Business assets and liabilities held for sale: Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Receivables from broker dealers and clearing organizations Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Intangibles and other assets Disposal Group, Including Discontinued Operation, Intangible Assets Liabilities Disposal Group, Including Discontinued Operation, Liabilities Total carrying value of BondPoint Disposal Group, Including Discontinued Operation, Net Assets (Liabilities) Disposal Group, Including Discontinued Operation, Net Assets (Liabilities) Goodwill adjustment allocated to BondPoint Goodwill, Written off Related to Sale of Business Unit Gain on sale of BondPoint Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Excluding Transaction Costs Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Excluding Transaction Costs Transaction costs Disposal Group, Not Discontinued Operation, Transaction Costs Disposal Group, Not Discontinued Operation, Transaction Costs Gain on sale of BondPoint, net of transaction costs Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Diluted earnings per share: Earnings Per Share, Diluted [Abstract] Net income (loss) available for common stockholders, net of dividends and undistributed earnings allocated to participating securities Net Income (Loss) Available to Common Stockholders, Diluted Weighted average shares of common stock outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Issued and outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Issuable pursuant to 2015 Management Incentive Plan (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted average shares of common stock outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted earnings per share (in dollars per share) Earnings Per Share, Diluted Anti-dilutive shares excluded from computation of EPS Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Revenue from Contract with Customer [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Market Making Market Making Segment [Member] Information pertaining to the reportable segment of the entity representing Market Making. Execution Services Execution Services Segment [Member] Information pertaining to the reportable segment of the entity representing Execution Services. Corporate Corporate Segment [Member] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Commissions, net Commissions, Net [Member] Commissions, Net [Member] Technology services Technology Services [Member] Technology Services [Member] Other sources of revenue Other Sources [Member] Other Sources [Member] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Services transferred at a point in time Transferred at Point in Time [Member] Services transferred over time Transferred over Time [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenues from contract with customers Revenue from Contract with Customer, Excluding Assessed Tax Total revenue Revenues Receivables related to revenue from contracts with customers Contract with Customer, Asset, Net Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] Selling Stockholders Over-Allotment Option [Member] Class of Stock [Line Items] Class of Stock [Line Items] Number of shares issued Purchase price per share (in dollars per share) Shares Issued, Price Per Share Offering price per share (in dollars per share) Shares Issued, Offering Price Per Share Shares Issued, Offering Price Per Share Number of shares of stock issued Number of shares issued upon exercise of stock options Regulatory Capital Requirements [Abstract] Schedule of regulatory capital and regulatory capital requirements Regulatory Capital and Regulatory Capital Requirement [Table Text Block] Tabular disclosure of regulatory capital and regulatory capital requirements. Borrowings Debt Disclosure [Text Block] Accounting Policies [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Capitalized software Software Development [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Estimated useful lives Property, Plant and Equipment, Useful Life Uncommitted facility Committed facility Committed Broker Dealer Credit Facility [Member] Represents information pertaining to the credit facility entered with broker-dealer subsidiaries on committed basis. Revolving credit facility Revolving Credit Facility [Member] Capital Structure Stockholders' Equity Note Disclosure [Text Block] Segment Reporting [Abstract] Geographic Information and Business Segments Segment Reporting Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of fair value of derivative instruments on a gross basis Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of net gain from derivative instruments not designated as hedging instruments Derivative Instruments, Gain (Loss) [Table Text Block] Collateralized Agreements [Abstract] Summary of the fair value of collateralized transactions Schedule of Customer Securities for which Entity has Right to Sell or Repledge [Table Text Block] Schedule of financial instruments owned and pledged, where counterparty has right to repledge Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block] Business Combinations [Abstract] Acquisition of KCG Business Combination Disclosure [Text Block] Earnings per Share Earnings Per Share [Text Block] Financial Assets and Liabilities Fair Value Disclosures [Text Block] 2019 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 and thereafter Long Term Debt Maturities Repayments of Principal in Year Four and Thereafter Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fourth fiscal year and thereafter following the latest fiscal year. Total principal of long-term borrowings Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] RSUs Restricted Stock Units (RSUs) [Member] Number of Shares Outstanding at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Outstanding at end of period (in shares) Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Outstanding at end of period (in dollars per share) Number of days prior to the grant that common stock and restricted stock units fair value is determined based on Common Stock And Restricted Stock Units Number Of Days Preceding Grant Fair Value Is Based On The number of days prior to the grant that common stock and restricted stock units fair value is determined based on. Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Lease liability Operating Lease, Liability Right-of-use asset Operating Lease, Right-of-Use Asset Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] United States UNITED STATES Ireland IRELAND United Kingdom UNITED KINGDOM Singapore SINGAPORE Others Other Countries [Member] Represents information related to other countries not listed separately. Revenues from External Customers [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Class A common stock and Class C common stock Common Class A And C [Member] Represents the information pertaining to classification of common stock of A and C representing ownership interest in a corporation. Class D common stock Class B common stock and Class D common stock Common Class B And D [Member] Represents the information pertaining to classification of common stock of B and D representing ownership interest in a corporation. Number of classes of common stock Number Of Classes Of Common Stock Represents the number of Classes of common stock. Number of votes Number of Votes to Stockholders Represents the information pertaining to number of votes provided to stockholders on all matters. Non-voting common interest units outstanding (in shares) Nonvoting Common Interest Units Outstanding Number of non-voting common interest units outstanding related to former Class A-2 profits, interests, Class B and East MIP Class B interests that were reclassified into non-voting common interest units. Number of non-voting common interest units forfeited or repurchased (in shares) Nonvoting Common Interest Units Forfeited Or Repurchased Number of non-voting common interest units forfeited or repurchased during the period. Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] SBI S B I Japannext [Member] Represents information related to SBI Japannext Co., Ltd, an equity method investment of the entity. Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Transfers of financial instruments between levels Fair Value Assets Transfers Amount Amount of transfers of assets measured on a recurring basis in and out of the levels of fair value hierarchy. Discount rate applied to cash flow forecasts to determine initial fair value of equity method investment. Discounted Cash Flow Method Discount Rate Discount rate applied to cash flow forecasts to determine initial fair value of equity method investment. Market approach average price/earnings multiples of comparable companies to corroborate the income approach Average Price To Earnings Multiples Of Comparable Companies Market approach average price/earnings multiples of comparable companies to .the income approach. Time period of projected income to determine fair value of equity method investment Time Period Of Projected Income To Determine Fair Value Of Equity Method Investment The time period of projected income to determine fair value of equity method investment. Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Equity securities Equity Securities [Member] U.S. and Non-U.S. government obligations U S And Non U S Government Obligations [Member] Represents information pertaining to the U.S. and non-US government obligations. Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Overnight and Continuous Overnight And Continuous [Member] Represents remaining contractual maturity of overnight and continuous. Less than 30 days Maturity Less than 30 Days [Member] 30 - 60 days Maturity30 To60 Days [Member] Maturity period that is more than 29 days but fewer than 61 days from the reporting date for repurchase agreements and similar transactions, for example, but not limited to, securities lending arrangements. 61 - 90 Days Maturity61 To90 Days [Member] Maturity period that is more than 60 days but fewer than 91 days from the reporting date for repurchase agreements and similar transactions, for example, but not limited to, securities lending arrangements. Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Remaining contractual maturity for securities sold under agreements to repurchase Repurchase Agreement Remaining Contractual Maturity Remaining contractual maturity for repurchase agreements. Remaining contractual maturity for securities loaned Securities Lending Transaction Remaining Contractual Maturity Remaining contractual maturity for securities lending transactions. Use of Estimates Use of Estimates, Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Securities Borrowed and Securities Loaned Securities Borrowed and Loaned Policy [Policy Text Block] Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase Repurchase and Resale Agreements Policy [Policy Text Block] Receivables from/Payables to Broker-dealers and Clearing Organizations Receivables from or Payables to Broker Dealers and Clearing Organizations [Policy Text Block] Disclosure of accounting policy for receivables from or payables to broker-dealers and clearing organizations. Financial Instruments Owned Including Those Pledged as Collateral and Financial Instruments Sold, Not Yet Purchased Fair Value of Financial Instruments, Policy [Policy Text Block] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Fair Value Option Fair Value Option [Policy Text Block] Disclosure of accounting policy for fair value election for certain eligible financial assets and liabilities. Derivative Instruments Derivatives, Policy [Policy Text Block] Property, Equipment and Occupancy Property, Plant and Equipment, Policy [Policy Text Block] Lease Loss Accrual Lease Loss Accrual [Policy Text Block] Disclosure of accounting policy for lease loss accrual. Capitalized Software Internal Use Software, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Intangible Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Exchange Memberships and Stock Exchange Memberships, Policy [Policy Text Block] Trading Income, net Trading Income [Policy Text Block] Disclosure of accounting policy for trading income. Commissions, net and Technology Services Commissions Net And Technology Services [Policy Text Block[ Disclosure of accounting policy for commissions, net and technology services. Interest and Dividends Income/Interest and Dividends Expense Interest and Dividends Income or Expense [Policy Text Block] Disclosure of accounting policy for interest and dividends income and interest and dividends expense. Brokerage, Exchange and Clearance Fees, Net Brokerage Exchange And Clearance Fees Net [Policy Text Block] Disclosure of accounting policy for brokerage, exchange and clearance fees, net. Payments for Order Flow Payments for Order Flow [Policy Text Block] Disclosure of accounting policy for payments for order flow. Income Taxes Income Tax, Policy [Policy Text Block] Comprehensive Income and Foreign Currency Translation Comprehensive Income, Policy [Policy Text Block] Share-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] Accounting Pronouncements, Recently Adopted and Accounting Pronouncements, Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Income Tax Disclosure [Abstract] Net income (loss) before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract] U.S. operations Income (Loss) from Continuing Operations before Income Taxes, Domestic Non-U.S. operations Income (Loss) from Continuing Operations before Income Taxes, Foreign Income before income taxes and noncontrolling interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision for income taxes Income Tax Expense (Benefit), Continuing Operations [Abstract] Current provision (benefit) Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State and Local Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Deferred provision (benefit) Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State and Local Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Provision for income taxes Income Tax Expense (Benefit) Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of businesses managed and operated Number Of Businesses Operated And Managed As Number of businesses the entity is managed and operated as. Number of reportable segments Number of Reportable Segments Number of operating segments Number of Operating Segments Number of non-operating segments Number Of Non-Operating Segments Number Of Non-Operating Segments Income (loss) before income taxes and noncontrolling interest Summary of assets and liabilities of businesses held for sale Disposal Groups, Including Discontinued Operations [Table Text Block] Offsetting Assets [Table] Offsetting Assets [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Currency forwards Foreign Exchange Forward [Member] Options Options Held [Member] Offsetting Assets [Line Items] Offsetting Assets [Line Items] Securities borrowed Offsetting Securities Borrowed [Abstract] Gross Amounts of Recognized Assets Securities Borrowed, Gross Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Securities Borrowed Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Securities Borrowed Gross Amounts Not Offset [Abstract] No definition available. Financial Instruments Securities Borrowed Not Offset Financial Instruments Represents the amount of securities borrowed that could be offset by securities loaned subject to master netting arrangements, but management elects not to offset. Cash Collateral Received Securities Borrowed, Collateral, Obligation to Return Cash Net Amount Securities Borrowed Net Represents the net amount of securities borrowed after the effects of master netting arrangements and collateral. Securities purchased under agreements to resell Securities Purchased under Agreements to Resell [Abstract] Gross Amounts of Recognized Assets Securities Purchased under Agreements to Resell, Gross Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Securities Purchased under Agreements to Resell Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Securities Purchased under Agreements to Resell, Amount Offset Against Collateral [Abstract] Financial Instruments Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities Cash Collateral Received Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Cash Net Amount Securities Purchased under Agreements to Resell, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Trading assets, at fair value: Offsetting Trading Assets at Fair Value [Abstract] Gross Amounts of Recognized Assets Derivative Asset, Fair Value, Gross Asset Gross Amounts Offset in the Consolidated Statement of Financial Condition Derivative Asset, Fair Value, Gross Liability Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Derivative Asset Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Derivative Fair Value of Derivative Asset Gross Amounts Not Offset [Abstract] No definition available. Financial Instruments Derivative Asset Not Offset Financial Instruments Represents the amount of derivative assets that could be offset by derivative liabilities subject master netting arrangements, but management elects not to offset. Cash Collateral Received Derivative, Collateral, Obligation to Return Cash Net Amount Derivative Fair Value of Derivative Asset after Application of Master Netting Agreements and Cash and Securities Collateral Represents the amount of fair value of derivative assets, net of master netting arrangements and collateral. Total Offsetting Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed [Abstract] Gross Amounts of Recognized Assets Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Gross Gross Amounts Offset in the Consolidated Statement of Financial Condition Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Liability Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Derivative Asset Securities Purchased under Agreements to Resell Securities Borrowed Gross Amounts Not Offset [Abstract] No definition available. Financial Instruments Derivative Asset Securities Purchased under Agreements to Resell Securities Borrowed Not Offset Financial Instruments Represents the amount of derivative assets, securities purchased under agreements to resell and securities borrowed that could be offset by liabilities subject to master netting arrangements, but management elects not to offset. Cash Collateral Received Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Collateral, Obligation to Return Cash Net Amount Derivative Asset Securities Purchased under Agreements to Resell Securities Borrowed Net Represents the fair value of derivative assets, securities purchased under agreements to resell and securities borrowed, net of master netting arrangements and collateral. Current income taxes receivable Income Taxes Receivable, Current Current taxes payable Taxes Payable, Current Deferred tax asset, alternative minimum tax Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Operating loss carryforwards Operating Loss Carryforwards Deferred tax asset, non-U.S. operating loss carryforward Deferred Tax Assets, Operating Loss Carryforwards, Foreign Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Tax Cuts and Jobs Act, incomplete accounting change in rate, provisional income tax expense Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense Amount of reasonable estimate for income tax expense for remeasurement of deferred tax asset from change in tax rate pursuant to Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete. Minimum Rental Commitments, Capital Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2020 Capital Leases, Future Minimum Payments Due in Two Years 2021 Capital Leases, Future Minimum Payments Due in Three Years Total minimum lease payments Capital Leases, Future Minimum Payments Due Minimum Rental Commitments, Operating Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Due Minimum Rental Commitments, Subleases Operating Leases, Future Minimum Payments Receivable [Abstract] 2019 Operating Leases, Future Minimum Payments Receivable, Current 2020 Operating Leases, Future Minimum Payments Receivable, in Two Years 2021 Operating Leases, Future Minimum Payments Receivable, in Three Years 2022 Operating Leases, Future Minimum Payments Receivable, in Four Years 2023 Operating Leases, Future Minimum Payments Receivable, in Five Years Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Receivable Minimum Rental Commitments, Net Rental Commitments Net Rental Commitments, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Net Rental Commitments, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Net Rental Commitments, Future Minimum Payments Due, Next Twelve Months Net Rental Commitments, Future Minimum Payments Due, Next Twelve Months 2020 Net Rental Commitments, Future Minimum Payments, Due In Two Years Net Rental Commitments, Future Minimum Payments, Due In Two Years 2021 Net Rental Commitments, Future Minimum Payments, Due In Three Years Net Rental Commitments, Future Minimum Payments, Due In Three Years 2022 Net Rental Commitments, Future Minimum Payments, Due In Four Years Net Rental Commitments, Future Minimum Payments, Due In Four Years 2023 Net Rental Commitments, Future Minimum Payments, Due In Five Years Net Rental Commitments, Future Minimum Payments, Due In Five Years Thereafter Net Rental Commitments, Future Minimum Payments, Due Thereafter Net Rental Commitments, Future Minimum Payments, Due Thereafter Total minimum lease payments Net Rental Commitments, Future Minimum Payments Due Net Rental Commitments, Future Minimum Payments Due Operating lease expense, net of amortization expense related to landlord incentives Operating Leases, Rent Expense Occupancy lease expense Occupancy Lease Expense Represents the amount of occupancy lease expense under operating leases. Communication equipment lease expense Communication Equipment Lease Expense Represents the amount of communication equipment lease expense under operating leases. Goodwill and Intangible Assets Disclosure [Abstract] Schedule of goodwill by segment Schedule of Goodwill [Table Text Block] Schedule of acquired intangible assets Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Number of shares of stock authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Furniture and equipment Furniture and Fixtures [Member] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] JV building microwave communication networks in US and Asia Joint Venture Building Microwave Communication Networks In U S And Asia [Member] Represents information related to a joint venture that the entity has invested in which is building microwave communication networks in the U.S. And Asia. JV building microwave communication networks in US and Europe Joint Venture Building Microwave Communication Networks In U S And Europe [Member] Represents information related to a joint venture that the entity has invested in which is building microwave communication networks in the U.S. And Europe. Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Number of other investors in JV Number Of Other Investors In Joint Venture The number of other investors in a joint venture. Ownership of voting shares of JV held be each investor (as a percent) Percentage Ownership Of Voting Shares Of Joint Venture Held By Each Investor The percentage ownership of voting shares of joint venture held be each investor. Ownership of equity of JV held be each investor (as a percent) Percentage Ownership Of Equity Of Joint Venture Held By Each Investor The percentage ownership of equity of joint venture held be each investor. Ownership of voting shares (as a percent) Equity Method Investment Voting Shares Percentage Percentage of voting equity interests acquired in a joint venture. Ownership interest (as a percent) Equity Method Investment, Ownership Percentage Equity investment, Carrying Amount, Asset Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Equity investment, Carrying Amount, Liability Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities Equity investment, Maximum Exposure to Loss Equity Method Investment Maximum Exposure To Loss This item represents the maximum exposure to loss for an equity method investment. Equity investment, VIEs' assets Equity Method Investment, Summarized Financial Information, Assets Schedule of reconciliation of net income before noncontrolling interest to net income available for common stockholders Schedule Of Reconciliation Of Net Income Before Noncontrolling Interest To Net Income Available For Common Stockholders Table Text Block Tabular disclosure of reconciliation of net income before noncontrolling interest to net income available for common stockholders. Schedule of basic earnings per share Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table Text Block] Schedule of diluted earnings per share Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Purchased technology Unpatented Technology [Member] ETF issuer relationships Exchange Traded Funds Issuer Relationships [Member] Represents information pertaining to relationships with issuer for exchange traded funds. ETF buyer relationships Exchange Traded Funds Buyer Relationships [Member] Represents information pertaining to relationships with buyer for exchange traded funds. Leases Lease Agreements [Member] FCC licenses Licensing Agreements [Member] Technology Developed Technology Rights [Member] Customer relationships Customer Relationships [Member] Favorable occupancy leases Off-Market Favorable Lease [Member] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Exchange memberships Exchange Memberships [Member] Represents information related to exchange memberships. Acquired Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Amount Finite-Lived Intangible Assets, Net Useful Lives (Years) Finite-Lived Intangible Asset, Useful Life Indefinite-lived intangibles Indefinite-lived Intangible Assets (Excluding Goodwill) Gross Carrying Amount Intangible Assets, Gross (Excluding Goodwill) Net Carrying Amount Intangible Assets, Net (Excluding Goodwill) Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at December 31, 2016 Unrecognized Tax Benefits Increase from Acquisition of KCG Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Decreases based on tax positions related to prior period Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Increase based on tax positions related to current period Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Balance at December 31, 2017 Summary of nonconsolidated VIE Equity Method Investments [Table Text Block] Tax Receivable Agreements [Abstract] Tax Receivable Agreements [Abstract] Payment on applicable cash tax savings (as a percent) Tax Receivable Agreement Payments Percentage Of Cash Tax Savings Represents the percentage of applicable cash tax savings, which the entity will pay to the counterparty under the terms of the agreement. First payment made First Payment Made Under Tax Receivable Agreement Company made its first payment under the tax receivable agreement. Minimum tax receivable agreement obligation over the agreed period Tax Receivable Agreement, Obligations Over Period, Minimum Yearly Payment Range Represents the minimum range of yearly payment on the carrying amount on the reporting date of the obligations relating to the tax receivable agreement to be paid over the agreed period. Maximum tax receivable agreement obligation over the agreed period Tax Receivable Agreement, Obligations Over Period, Maximum Yearly Payment Range Represents the maximum range of yearly payment on the carrying amount on the reporting date of the obligations relating to the tax receivable agreement to be paid over the agreed period. Period over which the obligations are to be settled Tax Receivable Agreement, Obligations, Settlement Term Represents the term of settlement of obligations under the tax receivable agreement. Deferred tax asset from tax receivable agreement Deferred Tax Asset, Tax Receivable Agreement Deferred Tax Asset, Tax Receivable Agreement Tax receivable agreement obligations Tax Receivable Agreement, Obligations Represents the carrying amount on the reporting date of the obligations relating to the tax receivable agreement. Issuance of tax receivable agreements in connection with employee exchange U.S. federal statutory rate (as a percent) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Reduction to additional paid-in capital as a result of differences between estimate and tax returns Addition (Reduction) To Additional Paid In Capital As Result Of Differences Between Estimate And Tax Returns Amount of addition (reduction) to additional paid-in capital as a result of differences between estimate and tax returns. Deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Property, Plant and Equipment [Abstract] Depreciation expense Depreciation Capitalized software development costs Capitalized Computer Software, Additions Amortization expense on capitalized software development costs Capitalized Computer Software, Amortization Capitalized compensation charges Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Compensation costs, amortization Compensation Costs, Amortization Compensation Costs, Amortization Statement of Cash Flows [Abstract] BondPoint BondPoint [Member] BondPoint [Member] DMM Business DMM Business [Member] DMM Business [Member] Class A-2 Interests Class A Two Interests [Member] Represents information pertaining to the Class A-2 interests representing ownership interest in a limited liability company. Class C common stock Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income (loss) Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation And Amortization Excluding Intangible Assets The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives. Amortization of purchased intangibles and acquired capitalized software Amortization of Intangible Assets Debt issue cost related to debt refinancing and prepayment Debt Related Commitment Fees and Debt Issuance Costs Amortization of debt issuance costs and deferred financing fees Amortization of Debt Issuance Costs and Discounts Termination of office leases Lease Abandonment Represents the amount of expense related to the lease abandonment or termination. Share based compensation Share-based Compensation Reserve for legal matters Loss Contingency, Loss in Period Write-down of assets Asset Impairment Charges Connectivity early termination Loss on Contract Termination Tax receivable agreement obligation reduction Decrease in Tax Receivable Agreement Obligations Reduction in tax receivable agreement obligations. Deferred taxes Deferred Income Tax Expense (Benefit) Gain on sale of businesses Other Other Operating Activities, Cash Flow Statement Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Securities borrowed Increase (Decrease) in Securities Borrowed Securities purchased under agreements to resell Increase (Decrease) in Receivables under Repurchase Agreements Receivables from broker dealers and clearing organizations Increase (Decrease) in Receivables from Brokers-Dealers and Clearing Organizations Trading assets, at fair value Increase (Decrease) in Trading Assets at Fair Value Represents the amount of increase (decrease) in fair value of trading assets. Other assets Increase (Decrease) in Other Operating Assets Securities loaned Increase (Decrease) in Securities Loaned Transactions Securities sold under agreements to repurchase Increase (Decrease) in Payables under Repurchase Agreements Payables to broker dealers and clearing organizations Increase (Decrease) in Payables to Broker-Dealers and Clearing Organizations Trading liabilities, at fair value Increase (Decrease) in Trading Liabilities at Fair Value Represents the amount of increase (decrease) in fair value of trading liabilities. Accounts payable and accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Expenses and Other Liabilities Represents the amount of increase (decrease) in accounts payable and accrued expenses and other liabilities. Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Development of capitalized software Payments to Develop Software Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of telecommunication assets Proceeds from Sale of Productive Assets Proceeds from sale of business Investment in joint ventures Payments to Acquire Interest in Joint Venture Investment in SBI Japannext Payments to Acquire Equity Method Investments Acquisition of KCG Holdings, net of cash acquired, described in Note 3 Payments to Acquire Business Two, Net of Cash Acquired Acquisition of Teza Technologies Payments to Acquire Businesses, Net of Cash Acquired Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Distribution from Virtu Financial to non-controlling interest Payments to Noncontrolling Interests Dividends Payments of Dividends Repurchase of stock Payments for Repurchase of Common Stock Stock option exercised Proceeds from Stock Options Exercised Short-term borrowings, net Proceeds from (Repayments of) Short-term Debt Proceeds from long-term borrowings Proceeds from Issuance of Long-term Debt Repayment of long term borrowings Repayments of Long-term Debt Repayment of KCG Notes Repayments of Notes Payable Tax receivable agreement obligations Payment Of Tax Receivable Agreement Obligations Cash outflow for payment of tax receivable agreement obligations. Debt issuance costs Payments of Debt Issuance Costs Issuance of common stock, net of offering costs Proceeds from Issuance of Common Stock Issuance of common stock in connection with secondary offering, net of offering costs Proceeds (Payments) From Issuance Of Common Stock, Net Of Offering Costs Proceeds (Payments) From Issuance Of Common Stock, Net Of Offering Costs Repurchase of Virtu Financial Units and corresponding number of Class C common stock in connection with secondary offering Payments For Repurchase Of Member Units And Common Stock Secondary Offering The cash outflow to reacquire member units and common stock in a secondary offering during the period. Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Supplementary disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid for taxes Income Taxes Paid, Net Non-cash investing activities Cash Flow Noncash Investing Activities Disclosure [Abstract] Share based compensation to developers relating to capitalized software Non Cash Compensation to Developers Subject to Capitalization of Software Represents the amount of non-cash compensation to developers subject to capitalization of software. Non-cash financing activities Cash Flow Noncash Financing Activities Disclosure [Abstract] Cash Flow Noncash Financing Activities Disclosure [Abstract] Tax receivable agreement described in Note 6 Noncash Financing Activities, Tax Receivable Agreement Noncash Financing Activities, Tax Receivable Agreement Discount on issuance of senior secured credit facility Non-Cash Financing Activities, Debt Discount Non-Cash Financing Activities, Debt Discount Secondary offerings described in Note 16 Noncash Financing From Secondary Offering Noncash Financing From Secondary Offering Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Due to and from Broker-Dealers and Clearing Organizations [Abstract] Receivables from/Payables to Broker-Dealers and Clearing Organizations Due to and from Broker-Dealers and Clearing Organizations Disclosure [Text Block] Tax Receivable Agreements Tax Receivable Agreements Disclosure [Text Block] The entire disclosure for tax receivable agreements. Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] KCG Kcg Holdings [Member] The information pertaining to KCG Holdings Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Aranda Aranda Investment Agreement [Member] Represents the information pertaining to Aranda investment agreement. Temasek Investment Temasek Investment [Member] Represents the information pertaining to Temasek investment. NIH Investment Agreement North Island Holdings Investment Agreement [Member] Represents the information pertaining to North Island Holdings Investment Agreement. Senior Secured Notes Due 2020 Senior Secured Notes Due2020 [Member] Represents information related to the senior secured notes due 2020. Business Acquisition [Line Items] Business Acquisition [Line Items] Common stock, par value (in dollars per share) Right to receive cash (in dollars per share) Shares Converted into Right to Receive Cash Amount of cash receivable per share without interest, less any applicable withholding taxes upon cancellation and extinguishment of shares issued in acquisition. Aggregate purchase price Other offering costs Payments of Stock Issuance Costs Redemption price as a percentage of the principal amount Debt Instrument, Redemption Price, Percentage Face amount Debt Instrument, Face Amount Employee compensation expense Allocated Share-based Compensation Expense Annual incentive compensation payments Expected Annual Incentive Compensation Payments The amount of expected annual incentive compensation payments. Cash purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Fair value (in dollars per share) Business Acquisition, Share Price Goodwill Goodwill Deferred tax assets Deferred Income Tax Assets, Net Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Debt Instrument [Line Items] Outstanding borrowings and financing capacity or unused available capacity under the Company’s borrowing arrangements Schedule of Debt [Table Text Block] Schedule of interest expense on debt Schedule Of Interest Expense On Debt [Table Text Block] Tabular disclosure of interest expense on debt. Schedule of reconciliation of the senior secured credit facility Schedule of Long-term Debt Instruments [Table Text Block] Schedule of aggregate future required principal payments based on terms of loan Schedule of Maturities of Long-term Debt [Table Text Block] Stock options Employee Stock Option [Member] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Expense recognized Unrecognized share-based compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted average period for compensation expense expected to be recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Reconciliation of net income before minority interest to net income available for common stockholders Net Income (Loss) Attributable to Parent [Abstract] Income (loss) before income taxes and noncontrolling interest Provision for income taxes Net income Noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income available for common stockholders Net Income (Loss) Attributable to Parent Share-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Basic earnings per share: Earnings Per Share, Basic [Abstract] Net income (loss) available for common stockholders Less: Dividends and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income (loss) available for common stockholders, net of dividends and undistributed earnings allocated to participating securities Net Income (Loss) Available to Common Stockholders, Basic Weighted average shares of common stock outstanding: Weighted Average Number of Shares Outstanding, Basic [Abstract] Outstanding (in shares) Basic earnings per share (in dollars per share) Earnings Per Share, Basic Offsetting Liabilities [Table] Offsetting Liabilities [Table] Offsetting Liabilities [Line Items] Offsetting Liabilities [Line Items] Securities loaned Offsetting Securities Loaned [Abstract] Gross Amounts of Recognized Liabilities Securities Loaned, Gross Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Securities Loaned Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Securities Loaned Gross Amounts Not Offset [Abstract] Financial Instruments Securities Loaned Not Offset Financial Instruments Represents the amount of securities loaned that could be offset by securities borrowed subject to master netting arrangements, but management elects not to offset. Cash Collateral Pledged Securities Loaned, Collateral, Right to Reclaim Cash Net Amount Securities Loaned Net Represents the net amount of securities loaned after the effects of master netting arrangements and collateral. Securities sold under agreements to repurchase Offsetting Securities Sold under Agreements to Repurchase [Abstract] Gross Amounts of Recognized Liabilities Securities Sold under Agreements to Repurchase, Gross Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Securities Sold under Agreements to Repurchase Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Securities Sold under Agreements to Repurchase Gross Amounts Not Offset [Abstract] Financial Instruments Securities Sold under Agreements to Repurchase Not Offset Financial Instruments Represents the amount of securities sold under agreements to repurchase that could be offset by securities purchased under agreements to resell subject to master netting arrangements, but management elects not to offset. Cash Collateral Pledged Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash Net Amount Securities Sold under Agreements to Repurchase Net Represents the net amount of securities sold under repurchase agreements after the effects of master netting arrangements and collateral. Trading liabilities, at fair value: Offsetting Trading Liabilities at Fair Value [Abstract] Gross Amounts of Recognized Liabilities Derivative Liability, Fair Value, Gross Liability Gross Amounts Offset in the Consolidated Statement of Financial Condition Derivative Liability, Fair Value, Gross Asset Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Derivative Liability Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Derivative Fair Value of Derivative Liability Gross Amounts Not Offset [Abstract] Financial Instruments Derivative Liabilities Not Offset Financial Instruments Represents the amount of derivative liabilities that could be offset by derivative assets subject to master netting arrangements, but management elects not to offset. Cash Collateral Pledged Derivative, Collateral, Right to Reclaim Cash Net Amount Derivative Fair Value of Derivative Liability after Application of Master Netting Agreements and Cash and Securities Collateral Represents the fair value of derivative liabilities, net of master netting arrangements and collateral. Total Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract] Gross Amounts of Recognized Liabilities Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross Gross Amounts Offset in the Consolidated Statement of Financial Condition Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset Net Amounts of Assets Presented in the Consolidated Statement of Financial Condition Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned Gross Amounts Not Offset In the Consolidated Statement of Financial Condition Derivative Liability Securities Sold under Agreements to Repurchase Securities Loaned Gross Amounts Not Offset [Abstract] Financial Instruments Derivative Liability Securities Sold under Agreements to Repurchase Securities Loaned Not Offset Financial Instruments Represents the amount of derivative liabilities, securities sold under agreements to repurchase and securities loaned that could be offset by assets subject to master netting arrangements, but management elects not to offset. Cash Collateral Pledged Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash Net Amount Derivative Liability Securities Sold under Agreements to Repurchase Securities Loaned Net Represents the fair value of derivative liabilities, securities sold under agreements to repurchase and securities loaned, net of master netting arrangements and collateral. Assets Assets [Abstract] Due from prime brokers Due from Correspondent Brokers Deposits with clearing organizations Receivables from Clearing Organizations Net equity with futures commission merchants Net Equity with Futures Commission Merchant Assets Represents the amount of net equity with futures commission merchants, asset. Unsettled trades with clearing organization Unsettled Trade Assets Represents the amount receivable for unsettled trades. Securities failed to deliver Securities Failed-to-Deliver Commissions and fees Commissions and Floor Brokerage Receivables Total receivables from broker-dealers and clearing organizations Receivables from Brokers-Dealers and Clearing Organizations Liabilities Liabilities [Abstract] Due to prime brokers Due to Correspondent Brokers Net equity with futures commission merchants Net Equity with Futures Commission Merchant Liabilities Represents the amount of net equity with futures commission merchants, liability. Unsettled trades with clearing organization Unsettled Trade Liabilities Represents the amount payable for unsettled trade liabilities. Securities failed to receive Securities Failed-to-Receive Commissions and fees Commissions Payable to Broker-Dealers and Clearing Organizations Total payables to broker-dealers and clearing organizations Payables to Broker-Dealers and Clearing Organizations Outstanding principal balance Short Term Credit Facilities Represents the carrying value of the outstanding principal balance on all of the entity's short-term credit facilities. Securities received as collateral: Securities Received as Collateral [Abstract] Securities borrowed Securities Borrowed At Market Value Amount, after the effects of master netting arrangements, of securities borrowed from entities in exchange for collateral. Includes assets not subject to a master netting arrangement and not elected to be offset, at market value. Securities purchased under agreements to resell Securities received as collateral Collateralized Agreements Financial Instruments Owned and Pledged as Collateral [Table] Financial Instruments Owned and Pledged as Collateral [Table] Equities Exchange traded notes Exchange Traded Notes [Member] Represents information pertaining to exchange traded notes. Financial Instruments Owned and Pledged as Collateral [Line Items] Financial Instruments Owned and Pledged as Collateral [Line Items] Financial instruments owned and pledged Financial Instruments, Owned and Pledged as Collateral, at Fair Value Condensed Financial Statements [Table] Condensed Financial Statements [Table] Other Product and Service, Other [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] VFH Parent Company [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Revenues: Revenues [Abstract] Expenses Costs and Expenses [Abstract] Operations and administrative General and Administrative Expense Income (loss) before equity in income of subsidiary Income Loss From Continuing Operations Before Minority Interest And Income Loss From Equity Method Investments Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, extraordinary items, and noncontrolling interest. Equity in income of subsidiary, net of tax Income (Loss) from Equity Method Investments Net income attributable to common stockholders Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign exchange translation adjustment, net of taxes Comprehensive income attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] VFH V F H Parent L L C [Member] Represents information pertaining to VFH Parent LLC, a wholly owned subsidiary of Virtu Financial LLC and the sole stockholder of the reporting entity. Outstanding principal amount Gain (loss) due to change in currency rates Foreign Currency Transaction Gain (Loss), Realized Entities [Table] Entities [Table] Virtu Americas LLC Virtu Americas Llc [Member] Represents information pertaining to Virtu Americas LLC. Virtu Financial BD LLC Virtu Financial Bd Llc [Member] Represents information pertaining to Virtu Financial BD LLC. Virtu Financial Capital Markets LLC Virtu Financial Capital Markets Llc [Member] Represents information related to Virtu Financial Capital Markets LLC (“VFCM”). Entity Information [Line Items] Entity Information [Line Items] Regulatory Capital Net Capital Regulatory Capital Requirement Minimum Net Capital Required Excess Regulatory Capital Excess Net Capital at 1500 Percent Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Class A-1 Class A One Interests [Member] Represents information pertaining to the Class A-1 interests representing ownership interest in a limited liability company. Class A-2 Class B Common Class B [Member] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Cash Cash Investment in subsidiary Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Other assets Other Assets Total assets Assets Liabilities, redeemable membership interest and equity Liabilities and Equity [Abstract] Payable to affiliate Due to Related Parties Accounts payable and accrued expenses and other liabilities Accounts Payable and Accrued Expenses and Other Liabilities Sum of the carrying values as of the balance sheet date of liabilities incurred and payable to vendors for goods and services received, expenses incurred but not paid and other liabilities not separately disclosed in the balance sheet. Total liabilities Liabilities Virtu Financial Inc. Stockholders' equity Members' Equity [Abstract] Common stock Common Stock, Value, Issued Treasury stock, at cost, 616,923 and 453,066 shares at December 31, 2017 and 2016, respectively Treasury Stock, Common, Value Additional paid-in capital Additional Paid in Capital Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total Virtu Financial Inc. stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and equity Liabilities and Equity Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock, shares (in shares) Treasury Stock, Common, Shares Income Taxes Income Tax Disclosure [Text Block] Statement of Financial Position [Abstract] Cash and cash equivalents Securities borrowed Receivables from broker dealers and clearing organizations Trading assets, at fair value: Financial Instruments, Owned, at Fair Value [Abstract] Financial instruments owned Financial Instruments, Owned and Not Pledged, at Fair Value Property, equipment and capitalized software (net of accumulated depreciation of $323,718 and $375,656 as of December 31, 2018 and December 31, 2017, respectively) Property, Plant and Equipment, Net Intangibles (net of accumulated amortization of $148,644 and $123,408 as of December 31, 2018 and December 31, 2017, respectively) Assets of business held for sale Disposal Group, Including Discontinued Operation, Assets Other assets ($48,273 and $98,364, at fair value, as of December 31, 2018 and December 31, 2017, respectively) Liabilities and equity Short-term borrowings Short-term Debt Securities loaned Securities sold under agreements to repurchase Payables to broker dealers and clearing organizations Trading liabilities, at fair value: Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract] Financial instruments sold, not yet purchased Financial Instruments Sold, Not yet Purchased, at Fair Value Long-term borrowings Commitments and Contingencies (Note 15) Commitments and Contingencies Virtu Financial Inc. Stockholders' equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock (par value $0.00001) Treasury stock, at cost, 2,178,771 and 616,923 shares at December 31, 2018 and December 31, 2017, respectively Retained earnings (accumulated deficit) Accumulated other comprehensive income Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total equity Schedule of stock options activity Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of activity related to restricted stock units Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Virtu Financial Virtu Financial Llc [Member] Represents information related to Virtu Financial LLC, a limited liability company that is managed by the reporting entity. Common stock exchange ratio Common Stock, Exchange Ratio Ratio applied in exchange of shares. Reconciliation of tax provision Effective Income Tax Rate Reconciliation, Amount [Abstract] Tax provision at the U.S. federal statutory rate Less: rate attributable to noncontrolling interest Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent State and local taxes, net of federal benefit Effective Income Tax Rate Reconciliation State And Local Income Taxes And Foreign Income Tax Rate Differential Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), and pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile, net of federal tax expense (benefit). Impact of 2017 Tax Act on deferred tax assets Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Impact of 2017 Tax Act on tax receivable agreement obligation Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Tax Receivable Agreement Obligation, Percent Percentage of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to increase (decrease) in income tax rate and tax receivable agreement obligation. Non-deductible expenses, net Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective tax rate Effective Income Tax Rate Reconciliation, Percent Amount of fine Loss Contingency Amount Of Fine Amount of fines from regulatory agencies. Minimum initial collateral advanced or received expressed as a percentage of fair value of the underlying securities borrowed or loaned Securities Borrowed and Securities Loaned Minimum Initial Collateral Advanced or Received Expressed as Percentage of Fair Value of Underlying Securities Borrowed or Loaned Represents the minimum initial collateral advanced or received expressed as a percentage of fair value of the underlying securities borrowed or loaned. Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] ITG Investment Technology Group, Inc. [Member] Investment Technology Group, Inc. [Member] First lien term loan Senior Secured First Lien Term Loan [Member] Senior Secured First Lien Term Loan [Member] Letter of credit Letter of Credit [Member] Swingline subfacility Swingline Subfacility [Member] Swingline Subfacility [Member] Subsequent Events [Line Items] Subsequent Event [Line Items] Dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Purchase price (in dollars per share) Purchase price Payments to Acquire Businesses, Gross Proceeds from borrowings Proceeds from Issuance of Debt Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Parent Company Condensed Financial Information of Parent Company Only Disclosure [Text Block] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value Portion at Other than Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Assets Assets, Fair Value Disclosure [Abstract] Receivables from broker dealers and clearing organizations Liabilities Liabilities, Fair Value Disclosure [Abstract] Long-term borrowings Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Joint Venture Corporate Joint Venture [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Amortization expense relating to finite-lived intangible assets Intangible assets Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill impairment Goodwill, Impairment Loss Summary of income before income taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Summary of provision for income taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of reconciliation of the tax provision at U.S. Federal Statutory Rate to the provision for income taxes Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of components of deferred tax assets and liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Summary of reconciliation of the beginning and ending amount of unrecognized tax benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Equities futures Equities Futures [Member] Represents information pertaining to equities futures. Commodity futures Commodity Contract [Member] Currency futures Foreign Exchange Future [Member] Fixed income futures Fixed Income Interest Rate [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivative instruments not designated as hedging instruments Not Designated as Hedging Instrument [Member] Derivative instruments designated as hedging instruments Designated as Hedging Instrument [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Receivables from broker dealers and clearing organizations Receivables From Broker Dealers And Clearing Organizations [Member] Primary financial statement caption encompassing receivables from broker-dealers and clearing organizations. Financial instruments owned Financial Instruments Owned [Member] Primary financial statement caption encompassing financial instruments owned. Payables to broker dealers and clearing organizations Payables To Broker Dealers And Clearing Organizations [Member] Primary financial statement caption encompassing payables to broker-dealers and clearing organizations. Financial instruments sold, not yet purchased Securities Sold, Not yet Purchased [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivatives Assets, Fair Value Derivatives Liabilities, Fair Value Derivatives Assets, Notional Derivative Asset, Notional Amount Derivatives Liabilities, Notional Derivative Liability, Notional Amount Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Regulatory capital Minimum capital required to be maintained in connection with the operation of the Company's DMM business Minimum Net Capital Required for Entity Required amount under exchange rules Required Net Capital under Exchange Act Represents the amount of minimum net capital required to be maintained by the entity under the exchange act. Required amount under exchange rules for every 0.1% NYSE transaction dollar volume Required Net Capital Under Exchange Act For Every Transaction Dollar Volume Required Net Capital Under Exchange Act For Every Transaction Dollar Volume Percentage of NYSE transaction dollar volume Percentage Of NYSE Transaction Dollar Volume Percentage Of NYSE Transaction Dollar Volume Interest Rate Line of Credit Facility, Interest Rate at Period End Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation And Presentation Of Financial Statements [Table] Organization, Consolidation And Presentation Of Financial Statements [Table] Organization, Consolidation And Presentation Of Financial Statements [Table] Organization, Consolidation And Presentation Of Financial Statements [Line Items] Organization, Consolidation And Presentation Of Financial Statements [Line Items] [Line Items] for Organization, Consolidation And Presentation Of Financial Statements [Table] Regulatory Requirement Regulatory Capital Requirement [Text Block] The entire disclosure regarding regulatory capital requirements for the entity. Sale of BondPoint Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Income Statement [Abstract] Other, net Trading income, net Trading Gain (Loss) Interest and dividends income Interest and Dividend Income, Operating Commissions, net and technology services Operating Expenses: Operating Expenses [Abstract] Brokerage, exchange and clearance fees, net Floor Brokerage, Exchange and Clearance Fees Communication and data processing Communications and Information Technology Employee compensation and payroll taxes Labor and Related Expense Payments for order flow Order Flow Fees Interest and dividends expense Interest and Dividend Expense Operating Represents the amount of interest and dividends expense incurred during the normal course of business. Termination of office leases Gain (Loss) on Contract Termination Debt issue cost related to debt refinancing and prepayment Debt Issue Cost Related To Debt Refinancing Debt issue costs related to debt refinancing. Transaction advisory fees and expenses Legal Fees Charges related to share based compensation at IPO Share-based Compensation Expense, Vested Upon Initial Public Offering The aggregate amount of noncash, equity-based employee remuneration vested upon initial public offering. Financing interest expense on long-term borrowings Total operating expenses Operating Expenses Earnings per share Basic (in dollars per share) Diluted (in dollars per share) Weighted average common shares outstanding Basic (in shares) Diluted (in shares) Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Intangibles, accumulated amortization Fair value of other assets Other Assets, Fair Value Disclosure Schedule of preliminary allocation of intangible assets, amortization period and goodwill Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Components of deferred tax assets and liabilities Components of Deferred Tax Assets and Liabilities [Abstract] Deferred income tax assets Components of Deferred Tax Assets [Abstract] Tax Receivable Agreement Deferred Tax Assets Tax Receivable Agreement Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the tax receivable agreement. Share-based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Intangibles Deferred Tax Assets, Goodwill and Intangible Assets Fixed assets and other Deferred Tax Assets, Property, Plant and Equipment Tax credits and net operating loss carryforwards Deferred Tax Assets, Tax Credit And Operating Loss Carryforwards Amount before allocation of valuation allowances of deferred tax asset attributable to deductible tax credit and operating loss carryforwards. Less: Valuation allowance on net operating loss carryforwards and tax credits Operating Loss Carryforwards And Tax Credits Valuation Allowance The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards and tax credits for which it is more likely than not that a tax benefit will not be realized. Total deferred income tax assets Deferred Tax Assets, Gross Deferred income tax liabilities Components of Deferred Tax Liabilities [Abstract] Intangibles Deferred Tax Liabilities, Intangible Assets Total deferred income tax liabilities Deferred Tax Liabilities, Gross Schedule of property, equipment and capitalized software Property, Plant and Equipment [Table Text Block] Disaggregation of revenue Disaggregation of Revenue [Table Text Block] Document And Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Shell Company Entity Shell Company Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Public Float Entity Public Float Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Class A and C Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Equity in income of subsidiary, net of tax Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital Acquisition of KCG, net of cash acquired, described in Note 3 Investments in subsidiaries, equity basis Proceeds from Equity Method Investment, Distribution Payments on repurchase of non-voting common interest Payments for Repurchase Of Common Units The cash outflow to reacquire common units during the period. Repurchase of stock Payments for Repurchase of Member Units And Common Stock The cash outflow to reacquire member units and common stock during the period. Purchase of treasury stock Issuance of common stock in connection with secondary offering, net of offering costs Proceeds From Issuance Of Common Stock Secondary Offering The cash inflow from the additional capital contribution to the entity in a secondary offering. Net increase (decrease) in Cash Cash, Period Increase (Decrease) Cash, beginning of period Cash, end of period Taxes paid Non-cash financing activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Tax receivable agreement described in Note 6 Non Cash Financing Activity, Tax Receivable Agreement Represents the non cash portion attributable to the tax receivable agreement. Secondary offerings described in Note 16 Schedule of total revenues by geographic area Revenue from External Customers by Geographic Areas [Table Text Block] Schedule of revenues, income (loss) before income taxes (“Pre-tax earnings”) and total assets by segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Collateralized Transactions Collateralized Agreements [Text Block] The entire disclosure for collateralized transactions. Non-U.S. government obligations Non-US Government Obligations [Member] Non-US Government Obligations [Member] Corporate Bonds Bonds [Member] Equity investment Fair Value Option Investment [Member] Represents the information pertaining to fair value option investment. Exchange stock Exchange Stock [Member] Represents the information pertaining to exchange stock. Other Other Investments [Member] Financial instruments owned, at fair value Financial instruments owned, at fair value, counterparty and cash collateral netting Financial Instruments Owned And Not Pledged At Fair Value Counter Party And Cash Collateral Netting The fair value as of the balance sheet date of financial instruments and other positions owned by the entity, counterparty and cash collateral netting. Financial instruments owned and pledged Other assets Financial instruments sold, not yet purchased, at fair value, counterparty and cash collateral netting Financial Instruments Sold Not Yet Purchased At Fair Value Counter Party And Cash Collateral Netting Fair value of obligations incurred from short sales, counterparty and cash collateral netting. Changes in goodwill Goodwill [Roll Forward] Balance at the beginning of the period Goodwill adjustment allocated to BondPoint Balance at the end of the period Organization and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Summary of receivables from and payables to brokers-dealers and clearing organizations Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block] Subsequent Events Subsequent Events [Text Block] Revenues from Contracts with Customers Revenue from Contract with Customer [Text Block] Technology Technology-Based Intangible Assets [Member] Trade names Trade Names [Member] Favorable leases Amounts preliminarily allocated to intangible assets, the amortization period and goodwill Intangible Assets, Net (Including Goodwill) [Abstract] Total Intangible Assets, Net (Including Goodwill) Amortization Years Finite-Lived Intangible Assets, Remaining Amortization Period Proceeds from sale of BondPoint Professional fees Professional Fees Compensation expense Salary and Wage, NonOfficer, Excluding Cost of Good and Service Sold Gain on sale of BondPoint, net of transaction costs Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Level 3 Level3 Communications [Member] Represents information related to Level 3 Communications, an affiliate of the entity. Dell Dell Inc And Affiliates [Member] Represents Dell Inc. and its affiliates, an affiliate of the entity. MarkIt Markit Group Holdings Limited [Member] Markit Group Holdings Limited [Member] Two microwave communication network JVs Microwave Communication Network Joint Ventures [Member] Represents information related to microwave communication network joint ventures. Related Party Transaction [Line Items] Related Party Transaction [Line Items] Payable to affiliates Due to Affiliate Payments for purchases Payments to Suppliers Payments to related party Related Party Transaction, Amounts of Transaction Number of microwave communication network JVs the Company makes payments to Number Of Microwave Communication Network Joint Ventures Payments Made To The number of microwave communication network joint ventures that the company makes payments to. Proceeds from sale of assets to joint venture Proceeds From Disposition Of Assets To Joint Venture Proceeds From Disposition Of Assets To Joint Venture Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Futures Future [Member] Others Other Contract [Member] Foreign exchange - forward contract Forward Contracts [Member] Not designated as hedging instruments Derivative instruments designed as hedging instruments: Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Gain impact that derivative instruments not designated as hedging instruments had on results of operations Derivative, Gain (Loss) on Derivative, Net Net gain from derivative instruments, which are recorded in accumulated other comprehensive income Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Commitments, Contingencies and Guarantees Commitments and Contingencies Disclosure [Text Block] Property, Equipment and Capitalized Software Property, Plant and Equipment Disclosure [Text Block] Senior Secured Credit Facility Fourth Amendment Senior Secured Credit Facility Fourth Amendment [Member] Represents the information pertaining to senior secured credit facility fourth amendment . Repayments of long-term debt Accelerated unamortized financing costs Debt Instrument Unamortized Discount Accelerated Amount of debt discount accelerated. Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Total Realized and Unrealized Gains / (Losses) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Net Transfers into (out of) Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net Settlement Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Ending Balance Change in Net Unrealized Gains / (Losses) on Investments still held at end of period Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Capitalized software costs Software and Software Development Costs [Member] Leasehold improvements Leasehold Improvements [Member] Property, Equipment and Capitalized Software Property, equipment and capitalized software, gross Property, Plant and Equipment, Gross Less: Accumulated depreciation and amortization Total property, equipment and capitalized software, net Authorized repurchase amount Stock Repurchase Program, Authorized Amount Increase in authorized repurchase amount Stock Repurchase Program, Increase In Authorized Amount Stock Repurchase Program, Increase In Authorized Amount Number of shares repurchased Value of shares repurchased Remaining capacity for future purchases Stock Repurchase Program, Remaining Authorized Repurchase Amount Payment receivable Tax Receivable Agreement Payment Receivable Amount of payment receivable in relation to a tax receivable agreement. Annual payment receivable Tax Receivable Agreement Receivable Annual Payment Amount of annual payment receivable in relation to a tax receivable agreement.