DW SEF Dw Sef Llc [Member] DW SEF LLC (DW SEF) is a swap execution facility regulated by the Commodities Future Trading Commission. Hedging Designation [Domain] Hedging Designation [Domain] Share repurchase program, amount authorized Stock Repurchase Program, Authorized Amount Supplemental disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Customer [Domain] Customer [Domain] TWL Tradeweb Llc [Member] Tradeweb LLC (TWL) is a registered broker-dealer under the Securities Exchange Act of 1934, a member of the Financial Industry Regulatory Authority, a registered independent introducing broker with the Commodities Future Trading Commission and a member of the National Futures Association. Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Vested in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Net income attributable to Tradeweb Markets Inc. Net income attributable to Tradeweb Markets Inc. Net income attributable to Tradeweb Markets Inc. Net income attributable to Tradeweb Markets Inc. Net Income (Loss) Attributable to Parent Consolidated Entities [Axis] Consolidated Entities [Axis] Entity Emerging Growth Company Entity Emerging Growth Company Income Tax Disclosure [Table] Income Tax Disclosure [Table] Disclosure of information pertaining to income taxes. Right-of-use assets Operating Lease, Right-of-Use Asset Excess Financial Resources Futures Commission Merchant, Commodity Exchange Act, Excess Net Capital Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Deferred costs Deferred Offering Costs Income Statement Location [Axis] Income Statement Location [Axis] Wholesale Wholesale Client Sector [Member] The wholesale client sector. Transaction costs Business Combination, Acquisition Related Costs Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Statistical Measurement [Domain] Statistical Measurement [Domain] Entity Address, Address Line One Entity Address, Address Line One TW SEF Tw Sef Llc [Member] TW SEF LLC (TW SEF) is a swap execution facility regulated by the Commodities Future Trading Commission. Foreign currency translation adjustment, tax benefit Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Schedule of Recognized Revenue and Remaining Deferred Revenue Balance Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Entity Filer Category Entity Filer Category Translation of Foreign Currency and Foreign Currency Forward Contracts Foreign Currency Transactions and Translations Policy [Policy Text Block] Floor Debt Instrument Floor Rate The Percentage of floor rate under debt instrument. Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Percentage of amount of U.S. federal, state and local income or franchise tax savings Tax Receivable Agreement, Percentage Of Amount Of Federal, State And Local Income Or Franchise Tax Savings The percentage of amount of U.S. federal, state and local income or franchise tax savings under the tax receivable agreement. Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Document Fiscal Year Focus Document Fiscal Year Focus Subsequent Event Type [Domain] Subsequent Event Type [Domain] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Amortization expense Amortization of Intangible Assets Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Stock repurchase program, remaining authorized repurchase amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Antidilutive shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Revenue recognized that was previously deferred Contract with Customer, Liability, Revenue Recognized TWEU Tradeweb Eu Bv [Member] Tradeweb EU B.V. (TWEU) is a trading venue and approved publication arrangement regulated by the Netherlands Authority for the Financial Markets. Sale of Stock [Axis] Sale of Stock [Axis] Subsequent Events [Abstract] Subsequent Events [Abstract] Business Combination and Asset Acquisition [Abstract] Commitment fee, percentage Line of Credit Facility, Commitment Fee Percentage Accounts receivable Accounts Receivable, Related Parties Weighted-average grant-date fair value (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 Business Acquisition [Axis] Business Acquisition [Axis] Financial Resources Futures Commission Merchant, Commodity Exchange Act, Adjusted Net Capital Title of Individual [Domain] Title of Individual [Domain] Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Foreign currency forward contracts not designated in accounting hedge relationship Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Award Type [Domain] Award Type [Domain] Assets Assets [Abstract] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Fair Value, Nonrecurring Fair Value, Nonrecurring [Member] Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Preferred stock, $0.00001 par value; 250,000,000 shares authorized; none issued or outstanding Preferred Stock, Value, Issued Furniture, Equipment, Purchased Software and Leasehold Improvements Property, Plant and Equipment, Policy [Policy Text Block] Distributions to non-controlling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Common stock, conversion ratio Common Stock Conversion Ratio Common Stock Conversion Ratio Deferred tax asset Other Noncash Income Tax Expense Entity Address, City or Town Entity Address, City or Town Retained Earnings Retained Earnings [Member] Initial Public Offering IPO [Member] Ownership interest Number of LLC Interests held by Tradeweb Markets Inc. Noncontrolling Interest, Ownership Percentage by Parent Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Restricted Cash Equivalents [Abstract] Restricted Cash Equivalents [Abstract] Activities related to the follow-on offering and other exchanges of LLC Interests, net of offering costs and cancellations Stock Issued During Period, Value, Conversion of Convertible Securities Dividends Payments of Ordinary Dividends Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] LLC Interests Limited Liability Company Units [Member] Limited Liability Company Units Related Party [Axis] Related Party [Axis] Accounts receivable Increase (Decrease) in Accounts Receivable Maximum performance modifier, percent Share-based Compensation Arrangement by Share-based Payment Award, Maximum Performance Modifier Share-based Compensation Arrangement by Share-based Payment Award, Maximum Performance Modifier Working capital adjustments Less: Preliminary working capital adjustments Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred Other fees Other Fees [Member] Other Fees Furniture, Equipment, Purchased Software and Leasehold Improvements Property, Plant and Equipment [Line Items] Number of shares withheld (in shares) Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Vest per year Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Entity Interactive Data Current Entity Interactive Data Current Deferred revenue Increase (Decrease) in Deferred Revenue Deferred revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue Basic (in dollars per share) Earnings per share - Basic (in dollars per share) Earnings Per Share, Basic Number of share owned (in shares) Number of share owned Number of share owned. Number of LLC Interests held by Tradeweb Markets Inc. (in shares) Minority Interest Number Of Interests Held By Parent The parent entity's interest in the subsidiary. Revenue Revenue from Contract with Customer [Text Block] Receivable from affiliates Receivable from affiliates Receivable from affiliates – Foreign currency forward contracts Due from Affiliates Document Type Document Type Cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract] Schedule of Breakdown of Revenues Between Fixed and Variable Revenues Disaggregation of Revenue [Table Text Block] Class C Common Stock Common Class C [Member] Entity Current Reporting Status Entity Current Reporting Status Receivable from brokers and dealers and clearing organizations Receivable from brokers and dealers and clearing organizations Receivables from Brokers-Dealers and Clearing Organizations Payroll taxes paid for stock-based compensation exercises Share-based payment arrangement, decrease for tax withholding obligation Share-based Payment Arrangement, Decrease for Tax Withholding Obligation Number of shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Tax Receivable Agreement Tax Receivable Agreement Liability Disclosure [Text Block] The entire disclosure of tax receivable agreement liability. Excess net capital Banking Regulation, Total Risk-Based Capital, Excess, Actual Related party, payable reversal Related Party Transaction, Payable Reversal Related Party Transaction, Payable Reversal Deferred taxes arising from share repurchases Adjustments to Additional Paid in Capital, Income Deferred Income Tax Effect from Share Repurchases Adjustments to Additional Paid in Capital, Income Deferred Income Tax Effect from Share Repurchases Credit loss recognized (reversed) Accounts Receivable, Credit Loss Expense (Reversal) Schedule of Revenue and Long-Lived Assets by Geographic Location Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Letter of credit issued Long-term Debt, Gross Payments on tax receivable agreement liability Payments on Tax Receivable Agreement, Liability Payments on Tax Receivable Agreement, Liability Deposits with Clearing Organizations Deposits With Clearing Organizations [Policy Text Block] Disclosure of accounting policy for deposits with clearing organizations. TESL Tradeweb Execution Services Limited [Member] Tradeweb Execution Services Limited Total assets measured at fair value Assets, Fair Value Disclosure Quoted Prices in active Markets for Identical Assets (Level 1) Quoted Prices in active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Conversion ratio Noncontrolling Interest, Conversion Ratio The conversion ratio of shares of non-controlling interests. Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Impairment of goodwill Goodwill, Impairment Loss Less: Foreign currency translation adjustments attributable to non-controlling interests Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest Document Transition Report Document Transition Report Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Software Development Costs Software Development [Member] Employee equity compensation payable Increase Decrease In Equity Compensation Payable The increase (decrease) during the period in equity compensation payable. Base rate Base Rate [Member] Intangible Assets Finite-Lived Intangible Assets [Line Items] Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] Total liabilities and equity Liabilities and Equity March 31, 2022 Share-based Payment Arrangement, Tranche One [Member] Schedule of the Ownership Interest in Noncontrolling Interest Schedule Of Ownership Interest In Noncontrolling Interest [Table Text Block] Tabular disclosure of ownership interest in noncontrolling interest. Tax Receivable Agreement Tax Receivable Agreement No definition available. Restricted cash Restricted cash Restricted Cash Additional paid-in capital Additional Paid in Capital Credit Risk Concentration Risk [Line Items] Liabilities and Equity Liabilities and Equity [Abstract] Schedule of Regulatory Capital Requirements Schedule Of Regulatory Capital Requirements [Table Text Block] Tabular disclosure of the regulatory capital requirements and regulatory capital for entities subject to regulation. Net proceeds Proceeds from Issuance Initial Public Offering Derivative [Line Items] Derivative [Line Items] Earnings Per Share Earnings Per Share [Text Block] Aggregate value of share repurchase Treasury Stock, Value, Acquired, Cost Method Expenses Operating Expenses [Abstract] Average price per share (in dollars per share) Treasury Stock Acquired, Average Cost Per Share Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Minimum Minimum [Member] Nonrecurring Adjustment [Domain] Nonrecurring Adjustment [Domain] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] EA Execution Access [Member] Execution Access Affiliated Entity Affiliated Entity [Member] Noncontrolling Interest [Abstract] Noncontrolling Interest [Abstract] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Number of LLC Interests held by non-controlling interests (in shares) Minority interest Number Of Interests Held By Noncontrolling Owners The equity interest of noncontrolling shareholders. Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Follow On Offering Follow On Offering [Member] Follow On Offering Trading Symbol Trading Symbol Deferred tax asset Deferred Income Tax Assets, Net Adjustments to non-controlling interests Minority Interest Increase Decrease From Adjustments Amount of increase (decrease) in noncontrolling interest from adjustments. Issuance of common stock from equity incentive plans Stock Issued During Period, Value, New Issues Share-based Payment Arrangement, Accelerated Cost Share-based Payment Arrangement, Accelerated Cost Cash paid for acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Nonrecurring Adjustment [Axis] Nonrecurring Adjustment [Axis] Beginning balance ( in shares) Ending balance (in shares) Shares, Outstanding Stockholders' Equity and Stock-Based Compensation Plans Share-based Payment Arrangement [Text Block] Significant Unobservable Inputs (Level 3) Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Leases Lessee, Leases [Policy Text Block] Accounting Policies [Abstract] Accounting Policies [Abstract] Derivative Instrument [Axis] Derivative Instrument [Axis] Offering costs from issuance of Class A common stock in follow-on offering Offering costs incurred Payments of Stock Issuance Costs Issuance of common stock from equity incentive plans (in shares) Stock Issued During Period, Shares, New Issues Transaction fees and commissions Transaction fees and commissions Transaction Fee Revenue [Member] Transaction fee revenues, both variable and fixed, recorded at a point in time when the trade occurs. Excess Regulatory Capital Excess Regulatory Capital Amount by which the entity's regulatory capital (as defined) exceeds the requirement. Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Accounts payable, accrued expenses and other liabilities Accounts Payable and Accrued Liabilities Letters of credit outstanding Letters of Credit Outstanding, Amount Subscription fees Subscription Fee And Market Data Revenue [Member] Subscription fee revenue from granting access to institutional investors to the entity's electronic marketplaces and fees from the sale of market data to Refinitiv. Lease liability Operating Lease, Liability Realized and unrealized gains (losses) on translation adjustments Foreign Currency Transaction Gain (Loss), before Tax Payable to brokers and dealers and clearing organizations Payable to brokers and dealers and clearing organizations Broker-Dealer, Payable to Other Broker-Dealer and Clearing Organization Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Common stock Common Stock, Value, Issued Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Adjusted For Refinitiv Transaction Adjusted For Refinitiv Transaction [Member] Reflects a new basis of accounting resulting from the Refinitiv transaction. Commitments and contingencies (Note 13) Commitments and Contingencies Subsequent Event [Table] Subsequent Event [Table] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Financial Instruments Not Measured at Fair Value Fair Value, by Balance Sheet Grouping [Table Text Block] Acquisitions Business Combination Disclosure [Text Block] Remaining percentage of tax benefits Tax Receivable Agreement Remaining Percentage of Amount of Federal State and Local Income or Franchise Tax Savings The remaining percentage of amount of U.S. federal, state and local income or franchise tax savings under the tax receivable agreement. Consulting service fee for follow on offering Consulting Service Fee for Follow on Offering The amount of consulting service incurred for follow on offering. Increase in Tradeweb Markets Inc.'s additional paid-in capital as a result of ownership changes in TWM LLC Noncontrolling Interest, Increase from Subsidiary Equity Issuance Ownership [Axis] Ownership [Axis] Document Period End Date Document Period End Date RSUs and PSRUs RSUs and PSRUs [Member] RSUs and PSRUs Additional dilutive shares (in shares) Dilutive effect (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Business Segment and Geographic Information Revenues from External Customers and Long-Lived Assets [Line Items] Total expenses Operating expenses Costs and Expenses Class of Stock [Axis] Class of Stock [Axis] Entity Registrant Name Entity Registrant Name Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Net interest income (expense) Interest Income (Expense), Net One-month LIBOR One Month London Inter Bank Offered Rate [Member] One Month London Inter Bank Offered Rate. Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Change in Contract with Customer Change In Contract with Customer, Liability [Roll Forward] Change In Contract with Customer, Liability Purchase of LLC Interests Payments for Repurchase of Redeemable Noncontrolling Interest Non-Controlling Interests Noncontrolling Interest [Line Items] Selling, General and Administrative Expenses Selling, General and Administrative Expenses [Member] Dividends (in dollars per share) Cash dividend declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Total revenue Total revenue Revenues Revenue from Contract with Customer, Excluding Assessed Tax Comprehensive income - Tradeweb Markets Inc. Net Income (Loss) Available to Common Stockholders, Basic [Abstract] (Increase) decrease in operating assets: Increase (Decrease) in Operating Assets [Abstract] Options Share-based Payment Arrangement, Option [Member] Furniture, Equipment, Purchased Software and Leasehold Improvements Furniture Equipment And Purchased Software [Member] Furniture, equipment and purchased software. Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Payable to affiliates Payable to affiliates Payable to affiliates – Foreign currency forward contracts Due to Affiliate Total LLC Interests outstanding Minority Interest Total Ownership Percentage The total ownership interest on noncontrolling interest expressed as a percentage. Common Stock Common Stock [Member] Variable Rate [Axis] Variable Rate [Axis] Business Segment and Geographic Information Segment Reporting Disclosure [Text Block] Decrease in Tradeweb Markets Inc.'s additional paid-in capital as a result of ownership changes in TWM LLC Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Other Stockholders Other Stockholders [Member] Other Stockholders Operating income Operating Income (Loss) Professional fees Professional fees Professional Fees Other Other Financial Service, Other [Member] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Hedging Designation [Axis] Hedging Designation [Axis] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Variable Rate [Domain] Variable Rate [Domain] Additional Paid-In Capital Additional Paid-in Capital [Member] Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Depreciation expense Depreciation Credit Risk Allowance for Credit Losses [Text Block] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Effect of exchange rate changes on cash, cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Accounts receivable, net of allowance for credit losses of $265 and $243 at September 30, 2021 and December 31, 2020, respectively Accounts receivable Account receivable excluding receivable from brokers and dealers and clearing organizations, net of allowance Account receivable excluding receivable from brokers and dealers and clearing organizations, net of allowance. Gross notional amount Derivative, Notional Amount Stock-based compensation expense APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition Stock surrendered (in shares) Stock Repurchased and Retired During Period, Shares Purchases of furniture, equipment, software and leasehold improvements Payments to Acquire Property, Plant, and Equipment Maximum Maximum [Member] Liquid Financial Assets Liquid Financial Assets Liquid financial assets calculated under the Commodity Exchange Act. Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Entity Information [Line Items] Entity Information [Line Items] Total liabilities Liabilities Legal Entity [Axis] Legal Entity [Axis] Award Type [Axis] Award Type [Axis] Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Total stockholders' equity attributable to Tradeweb Markets Inc. Total stockholder's equity Stockholders' Equity Attributable to Parent Common stock, shares issued (in shares) Common Stock, Shares, Issued Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Deferred taxes arising from issuance of common stock from equity incentive plans Adjustments to Additional Paid in Capital, Income Deferred Income Tax Effect from Share-based Compensation, Net Adjustments to Additional Paid in Capital, Income Deferred Income Tax Effect from Share-based Compensation, Net Receivable from/payable to affiliates, net Increase (Decrease) Due from Affiliates Capital distributions Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Declared Adjustment to additional paid in capital due to consulting service fee Adjustment to Additional Paid in Capital due to Consulting Service Fee The amount of adjustment to additional paid in capital for consulting service fee. Share repurchases pursuant to the Share Repurchase Program Payments for Repurchase of Common Stock Useful life Property, Plant and Equipment, Useful Life Non-cash financing activities - Items arising from LLC Interest ownership changes Noncash Investing and Financing Items [Abstract] TWD Tradeweb Direct Llc [Member] Tradeweb Direct LLC (TWD) is a registered broker-dealer under the Securities Exchange Act of 1934, and a member of the Financial Industry Regulatory Authority. Balance Sheet Location [Axis] Balance Sheet Location [Axis] Required Liquid Financial Assets Required Liquid Financial Assets Amount of liquid financial assets required to be maintained under the Commodity Exchange Act. Measurement Frequency [Domain] Measurement Frequency [Domain] Accrued compensation Increase (Decrease) in Employee Related Liabilities Total Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net City Area Code City Area Code Public offering price (in dollars per share) Share Price Retained earnings Retained Earnings (Accumulated Deficit) Initial term of lease Lessee, Operating Lease, Term of Contract Tradeweb Markets Inc Tradeweb Markets Inc [Member] Tradeweb Markets Inc., the reporting entity. RSUs Restricted Stock Units (RSUs) [Member] Schedule of Preliminary Purchase Price Allocated Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Business Acquisition [Line Items] Business Acquisition [Line Items] Deferred revenue Contract with Customer, Liability, Related Parties Amount of obligation to transfer good or service to related parties for which consideration has been received or is receivable. March 31, 2023 Share-based Payment Arrangement, Tranche Two [Member] Expenses Interest Income, Securities, Operating, by Taxable Status [Abstract] Deposits with clearing organizations Less: Deposits with clearing organizations acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits with Clearing Organizations Income Statement [Abstract] Income Statement [Abstract] Amendment Flag Amendment Flag Concentration Risk [Table] Concentration Risk [Table] Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Bank Stockholders Bank Stockholders [Member] Information relating to the Bank Stockholders. Proceeds from stock-based compensation exercises Proceeds from Stock Options Exercised Software development costs, net of accumulated amortization Capitalized Computer Software, Net Accrued compensation Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Employees Related Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Employees Related Liabilities Tax receivable agreement liability and deferred taxes arising from LLC Interest ownership exchanges Adjustments to Additional Paid in Capital Tax Receivable Agreement Liability and Deferred Taxes Reorganization Transaction and IPO Amount of decrease to additional paid in capital (APIC) resulting from tax receivable agreement liability and deferred taxes arising from the reorganization transactions and IPO. Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Provision for income taxes Income Tax Expense (Benefit) Total equity Beginning balance Ending balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Change from net income attributable to Tradeweb Markets Inc. and transfers (to) from non-controlling interests Net Income Attributable To Parent And Transfers (To) From Noncontrolling Interest The amount of net income (loss) attributable to parent and transfers (to) from noncontrolling interests. Equity Components [Axis] Equity Components [Axis] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] TEL Tradeweb Europe Limited [Member] Tradeweb Europe Limited (TEL) is a Multilateral Trading Facility regulated by the Financial Conduct Authority in the UK, which maintains branches in Asia which are regulated by certain Asian securities regulators. Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Sale of Stock [Domain] Sale of Stock [Domain] Weighted average shares outstanding Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Schedule of Information Regarding Revenue by Client Sector Schedule of Segment Reporting Information, by Segment [Table Text Block] Technology and communications Technology and communications Communications and Information Technology Entity File Number Entity File Number Stock-Based Compensation Share-based Payment Arrangement [Policy Text Block] Share repurchases pursuant to the Share Repurchase Program Stock Repurchased During Period, Value Accrued compensation Employee-related Liabilities Fair Value of Financial Instruments Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Schedule of Balances From Transactions with Affiliates Included in the Consolidated Statements Schedule of Related Party Transactions [Table Text Block] Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Product and Service [Axis] Product and Service [Axis] Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Small Business Entity Small Business Equity investment without readily determinable fair values Equity Securities without Readily Determinable Fair Value, Amount Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Refinitiv Refinitiv [Member] Refinitiv, formerly the Thomson Reuters Financial & Risk Business. Equity Component [Domain] Equity Component [Domain] Other - See Note 10 Stockholders' Equity, Other Share repurchases pursuant to the share repurchase program (in shares) Stock Repurchased During Period, Shares Foreign currency translation adjustments, with no tax benefit for each of the three and nine months ended September 30, 2021 and 2020 Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Subscription fees Subscription fees Subscription Fee Revenue [Member] Subscription fee revenue from granting access to institutional investors to the entity's electronic marketplaces. All-cash acquisition Purchase price, net of cash and deposits acquired and excluding working capital adjustments Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net of Acquired Cash and Restricted Cash, Deposits with Clearing Organizations Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net of Acquired Cash and Restricted Cash, Deposits with Clearing Organizations Statement [Line Items] Statement Statement [Line Items] Liabilities Liabilities [Abstract] Software Development Costs Internal Use Software, Policy [Policy Text Block] Tradeweb Markets LLC TradeWeb Markets Llc [Member] Tradeweb Markets LLC. Entity Address, State or Province Entity Address, State or Province Allowance for Credit Losses Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Income before taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Significant Observable Inputs (Level 2) Significant Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Deposits with clearing organizations Increase (Decrease) in Deposit Assets Variable Variable Pricing [Member] Contract with customer in which amount of consideration is based on variable components such as transaction based fees. Segment Reporting [Abstract] Segment Reporting [Abstract] Entity [Domain] Entity [Domain] Useful life of intangible assets Finite-Lived Intangible Asset, Useful Life Customer [Axis] Customer [Axis] Use of Estimates Use of Estimates, Policy [Policy Text Block] Schedule of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Minimum performance modifier, percent Share-based Compensation Arrangement by Share-based Payment Award, Minimum Performance Modifier Share-based Compensation Arrangement by Share-based Payment Award, Minimum Performance Modifier Entity Shell Company Entity Shell Company Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Local Phone Number Local Phone Number Schedule of Total Stock-based Compensation Expense Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Vesting [Axis] Vesting [Axis] Proceeds from issuance of Class A common stock in follow-on offering, net of underwriting discounts Proceeds from Issuance of Common Stock Total assets Assets Other assets Other Assets Related Parties Other assets from related parties. Non-employee director Director [Member] Common Stock, shares authorized (in shares) Common Stock, Shares Authorized Geographical [Domain] Geographical [Domain] Numerator: Net Income (Loss) Attributable to Parent [Abstract] Title of Individual [Axis] Title of Individual [Axis] 2019 Omnibus Equity Incentive Plan Omnibus2019 Equity Incentive Plan [Member] Represents the information pertaining to omnibus 2019 equity incentive plan. Non- Controlling Interests Noncontrolling Interest [Member] Product and Service [Domain] Product and Service [Domain] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] April Two Thousand And Twenty Follow On Offering April Two Thousand And Twenty Follow On Offering [Member] April Two Thousand And Twenty Follow On Offering Derivative Contract [Domain] Derivative Contract [Domain] March 31, 2025 Share-based Payment Arrangement, Tranche Four [Member] Share-based Payment Arrangement, Tranche Four Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Less: Net income attributable to non-controlling interests Less: Net income attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Non-Controlling Interests Noncontrolling Interest Disclosure [Text Block] Schedule of Financial Resources and Liquid Financial Resources Futures Commission Merchant, Minimum Financial Requirement [Table Text Block] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Revolving credit facility Revolving Credit Facility [Member] Significant Accounting Policies Significant Accounting Policies [Text Block] Accounts Payable and Accrued Liabilities Accounts Payable and Accrued Liabilities [Member] Distributions to non-controlling interests Payments Of Capital Distribution To Noncontrolling Interest Amount of cash outflow in the form of capital distribution to noncontrolling interests. Measurement Frequency [Axis] Measurement Frequency [Axis] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Entity Tax Identification Number Entity Tax Identification Number Deferred IPO and Follow-On Offering Costs Deferred Charges, Policy [Policy Text Block] Subsequent Event [Line Items] Subsequent Event [Line Items] DW Dealerweb [Member] Dealerweb Inc. (DW) is a registered broker-dealer under the Securities Exchange Act of 1934, a member of the Financial Industry Regulatory Authority, a registered independent introducing broker with the Commodities Future Trading Commission and a member of the National Futures Association. Geographical [Axis] Geographical [Axis] Basic (in shares) Weighted average shares of Class A and Class B common stock outstanding - Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in dollars per share) Earnings per share - Diluted (in dollars per share) Earnings Per Share, Diluted NFI Acquisition NFI Acquisition [Member] NFI Acquisition Vesting [Domain] Vesting [Domain] Total liabilities measured at fair value Financial Liabilities Fair Value Disclosure Income taxes paid, net of (refunds) Income Taxes Paid, Net International Non-US [Member] Subsequent Events Subsequent Events [Text Block] Comprehensive income attributable to Tradeweb Markets Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Intangible assets, net of accumulated amortization Intangible Assets, Net (Excluding Goodwill) Deferred revenue Deferred revenue balance - beginning of period Deferred revenue balance - ending of period Contract with Customer, Liability Fixed Fixed-price Contract [Member] Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities New billings Contract With Customer Liability, New Billings Amount of deferred revenue recognized for new billing arising during the current reporting period. Deferred tax liability Deferred Income Tax Liabilities, Net Related Party Transactions Related Party Transaction [Line Items] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Activities related to the follow-on offering and other exchanges of LLC Interests, net of offering costs and cancellations (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Class C and Class D Common Stock Class C and Class D Common Stock [Member] Class C and Class D Common Stock Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Excess Liquid Financial Assets Excess Liquid Financial Assets The amount by which actual liquid financial assets exceeds (does not exceed) required liquid financial assets under the Commodity Exchange Act Entities [Table] Entities [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Target performance modifier, percent Share-based Compensation Arrangement by Share-based Payment Award, Target Performance Modifier Share-based Compensation Arrangement by Share-based Payment Award, Target Performance Modifier Business Combinations Business Combinations Policy [Policy Text Block] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Other assets Other Assets Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Accounts payable, accrued expenses and other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Establishment of liabilities under tax receivable agreement Liabilities Assumed Limited Liability Company (LLC) Members' Equity [Abstract] Limited Liability Company (LLC) Members' Equity [Abstract] Total LLC Interests outstanding (in shares) Minority Interest Total Number Of Interests The total number of shares of the subsidiary. Derivative [Table] Derivative [Table] Revenues Revenue: Revenues [Abstract] Class D Common Stock Common Class D [Member] Classification of common stock that has different rights than provided to other classes of common stock, representing interest in a corporation. Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Class B Common Stock Common Class B [Member] TWJ Tradeweb Japan Kk [Member] Tradeweb Japan K.K. (TWJ) is a security house regulated by the Japanese Financial Services Agency and the Japan Securities Dealers Association. Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Total Fair Value Fair Value, Inputs, Level 1, 2 and 3 [Member] Accounts payable, accrued expenses and other liabilities Accounts Payable, Accrued Expenses and Other Liabilities Related Parties Accounts Payable, Accrued Expenses and Other Liabilities Related Parties Consolidated Entities [Domain] Consolidated Entities [Domain] General and administrative General and administrative Other General and Administrative Expense Revolving credit facility, term Debt Instrument, Term Income Statement Location [Domain] Income Statement Location [Domain] Customer Relationships Customer Relationships [Member] Commitments and Contingencies Loss Contingencies [Line Items] Furniture, equipment, purchased software and leasehold improvements, net of accumulated depreciation and amortization Property, Plant and Equipment, Net Refinitiv market data fees Market Data Revenue [Member] Market data revenue earned from the sale of market data to Refinitiv, which redistributes the data. Includes real-time market data fees and historical data sets. Voting power percentage Voting power percentage Voting power percentage. Equity-settled PRSUs Equity Settled Performance Based Restricted Stock Units [Member] Equity Settled Performance Based Restricted Stock Units [Member] Common stock repurchased (in shares) Treasury Stock, Shares, Acquired Tax receivable agreement liability Tax Receivable Agreement Liability The carrying amount as on the balance sheet date of tax receivable agreement liability. Earnings Per Share [Abstract] Earnings Per Share [Abstract] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Foreign currency translation adjustments attributable to Tradeweb Markets Inc. Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Accounts receivable, allowance for credit losses Allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss Regulatory Capital Regulatory Capital Regulatory capital as calculated for each entity under applicable regulations. Document Quarterly Report Document Quarterly Report Revenue Revenues Other assets Increase (Decrease) in Other Operating Assets Foreign currency forward contracts Foreign Exchange Contract [Member] March 31, 2024 Share-based Payment Arrangement, Tranche Three [Member] Consulting service fee for IPO Consulting Service Fee for IPO The amount of consulting service incurred for IPO. Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Revenue recognized Contract With Customer, Liability, Revenue Recognized Including New Billings Contract With Customer, Liability, Revenue Recognized Including New Billings Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Total stock-based compensation expense Share-based Payment Arrangement, Expense Net Income Per Share Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Regulatory Capital Requirements Regulatory Capital Requirements [Text Block] The entire disclosure of capital requirements and required financial resources under applicable regulations. Ownership percentage, continuing LLC Owners Number of LLC Interests held by non-controlling interests Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Document Fiscal Period Focus Document Fiscal Period Focus Effective tax rate Effective Income Tax Rate Reconciliation, Percent Employee compensation and benefits Employee compensation and benefits Labor and Related Expense Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Receivable from and Payable to Broker and Dealers and Clearing Organizations Industry Specific Policies, Broker Dealer [Policy Text Block] Class A Common Stock Common Class A [Member] Beginning of period End of period Cash, cash equivalents and restricted cash shown in the statement of cash flows Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Schedule of Derivative Values Schedule of Derivative Instruments [Table Text Block] Dividends Dividends U.S. UNITED STATES Shares issued to underwriters (in shares) Sale of Stock, Number of Shares Issued in Transaction Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Equity Incentive Plan Equity Incentive Plan [Member] Represents information about equity incentive plan. Entity Central Index Key Entity Central Index Key Income Tax Income Tax, Policy [Policy Text Block] LIBOR London Interbank Offered Rate (LIBOR) [Member] Intangible assets amortization period Finite-Lived Intangible Assets, Remaining Amortization Period Security Exchange Name Security Exchange Name Intangible Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Increase (decrease) in operating liabilities: Increase (Decrease) in Operating Liabilities [Abstract] Cash equivalents – Money market funds Cash and Cash Equivalents, Fair Value Disclosure Restricted Cash Restricted Assets Disclosure [Text Block] Diluted (in shares) Weighted average shares of Class A and Class B common stock outstanding - Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax Regulatory Capital Requirement Regulatory Capital Requirement Amount of regulatory capital required to be maintained for each entity under applicable regulations. Amortization expense Amortization Underwriter Over-Allotment Option [Member] Income Taxes Income Tax Disclosure [Text Block] Regulatory Capital Requirements Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Denominator: Weighted Average Number of Shares Outstanding, Basic [Abstract] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Related Party [Domain] Related Party [Domain] Current Fiscal Year End Date Current Fiscal Year End Date Spread Debt Instrument, Basis Spread on Variable Rate Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Equity Members' Equity [Abstract] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Schedule of Affiliates were Included in the Consolidated Statements of Income Schedule Of Related Party Transactions Affiliates [Table Text Block] Schedule Of Related Party Transactions Affiliates. Occupancy Occupancy Occupancy, Net Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Tax liability Accrued Income Taxes Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Revenues Disaggregation of Revenue [Abstract] Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Pushdown Accounting Consolidation, Policy [Policy Text Block] Comprehensive income - Non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest [Abstract] Payroll taxes paid for stock-based compensation Payment, Tax Withholding, Share-based Payment Arrangement Class of Stock [Domain] Class of Stock [Domain] Stock-based compensation expense under the Option Plan APIC, Share-based Payment Arrangement, Option, Increase for Cost Recognition Required Financial Resources Futures Commission Merchant, Commodity Exchange Act, Required Net Capital Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract] Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract] Foreign currency forward contracts – Gross notional amount Foreign Exchange Forward [Member] Schedule of the Impact on Equity Due to Changes in the Company’s Ownership Interest in Noncontrolling Interest Schedule Of Impact On Equity Due To Changes In The Company’s Ownership Interest In Noncontrolling Interest [Table Text Block] Tabular disclosure of impact on equity due to changes in the Company’s ownership interest in noncontrolling interest. Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Other assets – Memberships in clearing organizations Receivables from Clearing Organizations Cash equivalents – Money market funds Money Market Funds [Member] Loss Contingencies [Table] Loss Contingencies [Table] Cash and cash equivalents Less: Cash acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Grant date fair value Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Grant Date Fair Value Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Grant Date Fair Value Business Segment and Geographic Information Segment Reporting Information [Line Items] Ownership [Domain] Ownership [Domain] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Market Data Market Data Client Sector [Member] The market data client sector. Equity Investments Without Readily Determinable Fair Value Equity Securities without Readily Determinable Fair Value [Policy Text Block] Title of 12(b) Security Title of 12(b) Security Schedule of Fair Value Measurements Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Long-lived assets Long-Lived Assets Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Fed Funds Effective Rate Fed Funds Effective Rate Overnight Index Swap Rate [Member] Statement [Table] Statement [Table] Net transfers (to) from non-controlling interests Transfers From (To) Noncontrolling Interests Amount of net transfers from (to) non controlling interest. Unrecognized compensation expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Statistical Measurement [Axis] Statistical Measurement [Axis] Capitalized software development costs Payments for Software Institutional Institutional Client Sector [Member] The institutional client sector. Subsequent Event Subsequent Event [Member] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table] Cover [Abstract] Receivable from/payable to brokers and dealers and clearing organizations, net Increase (Decrease) in Receivables from Brokers-Dealers and Clearing Organizations Other - See Note 10 Noncash Financing Activities, Other Noncash Financing Activities, Other Goodwill Goodwill Income Tax Disclosure [Line Items] Income Tax Disclosure [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Retail Retail Client Sector [Member] The retail client sector. Public Investors Public Investors [Member] This member stands for public investors, collectively. Deposits with clearing organizations Deposits with clearing organizations Deposits with Clearing Organizations and Others, Securities Amortization of pushdown accounting allocation Amortization Period Pushdown Accounting Adjustment Amortization period for pushdown accounting adjustments. Subsequent Event Type [Axis] Subsequent Event Type [Axis] Cash and restricted cash Restricted Cash and Cash Equivalents, Fair Value Disclosure Restricted Cash and Cash Equivalents, Fair Value Disclosure Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Related Party Transactions Related Party Transactions Disclosure [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Deferred revenue acquired in connection with the NFI Acquisition Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination Deferred taxes Deferred Income Tax Expense (Benefit) Employee equity compensation payable Equity Compensation Payable Equity compensation payable to employees. Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]