Document and Entity Information Statement [Table] Statement [Line Items] Statement Document Type Document Period End Date Entity Registrant Name Entity Current Reporting Status Entity Filer Category Entity Interactive Data Current Entity Small Business Entity Emerging Growth Company Entity Ex Transition Period Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag Consolidated Statements of Financial Condition Assets [Abstract] Assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and cash equivalents Restricted Cash. Restricted cash Receivables from Brokers-Dealers and Clearing Organizations Receivable from brokers and dealers and clearing organizations Deposits with Clearing Organizations and Others, Securities Deposits with clearing organizations 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 Accounts receivable, net of allowance for credit losses of $150 and $195 at March 31, 2020 and December 31, 2019, respectively Property, Plant and Equipment, Net Furniture, equipment, purchased software and leasehold improvements, net of accumulated depreciation and amortization Operating Lease, Right-of-Use Asset Right-of-use assets Capitalized Computer Software, Net Software development costs, net of accumulated amortization Goodwill Goodwill Intangible Assets, Net (Excluding Goodwill) Intangible assets, net of accumulated amortization Due from Affiliates Receivable from affiliates Deferred Income Tax Assets, Net Deferred tax asset Other Assets Other assets Assets Total assets Liabilities and Equity [Abstract] Liabilities and Stockholders' Equity Liabilities [Abstract] Liabilities Payables to Broker-Dealers and Clearing Organizations Payable to brokers and dealers and clearing organizations Employee-related Liabilities Accrued compensation Contract with Customer, Liability Deferred revenue balance - end of period Deferred revenue balance - beginning of period Deferred revenue Accounts Payable and Accrued Liabilities Accounts payable, accrued expenses and other liabilities Equity compensation payable to employees. Equity Compensation Payable Employee equity compensation payable Operating Lease, Liability Lease liability Due to Affiliate Payable to affiliates Deferred Income Tax Liabilities, Net Deferred tax liability The carrying amount as on the balance sheet date of tax receivable agreement liability. Tax Receivable Agreement Liability Tax receivable agreement liability Liabilities Total liabilities Commitments and Contingencies. Commitments and contingencies (Note 14) Members' Equity [Abstract] Stockholders' Equity Preferred Stock, Value, Issued Preferred stock, $.00001 par value; 250,000,000 shares authorized; none issued or outstanding Common Stock, Value, Issued Common stock Additional paid-in capital Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Retained Earnings (Accumulated Deficit) Retained earnings Stockholders' Equity Attributable to Parent Total stockholders' equity attributable to Tradeweb Markets Inc. Total stockholder's equity Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Equity at end of period Equity at beginning of period Total equity Liabilities and Equity Total liabilities and stockholders' equity Allowance for Doubtful Accounts Receivable Ending balance - March 31, 2020 Beginning balance, prior to adoption of ASC 326 - December 31, 2019 Allowance for doubtful accounts Preferred Stock, Par or Stated Value Per Share Preferred stock, par value Preferred Stock, Shares Authorized Preferred stock, shares authorized Preferred Stock, Shares Issued Preferred stock, shares issued Preferred Stock, Shares Outstanding Preferred stock, shares outstanding Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, par value per share Common Stock, Shares Authorized Common Stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Number of shares owned Common Stock, Shares, Outstanding Common stock, shares outstanding Consolidated Statements of Income Revenues [Abstract] Revenue: Revenues Revenue from Contract with Customer, Excluding Assessed Tax Gross revenues Gross revenue Operating Expenses [Abstract] Expenses Labor and Related Expense Employee compensation and benefits Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Communications and Information Technology Technology and communications Other General and Administrative Expense General and administrative Professional Fees Professional fees Occupancy, Net Occupancy Costs and Expenses Operating expenses Total expenses Operating Income (Loss) Operating income Operating income Investment Income, Interest Net interest income Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income before taxes Income Tax Expense (Benefit) Provision for income taxes Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income Net income Represents the amount of profit loss after pre-IPO. Profit Loss After Pre IPO Net income attributable to Tradeweb Markets Inc. and non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to non-controlling interests Less: Net income attributable to non-controlling interests Net Income (Loss) Attributable to Parent Net income attributable to Tradeweb Markets Inc. Net income attributable to Tradeweb Markets Inc. Earnings Per Share EPS calculations for post-IPO and pre-IPO periods Earnings Per Share, Basic Earnings per share - Basic Basic Earnings Per Share, Diluted Earnings per share - Diluted Diluted Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted average shares outstanding Weighted Average Number of Shares Outstanding, Basic Weighted average outstanding - Basic Basic Weighted Average Number of Shares Outstanding, Diluted Diluted Weighted average outstanding - Diluted Consolidated Statements of Comprehensive Income Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Foreign currency translation adjustments attributable to Tradeweb Markets Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to Tradeweb Markets Inc. Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest Foreign currency translation adjustments attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to non-controlling interests Consolidated Statements of Changes in Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity Members' Equity Members' capital end of period Members' capital beginning of period Shares, Outstanding Equity at end of period (in shares) Equity at beginning of period ( in shares) Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Comprehensive income: Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock Adjustment to Class C Shares and Class P© shares in mezzanine capital Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Declared Capital distributions Capital distributions Stock Issued During Period, Value, Conversion of Convertible Securities Activities related to exchanges of LLC Interests, net of offering costs and cancellations Stock Issued During Period, Shares, Conversion of Convertible Securities Activities related to exchanges of LLC Interests, net of offering costs and cancellations (in shares) Stock Issued During Period, Value, New Issues Issuance of common stock from equity incentive plans Stock Issued During Period, Shares, New Issues Issuance of common stock from equity incentive plans (in shares) Shares issued 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. Adjustments to Additional Paid in Capital Tax Receivable Agreement Liability and Deferred Taxes Reorganization Transaction and IPO Tax receivable agreement liability and deferred taxes arising from LLC Interest ownership exchanges Amount of increase (decrease) in noncontrolling interest from adjustments. Minority Interest Increase Decrease From Adjustments Adjustments to non-controlling interests Dividends Dividends ($0.08 per share) Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition Stock-based compensation expense under the PRSU Plan Amount reclassified to members capital Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition Stock-based compensation expense under the Option Plan Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Payroll taxes paid for stock-based compensation exercises Limited Liability Company (LLC) Members' Equity, Unit-based Compensation Stock-based compensation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation adjustments Common Stock, Dividends, Per Share, Declared Dividends Cash dividend declared Per Share Consolidated Statements of Cash Flows Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash used in operating activities: Share-based Compensation Stock-based compensation expense Deferred Income Tax Expense (Benefit) Deferred taxes Deferred tax asset Increase (Decrease) in Operating Assets [Abstract] (Increase) decrease in operating assets: Increase (Decrease) in Receivables from Brokers-Dealers and Clearing Organizations Receivable from/payable to brokers and dealers and clearing organizations, net Increase (Decrease) in Deposit Assets Deposits with clearing organizations Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) Due from Affiliates Receivable from/payable to affiliates, net Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Operating Liabilities [Abstract] Increase (decrease) in operating liabilities: Increase (Decrease) in Employee Related Liabilities Accrued compensation Increase (Decrease) in Deferred Revenue Deferred revenue Increase (Decrease) in Accounts Payable and Accrued Liabilities Accounts payable, accrued expenses and other liabilities The increase (decrease) during the period in equity compensation payable. Increase Decrease In Equity Compensation Payable Employee equity compensation payable Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities Payments to Acquire Property, Plant, and Equipment Purchase of furniture, equipment, software and leasehold improvements Payments for Software Capitalized software development costs Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Proceeds from Issuance of Common Stock Proceeds from stock-based compensation exercises Received net proceeds Payments of Stock Issuance Costs Offering costs from follow-on offering Payments of Ordinary Dividends Dividends Amount of cash outflow in the form of capital distribution to noncontrolling interests. Payments Of Capital Distribution To Noncontrolling Interest Capital distributions to non-controlling interests Payment, Tax Withholding, Share-based Payment Arrangement Payroll taxes paid for stock-based compensation exercises Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Effect of exchange rate changes on cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract] Cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents End of period Beginning of period Cash, cash equivalents and restricted cash shown in the statement of cash flows Supplemental Cash Flow Information [Abstract] Supplemental disclosure of cash flow information Income Taxes Paid Income taxes paid Noncash Investing and Financing Items [Abstract] Non-cash financing activities - Items arising from LLC Interest ownership changes Liabilities Assumed Establishment of liabilities under tax receivable agreement Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization Significant Accounting Policies Entities [Table] Entity Information [Line Items] Significant Accounting Policies [Text Block] Significant Accounting Policies Restricted Cash Restricted Assets Disclosure [Text Block] Restricted Cash Intangible Assets and Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Goodwill and Intangible Assets Revenue Revenue from Contract with Customer [Text Block] Revenue Income Taxes Income Tax Disclosure [Text Block] Income Taxes No definition available. Tax Receivable Agreement The entire disclosure of tax receivable agreement liability. Tax Receivable Agreement Liability Disclosure [Text Block] Tax Receivable Agreement Stockholder's Equity Stockholders' Equity Note Disclosure [Text Block] Stockholders’ Equity Non-Controlling Interests Noncontrolling Interest Disclosure [Text Block] Non-Controlling Interests Stock-Based Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock-Based Compensation Plans Related Party Transactions Related Party Transactions Disclosure [Text Block] Related Party Transactions Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Fair Value of Financial Instruments Credit Risk Allowance for Credit Losses [Text Block] Credit Risk Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Earnings Per Share [Text Block] Earnings Per Share Regulatory Capital Requirements The entire disclosure of capital requirements and required financial resources under applicable regulations. Regulatory Capital Requirements [Text Block] Regulatory Capital Requirements Business Segment and Geographic Information Segment Reporting Disclosure [Text Block] Business Segment and Geographic Information Subsequent Events Subsequent Events [Text Block] Subsequent Events Basis of Accounting, Policy [Policy Text Block] Basis of Accounting Use of Estimates, Policy [Policy Text Block] Use of Estimates Consolidation, Policy [Policy Text Block] Basis of Presentation and Consolidation Pushdown Accounting [Policy Text Block] Pushdown Accounting Cash and Cash Equivalents, Policy [Policy Text Block] Cash and Cash Equivalents Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Allowance for Credit Losses Brokers and Dealers Disclosure [Text Block] Receivable from and Payable to Brokers and Dealers and Clearing Organizations Disclosure of accounting policy for deposits with clearing organizations. Deposits With Clearing Organizations Deposits with Clearing Organizations