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Transaction rebates Transaction Rebates [Member] Transaction Rebates [Member] Retained earnings Retained Earnings (Accumulated Deficit) Restructuring and Related Activities [Abstract] Product and Service [Axis] Product and Service [Axis] Contract value of resale and repurchase agreements Contract Value Of Resale And Repurchase Agreements Contract value of resale and repurchase agreements. 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short-term investments Proceeds from Sale, Maturity and Collection of Short-Term Investments Income tax provision Income Tax Expense (Benefit) Gain (loss) currency translation adjustment Gain (Loss), Foreign Currency Transaction, before Tax Transaction-based expenses Transaction-based expenses Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Performance-based long-term incentive program weighted percentage Performance Based Long Term Incentive Program Weighted Percentage Performance Based Long Term Incentive Program Weighted Percentage Principles of Consolidation Consolidation, Policy [Policy Text Block] Net decrease in cash and cash equivalents and restricted cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Option to increase available aggregate amount Line Of Credit Facility, Optional Increase In Maximum Borrowing Capacity Line Of Credit Facility, Optional Increase In Maximum Borrowing Capacity Long-term debt - senior unsecured notes: Changes in Long-Term Debt Obligations [Roll Forward] Changes in Long-Term Debt Obligations Number of equity exchanges (in exchanges) Number Of Equity Exchanges Number Of Equity Exchanges Net income attributable to Nasdaq Net income attributable to Nasdaq Net income attributable to common shareholders Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Demand deposits Demand Deposits [Member] Investments Investments [Member] Unamortized debt issuance expense Unamortized Debt Issuance Expense Statement [Table] Statement [Table] Second Anniversary Share-Based Payment Arrangement, Tranche Two [Member] Other revenues Reconciling items Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member] Restatement Determination Date: Restatement Determination Date [Axis] Proceeds from stock options exercised Proceeds from Stock Options Exercised Schedule of Remaining Performance Obligation Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Interest income Investment Income, Interest Schedule of Estimated Deferred Revenue Estimated Deferred Revenue [Table Text Block] The year in which deferred revenue is expected to be recognized. Schedule of Changes in Deferred Revenue Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Receivables, net Increase (Decrease) in Receivables Revenues: Revenues [Abstract] Basis of Presentation and Principles of Consolidation Basis of Presentation and Significant Accounting Policies [Text Block] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Schedule of Derivative Contracts Cleared Schedule of Derivative Contracts Cleared [Table Text Block] Schedule of Derivative Contracts Cleared.