Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Weighted Average Number of Common Shares: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Trading Arrangement: Trading Arrangement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Title of each class Title of 12(b) Security Document Fiscal Year Focus Document Fiscal Year Focus Adjustment to Compensation, Amount Adjustment to Compensation Amount Schedule of Trading Securities and Other Trading Assets, Major Types of Trading Securities and Assets [Axis] Financial Instrument [Axis] Segment Reporting [Abstract] Future estimated amortization expense Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block] 2027 Lessee, Operating Lease, Liability, to be Paid, Year One Employee taxes paid on restricted stock vesting Payment, Tax Withholding, Share-Based Payment Arrangement Interest rate [Member] Interest Rate [Member] Interest Rate [Member] Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Long-Term Debt Instruments [Table Text Block] Services transferred over time [Member] Transferred over Time [Member] Intangible assets—other, net Other Indefinite-Lived Intangible Assets Guarantor Obligations, Maximum Exposure, Undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Restatement Determination Date Restatement Determination Date 2027 Finance Lease, Liability, to be Paid, Year One Derivative Instrument [Axis] Derivative Instrument [Axis] Operating Leases, Future Minimum Payments Due [Table] Operating Leases, Future Minimum Payments Due [Table] Operating Leases, Future Minimum Payments Due [Table] Vesting of issued restricted Class A common stock, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Measurement Frequency [Axis] Measurement Frequency [Axis] Expense related to Performance Bonds Expense related to Performance Bonds [Member] Expense related to Performance Bonds Amendment Flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Preferred Stock, Convertible, Shares Issuable Conversion of Stock, Shares Converted Shares Acquired, Average Cost Per Share Shares Acquired, Average Cost Per Share Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Finance Lease, Principal Payments Finance Lease, Principal Payments $750.0 million Fixed Rate Notes Due September 2043, stated rate of 5.30% [Member] $750.0 million Fixed Rate Notes Due September 2043 Interest Equal To 5.3% [Member] $750.0millionFixedRateNotesDueSeptember2043InterestEqualTo5.3% Technology-Related Intellectual Property [Member] Developed Technology Rights [Member] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Interest paid Interest Paid, Including Capitalized Interest, Operating and Investing Activities Interest from Performance Bonds [Member] Interest from Performance Bonds [Member] Interest from Performance Bonds Foreign Exchange [Member] Foreign Exchange [Member] Leases [Abstract] Leases [Abstract] Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Debt Instrument, Maturity Date Debt Instrument, Maturity Date Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Entity Address, State Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Agreement automatic renewal period (in years) Agreement Automatic Renewal, Period Agreement Automatic Renewal, Period Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Total current liabilities Liabilities, Current 2030 Lessee, Operating Lease, Liability, to be Paid, Year Four Clearing Firm, Market Data And Other Customer Relationships [Member] Customer Relationships [Member] Statement [Table] Fair Value of Debt Instruments [Table] Fair Value of Debt Instruments Intangible assets—trading products Intangible assets, trading products Intangible assets, trading products Entity Address, City Entity Address, City or Town Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Class of Stock [Axis] Class of Stock [Axis] Long-term debt Unsecured Long-Term Debt, Noncurrent Intangible assets—other, net Intangible assets—other, net Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Net Income (Loss) Available to Common Stockholders, Basic Net Income (Loss) Available to Common Stockholders, Basic Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Sublease Income Sublease Income Accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Non-Operating Income (Expense) Nonoperating Income (Expense) [Abstract] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Investment income Investment Income, Nonoperating $750.0 Million Fixed Rate Notes Due March 2032, Interest Equal To 2.65% $750.0 Million Fixed Rate Notes Due March 2032, Interest Equal To 2.65% [Member] $750.0 Million Fixed Rate Notes Due March 2032, Interest Equal To 2.65% Subsequent Event Type [Axis] Subsequent Event Type [Axis] Derivative investments, net Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Remaining Lease Term Operating Lease, Remaining Lease Term New Accounting Pronouncements, Policy New Accounting Pronouncements, Policy [Policy Text Block] Income tax benefit (expense) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Other Comprehensive Income (Loss), before Tax Other Comprehensive Income (Loss), before Tax FutureLosses FutureLosses FutureLosses Proceeds from debt, net of issuance costs Proceeds from Debt, Net of Issuance Costs Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Lessee, Operating Lease, Liability, Maturity Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Contingencies Contingencies Disclosure [Text Block] Income taxes payable Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Change in: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net Cash Used in Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Payments under Guarantee Payments under Guarantee Payments under Guarantee Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Debt Instrument, Face Amount Debt Instrument, Face Amount 2028 Lessee, Operating Lease, Liability, to be Paid, Year Two Expenses Costs and Expenses [Abstract] Name of each exchange on which registered Security Exchange Name Finance Lease, Weighted Average Remaining Lease Term Finance Lease, Weighted Average Remaining Lease Term Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Class B Common Stock [Member] Common Class B [Member] Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Operating Lease, Liability, Current Operating Lease, Liability, Current Finance Leases, Future Minimum Payments Due [Table] Capital Leases, Future Minimum Payments Due [Table] Capital Leases, Future Minimum Payments Due [Table] Finance Lease, Right-of-Use Asset Finance Lease, Right-of-Use Asset, after Accumulated Amortization Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Earnings per Share Attributable to Common Shareholders of CME Group: Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Trading Securities at Fair Value Debt Securities, Trading, and Equity Securities, FV-NI Total Liabilities Liabilities Trading symbol Trading Symbol Preferred Stock, Conversion Basis Convertible Preferred Stock, Shares Issued upon Conversion Total intangible assets - other, net Intangible Asset, Excluding Goodwill, Indefinite-Lived Purchases of property, net Payments to Acquire Property, Plant, and Equipment Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Company Selected Measure Name Company Selected Measure Name Purchases of available-for-sale marketable securities Payments to Acquire Debt Securities, Available-for-Sale Financial instruments measured at fair value on a recurring basis Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Investments in privately-held equity investments Payments to Acquire Other Investments Defined Benefit Plans [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Equities [Member] Equities [Member] Equities [Member] Payment per cooperative PaymentPerCooperative PaymentPerCooperative Other current liabilities Increase (Decrease) in Other Accrued Liabilities Cash Flows from Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Overdistributed earnings allocated to preferred stock [Abstract] Overdistributed earnings allocated to preferred stock Overdistributed earnings allocated to preferred stock Present Value of Operating Lease Liability Operating Leases, Future Minimum Payments, Present Value of Net Minimum Payments Operating Leases, Future Minimum Payments, Present Value of Net Minimum Payments Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Diluted (in shares) Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Cash dividends on common stock, per share (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] 2028 Finance Lease, Liability, to be Paid, Year Two Underlying Security Market Price Change Underlying Security Market Price Change, Percent 2030 Finance Lease, Liability, to be Paid, Year Four Lessee, Operating Lease, Term of Contract Operating Lease Term of Contract Operating Lease Term of Contract Other [Member] Other Intangible Assets [Member] Guarantees Guarantees [Text Block] Income tax benefit (expense) OCI, Foreign Currency Transaction and Translation Gain (Loss), Arising During Period, Tax Operating Lease, Payments Operating Lease, Payments Award Timing Predetermined Award Timing Predetermined [Flag] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Indefinite-lived Intangible Assets, Major Class Name [Domain] Intangible Asset, Indefinite-Lived, Class [Domain] Total Operating Lease Payments Lessee, Operating Lease, Liability, to be Paid Performance Bonds and Guaranty Fund Contributions Performance Bonds and Guaranty Fund Contributions [Text Block] Performance Bonds and Guaranty Fund Contributions [Text Block] Effect of stock options, restricted stock and performance shares Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Net Income Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest All Executive Categories All Executive Categories [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Line of Credit Facility, Commitment Fee Amount Line of Credit Facility, Commitment Fee Amount Interest and other borrowing costs Interest and Debt Expense Depreciation and amortization Depreciation Antidilutive Securities Excluded from Computation of Earnings Per Share, by Antidilutive Securities [Axis] Antidilutive Securities [Axis] Operating Lease, Right-of-Use Asset Operating Lease, Right-of-Use Asset Technology Information Technology and Data Processing Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Basic And Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Segment Reporting Segment Reporting [Text Block] Proceeds from maturities of available-for-sale marketable securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Expiration Date Trading Arrangement Expiration Date Investments, Fair Value Disclosure Investments, Fair Value Disclosure 2030 Long-Term Debt, Maturity, Year Four Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Common stock, shares authorized (in shares) Common Stock, Shares Authorized $750.0 Million Fixed Rate Notes Due March 2030, Interest Equal to 4.4% $750.0 Million Fixed Rate Notes Due March 2030, Interest Equal to 4.4% [Member] $750.0 Million Fixed Rate Notes Due March 2030, Interest Equal to 4.4% Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Exercise Price Award Exercise Price Cash Flows from Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Vesting of issued restricted Class A common stock Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Fair Value, Recurring [Member] Fair Value, Recurring [Member] Share Repurchase Program, Authorized, Amount Share Repurchase Program, Authorized, Amount Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Interest Rate Swap [Member] Interest Rate Swap [Member] Common Stock And Additional Paid-In Capital [Member] Common Stock Including Additional Paid in Capital [Member] Debt Debt Disclosure [Text Block] Repayment of debt Repayments of Long-Term Debt Total Amortizable Intangible Assets [Member] Finite-Lived Intangible Assets [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Lease Contractual Term [Axis] Lease Contractual Term [Axis] Loss Contingency [Abstract] Loss Contingency [Abstract] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Total Expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Thereafter Long-Term Debt, Maturity, after Year Five Finance Lease, Weighted Average Discount Rate, Percent Finance Lease, Weighted Average Discount Rate, Percent Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Total CME Group Shareholders’ Equity Balance Balance Stockholders' Equity Attributable to Parent Equity, Attributable to Parent Total Non-Operating Income (Expense) Nonoperating Income (Expense) Assets Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount $700.0 Million Fixed Rate Notes Due June 2048, stated rate of 4.15% [Member] [Domain] [Domain] $700.0 Million Fixed Rate Notes Due June 2048, Interest Equal To 4.15% [Member] [Domain] [Domain] $700.0 Million Fixed Rate Notes Due June 2048, Interest Equal To 4.15% [Member] [Domain] [Domain] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Operating Lease, Liability Operating Lease, Liability Professional fees and outside services Professional Fees Insider Trading Policies and Procedures [Line Items] Finance Lease, Liability Finance Lease, Liability Other Proceeds from (Payment for) Other Financing Activity Accounts receivable, allowance Accounts Receivable, Allowance for Credit Loss, Current Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Deferred income taxes Deferred Income Tax Expense (Benefit) Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 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] Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Common stock Common Stock, Value, Outstanding Accumulated depreciation and amortization, property Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Additional paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Repurchase of Class A common stock, including costs Payments for (Proceeds from) Derivative Instrument, Financing Activities Schedule of Guarantor Obligations [Table] Guarantor Obligation [Table] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Income Statement [Abstract] Income Statement [Abstract] Shareholders' Equity: Equity, Attributable to Parent [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Net realized and unrealized (gains) losses on investments Gain (Loss) on Investments Finance Lease, Liability, Noncurrent Finance Lease, Liability, Noncurrent Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] City Area Code City Area Code Variable Rate [Domain] Variable Rate [Domain] Restricted Stock [Member] Restricted Stock [Member] Total Finance Lease Payments Finance Lease, Liability, to be Paid Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Subsequent Events [Text Block] Subsequent Events [Text Block] Debt Instrument, Fair Value Disclosure Debt Instrument, Fair Value Disclosure Cash dividends Payments of Dividends Name Forgone Recovery, Individual Name Other Investment Not Readily Marketable, Fair Value Other Investment Not Readily Marketable, Fair Value Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Operating Lease Payments, Less Imputed Interest Operating Leases, Future Minimum Payments, Interest Included in Payments Operating Leases, Future Minimum Payments, Interest Included in Payments Components of intangible assets Intangible Asset [Text Block] Statement [Line Items] Statement [Line Items] Total Assets Assets Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Present Value of Finance Lease Liability Finance leases, future minimum payments, present value of net minimum payments Finance leases, future minimum payments, present value of net minimum payments Equity Securities without Readily Determinable Fair Value, Amount Equity Securities without Readily Determinable Fair Value, Amount Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Forward starting interest rate swap agreement fixed rate Forward starting interest rate swap agreement fixed rate Forward starting interest rate swap agreement, fixed rate Other assets Increase (Decrease) in Other Operating Assets PEO PEO [Member] 2028 Long-Term Debt, Maturity, Year Two $500.0 Million Fixed Rate Notes Due June 2028, Interest Equal To 3.75% [Domain] $500.0 Million Fixed Rate Notes Due June 2028, Interest Equal To 3.75% [Domain] $500.0 Million Fixed Rate Notes Due June 2028, Interest Equal To 3.75% Stock Repurchased and Retired During Period, Shares Stock Repurchased and Retired During Period, Shares Marketable securities Marketable Securities, Current Other liabilities Other Liabilities, Noncurrent Goodwill Goodwill Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Net unrealized holding gains (losses) arising during the period OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Thereafter Finance Lease, Liability, to be Paid, after Year Five $750.0 Million Fixed Rate Notes Due March 2025, stated rate of 3.00% [Member] $750.0 Million Fixed Rate Notes Due March 2025, Interest Equal To 3.00% [Member] Seven Hundred Fifty Million Fixed Rate Notes Due March Two Thousand Twenty Five, Interest Equal To Three Point Zero Percent [Member] [Member] [Member] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Operating Lease, Liability, Noncurrent Operating Lease, Liability, Noncurrent Retained Earnings [Member] Retained Earnings [Member] Investment Securities [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Investment securities, net OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Common stock, shares outstanding (in shares) Balance (in shares) Balance (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Accumulated Foreign Currency Adjustment Attributable to Parent Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Corporate Debt Securities [Member] Corporate Debt Securities [Member] Diluted (in dollars per share) Earnings per common share, diluted (in dollars per share) Earnings Per Share, Diluted Statement [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Net Cash Provided by Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Other current assets Increase (Decrease) in Prepaid Expense and Other Assets Unrealized Loss on Investments Unrealized Gain (Loss) on Investments Amortization of purchased intangibles Amortization of purchased intangibles Intangible Asset, Finite-Lived, Amortization Expense Intangible Assets [Line Items] Intangible Asset, Finite-Lived [Line Items] Lease Contractual Term [Domain] Lease Contractual Term [Domain] Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] 2029 Long-Term Debt, Maturity, Year Three Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Revenues Revenue from Contract with Customer, Excluding Assessed Tax Cash Flows from Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, net of accumulated depreciation and amortization of $1,028.3 and $1,005.7 Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Lessee, Operating Lease, Option to Terminate Operating Lease, Option to Early Terminate, Months Operating Lease, Option to Early Terminate, Months Major Types of Trading Securities and Assets [Domain] Financial Instruments [Domain] Stock Repurchased During Period, Value Stock Repurchased During Period, Value Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Intangible Assets And Goodwill Intangible Asset and Goodwill [Text Block] Underlying Securities Award Underlying Securities Amount Operating Lease, Weighted Average Discount Rate, Percent Weighted Average Discount Rate Operating Lease Weighted Average Discount Rate Operating Lease Preferred Stock [Member] Preferred Stock [Member] Schedule of Maturities of Long-term Debt [Table Text Block] Schedule of Maturities of Long-Term Debt [Table Text Block] Average Daily Clearing Settlement Average Daily Clearing Settlement Average Daily Clearing Settlement Guarantees [Abstract] Guarantees [Abstract] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Lease, Cost [Table Text Block] Lease, Cost [Table Text Block] Other current assets (includes $6.4 and $6.5 in restricted cash) Other Assets, Current Performance bonds and guaranty fund contributions Margin Deposits And Guaranty Funds Liabilities Current Margin Deposits And Guaranty Funds Liabilities Current Margin Deposits And Guaranty Funds Liabilities Current. All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Income tax benefit (expense) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Operating Income Operating Income (Loss) Current Fiscal Year End Date Current Fiscal Year End Date Finance Lease, Liability, Fiscal Year Maturity Finance Lease, Liability, to be Paid, Maturity [Table Text Block] Remainder of 2026 Finance Lease, Liability, to be Paid, Remainder of Fiscal Year Revenue Recognition [Abstract] Revenue Recognition [Abstract] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Stock Repurchased During Period, Shares Stock Repurchased During Period, Shares Market data and information services MarketData [Member] MarketData [Member] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Equity Securities without Readily Determinable Fair Value, Impairment Loss, Cumulative Amount Equity Securities without Readily Determinable Fair Value, Impairment Loss, Cumulative Amount Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Thereafter Intangible Asset, Finite-Lived, Estimated Amortization Expense, after Year Five Equity Securities [Member] Equity Securities [Member] Energy [Member] Energy [Member] Energy [Member] Reclassification of net unrealized (gains) losses to interest expense and other non-operating income (expense) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax One-time charges and miscellaneous revenues [Member] One-time charges and miscellaneous revenues [Member] One-time charges and miscellaneous revenues [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Schedule of Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Statement, Equity Components [Axis] Equity Components [Axis] Other Other Cost and Expense, Operating Accounts receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Performance Bonds and Guaranty Fund Contributions [Abstract] Performance Bonds and Guaranty Fund Contributions [Abstract] Performance Bonds and Guaranty Fund Contributions [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Other OtherRevenue [Member] OtherRevenue [Member] Class A Common Stock [Member] Common Class A [Member] Entity Interactive Data Current Entity Interactive Data Current Finance Lease, Liability, Current Finance Lease, Liability, Current Variable Rate [Axis] Variable Rate [Axis] Undistributed Earnings (Loss) Available to Common Shareholders, Basic Undistributed Earnings (Loss) Available to Common Shareholders, Basic Deferred income tax liabilities, net Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business 2029 Lessee, Operating Lease, Liability, to be Paid, Year Three Termination Date Trading Arrangement Termination Date Federal Reserve Bank Advances Federal Reserve Bank Advances [Member] Subsequent Events [Abstract] Subsequent Events [Abstract] Family Farmer and Ranchers Protection Fund [Member] Family Farmer and Ranchers Protection Fund [Member] Family Farmer and Ranchers Protection Fund [Member] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Defined benefit plans, net Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other current liabilities Other Liabilities, Current Marketable Securities Marketable Securities Other assets Other Assets, Noncurrent 2029 Finance Lease, Liability, to be Paid, Year Three Operating Leases, Future Minimum Payments Due [Line Items] Operating Leases, Future Minimum Payments Due [Line Items] [Line Items] for Operating Leases, Future Minimum Payments Due [Table] Document Type Document Type Fair Value as of Grant Date Award Grant Date Fair Value Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Goodwill [Table] Goodwill [Table] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Share Repurchase Program, Remaining Authorized, Amount Share Repurchase Program, Remaining Authorized, Amount Foreign currency translation, net Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Arrangement Duration Trading Arrangement Duration Subsequent Event [Line Items] Subsequent Event [Line Items] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Income before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Assigned Value Intangible Asset, Finite-Lived, before Accumulated Amortization Total Revenues Revenues Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Equity in net earnings of unconsolidated subsidiaries Income (Loss) from Equity Method Investments Net Income (Loss) from Continuing Operations Available to Common Shareholders, Diluted Net Income (Loss) from Continuing Operations Available to Common Shareholders, Diluted Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to 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Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, $0.01 par value, 10,000 shares authorized at March 31, 2026 and December 31, 2025; no shares issued and outstanding as of March 31, 2026 and 4,584 issued and outstanding as of December 31, 2025 Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Class of Stock [Domain] Class of Stock [Domain] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Translation Adjustment Functional to Reporting Currency, Increase (Decrease), Gross of Tax Translation Adjustment Functional to Reporting Currency, Increase (Decrease), Gross of Tax Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total Assets at Fair Value Assets, Fair Value Disclosure 2031 Finance Lease, Liability, to be Paid, Year Five Name Measure Name Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Other Other Noncash Income (Expense) 2031 Lessee, Operating Lease, Liability, to be Paid, Year Five Finance Lease, Expense Finance Lease, Expense Finance Lease, 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Year Five Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Weighted Average Remaining Lease Term EBS Foreign Exchange EBS Foreign Exchange [Member] EBS Foreign Exchange Non-PEO NEO Non-PEO NEO [Member] Entity Address, Street Address Entity Address, Address Line One Income tax provision Income Tax Expense (Benefit) Class B Common Stock, Class B-1 [Member] Class B Common Stock, Class B1 [member] Class B Common Stock, Class B1 [Member] Award Timing Method Award Timing Method [Text Block] Net change in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Lessee, Operating Lease, Renewal Term Operating Lease Renewal Term Operating Lease Renewal Term Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Net change in defined benefit plans arising during the period Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Net Income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Contingent liability to SGX, amount of irrevocable letters of credit Guarantee Collateral Guarantee Collateral Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Restatement Determination Date: Restatement Determination Date [Axis] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] $500.0 Million Fixed Rate Notes Due June 2028, stated rate of 3.75% [Member] [Domain] $750 Million Fixed Rate Notes Due March 2030, Interest Equal To 4.4% [Domain] $750 Million Fixed Rate Notes Due March 2030, Interest Equal To 4.4% Lessee, Leases [Policy Text Block] Lessee, Leases [Policy Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Change in performance bond and guaranty fund contributions Change in performance bond and guaranty fund contributions Change in performance bond and guaranty fund contributions Revenues Revenues [Abstract] Nonrecurring fair value [Abstract] Nonrecurring fair value [Abstract] Nonrecurring fair value [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]