v3.26.3
Revenue Recognition (Schedule of Disaggregation of Revenue) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Disaggregation of Revenue [Line Items]        
Total Revenues $ 1,737.3 $ 1,537.6 $ 5,323.6 $ 4,871.9
Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Revenues 1,350.5 1,201.1 4,190.9 3,871.9
Services transferred over time        
Disaggregation of Revenue [Line Items]        
Revenues 380.7 331.3 1,115.3 984.2
One-time charges and miscellaneous revenues        
Disaggregation of Revenue [Line Items]        
Revenues 6.1 5.2 17.4 15.8
Clearing and transaction fees        
Disaggregation of Revenue [Line Items]        
Revenues 1,378.1 1,227.9 4,273.2 3,953.2
Total Revenues 1,378.1 1,227.9 4,273.2 3,953.2
Clearing and transaction fees | Interest rates        
Disaggregation of Revenue [Line Items]        
Revenues 473.6 417.2 1,427.8 1,315.0
Clearing and transaction fees | Equity indexes        
Disaggregation of Revenue [Line Items]        
Revenues 298.7 261.9 938.3 867.7
Clearing and transaction fees | Foreign exchange        
Disaggregation of Revenue [Line Items]        
Revenues 53.9 44.9 160.5 150.7
Clearing and transaction fees | Energy        
Disaggregation of Revenue [Line Items]        
Revenues 195.6 178.3 646.3 612.1
Clearing and transaction fees | Agricultural commodities        
Disaggregation of Revenue [Line Items]        
Revenues 178.3 155.9 529.6 495.0
Clearing and transaction fees | Metals        
Disaggregation of Revenue [Line Items]        
Revenues 79.3 79.4 274.4 235.4
Clearing and transaction fees | BrokerTec fixed income        
Disaggregation of Revenue [Line Items]        
Revenues 41.1 39.3 121.4 112.2
Clearing and transaction fees | EBS foreign exchange        
Disaggregation of Revenue [Line Items]        
Revenues 32.9 30.5 103.1 103.2
Clearing and transaction fees | Interest rate swap and other        
Disaggregation of Revenue [Line Items]        
Revenues 24.7 20.5 71.8 61.9
Market data and information services        
Disaggregation of Revenue [Line Items]        
Revenues 243.1 202.5 705.3 595.1
Total Revenues 243.1 202.5 705.3 595.1
Other        
Disaggregation of Revenue [Line Items]        
Revenues 116.1 107.2 345.1 323.6
Total Revenues $ 116.1 $ 107.2 $ 345.1 $ 323.6