v3.26.1
Revenue Recognition (Schedule of Disaggregation of Revenue) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Total Revenues $ 1,706.2 $ 1,692.0 $ 3,586.3 $ 3,334.3
Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Revenues 1,323.4 1,361.7 2,840.4 2,670.8
Services transferred over time        
Disaggregation of Revenue [Line Items]        
Revenues 377.3 324.7 734.6 652.9
One-time charges and miscellaneous revenues        
Disaggregation of Revenue [Line Items]        
Revenues 5.5 5.6 11.3 10.6
Clearing and transaction fees        
Disaggregation of Revenue [Line Items]        
Revenues 1,352.5 1,388.0 2,895.1 2,725.3
Total Revenues 1,352.5 1,388.0 2,895.1 2,725.3
Clearing and transaction fees | Interest rates        
Disaggregation of Revenue [Line Items]        
Revenues 433.0 461.6 954.2 897.9
Clearing and transaction fees | Equity indexes        
Disaggregation of Revenue [Line Items]        
Revenues 324.0 301.6 639.6 605.8
Clearing and transaction fees | Foreign exchange        
Disaggregation of Revenue [Line Items]        
Revenues 49.8 52.4 106.6 105.8
Clearing and transaction fees | Agricultural commodities        
Disaggregation of Revenue [Line Items]        
Revenues 183.8 174.7 351.3 339.0
Clearing and transaction fees | Energy        
Disaggregation of Revenue [Line Items]        
Revenues 187.0 217.4 450.7 433.8
Clearing and transaction fees | Metals        
Disaggregation of Revenue [Line Items]        
Revenues 76.7 85.1 195.1 156.0
Clearing and transaction fees | BrokerTec fixed income        
Disaggregation of Revenue [Line Items]        
Revenues 40.1 37.1 80.3 72.9
Clearing and transaction fees | EBS foreign exchange        
Disaggregation of Revenue [Line Items]        
Revenues 33.8 37.5 70.2 72.7
Clearing and transaction fees | Interest rate swap        
Disaggregation of Revenue [Line Items]        
Revenues 24.3 20.6 47.1 41.4
Market data and information services        
Disaggregation of Revenue [Line Items]        
Revenues 238.1 198.1 462.2 392.6
Total Revenues 238.1 198.1 462.2 392.6
Other        
Disaggregation of Revenue [Line Items]        
Revenues 115.6 105.9 229.0 216.4
Total Revenues $ 115.6 $ 105.9 $ 229.0 $ 216.4