v3.26.3
Earnings Per Share (Schedule of Earnings Per Share Calculation) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Earnings Per Share [Abstract]        
Net Income $ 1,036.9 $ 908.0 $ 3,233.0 $ 2,889.3
Less: preferred stock dividends 0.0 (5.7) 0.0 (17.2)
Add: overdistributed earnings allocated to preferred stock 0.0 0.0 1.2 0.0
Less: undistributed earnings allocated to preferred stock 0.0 (5.7) 0.0 (19.1)
Net Income Attributable to Common Shareholders of CME Group - Basic 1,036.9 896.6 3,234.2 2,853.0
Less: overdistributed earnings allocated to preferred stock 0.0 0.0 (1.2) 0.0
Net Income Attributable to Common Shareholders of CME Group - Diluted $ 1,036.9 $ 896.6 $ 3,233.0 $ 2,853.0
Weighted Average Number of Common Shares:        
Basic (in shares) 358,019 359,686 359,336 359,653
Effect of restricted stock and performance shares (in shares) 622 736 624 677
Effect of convertible preferred shares (in shares) 0 0 1,058 0
Diluted (in shares) 358,641 360,422 361,018 360,330
Earnings per Common Share Attributable to Common Shareholders of CME Group:        
Basic (in dollars per share) $ 2.90 $ 2.49 $ 9.00 $ 7.93
Diluted (in dollars per share) $ 2.89 $ 2.49 $ 8.96 $ 7.92