v3.25.2
Earnings per Share - Computation of Basic and Diluted EPS (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Earnings Per Share [Abstract]        
Net income attributable to SS&C common stockholders $ 180.8 $ 190.3 $ 393.8 $ 347.9
Shares attributable to SS&C:        
Weighted-average common shares outstanding – used in calculation of basic EPS 244.9 246.2 245.4 246.6
Weighted-average common stock equivalents – stock options and restricted shares 7.3 6.1 8.1 6.1
Weighted-average common and common equivalent shares outstanding – used in calculation of diluted EPS 252.2 252.3 253.5 252.7
Earnings per share attributable to SS&C common stockholders - Basic $ 0.74 $ 0.77 $ 1.6 $ 1.41
Earnings per share attributable to SS&C common stockholders - Diluted $ 0.72 $ 0.75 $ 1.55 $ 1.38