v3.26.1
Stock-Based Compensation, Stock Options (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Stock Options [Abstract]      
Stock-based compensation expense $ 22.1 $ 26.4 $ 10.8
Stock Options      
Stock Options [Abstract]      
Stock-based compensation expense 0.1 1.7 1.0
Fair value of awards vesting $ 0.7 $ 1.0 $ 1.2
Unvested awards 0.0    
Stock Options Activity [Rollforward]      
Outstanding, beginning of year (in shares) 0.5    
Granted (in shares) 0.0 0.0 0.0
Exercised (in shares) (0.3)    
Outstanding, end of year (in shares) 0.2 0.5  
Exercisable, end of year (in shares) 0.2    
Weighted Average Exercise Price [Rollforward]      
Outstanding, beginning of year (in dollars per share) $ 12.94    
Exercised (in dollars per share) 12.56    
Forfeited or expired (in dollars per share) 12.49    
Outstanding, end of year (in dollars per share) 13.43 $ 12.94  
Exercisable, end of year (in dollars per share) $ 13.43    
Weighted-Average Remaining Contractual Term [Abstract]      
Weighted average remaining contractual term, outstanding at end of year 5 years    
Weighted average remaining contractual term, exercisable at end of year 5 years    
Aggregate Intrinsic Value [Abstract]      
Aggregate intrinsic value, outstanding at end of year $ 44.1    
Aggregate intrinsic value, exercisable at end of year 44.1    
Additional Information Related to Stock Options Exercised [Abstract]      
Intrinsic value of stock options exercised 37.4 $ 8.1 $ 12.4
Proceeds from stock options exercised $ 3.5 $ 1.0 $ 2.6
Stock Options | Maximum      
Assumptions for Stock Awards Granted [Abstract]      
Stock option term 10 years