v3.26.1
Equity Awards - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Aug. 31, 2025
May 31, 2025
Aug. 31, 2024
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Aug. 03, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Common Stock, Capital Shares Reserved for Future Issuance             1,425,000
Number of shares available for future grant       1,243,836      
Stock option expense       $ 1.8 $ 1.2 $ 2.0  
Aggregate intrinsic value for outstanding options       16.8      
Aggregate intrinsic value for exercisable options       16.7      
Total intrinsic value of options exercised       1.0 14.4 18.8  
Restricted stock or unit expense       $ 19.5 $ 17.6 $ 17.9  
Options granted       29,424 5,476 5,558  
Threshold Performance Level [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Vesting Percentage of Target PSA's       50.00%      
Maximum Performance Level [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Vesting Percentage of Target PSA's       200.00%      
Fiscal 2025 Board of Directors Stock Option Award [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Options granted     9,735        
Fiscal 2025 Board of Directors Restricted Stock Award [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Share-based compensation vesting period 1 year            
Performance Vesting Stock Options [Member] | Long Term Compensation Plan [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Stock based compensation plan, description       The performance vesting criteria are based on certain levels of average annual return on equity (as defined in the Performance Stock Award Agreements) ranging from 10.0% to 20.0% measured at the end of fiscal 2028 (three-year performance period) as modified by total stockholder return. Performance outcomes (taking into account both criteria) will result in a threshold vesting percentage of 50% of target, and maximum performance will result in a vesting percentage of 200% of target. If the threshold vesting percentage is not achieved, none of the Performance Stock Awards will be earned.      
Performance Vesting Stock Options [Member] | Long Term Compensation Plan [Member] | Minimum [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Percentage of average return on invested capital   10.00%          
Performance Vesting Stock Options [Member] | Long Term Compensation Plan [Member] | Maximum [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Percentage of average return on invested capital   20.00%          
Performance share units [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Allocated share based compensation expense       $ 17.4      
Performance share units [Member] | Fiscal 2025 Stock Awards [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of shares available for future grant   29,273          
Performance stock options [Member] | Fiscal 2025 Stock Awards [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of shares available for future grant   14,712          
Fiscal Two Thousand Twenty Five Time Vesting Stock Options [Member] | Long Term Compensation Plan [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of shares available for future grant       14,712      
Share-based compensation vesting period       3 years      
Fiscal Two Thousand Twenty Five Time Vesting Restricted Stock [Member] | Long Term Compensation Plan [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Share-based compensation vesting period       3 years      
Time Vesting Restricted Stock [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of shares available for future grant       29,273      
Employee Stock Option              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Weighted-average period of recognition of unrecognized compensation cost       1 year 10 months 24 days      
Unrecognized compensation expense       $ 2.3      
Restricted Stock [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Weighted-average period of recognition of unrecognized compensation cost       1 year 3 months 18 days      
Unrecognized compensation expense       $ 17.8