Annual report [Section 13 and 15(d), not S-K Item 405]

Stock Compensation Plans - Schedule of Restricted Stock Units ("RSUs"), Performance Stock Units ("PSUs"), and Restricted Stock Awards ("RSAs") Granted (Parenthetical) (Detail)

v3.25.1
Stock Compensation Plans - Schedule of Restricted Stock Units ("RSUs"), Performance Stock Units ("PSUs"), and Restricted Stock Awards ("RSAs") Granted (Parenthetical) (Detail)
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Director [Member]      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-based compensation vesting percentage 100.00%    
Vesting period 1 year    
Officers and Key Employees [Member]      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-based compensation vesting percentage 100.00%    
Vesting period 3 years    
Time Vest One-Third Per Year [Member] | Officers and Key Employees [Member]      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-based compensation vesting percentage 0.333%    
Performance Vest One-Third Per Year [Member] | Officers and Key Employees [Member]      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Vesting period 3 years 3 years 3 years