v3.26.1
Stock Options and Stock-Based Compensation - Stock Compensation Expense for Time Based Options and Performance Based Options (Detail) - USD ($)
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total cost of stock-based compensation included in income before income taxes $ 5,411,000 $ 5,714,000 $ 4,982,000
Effect on basic earnings per share $ 2.15 $ 1.85 $ 1.48
Effect on diluted earnings per share $ 2.14 $ 1.83 $ 1.47
Time Based Options and Performance Based Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total cost of stock-based compensation included in income before income taxes $ 5,411,000 $ 5,714,000 $ 4,982,000
Amount of income tax benefit recognized (1,241,000) (1,256,000) (987,000)
Amount charged to net income $ 4,170,000 $ 4,458,000 $ 3,995,000
Effect on basic earnings per share $ 0.08 $ 0.09 $ 0.08
Effect on diluted earnings per share $ 0.08 $ 0.09 $ 0.08
Time Based Options and Performance Based Options [Member] | Cost of Revenue [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total cost of stock-based compensation included in income before income taxes $ 2,641,000 $ 2,794,000 $ 2,797,000
Time Based Options and Performance Based Options [Member] | General and Administrative [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total cost of stock-based compensation included in income before income taxes $ 2,770,000 $ 2,920,000 $ 2,185,000