Weighted Average Shares and Net Income Per Share - Calculations of Basic and Diluted Weighted Average Common Shares (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Income	$ 19,898,000	$ 14,656,000	$ 39,703,000	$ 31,347,000
Basic:
Weighted average common shares outstanding	17,123,000	17,386,000	17,133,000	17,446,000
Basic	$ 1.16	$ 0.84	$ 2.32	$ 1.8
Diluted:
Weighted average common shares outstanding	17,123,000	17,386,000	17,133,000	17,446,000
Treasury stock impact of stock options	223,000	264,000	232,000	280,000
Total common and common equivalent shares	17,346,000	17,650,000	17,365,000	17,726,000
Diluted	$ 1.15	$ 0.83	$ 2.29	$ 1.77