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, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Income	$ 14,656,000	$ 16,072,000	$ 31,347,000	$ 32,915,000
Basic:
Basic weighted average common shares outstanding	17,386,000	17,841,000	17,446,000	17,869,000
Basic	$ 0.84	$ 0.90	$ 1.80	$ 1.84
Diluted:
Weighted Average Number of Shares Outstanding, Basic	17,386,000	17,841,000	17,446,000	17,869,000
Treasury stock impact of stock options	264,000	391,000	280,000	357,000
Total common and common equivalent shares	17,650,000	18,232,000	17,726,000	18,226,000
Diluted	$ 0.83	$ 0.88	$ 1.77	$ 1.81