Weighted Average Shares and Net Income Per Share - Calculations of Basic and Diluted Weighted Average Common Shares (Detail) - USD ($)	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net Income	$ 16,691,000	$ 16,843,000
Basic:
Basic weighted average common shares outstanding	17,506,000	17,897,000
Basic	$ 0.95	$ 0.94
Diluted:
Weighted Average Number of Shares Outstanding, Basic	17,506,000	17,897,000
Treasury stock impact of stock options	297,000	323,000
Total common and common equivalent shares	17,803,000	18,220,000
Diluted	$ 0.94	$ 0.92