Weighted Average Shares and Net Income Per Share - Calculations of Basic and Diluted Weighted Average Common Shares (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income	$ 13,858,000	$ 11,380,000	$ 46,773,000	$ 31,547,000
Basic:
Basic weighted average common shares outstanding	17,785,000	17,899,000	17,841,000	17,939,000
Basic	$ 0.78	$ 0.64	$ 2.62	$ 1.76
Diluted:
Weighted Average Number of Shares Outstanding, Basic	17,785,000	17,899,000	17,841,000	17,939,000
Treasury stock impact of stock options	426,000	281,000	380,000	217,000
Total common and common equivalent shares	18,211,000	18,180,000	18,221,000	18,156,000
Diluted	$ 0.76	$ 0.63	$ 2.57	$ 1.74