Schedule of Earnings Per Share (Detail) - shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Weighted-Average Shares of Common Stock Outstanding	41,543,067	42,021,892	46,620,894
Assumed Exercise of Outstanding Dilutive Options	570,325	623,779	539,135
Less Shares Repurchased from Proceeds of Assumed Exercised Options	(429,815)	(481,853)	(374,380)
Restricted Stock Units	143,132	121,525	146,731
Weighted-Average Common Stock and Dilutive Securities Outstanding	41,826,709	42,285,343	46,932,380