Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding Options at Beginning of Year	708,501	1,160,091	1,042,925
Number of Shares, Granted	11,316	187,121	187,375
Number of Shares, Exercised	(247,578)	(623,617)	(62,326)
Number of Shares, Cancelled	(15,390)	(15,094)	(7,883)
Number of Shares, Outstanding Options at End of Year	456,849	708,501	1,160,091
Number of Shares, Options Exercisable at End of Year	314,624	416,817	868,081
Weighted-Average Exercise Price, Outstanding Options at Beginning of Year	$ 83.85	$ 80.36	$ 76.88
Weighted-Average Exercise Price, Granted	140.42	61.92	91.58
Weighted-Average Exercise Price, Exercised	86.97	70.57	88.28
Weighted-Average Exercise Price, Cancelled	76.63	92.51	102.69
Weighted-Average Exercise Price, Outstanding Options at End of Year	83.81	83.85	80.36
Weighted-Average Fair Value of Options Granted During the Year	$ 49.18	$ 22.68	$ 27.35