Stock Options Outstanding (Detail)	6 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding, Number of Shares Outstanding | shares	492,451
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 8 months 19 days
Options Outstanding, Weighted-Average Exercise Price	$ 89.09
Options Exercisable , Number of Shares Outstanding | shares	301,348
Options Exercisable, Weighted-Average Exercise Price	$ 89.43
$59.32 - $81.56 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	59.32
Range of Exercise Prices, Upper Range	$ 81.56
Options Outstanding, Number of Shares Outstanding | shares	172,395
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 9 months 25 days
Options Outstanding, Weighted-Average Exercise Price	$ 62.87
Options Exercisable , Number of Shares Outstanding | shares	85,585
Options Exercisable, Weighted-Average Exercise Price	$ 64.96
$87.37 - $93.03 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	87.37
Range of Exercise Prices, Upper Range	$ 93.03
Options Outstanding, Number of Shares Outstanding | shares	151,569
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 3 months 29 days
Options Outstanding, Weighted-Average Exercise Price	$ 91.57
Options Exercisable , Number of Shares Outstanding | shares	109,241
Options Exercisable, Weighted-Average Exercise Price	$ 91.57
$99.37 - $143.09 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	99.37
Range of Exercise Prices, Upper Range	$ 143.09
Options Outstanding, Number of Shares Outstanding | shares	168,487
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 11 months 23 days
Options Outstanding, Weighted-Average Exercise Price	$ 113.68
Options Exercisable , Number of Shares Outstanding | shares	106,522
Options Exercisable, Weighted-Average Exercise Price	$ 106.90