Stock Options Outstanding (Detail)	6 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding, Number of Shares Outstanding | shares	311,454
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 2 months 8 days
Options Outstanding, Weighted-Average Exercise Price	$ 91.85
Options Exercisable , Number of Shares Outstanding | shares	216,868
Options Exercisable, Weighted-Average Exercise Price	$ 88.85
$59.32 - $81.28 [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	$ 81.28
Options Outstanding, Number of Shares Outstanding | shares	113,790
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	6 years 1 month 24 days
Options Outstanding, Weighted-Average Exercise Price	$ 62.53
Options Exercisable , Number of Shares Outstanding | shares	71,386
Options Exercisable, Weighted-Average Exercise Price	$ 63.73
$87.37 - $106.24 [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	$ 106.24
Options Outstanding, Number of Shares Outstanding | shares	126,467
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	4 years 10 months 9 days
Options Outstanding, Weighted-Average Exercise Price	$ 95.75
Options Exercisable , Number of Shares Outstanding | shares	122,751
Options Exercisable, Weighted-Average Exercise Price	$ 95.7
$118.27 - $166.75 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	118.27
Range of Exercise Prices, Upper Range	$ 166.75
Options Outstanding, Number of Shares Outstanding | shares	71,197
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	8 years 7 months 2 days
Options Outstanding, Weighted-Average Exercise Price	$ 131.77
Options Exercisable , Number of Shares Outstanding | shares	22,731
Options Exercisable, Weighted-Average Exercise Price	$ 130.79