Summary of Options (Detail) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
NUMBER OF SHARES
Options outstanding, beginning balance | shares	3,116,500
Granted | shares	569,600
Exercised | shares	(681,100)
Cancelled | shares	(127,100)
Options outstanding, ending balance | shares	2,877,900
Vested and expected to vest, end of period | shares	2,806,400
Exercisable, end of period | shares	1,109,400
PER SHARE EXERCISE PRICE
Options outstanding, beginning balance | $ / shares	$ 64.34	[1]
Granted | $ / shares	91.89	[1]
Exercised | $ / shares	57.21	[1]
Cancelled | $ / shares	77.10	[1]
Options outstanding, ending balance | $ / shares	70.90	[1]
Vested and expected to vest, end of period | $ / shares	70.52	[1]
Exercisable, end of period | $ / shares	$ 61.36	[1]
REMAINING CONTRACTUAL LIFE IN YEARS
Options outstanding, ending balance	6 years 6 months 3 days	[1]
Vested and expected to vest, end of period	6 years 5 months 15 days	[1]
Exercisable, end of period	4 years 1 month 6 days	[1]
AGGREGATE INTRINSIC VALUE
Options outstanding, ending balance | $	$ 51.9	[1]
Vested and expected to vest, end of period | $	51.5	[1]
Exercisable, end of period | $	$ 29.9	[1]

[1] Weighted Average