Stock Repurchase Program - Additional Information (Detail) - USD ($) shares in Thousands, $ in Millions	1 Months Ended		3 Months Ended
	Feb. 28, 2021	Dec. 31, 2020	Jan. 31, 2021		Jan. 31, 2020	Jun. 19, 2020
Accelerated Share Repurchases [Line Items]
Stock repurchase program authorized amount						$ 500.0
Remaining amount available for further repurchases			$ 205.1
Purchases of treasury stock (in shares)			837	[1]	579
December 2019, ASR
Accelerated Share Repurchases [Line Items]
Stock repurchase program authorized amount		$ 250.0
Prepayment to repurchase stock		250.0
Initial share delivery		$ 200.0
December 2019, ASR | Subsequent Event
Accelerated Share Repurchases [Line Items]
Stock repurchase program, prepayment during prior period, future derivative settlement	$ 50.0

[1] Does not include the $50.0 million equity forward contract, from the December 2020 ASR.