Common Stock Repurchase Program - Repurchases (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended			3 Months Ended			9 Months Ended
	Oct. 31, 2023	Jul. 31, 2023	May 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2023	Sep. 30, 2022
Common stock repurchase program
Cash paid for repurchase of common stock							$ 990.0	$ 1,061.0
Authorized share repurchases				$ 508.5			$ 508.5
Accelerated Share Repurchase Agreement (ASR) [Member]
Common stock repurchase program
Shares repurchased (in shares)			0.4	2.2	1.5	1.9
Cash paid for repurchase of common stock				$ 350.0	$ 250.0	$ 350.0
Initial stock repurchase price (in dollars per share)						$ 150.34
Weighted average final purchase price (in dollars per share)			$ 153.90	$ 156.87	$ 163.62
10b5-1 Plan [Member]
Common stock repurchase program
Shares repurchased (in shares)				0.1	0.1
Total repurchases (in dollars)	$ 1.5	$ 2.0
Cash paid for repurchase of common stock				$ 19.5	$ 22.0
Weighted average final purchase price (in dollars per share)				$ 168.04	$ 164.79