Shareholders' Equity (Shares Repurchased Under Stock Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended						9 Months Ended
	Apr. 30, 2021	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Oct. 25, 2022
Class of Stock [Line Items]
Aggregate purchase price		$ 428.2	$ 403.9	$ 380.9	$ 879.2	$ 736.1	$ 306.1
Shares of treasury stock retired (in shares)	16.0
Stock Repurchase Program Board Authorized Repurchases
Class of Stock [Line Items]
Shares repurchased (in shares)		3.8			7.9			10.9	19.2
Aggregate purchase price		$ 428.2			$ 879.2			$ 1,213.1	$ 1,921.4
Average purchase price per share (in dollars per share)		$ 113.51			$ 111.96			$ 110.96	$ 100.13
Remaining amount available for share repurchase		$ 681.5						$ 681.5
Stock Repurchase Program Board Authorized Repurchases | Subsequent Event
Class of Stock [Line Items]
Increase in share repurchase authorization										$ 1,000.0