Shareholders' Equity (Narrative) (Details) - USD ($)			1 Months Ended			3 Months Ended
	Apr. 20, 2021	Jul. 29, 2016	May 30, 2021	Mar. 31, 2021	Feb. 28, 2021	Mar. 31, 2021	Mar. 31, 2020
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, repurchased cost						$ 10,000,000.0	$ 34,400,000
Quarterly dividends declared					$ 0.21
Dividends declared				$ 0.21		$ 0.21	$ 0.20
Dividends payable, date to be paid, year and month				2021-03		2021-03
Subsequent Event [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared	$ 0.21
Scenario Forecast [Member]
Equity Class Of Treasury Stock [Line Items]
Dividends declared			$ 0.21
Dividends payable, date to be paid, year and month			2021-05
Common Stock
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, expiration date		Dec. 31, 2023
Stock repurchase program, remaining authorized repurchase amount				$ 583,800,000		$ 583,800,000
Shares repurchase program, shares repurchased						125,635	382,170
Common Stock | Share Repurchase Program Excluding Accelerated Share Repurchase
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, shares repurchased						100,000
Shares repurchase program, repurchased cost						$ 10,000,000.0
Shares repurchase program, average price per share						$ 79.60
Common Stock | Share Repurchase Program Including Accelerated Share Repurchase
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, shares repurchased						9,800,000
Shares repurchase program, repurchased cost						$ 616,200,000
Shares repurchase program, average price per share						$ 62.57
Common Stock | Maximum [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, authorized amount		$ 1,200,000,000.0