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Earnings Per Share (Narrative) (Details) - USD ($)		12 Months Ended
	Jul. 24, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 28, 2020
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)		3,338,028	1,898,023	1,994,632
Common stock acquired		$ 399,600,000	$ 165,800,000	$ 144,400,000
Stock repurchase program, average price per share (in dollars per share)		$ 119.70	$ 87.35	$ 72.39
July 2019 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount	$ 400,000,000
Stock repurchase program period	2 years
Stock repurchase program, shares acquired (in shares)		2,368,374	1,393,626
Common stock acquired		$ 274,600,000	$ 125,000,000.0
Stock repurchase program, average price per share (in dollars per share)		$ 115.93	$ 89.70
October 2020 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount					$ 500,000,000
Stock repurchase program, shares acquired (in shares)		969,654
Common stock acquired		$ 125,000,000.0
Stock repurchase program, average price per share (in dollars per share)		$ 128.91
Stock repurchase program, remaining amount	$ 375,000,000.0
Other Share Repurchase Programs
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)			504,397
Common stock acquired			$ 40,800,000
Stock repurchase program, average price per share (in dollars per share)			$ 80.85

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