Earnings Per Share (Narrative) (Details) - USD ($)			1 Months Ended			3 Months Ended	12 Months Ended
	Jul. 24, 2019	Aug. 30, 2013	Jan. 31, 2019	Oct. 31, 2014	May 31, 2014	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]
Issuance of stock at the separation and distribution (in shares)		46,743,316
Stock repurchase program, shares acquired (in shares)						379,054	1,898,023	1,994,632
Common stock acquired							$ 165,800,000	$ 144,400,000	$ 206,000,000.0
Stock repurchase program, average price per share (in dollars per share)						$ 77.20	$ 87.35	$ 72.39
July 2019 Share Purchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)	1,393,626
Common stock acquired	$ 125,000,000.0
Stock repurchase program, remaining amount	$ 275,000,000.0
May 2014 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)					1,040,636
Stock repurchase program, average price per share (in dollars per share)					$ 48.07
October 2014 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)				4,169,349
Stock repurchase program, average price per share (in dollars per share)				$ 59.96
January 2016 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares acquired (in shares)			7,489,388
Stock repurchase program, average price per share (in dollars per share)			$ 66.76
Stock repurchase program, authorized amount						$ 400,000,000			$ 400,000,000