Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 29, 2018	May 25, 2017
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	0.9
Value of shares repurchased	$ 50,000,000	$ 175,000,000
Treasury stock acquired, average cost per share (in usd per share)	$ 56.19
5/25/2017 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount (in usd)					$ 200,000,000.0
Shares repurchased		2.7	0.3
Value of shares repurchased		$ 175,000,000.0	$ 25,000,000.0
Treasury stock acquired, average cost per share (in usd per share)		$ 64.94	$ 79.75
Amount remaining of authorized amount for repurchase under the share repurchase program (in usd)	$ 0
11/29/2018 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount (in usd)				$ 300,000,000.0
Shares repurchased	0.0