Earnings (Loss) Per Share and Stock Repurchase Program Narrative (Details) - USD ($)				1 Months Ended	12 Months Ended
	Nov. 06, 2018	Feb. 26, 2018	Jan. 16, 2018	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (shares)					9,022,386
Repurchase of common stock	$ 500,000,000.0	$ 150,000,000.0			$ 365,300,000	$ 32,300,000	$ 6,000,000.0
Authorization remaining under aggregate stock repurchase program					$ 409,700,000
Stock Purchase Agreement
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (shares)			2,000,000.0			762,623
Repurchase of common stock			$ 75,300,000	$ 150,000,000.0		$ 25,000,000.0
Average cost per share of stock acquired (USD per share)			$ 37.64