Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ 24,464	$ (53,918)	$ 40,146	$ (44,122)
Fair Value Adjustment of Warrants, net of tax	(10,448)	0	(7,473)	0
Undistributed Continuing Operation Earnings (Loss), Diluted	$ 14,016	$ (53,918)	$ 32,673	$ (44,122)
Weighted-average shares outstanding for basic earnings per share (in shares)	58,739	59,035	58,790	59,084
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	8,100		8,100
Weighted Average Number Diluted Shares Outstanding Adjustment		8,500		7,200
Common equivalent shares:
Effect of stock-based compensation awards (in shares)	9,624	0	9,994	0
Basic earnings per share from continuing operations (in dollars per share)	$ 0.42	$ (0.91)	$ 0.68	$ (0.75)
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.21	$ (0.91)	$ 0.48	$ (0.75)
Amazon Warrant [Member]
Earnings Per Share Reconciliation [Abstract]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		13,600		13,600