Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ 32,933	$ (28,229)	$ 73,079	$ (72,351)
Fair Value Adjustment of Warrants, net of tax	(16,801)	0	(24,274)	0
Undistributed Continuing Operation Earnings (Loss), Diluted	$ 16,132	$ (28,229)	$ 48,805	$ (72,351)
Weighted-average shares outstanding for basic earnings per share (in shares)	58,739	58,733	58,773	58,965
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	8,100		8,100
Weighted Average Number Diluted Shares Outstanding Adjustment		9,900		8,100
Common equivalent shares:
Effect of stock-based compensation awards (in shares)	9,584	0	9,856	0
Basic earnings per share from continuing operations (in dollars per share)	$ 0.56	$ (0.48)	$ 1.24	$ (1.23)
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.24	$ (0.48)	$ 0.71	$ (1.23)
Amazon Warrant [Member]
Earnings Per Share Reconciliation [Abstract]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	14,800	14,900	14,800	14,900