Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ (26,632)	$ 24,464	$ (3,998)	$ 40,146
fair value adjustment to warrants, net of tax	0	(10,448)	0	(7,473)
Undistributed Earnings (Loss) from Continuing Operations Available to Common Shareholders, Diluted	$ (26,632)	$ 14,016	$ (3,998)	$ 32,673
Weighted-average shares outstanding for basic earnings per share (in shares)	58,909	58,739	58,874	58,790
Common equivalent shares:
Effect of stock-based compensation awards (in shares)	0	9,624	0	9,994
Weighted-average shares outstanding assuming dilution (in shares)	58,909	68,363	58,874	68,784
Basic earnings per share from continuing operations (in dollars per share)	$ (0.45)	$ 0.42	$ (0.07)	$ 0.68
Diluted earnings per share from continuing operations (in dollars per share)	$ (0.45)	$ 0.21	$ (0.07)	$ 0.48
Equivalent shares not included in weighted average shares outstanding because they would be anti-dilutive	10,900		10,800
Amazon Warrant AB [Member]
Earnings Per Share Reconciliation [Abstract]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	39,500	14,800	39,500	14,800