Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 06, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock Repurchased During Period, Shares												380,637
shares repurchased from related party, price paid												$ 8,500
purchase price per shares, repurchased shares												$ 22.42
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ (41,104)	$ 105,085	$ (26,632)	$ 22,634	$ (5,196)	$ 32,933	$ 24,464	$ 15,682	$ 59,983	$ 67,883	$ 21,740
fair value adjustment to warrants, net of tax									(6,219)	(7,118)	0
Undistributed Earnings (Loss) from Continuing Operations Available to Common Shareholders, Diluted									$ 53,764	$ 60,765	$ 21,740
Weighted-average shares outstanding for basic earnings per share (in shares)	58,929,000	58,919,000	58,909,000	58,838,000	58,740,000	58,739,000	58,739,000	58,840,000	58,899,000	58,765,000	58,907,000
Restricted stock (in shares)									317,600	329,600	241,000
Common equivalent shares:
Effect of stock-based compensation awards (in shares)									10,449,000	9,591,000	779,000
Weighted-average shares outstanding assuming dilution (in shares)	58,929,000	68,718,000	58,909,000	60,437,000	58,740,000	68,323,000	68,363,000	59,558,000	69,348,000	68,356,000	59,686,000
Basic earnings per share from continuing operations (in dollars per share)	$ (0.70)	$ 1.78	$ (0.45)	$ 0.38	$ (0.09)	$ 0.56	$ 0.42	$ 0.27	$ 1.02	$ 1.16	$ 0.37
Diluted earnings per share from continuing operations (in dollars per share)	$ (0.70)	$ 0.19	$ (0.45)	$ 0.25	$ (0.09)	$ 0.24	$ 0.21	$ 0.26	$ 0.78	$ 0.89	$ 0.36
Equivalent shares not included in weighted average shares outstanding because they would be anti-dilutive											7,800,000
Amazon Warrant AB [Member]
Earnings Per Share Reconciliation [Abstract]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	39,500,000				14,800,000				39,500,000	14,800,000