Income Taxes from Continuing Operations - Net Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carry-forward	$ 25,100	$ 25,657
Stock-based compensation	7,668	8,922
Chargeback reserves	17,802	0
Reserve for product returns	9,479	16,208
Inventory valuation reserve	10,207	11,503
Long-term debt	3,084	6,383
Other	10,805	18,808
Total deferred tax assets	84,145	87,481
Valuation allowance	(10,531)	(9,856)	$ (8,800)
Net deferred tax assets	73,614	77,625
Deferred tax liabilities:
Prepaid expenses	(1,709)	(3,091)
Depreciation & amortization – tax over book	(108,788)	(226,855)
Total deferred tax liabilities	(110,497)	(229,946)
Net deferred income tax liability	$ (36,883)	$ (152,321)