Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Inventory reserve	$ 700	$ 902
Other reserves and allowances	52	4,233
Income tax basis in excess of financial statement basis in intangible assets	1,669	3,394
Deductible stock-based compensation	3,760	4,693
Net operating loss carryforward	13,530	9,496
Tax credit carryforwards	428	2,758
Total deferred tax assets, gross	20,139	25,476
Total deferred tax assets	(10,711)	(8,292)
Total deferred tax assets	9,428	17,184
Deferred tax liabilities:
Prepaid & other expenses	(265)	(139)
Fixed assets	(4,946)	(5,913)
Intangible assets	(15,953)	(21,392)
Total deferred tax liabilities	(21,164)	(27,444)
Net deferred tax liability	$ (11,736)	$ (10,260)