Income Taxes - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating losses	$ 92,176	$ 91,893
Inventory reserve	2,413	3,161
Accrued liabilities	2,397	2,794
Other	4,162	4,697
Total deferred tax assets	101,266	102,910
Valuation allowance	(100,810)	(102,747)
Allowance for doubtful accounts	118	365
Net deferred tax assets	456	163
Deferred tax liabilities:
Depreciation and amortization	(456)	(163)
Total deferred tax liabilities	(456)	(163)
Total deferred income taxes	$ 0	$ 0