Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets:
Sales allowances and doubtful accounts	$ 1,964	$ 506
Inventory reserve	962	619
Deferred revenue	590	0
Accrued expenses	23	664
Property, plant and equipment	258	214
Tax operating loss carryforwards	9,951	9,327
Tax credit and other carryforwards	1,299	168
Stock compensation	538	1,817
Total deferred tax assets	15,585	13,315
Less valuation allowance	(12,120)	(13,309)
Net deferred tax assets	3,465	6
Deferred Tax Liabilities:
Convertible debt conversion features	(3,514)	0
Foreign exchange	(28)	0
Intangible assets	(138)	(165)
Total deferred tax liabilities	(3,680)	(165)
Net deferred tax liability	$ (215)	$ (159)