Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Sales returns reserve	$ 112	$ 79
Allowance for doubtful accounts	9
Net operating loss carryforwards	20,286	14,204
Stock options	8,409	180
Deferred revenue	6	12
Fixed assets	13	21
Goodwill	(12)
Interest expense limitation	1,109	574
Other	(729)	97
Less: valuation allowances	(29,203)	(15,167)
Deferred tax liabilities:
Foreign currency exchange gain/loss	0	0
Net deferred tax assets (liabilities)	$ 0	$ 0