Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Accrued expenses	$ 83	$ 57
Deferred revenue	522	0
Stock-based compensation	671	701
Fixed assets	320
Fixed assets		(37)
Goodwill	236	292
Intangible amortization	0	50
R&D credit	2,700	0
Texas margin tax temporary credit	186	209
Other	126	10
Total deferred tax assets	45,206	9,370
Deferred tax liabilities:
Inventory	(61)	0
Intangible amortization	(3,287)	0
Total deferred tax liabilities	(3,348)	0
Valuation allowance	(41,858)	(9,370)
Net deferred tax liability	0	0
Federal
Deferred tax assets:
Tax benefit of operating loss carry forward	30,377	8,088
State
Deferred tax assets:
Tax benefit of operating loss carry forward	$ 9,985	$ 0