Income Taxes - Provision for Income Tax Benefit by Applying Statutory Federal Income Tax Rate to Operating Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Tax on the loss before income tax expense computed at the federal statutory rate	$ (5,174)	$ (6,463)
State tax (benefit) at statutory rate, net of federal benefit	(2,293)	(1,691)
Foreign rate differential	51	10
Change in valuation allowance	8,231	6,696
Change in research and development credits	(303)	(200)
Stock based compensation—ISOs	71	149
Change in fair value of warrants	(2,444)	1,461
Change in fair value of contingent consideration	911	61
Change in net operating loss true up	846	(725)
Change in state rate true up		701
Other	$ 104	$ 1