Income Taxes - Summary of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ (265)
State	2	$ (1)
Foreign	63	40
Total current	(200)	39
Deferred:
Federal	265	(530)
State		0
Foreign	(52)	(55)
Total deferred	213	(585)
Total income tax expense (benefit)	$ 13	$ (546)