Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 0	$ 0	$ 0
State	139	699	1
Foreign	495	620	580
Total Current	634	1,319	581
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	(21)	93	35
Total Deferred	(21)	93	35
Provision for income taxes	$ 613	$ 1,412	$ 616