Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 0	$ 0	$ 0
State	165	139	699
Foreign	364	495	620
Total Current	529	634	1,319
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	(36)	(21)	93
Total Deferred	(36)	(21)	93
Provision for income taxes	$ 493	$ 613	$ 1,412

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