Income Taxes - Summary of Expense for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Current:
Federal	$ 0	$ 0
State	29	40
Foreign	0	0
Gross	29	40
Deferred:
Federal	0	0
State	0	0
Foreign	0	0
Gross	0	0
Total	$ 29	$ 40

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