Income Taxes - Components of Tax Benefit (Provision) Allocated to Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Current:
Federal	$ 16	$ (4)
State	(9)	10
Foreign	(8)	(27)
Sub-total	(1)	(21)
Deferred:
Federal	0	0
State	0	0
Foreign	0	0
Sub-total	0	0
Total tax benefit (provision)	$ (1)	$ (21)

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

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