Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Tax [Line Items]
Federal statutory tax rate			21.00%
Company's effective tax rate			0.00%
Tax expense (benefit)		$ 2,000		$ (34,000)
Tax benefit in other comprehensive income		0		(100,000)
Korea
Income Tax [Line Items]
Tax benefit	$ 0	$ 0	$ 0	$ 0