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 Disclosure [Abstract]
Current income tax expense or benefit	$ 0	$ 0	$ 0	$ 0
Deferred income tax expense or benefit	$ 0	$ 0	$ 0	$ 0