Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Deferred:
Federal	$ 42	$ 69	$ 42
Total deferred	42	69	42
Total income tax expense	$ 42	$ 69	$ 42