Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Operating cash flows for operating leases	$ 153	$ 143	$ 253	$ 229
Operating cash flows from tenant improvement incentives from operating leases	0	(27)	0	(1,004)
Operating cash flows for finance leases	2	2	4	4
Financing cash flows for finance leases	$ 19	$ 21	$ 35	$ 41