Leases - Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Leases [Abstract]
Operating lease expense	$ 671	$ 1,794
Variable lease expense	124	369
Total operating lease expense	795	2,163
Amortization of right-of-use asset	2	6
Interest on lease liabilities	0	0
Total finance lease expense	$ 2	$ 6