Leases and Contingencies - Summary of Operating Lease Liabilities Included in Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Jan. 01, 2019
Assets And Liabilities Lessee [Abstract]
Current operating lease liability	$ 2,829	$ 2,571
Non-current operating lease liabilities	26,047	$ 28,170
Total operating lease liabilities	$ 28,876		$ 32,100