Prepaid Expenses and Other Assets - Summary of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Prepaid Expense and Other Assets [Abstract]
Revenues in excess of billings	$ 8,838	$ 8,282
Prepaid expenses	6,407	6,664
Contract retainage	2,277	1,832
Income tax receivable		2,675
Other	300	350
Total prepaid expenses and other assets	$ 17,822	$ 19,803