Prepaid Expenses and Other Assets - Summary of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense and Other Assets [Abstract]
Prepaid expenses	$ 7,494	$ 6,209
Contract retainage	1,449
Revenues in excess of billings	4,841
Income tax receivable	2,230	4,024
Other	864	167
Total prepaid expenses and other assets	$ 16,878	$ 10,400