Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Trade accounts payable, including amounts due to subcontractors	$ 45,409	$ 58,985
Compensation and related benefits	5,246	8,232
Current portion of earnout liability	2,989	13,527
Accrued warranty	4,464	2,684
Other	12,678	12,182
Total accounts payable and accrued expenses	$ 70,786	$ 95,610