Accounts Receivable - Contract Receivables (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Retainages	$ 52,031	$ 17,896
Accounts receivable—trade, net	274,700	208,474
Contract receivables [Member]
Accounts Notes And Loans Receivable [Line Items]
Contracts receivable	181,401	164,898
Unbilled	4,303	4,303
Less allowances	(14,312)	(14,325)
Accounts receivable—trade, net	274,700	208,474
Contract receivables [Member] | Completed contracts [Member]
Accounts Notes And Loans Receivable [Line Items]
Contracts receivable	$ 51,277	$ 35,702