Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities
Retention amounts included in accounts payable	$ 9,266	$ 10,562
Accrued expenses and other current liabilities
Payroll and related employee benefits	38,278	42,718
Insurance, including self-insurance reserves	42,614	42,546
Reserve for estimated losses on uncompleted contracts	13,161	12,801
Corporate income taxes and other taxes	6,033	3,368
Accrued administrative cost	5,619	3,791
Other	134	2,782
Total accrued expenses and other current liabilities	$ 105,839	$ 108,006