Supplemental Balance Sheet Information - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Supplemental Balance Sheet Data [Abstract]
Vendor and other accrued expenses	$ 33,108	$ 56,570
Estimated casualty and healthcare liabilities	14,610	15,255
Job costs	8,707	12,403
Accrued compensation	23,398	22,184
Income tax payable and deferred income taxes	5,187	6,539
Total	$ 85,010	$ 112,951