Accounting Policies - Classification of Current Assets and Current Liabilities and Retainage (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Line Items]
Billings in excess of costs and estimated earnings	$ 62,698	$ 87,475
Increase (decrease) in billings in excess of costs and estimated earnings	(27,761)	45,700	$ 19,100
Prepaid expenses and other current assets	51,832	66,999
Increase (decrease) in prepaid expenses and other assets	$ (16,759)	$ 28,895	$ (3,465)
Retainage Collection period upon completion of contract	1 year
Contract receivable retainage due after 12 months percent	10.00%
Bayou Coating
Accounting Policies [Line Items]
Increase (decrease) in billings in excess of costs and estimated earnings	$ (24,800)
Increase (decrease) in prepaid expenses and other assets	$ (15,200)
Minimum
Accounting Policies [Line Items]
Construction period (less than 1 month)	1 month
Collection period for municipalities	60 days
Collection period for other than municipalities	30 days
Retainage, percent of contract value withheld	5.00%
Maximum
Accounting Policies [Line Items]
Construction period (less than 1 month)	24 months
Collection period for municipalities	90 days
Collection period for other than municipalities	45 days
Retainage, percent of contract value withheld	15.00%