Assets And Liabilities Held For Sale - Summary of Assets and Liabilities Held-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets held for sale:
Cash and cash equivalents	$ 989	$ 0	$ 2,443
Total current assets	70,314	0
Liabilities held for sale:
Total current liabilities	20,900	$ 0
Bayou | Held-for-sale assets
Assets held for sale:
Cash and cash equivalents	989
Receivables	6,368
Costs and estimated earnings in excess of billings	1,299
Inventories	3,727
Prepaid expenses and other current assets	827
Total current assets	13,210
Property, plant & equipment, less accumulated depreciation	53,887
Identified intangible assets, less accumulated amortization	3,217
Total assets held for sale	70,314
Liabilities held for sale:
Accounts payable	5,763
Accrued expenses	1,805
Billings in excess of costs and estimated earnings	5,478
Total current liabilities	13,046
Debt	7,757
Other liabilities	97
Total liabilities held for sale	$ 20,900