XML 41 R28.htm IDEA: XBRL DOCUMENT v3.7.0.1
Receivables (Details Textual) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Other receivables $ 18,371   $ 20,643
Sales revenue, net | Customer concentration risk | Sonatrach      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Concentration risk, percentage 9.00% 15.00%  
Receivables, net      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Income taxes receivable $ 38,000   38,000
Nontrade receivables 9,800   11,500
Receivables, net | Escrow | Environmental services      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Other receivables $ 8,000   $ 8,000