Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Accounts receivable
Trade accounts receivable		$ 322,751		$ 322,751		$ 340,223
Less: Allowance for doubtful accounts		(24,516)		(24,516)		(15,119)
Trade accounts receivable, net		298,235		298,235		325,104
Other receivables	[1]	23,293		23,293		28,145
Provision for doubtful accounts related to trade accounts receivable		10,005	$ (170)	10,615	$ 7,176
Inventories
Finished goods		35,898		35,898		30,525
Work-in-process		69,938		69,938		28,690
Raw materials and purchased parts		75,927		75,927		87,985
Stores and supplies		28,533		28,533		31,722
Inventories		$ 210,296		$ 210,296		$ 178,922

[1] Other receivables include insurance claim receivables, employee receivables, tax claim receivables, receivables from affiliates and other miscellaneous receivables not included in Trade accounts receivable, net.