Accounts Receivable and Inventories (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Dec. 31, 2011
Accounts receivable
Trade accounts receivable	$ 638,372			$ 638,372			$ 636,304
Less: Allowance for doubtful accounts	(18,969)			(18,969)			(17,829)
Trade accounts receivable, net	619,403			619,403			618,475
Other receivables	40,296	[1]		40,296	[1]		44,431	[1]
Provision for doubtful accounts related to trade accounts receivable	1,802		1,411	8,665		5,159
Inventories
Finished goods	81,858			81,858			78,445
Work-in-process	40,034			40,034			34,041
Raw materials and purchased parts	101,581			101,581			92,995
Stores and supplies	39,039			39,039			36,453
Inventories	$ 262,512			$ 262,512			$ 241,934

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