Accounts Receivable (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 176,000	$ 168,575
Less: Allowance for doubtful accounts	(2,592)	(2,807)
Accounts receivable, net	173,408	165,768
Accounts receivable - trade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	133,385	130,486
Accounts receivable - grants [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	23,220	20,753
Accounts receivable - insurance claims [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 19,395	$ 17,336