Accounts Receivable and Other Receivables (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	$ 52,068	$ 50,040
Less: allowance for doubtful accounts	(779)	(828)
Accounts Receivable, Net	51,289	49,212
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for Doubtful Accounts Receivable	828	933	966
Allowance for Doubtful Accounts Receivable, Charge-offs	0	51	0
Allowance for Doubtful Accounts Receivable, Recoveries	(49)	(156)	(33)
Allowance for Doubtful Accounts Receivable	779	828	933
Other receivables	$ 2,986	$ 4,036