Schedule II Valuation of Qualifying Accounts and Reserves (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance Beginning of Period	$ 791	$ 775	$ 775
Valuation Allowances and Reserves, Charged to Cost and Expense	205	83	3
Valuation Allowances and Reserves, Charged to Other Accounts	0	0	0
Valuation Allowances and Reserves, Deductions	167	67	3
Valuation Allowances and Reserves, Balance End of Period	$ 829	$ 791	$ 775