Finacial Statement Schedule Finacial Statement Schedule (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	$ (593)	$ (541)	$ (505)
Valuation Allowances and Reserves, Period Increase (Decrease)	(12)	(193)	(214)
Valuation Allowances and Reserves, Deductions	141	141	178
Valuation Allowances and Reserves, Ending Balance	(464)	(593)	(541)
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	0	0	0
Valuation Allowances and Reserves, Period Increase (Decrease)	(361)	0	0
Valuation Allowances and Reserves, Deductions	0	0	0
Valuation Allowances and Reserves, Ending Balance	$ (361)	$ 0	$ 0