Valuation and Qualifying Accounts Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance	$ 450		$ 450		$ 460		$ 1,670
Charged to Costs and Expenses	70		159		54
Deductions	$ (70)	[1]	$ (169)	[1]	$ (1,264)	[1]

[1] Accounts written off, net of recoveries.