Valuation and Qualifying Accounts and Reserves - Allowance for Doubtful Accounts (Details) (Allowance for Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 85	$ 141	$ 22
Charged to Costs and Expenses	219	665	282
Reversals	0	0	0
Utilizations	(162)	(721)	(163)
Ending Balance	$ 142	$ 85	$ 141