Loan and Security Agreement 2009 Loan and Security Agreement (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
	Feb. 28, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Loan and Security Agreement [Abstract]
Commitment fee	$ 100	$ 100	$ 100	$ 100
Annual fee		$ 100	$ 100	$ 100