Stock Warrants (Summary of Activity) (Details) (Stock warrants, USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Stock warrants
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares)	158	108
Granted (in shares)	0	83
Cancelled or expired (in shares)	(114)	(33)
Outstanding, ending balance (in shares)	44	158
Vested, ending balance (in shares)	22
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, weighted-average exercise price, beginning balance	$ 5.25	$ 8.88
Granted, weighted-average exercise price		$ 5.01
Cancelled or expired, weighted-average exercise price	$ 4.15	$ 16.53
Outstanding, weighted-average exercise price, ending balance	$ 1.50	$ 5.25
Vested, weighted-average exercise price	$ 1.50