Stock Options (Details 4) (Stock options, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Stock options
Share-based compensation
Closing stock price (in dollars per share)	$ 0.58
Aggregate intrinsic value of options exercised	$ 6,000	$ 67,000
Aggregate intrinsic value of exercisable options	0
Weighted-average fair value per option granted (in dollars per share)	$ 1.60	$ 2.24
Share based compensation expense	$ 1,322,000	$ 1,501,000
Weighted average significant assumptions used to determine fair values of stock options
Risk-free interest rate at grant date (as a percent)	0.02%	0.09%
Expected stock price volatility (as a percent)	71.00%	82.00%
Expected option life	6 years	6 years
Expected turn-over rate (as a percent)	5.00%	5.90%
Expected exercise multiple (as a percent)	2.20%	2.20%
Expiration of awards from date of grant	10 years