Share-Based Payments - Black-Scholes Assumptions (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Weighted average grant date fair value, granted (in dollars per share)	$ 2.16	$ 2.85
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk-free interest rate, average	1.30%	1.60%
Expected option life, average	7 years 2 months 12 days	7 years 1 month 24 days
Expected price volatility, average	51.40%	51.90%
Expected dividend yield	0.00%	0.00%