|
Employee Stock and Benefit Plans - Fair Value Assumptions, Stock Options (Details) (Stock Options [Member])
|
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Expected term (in years) | 5 years 7 months 6 days | 5 years 7 months 6 days | ||
| Volatility | 53.00% | 55.00% | 53.00% | 55.00% |
| Dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
|
Minimum [Member]
|
||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Expected term (in years) | 5 years 3 months 18 days | 5 years 3 months 18 days | ||
| Risk-free interest rate | 0.60% | 1.00% | 0.60% | 1.00% |
|
Maximum [Member]
|
||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Expected term (in years) | 6 years | 6 years | ||
| Risk-free interest rate | 0.70% | 1.60% | 0.80% | 2.30% |