|
Stockholders' Equity, Equity Incentive Plans and Warrants (Schedule of Fair Value Assumptions) (Details)
|
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Forfeiture Rate, Minimum | 0.00% | 0.00% | 0.00% |
| Forfeiture Rate, Maximum | 9.45% | 10.62% | 12.25% |
|
EIP and NEDSOP [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Risk-free interest rate | 1.07% | 1.19% | 1.84% |
| Expected dividend yield | 0.00% | 0.00% | 0.00% |
| Volatility | 82.00% | 81.00% | 85.00% |
| Expected Term | 5 years 3 months 18 days | 5 years 2 months 10 days | 5 years 4 months 24 days |
|
2000ESPP [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Risk-free interest rate | 0.09% | 0.12% | 0.17% |
| Expected dividend yield | 0.00% | 0.00% | 0.00% |
| Volatility | 63.00% | 64.00% | 70.00% |
| Expected Term | 6 months | 6 months | 6 months |
| Forfeiture Rate | 0.00% | 0.00% | 0.00% |