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Equity Incentive Plans and Stock-Based Compensation (Tables) | 9 Months Ended
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Sep. 30, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] |
Shares available for grant under stock-based incentive plans |
| Shares Available for Grant
Shares available as of December 31, 2011 | 2,812,876 |
Increase in shares approved for issuance | 6,500,000 |
Stock options granted (1) | (7,592,911 | )
Stock options forfeited (2) | 1,201,539 |
Stock options expired under former plans | (101,562 | )
Nonvested equity stock and stock units granted (3) | (760,130 | )
Nonvested equity stock and stock units forfeited (3) | 157,973 |
Total available for grant as of September 30, 2012 | 2,217,785 |
_________________________________________
(1) | Amount includes 2,840,986 shares that were granted from the stock option exchange program (discussed below).
(2) | Amount excludes 6,449,255 shares that were surrendered from the stock option exchange program (discussed below) as the shares are no longer available for grant.
(3) | For purposes of determining the number of shares available for grant under the 2006 Plan against the maximum number of shares authorized, each restricted stock granted reduces the number of shares available for grant by 1.5 shares and each restricted stock forfeited increases shares available for grant by 1.5 share
Schedule of stock option activity |
| Options Outstanding |  |  |  |
| Number of Shares |  | Weighted Average Exercise Price Per Share |  | Weighted Average Remaining Contractual Term (years) |  | Aggregate Intrinsic Value
| (Dollars in thousands, except per share amounts)
Outstanding as of December 31, 2011 | 14,587,596 |  |  | $ | 19.73 |  |  |  |  |  |
Options granted | 7,592,911 |  |  | 5.83 |  |  |  |  |  |
Options exercised | (221,934 | ) |  | 4.44 |  |  |  |  |  |
Options forfeited | (1,201,539 | ) |  | 11.74 |  |  |  |  |  |
Options surrendered in stock option exchange program | (6,449,255 | ) |  | 21.11 |  |  |  |  |  |
Outstanding as of September 30, 2012 | 14,307,779 |  |  | 12.64 |  |  | 6.22 |  | $ | 1,506 |
Vested or expected to vest at September 30, 2012 | 12,492,826 |  |  | 13.48 |  |  | 5.84 |  | 1,173 |
Options exercisable at September 30, 2012 | 6,386,017 |  |  | 19.29 |  |  | 3.66 |  | — |
Weighted-average assumptions for Stock Option Plans |
| Stock Option Plans
| Three Months Ended |  | Nine Months Ended
| September 30, |  | September 30,
| 2012 |  | 2011 |  | 2012 |  | 2011
Stock Option Plans |  |  |  |  |  |  |  |  |  |  |
Expected stock price volatility | 65 | % |  | 75 | % |  | 60-68% |  |  | 50-75% |
Risk free interest rate | 0.6 | % |  | 2.3 | % |  | 0.6-0.9% |  |  | 2.3-2.8% |
Expected term (in years) | 5.5 |  |  | 6.1 |  |  | 5.5-5.7 |  |  | 6.0-6.1 |
Weighted-average fair value of stock options granted to employees | $ | 3.06 |  |  | $ | 9.48 |  |  | $ | 3.61 |  |  | $ | 10.43 |
Weighted-average assumptions for Employee Stock Purchase Plan |
| Employee Stock Purchase Plan
|  | Nine Months Ended
|  | September 30,
|  | 2012 |  | 2011
Employee Stock Purchase Plan |  |  |  |  |  |
Expected stock price volatility |  | 63 | % |  | 56 | %
Risk free interest rate |  | 0.2 | % |  | 0.1 | %
Expected term (in years) |  | 0.5 |  |  | 0.5 |
Weighted-average fair value of purchase rights granted under the purchase plan |  | $ | 1.61 |  |  | $ | 5.96 |
Schedule of nonvested equity stock and stock units activity |
Nonvested Equity Stock and Stock Units |  | Shares |  | Weighted- Average Grant-Date Fair Value
Nonvested at December 31, 2011 |  | 763,510 |  |  | $ | 18.02 |
Granted |  | 506,753 |  |  | 6.95 |
Vested |  | (312,099 | ) |  | 18.31 |
Forfeited |  | (105,315 | ) |  | 13.52 |
Nonvested at September 30, 2012 |  | 852,849 |  |  | 11.88 |

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