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Stockholders' Equity, Equity Incentive Plans and Warrants (Tables)
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12 Months Ended |
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Dec. 31, 2013
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| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] |
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| Share-based compensation expense |
The following table summarizes share-based compensation expense for the years ended December 31, (in thousands): | | | | | | | | | | | | | | | | 2011 | | 2012 | | 2013 | Cost of goods sold | | $ | 828 |
| | $ | 617 |
| | $ | 334 |
| Sales and marketing | | 540 |
| | 419 |
| | 274 |
| Research and development | | 2,200 |
| | 1,705 |
| | 1,054 |
| General and administrative | | 1,548 |
| | 1,024 |
| | 1,028 |
| Share-based compensation expense before taxes | | 5,116 |
| | 3,765 |
| | 2,690 |
| Related deferred income tax benefits | | — |
| | — |
| | — |
| Share-based compensation expense | | $ | 5,116 |
| | $ | 3,765 |
| | $ | 2,690 |
| Share-based compensation expense is derived from: | | | | | | | Stock options | | $ | 1,434 |
| | $ | 1,508 |
| | $ | 1,924 |
| Restricted stock awards | | 2,303 |
| | 1,958 |
| | 489 |
| Stock bonus plan | | 1,005 |
| | — |
| | — |
| 2000 ESPP | | 374 |
| | 299 |
| | 277 |
| Total | | $ | 5,116 |
| | $ | 3,765 |
| | $ | 2,690 |
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| Summary of stock option activity |
A summary of stock option activity is as follows: | | | | | | | | | | | | | | | | | Number of shares | | Weighted average exercise price | | Weighted average remaining contractual term (in years) | | Aggregate intrinsic value | Outstanding at January 1, 2013 | | 8,952,129 |
| | $ | 2.93 |
| | | | | Granted | | 2,331,500 |
| | 1.57 |
| | | | | Exercised | | (210,551 | ) | | 1.53 |
| | | | | Forfeited | | (268,985 | ) | | 1.47 |
| | | | | Expired | | (953,595 | ) | | 3.94 |
| | | | | Outstanding at December 31, 2013 | | 9,850,498 |
| | $ | 2.58 |
| | 4.35 | | $ | 12,056,111 |
| Vested and expected to vest at December 31, 2013 | | 9,511,564 |
| | $ | 2.62 |
| | 4.28 | | $ | 11,423,719 |
| Exercisable at December 31, 2013 | | 6,155,904 |
| | $ | 3.17 |
| | 3.65 | | $ | 5,528,671 |
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| Summary of restricted stock activity |
A summary of restricted stock award activity for 2013 is as follows: | | | | | | | | | | | Number of shares | | Weighted average grant date fair value | Outstanding at January 1, 2013 | | 655,402 |
| | $ | 2.16 |
| Granted | | 30,000 |
| | 1.74 |
| Vested | | (567,268 | ) | | 2.22 |
| Forfeited | | (25,323 | ) | | 1.84 |
| Outstanding and unvested at December 31, 2013 | | 92,811 |
| | $ | 1.73 |
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| Schedule of valuation assumptions for equity awards |
To estimate compensation expense for the years ended December 31, 2011, 2012, and 2013 we used the Black-Scholes pricing model with the following weighted-average assumptions for equity awards granted: | | | | | | | | | | | | | | | | | | | | | | EIP and NEDSOP | | ESPP | | | Years Ended December 31, | | Years Ended December 31, | | | 2011 | | 2012 | | 2013 | | 2011 | | 2012 | | 2013 | Risk-free interest rate | | 1.84 | % | | 1.19 | % | | 1.07 | % | | 0.17 | % | | 0.12 | % | | 0.09 | % | Expected dividend yield | | — | % | | — | % | | — | % | | — | % | | — | % | | — | % | Volatility | | 85 | % | | 81 | % | | 82 | % | | 70 | % | | 64 | % | | 63 | % | Expected Term | | 5.4 years |
| | 5.2 years |
| | 5.3 years |
| | 0.5 years |
| | 0.5 years |
| | 0.5 years |
| Forfeiture Rate | | 0%-12.25% |
| | 0%-10.62% |
| | 0%-9.45% |
| | — | % | | — | % | | — | % |
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