v2.4.0.8

Stock Option Plans (Tables) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2013 | Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |  |
Summary of Assumptions Used in Pricing Model |  | The assumptions used in the Black-Scholes option pricing model for the years ended December 31, 2012 and 2011 are set forth below:
|  | 2012 |  |  | 2011 |
Valuation assumptions |  |  |  |  |  |  |  |
Expected dividend yield |  |  | 0% |  |  |  | 0% |
Expected volatility |  |  | 71%—76% |  |  |  | 68%—72% |
Expected term (years) |  |  | 6.00 |  |  |  | 5.37— 6.23 |
Risk-free interest rate |  |  | 0.80%—1.10% |  |  |  | 1.34%—2.51% |
Schedule of Stock Option Activity | Stock option activity under the Company’s award plans during the period indicated is as follows:
|  | Number of shares |  |  | Weighted average exercise price |  |  | Weighted average remaining contractual term |
Balances at December 31, 2012 |  |  | 2,313,526 |  |  | $ | 5.90 |  |  |  | 7.87 |
Granted |  |  | 764,209 |  |  |  | 11.07 |  |  |  |  |
Exercised |  |  | (17,649 | ) |  |  | (3.10 | ) |  |  |  |
Forfeited |  |  | (325,604 | ) |  |  | (6.94 | ) |  |  |  |
Expired |  |  | (36,865 | ) |  |  | (5.15 | ) |  |  |  |
Balances at September 30, 2013 |  |  | 2,697,617 |  |  |  | 7.26 |  |  |  | 7.68 |
Vested at September 30, 2013 |  |  | 992,112 |  |  |  | 4.67 |  |  |  | 5.79 |
Vested and Expected to Vest at September 30, 2013(1) |  |  | 2,434,816 |  |  |  | 6.20 |  |  |  | 6.91 |
(1) |  | The number of stock options expected to vest takes into account an estimate of expected forfeitures.
| Stock option activity during the years indicated is as follows:
|  | Number of shares |  |  | Weighted average exercise price |  |  | Weighted average remaining contractual term |
Balances at December 31, 2010 |  |  | 1,448,145 |  |  |  | 2.71 |  |  |  | 6.99 |
Granted |  |  | 2,429,684 |  |  |  | 6.48 |  |  |  |  |
Exercised |  |  | (75,840 | ) |  |  | (2.43 | ) |  |  |  |
Forfeited |  |  | (145,214 | ) |  |  | (3.34 | ) |  |  |  |
Expired |  |  | (42,245 | ) |  |  | (2.94 | ) |  |  |  |
Balances at December 31, 2011 |  |  | 3,614,530 |  |  |  | 5.22 |  |  |  | 6.67 |
Granted |  |  | 548,571 |  |  |  | 7.12 |  |  |  |  |
Exercised |  |  | (194,570 | ) |  |  | (2.43 | ) |  |  |  |
Forfeited |  |  | (1,210,857 | ) |  |  | (6.30 | ) |  |  |  |
Expired |  |  | (444,148 | ) |  |  | (2.29 | ) |  |  |  |
Balances at December 31, 2012 |  |  | 2,313,526 |  |  |  | 5.90 |  |  |  | 7.87 |
Exercisable at December 31, 2012 |  |  | 808,633 |  |  |  | 4.06 |  |  |  | 6.43 |
Vested and Expected to Vest at December 31, 2012(1) |  |  | 2,194,790 |  |  |  | 5.85 |  |  |  | 7.83 |
(1) |  | The number of stock options expected to vest takes into account an estimate of expected forfeitures.
Summary of Additional Information About Stock Options |  | The following table summarizes additional information about stock options outstanding as of December 31, 2012:
Options outstanding |  |  | Options exercisable |
Exercise price |  | Number of options |  |  | Weighted average remaining life (years) |  |  | Aggregate intrinsic value |  |  | Number of options |  |  | Weighted average remaining life (years) |  |  | Aggregate intrinsic value |
$0.38 |  |  | 57,264 |  |  |  | 8.07 |  |  | $ | 385 |  |  |  | 57,264 |  |  |  | 8.07 |  |  | $ | 385 |
$1.34 |  |  | 106,777 |  |  |  | 3.10 |  |  |  | 617 |  |  |  | 106,777 |  |  |  | 3.10 |  |  |  | 617 |
$1.92 |  |  | 23,143 |  |  |  | 4.25 |  |  |  | 120 |  |  |  | 23,143 |  |  |  | 4.25 |  |  |  | 120 |
$2.74 |  |  | 186,286 |  |  |  | 4.62 |  |  |  | 815 |  |  |  | 186,286 |  |  |  | 4.62 |  |  |  | 815 |
$3.29 |  |  | 183,442 |  |  |  | 6.77 |  |  |  | 703 |  |  |  | 126,014 |  |  |  | 6.72 |  |  |  | 483 |
$5.91 |  |  | 169,857 |  |  |  | 7.64 |  |  |  | 205 |  |  |  | 42,571 |  |  |  | 7.59 |  |  |  | 51 |
$7.12 |  |  | 1,586,757 |  |  |  | 8.77 |  |  |  | — |  |  |  | 266,578 |  |  |  | 8.53 |  |  |  | — |
|  |  | 2,313,526 |  |  |  | 7.87 |  |  | $ | 2,845 |  |  |  | 808,633 |  |  |  | 6.43 |  |  | $ | 2,471 |
The following table summarizes additional information about stock options outstanding as of December 31, 2011:
Options outstanding |  |  | Options exercisable |
Exercise price |  | Number of options |  |  | Weighted average remaining life (years) |  |  | Aggregate intrinsic value |  |  | Number of options |  |  | Weighted average remaining life (years) |  |  | Aggregate intrinsic value |
$0.38 |  |  | 145,406 |  |  |  | 9.07 |  |  | $ | 978 |  |  |  | 145,406 |  |  |  | 9.07 |  |  | $ | 978 |
$1.34 |  |  | 257,680 |  |  |  | 4.10 |  |  |  | 1,489 |  |  |  | 257,680 |  |  |  | 4.10 |  |  |  | 1,489 |
$1.68 |  |  | 58,286 |  |  |  | 2.84 |  |  |  | 317 |  |  |  | 58,286 |  |  |  | 2.84 |  |  |  | 317 |
$1.92 |  |  | 23,143 |  |  |  | 5.26 |  |  |  | 120 |  |  |  | 23,143 |  |  |  | 5.26 |  |  |  | 120 |
$1.96 |  |  | 3,015 |  |  |  | 9.07 |  |  |  | 16 |  |  |  | 3,015 |  |  |  | 9.07 |  |  |  | 16 |
$2.74 |  |  | 312,572 |  |  |  | 5.54 |  |  |  | 1,368 |  |  |  | 307,572 |  |  |  | 5.54 |  |  |  | 1,346 |
$3.29 |  |  | 564,286 |  |  |  | 7.50 |  |  |  | 2,163 |  |  |  | 212,929 |  |  |  | 7.35 |  |  |  | 816 |
$5.91 |  |  | 363,142 |  |  |  | 8.41 |  |  |  | 438 |  |  |  | — |  |  |  | — |  |  |  | — |
$7.12 |  |  | 1,887,000 |  |  |  | 6.58 |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
|  |  | 3,614,530 |  |  |  | 6.67 |  |  | $ | 6,889 |  |  |  | 1,008,031 |  |  |  | 5.91 |  |  | $ | 5,082 |

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- Definition Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the number and weighted-average exercise prices (or conversion ratios) for share options (or share units) that were outstanding at the beginning and end of the year, vested and expected to vest, exercisable or convertible at the end of the year, and the number of share options or share units that were granted, exercised or converted, forfeited, and expired during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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