v2.4.1.9

Employee Stock and Benefit Plans (Tables) | 12 Months Ended
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Dec. 31, 2014
Share-based Compensation [Abstract] |
Stock-based employee compensation | Stock-based employee compensation is included in the consolidated statements of operations as follows:
|  | Year Ended December 31,
|  | 2014 |  | 2013 |  | 2012
|  | (in thousands)
Cost of revenues |  | $ | 757 |  |  | $ | 421 |  |  | $ | 272 |
Research and development |  | 2,463 |  |  | 1,038 |  |  | 649 |
Sales and marketing |  | 2,394 |  |  | 1,244 |  |  | 993 |
General and administrative |  | 4,217 |  |  | 1,842 |  |  | 1,008 |
Total stock-based employee compensation |  | $ | 9,831 |  |  | $ | 4,545 |  |  | $ | 2,922 |
Fair value assumptions of options granted to employees | The fair value of each option granted to employees is estimated on the date of grant using the Black-Scholes option-pricing model based on the following assumptions:
|  | Year Ended December 31,
|  | 2014 |  | 2013 |  | 2012
Expected term (in years) |  | 5.3 to 5.9 |  | 5.4 to 6.1 |  | 5.3 to 6.1
Volatility |  | 48% to 52% |  | 52% to 53% |  | 52% to 53%
Risk-free interest rate |  | 1.5% to 1.7% |  | 0.7% to 1.5% |  | 0.6% to 0.9%
Dividend yield |  | — |  | — |  | —
Stock option activity | A summary of the Company’s stock option activity is as follows:
|  | Outstanding Shares |  | Weighted Average Exercise Price |  | Weighted Average Remaining Contractual Life (Years) |  | Aggregate Intrinsic Value
|  |  |  |  |  |  |  | (in thousands)
Balance as of December 31, 2011 |  | 6,312,041 |  |  | $ | 3.36 |  |  | 6.9 |  | $ | 16,012 |
Granted |  | 1,478,781 |  |  | 8.94 |  |  |  |  |
Exercised |  | (724,316 | ) |  | 2.86 |  |  |  |  |
Canceled |  | (552,998 | ) |  | 6.79 |  |  |  |  |
Balance as of December 31, 2012 |  | 6,513,508 |  |  | 4.39 |  |  | 6.6 |  | 67,711 |
Granted |  | 2,001,400 |  |  | 15.78 |  |  |  |  |
Exercised |  | (952,871 | ) |  | 4.32 |  |  |  |  |
Canceled |  | (522,944 | ) |  | 10.71 |  |  |  |  |
Balance as of December 31, 2013 |  | 7,039,093 |  |  | 7.17 |  |  | 6.5 |  | 112,312 |
Granted |  | 2,744,150 |  |  | 26.16 |  |  |  |  |
Exercised |  | (1,216,710 | ) |  | 6.28 |  |  |  |  |
Canceled |  | (961,126 | ) |  | 16.91 |  |  |  |  |
Balance as of December 31, 2014 |  | 7,605,407 |  |  | 12.93 |  |  | 6.5 |  | 188,743 |
Vested and expected to vest—December 31, 2014 |  | 6,931,052 |  |  | 11.87 |  |  | 6.2 |  | 179,352 |
Exercisable—December 31, 2014 |  | 4,598,180 |  |  | 5.68 |  |  | 5.0 |  | 146,714 |
Schedule of exercise price range, outstanding and vested | The following table summarizes the outstanding and vested stock options at December 31, 2014:
|  | Outstanding |  | Vested
Exercise Price |  | Number of Shares |  | Weighted Average Exercise Price Per Share |  | Weighted Average Remaining Contractual Life (Years) |  | Number of Shares |  | Weighted Average Exercise Price Per Share
$1.00 - $1.50 |  | 238,559 |  |  | $ | 1.40 |  |  | 1.5 |  | 238,559 |  |  | $ | 1.40 |
$1.90 - $1.90 |  | 941,482 |  |  | 1.90 |  |  | 2.1 |  | 941,482 |  |  | 1.90 |
$2.10 - $2.80 |  | 461,758 |  |  | 2.62 |  |  | 3.9 |  | 461,758 |  |  | 2.62 |
$3.80 - $3.80 |  | 1,148,568 |  |  | 3.80 |  |  | 4.8 |  | 1,126,625 |  |  | 3.80 |
$4.10 - $8.40 |  | 924,121 |  |  | 5.55 |  |  | 6.0 |  | 826,292 |  |  | 5.35 |
$8.90 - $12.68 |  | 846,930 |  |  | 11.20 |  |  | 7.9 |  | 392,645 |  |  | 10.93 |
$13.50 - $20.80 |  | 962,889 |  |  | 18.50 |  |  | 8.5 |  | 250,599 |  |  | 17.03 |
$22.31 - $23.51 |  | 383,050 |  |  | 23.28 |  |  | 9.6 |  | 45,009 |  |  | 22.55 |
$26.86 - $26.86 |  | 701,350 |  |  | 26.86 |  |  | 9.0 |  | 29,728 |  |  | 26.86 |
$30.58 - $30.58 |  | 996,700 |  |  | 30.58 |  |  | 9.4 |  | 66,927 |  |  | 30.58 |
|  | 7,605,407 |  |  | 12.93 |  |  | 6.5 |  | 4,379,624 |  |  | 5.58 |

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- Definition Tabular disclosure of the allocation of equity-based compensation costs to a given line item on the balance sheet and income statement for the period. This may include the reporting line for the costs and the amount capitalized and expensed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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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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