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Noncash Share-based Compensation (Tables) | 12 Months Ended
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Dec. 31, 2014
Noncash Share-based Compensation [Abstract] |
Schedule of Share-based Compensation Expense | Noncash share based compensation expense is allocated to expense categories on the Consolidated Statements of Comprehensive Income. The following table summarizes noncash share based compensation expense, net of amounts capitalized, for the years ended December 31, 2014, 2013 and 2012.
| For the Year Ended December 31,
| 2014 |  | 2013 |  | 2012
Share-based compensation: |  |  |  |  |
Cost of revenue | $ | 3,469 |  |  | $ | 2,071 |  |  | $ | 1,451 |
Operating expenses: |  |  |  |  |
Selling and marketing | 5,142 |  |  | 3,834 |  |  | 2,335 |
General and administrative | 9,375 |  |  | 7,055 |  |  | 3,938 |
Research and development | 4,679 |  |  | 3,139 |  |  | 1,921 |
Total included in operating expenses | 19,196 |  |  | 14,028 |  |  | 8,194 |
Total share-based compensation expense | $ | 22,665 |  |  | $ | 16,099 |  |  | $ | 9,645 |
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] | Stock Options: The following table summarizes the Company’s stock option activity for the year ended December 31, 2014:
| Number of shares under option |  | Weighted average exercise price |  | Weighted average remaining contractual term (year) |  | Aggregate intrinsic value (1)
Outstanding, December 31, 2013 | 1,160 |  |  | $ | 11.12 |  |  |  |  |
Granted | — |  |  | — |  |  |  |  |
Exercised | (196) |  |  | 7.37 |  |  |  |  |
Forfeited | — |  |  | — |  |  |  |  |
Expired | (3) |  |  | 14.93 |  |  |  |  |
Outstanding, December 31, 2014 | 961 |  |  | $ | 11.87 |  |  | 2.80 |  | $ | 15,006 |
Vested and exercisable at December 31, 2014 | 961 |  |  | $ | 11.87 |  |  | 2.80 |  | $ | 15,006 |
(1) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $27.48 and the grant date fair value.
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] | The following table summarizes the Company's unvested RSUs as of December 31, 2014, and changes during the year then ended, is as follows:
| Number of shares |  | Weighted average grant date fair value |  | Weighted average remaining contractual term (year) |  | Aggregate intrinsic value (1)
Unvested at December 31, 2013 | 1,543 |  |  | $ | 18.25 |  |  |  |  |
Granted | 1,028 |  |  | 33.46 |  |  |  |  |
Vested | (582 | ) |  | 17.42 |  |  |  |  |
Forfeited | (125 | ) |  | 25.28 |  |  |  |  |
Unvested at December 31, 2014 | 1,864 |  |  | $ | 26.67 |  |  | 4.65 |  | $ | 51,231 |
Expected to vest at December 31, 2014 | 1,822 |  |  | $ | 26.60 |  |  | 4.64 |  | $ | 50,067 |
(1) The aggregate intrinsic value was calculated based on the fair value of the Company’s common stock on December 31, 2014 of $27.48.
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block] | The following table summarizes the Company's SARs activity for the year ended December 31, 2014:
| Stock appreciation rights |  | Weighted average exercise price |  | Weighted average remaining contractual term (year) |  | Aggregate intrinsic value (1)
Outstanding, December 31, 2013 | 721 |  |  | $ | 10.74 |  |  |  |  |
Granted | — |  |  | — |  |  |  |  |
Exercised | (48 | ) |  | 10.59 |  |  |  |  |
Forfeited | — |  |  | — |  |  |  |  |
Expired | — |  |  | — |  |  |  |  |
Outstanding, December 31, 2014 | 673 |  |  | $ | 10.75 |  |  | 5.82 |  | $ | 11,260 |
Exercisable at December 31, 2014 | 662 |  |  | $ | 10.74 |  |  | 5.81 |  | $ | 11,083 |
Vested and expected to vest at December 31, 2014 | 673 |  |  | $ | 10.75 |  |  | 5.82 |  | $ | 11,260 |
(1) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $27.48 and the exercise price of the underlying SARs.
Schedule of Assumptions Used [Table Text Block] | Significant assumptions used in the Monte Carlo simulation model for MSUs granted during December 31, 2014, 2013 and 2012 are as follows:
| For the Year Ended December 31,
| 2014 | 2013 |  | 2012
Volatility | 50.86% | 57% |  | 61%
Risk-free interest rate | 0.68% | 0.35% |  | 0.28%
Expected option life in years | 2.88 | 2.84 |  | 1.9
Dividend yield | — | — |  | —
The assumptions related to fiscal year 2014 are presented on weighted average basis for the various awards granted throughout the period. Employee stock purchase plan: In June 2013, the Board of Directors authorized an Employee Stock Purchase Plan (“ESPP”) which provides for eligible employees to purchase shares on an after-tax basis in an amount between 1% and 10% of their annual pay: (i) on June 30 of each year at a 5% discount of the fair market value of our common stock on January 1 or June 30, whichever is lower, and (ii) on December 31 of each year at a 5% discount of the fair market value of our common stock on July 1 or December 31, whichever is lower. An employee may not purchase more than $5,000 in either of the six-month measurement periods described above or more than $10,000 annually. During the year ended December 31, 2014, the Company issued 13,392 shares under the ESPP. As of December 31, 2014, 486,608 shares remain authorized and available for issuance under the ESPP. As of December 31, 2014, the Company held approximately $0.4 million on behalf of employees for future purchases under the ESPP and this amount was recorded in accrued liabilities in the Company's consolidated balance sheet.
Schedule of Nonvested Performance-based Units Activity [Table Text Block] |
| Number of unvested awards |  | Weighted average grant date fair value |  | Weighted average remaining contractual term (year) |  | Aggregate intrinsic value (1)
Unvested at December 31, 2013 | 469 |  |  | 34.24 |  |  |  |  |
Granted | 198 |  |  | $ | 48.54 |  |  |  |  |
Exercised | (205 | ) |  | 26.08 |  |  |  |  |
Forfeited | (18 | ) |  | 43.07 |  |  |  |  |
Expired | — |  |  | — |  |  |  |  |
Unvested at December 31, 2014 | 444 |  |  | $ | 44.03 |  |  | 6.30 |  | $ | 12,209 |
(1) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $27.48 and the grant date fair value of the underlying MSUs.
Market Stock Units Valuation Assumptions [Table Text Block] | Significant assumptions used in the Monte Carlo simulation model for MSUs granted during December 31, 2014, 2013 and 2012 are as follows:
| For the Year Ended December 31,
| 2014 | 2013 |  | 2012
Volatility | 50.86% | 57% |  | 61%
Risk-free interest rate | 0.68% | 0.35% |  | 0.28%
Expected option life in years | 2.88 | 2.84 |  | 1.9
Dividend yield | — | — |  | —
The assumptions related to fiscal year 2014 are presented on weighted average basis for the various awards granted throughout the period. Employee stock purchase plan: In June 2013, the Board of Directors authorized an Employee Stock Purchase Plan (“ESPP”) which provides for eligible employees to purchase shares on an after-tax basis in an amount between 1% and 10% of their annual pay: (i) on June 30 of each year at a 5% discount of the fair market value of our common stock on January 1 or June 30, whichever is lower, and (ii) on December 31 of each year at a 5% discount of the fair market value of our common stock on July 1 or December 31, whichever is lower. An employee may not purchase more than $5,000 in either of the six-month measurement periods described above or more than $10,000 annually. During the year ended December 31, 2014, the Company issued 13,392 shares under the ESPP. As of December 31, 2014, 486,608 shares remain authorized and available for issuance under the ESPP. As of December 31, 2014, the Company held approximately $0.4 million on behalf of employees for future purchases under the ESPP and this amount was recorded in accrued liabilities in the Company's consolidated balance sheet.

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- Definition Disclosure of the number and weighted-average grant date fair value for restricted stock and restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock and restricted stock units that were granted, vested, or forfeited during the year. + References No definition available. + 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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