Stock-Based Compensation	9 Months Ended
Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation at fair value. The fair value of stock options is determined at the grant date using the Black-Scholes option pricing model. The fair value of restricted stock units (“RSUs”) is equal to the closing price of the underlying common stock on the grant date. The fair value of an award that is ultimately expected to vest is recognized on a straight-line basis over the requisite service or performance period and is classified in the condensed consolidated statements of operations and comprehensive income in a manner consistent with the classification of the recipient’s compensation. The expected vesting of the Company’s performance-based RSUs is based upon the likelihood that the Company achieves the defined performance goals. The level of achievement of performance goals, if any, is determined by the compensation committee of the Company’s Board of Directors. Stock-based awards to non-employee consultants are expensed at their fair value as services are provided according to the terms of their agreements and are classified in selling, general and administrative expenses in the accompanying condensed consolidated statements of operations and comprehensive income. In May 2015, the Company’s stockholders approved the 2015 Equity Incentive Plan (the “2015 Plan”) to provide stock-based awards, including nonqualified stock options, incentive stock options, restricted stock and other equity securities, as incentives and rewards for employees, consultants and non-employee directors. In May 2017, the Company’s stockholders amended and restated the 2015 Plan (the “Amended 2015 Plan”), primarily to increase the number of shares available under the plan by 8.0 million shares. All grants in June 2017 or later were made under the Amended 2015 Plan, which continues to permit the grant of stock-based awards, including nonqualified stock options, incentive stock options, restricted stock and other equity securities to employees, consultants and non-employee directors. Members of the Company’s board of directors have received a portion of their annual compensation in the form of equity awards under the 2015 Plan. An aggregate amount of approximately 96,000 and 126,000 RSUs were granted in January 2017 and 2016, respectively. These RSUs vest in full on the first anniversary of the grant date. The estimated aggregate grant date fair value of the RSUs granted to the directors in January 2017 and 2016 was $1.0 million for each year. During the nine months ended September 30, 2017 and 2016, the Company granted approximately 209,000 and 249,000 stock options, respectively, to its employees, with an estimated aggregate grant date fair value of $0.9 million for each year. Additionally, during the nine months ended September 30, 2017 and 2016, the Company granted 964,000 and 573,000 service-based RSUs, respectively, to its employees, with an estimated aggregate grant date fair value of $8.5 million and $4.0 million, respectively. Employee stock options and service-based RSUs generally vest over a four-year service period, with 25% vesting on the first anniversary of the grant date and the remainder vesting ratably on a quarterly basis thereafter. In March 2017 and 2016, the Company awarded approximately 1,190,000 and 1,335,000 performance-based RSUs to the Company’s executives and employees (the “Bonus RSUs”). The Company records stock-based compensation expense over the requisite service period related to performance-based RSUs when it is considered probable that the performance conditions will be met. Vesting of the March 2017 and 2016 Bonus RSUs is and was dependent upon the Company’s achievement of defined performance goals over a one-year period (fiscal year 2017 for the March 2017 Bonus RSUs and fiscal year 2016 for the March 2016 Bonus RSUs). Management believes it is probable that certain of the March 2017 Bonus RSUs will vest. The level of achievement, if any, of performance goals will be determined by the compensation committee of the Company’s Board of Directors and, if such goals are achieved, the March 2017 Bonus RSUs will vest, subject to continued employment, through March 2018. Certain of the March 2016 Bonus RSUs vested in March 2017. The estimated aggregate grant date fair value of the March 2017 and 2016 Bonus RSUs was $10.5 million and $9.4 million, respectively. Additionally, in March 2017 and 2016, the Company awarded approximately 173,000 and 119,000 performance-based RSUs, respectively, to the Company’s executives (the “Performance RSUs”). Vesting of the 2017 and 2016 Performance RSUs is and was dependent upon the Company’s achievement of defined performance goals over a two-year period (fiscal years 2017 and 2018 for the Performance RSUs granted in 2017 and fiscal years 2016 and 2017 for the Performance RSUs granted in 2016). Management believes it is probable that certain of the Performance RSUs will vest. The number of Performance RSUs that will ultimately vest may range from 0% to 150% of the original grant based on the level of achievement of the performance goals. If the Company achieves the performance goals, 50% of the Performance RSUs will vest in March in the year after the performance period ends and the remaining 50% will vest in March of the third year after grant, in each case subject to the executive’s continued service as of the vesting date. The estimated aggregate grant date fair value of the Performance RSUs was $1.5 million for the 2017 grants and $0.8 million for the 2016 grants. In June 2017 and June 2016, the Company granted approximately 8,000 and 35,000 RSUs, respectively, to non-employee consultants. The RSUs are generally subject to service-based vesting. The RSUs will vest 50% in June of the year after the grant and the remaining 50% will vest quarterly thereafter. The estimated aggregate grant date fair value of the RSUs granted to non-employee consultants during the nine months ended September 30, 2017 and 2016 was $0.1 million and $0.3 million, respectively.

Stock-Based Compensation

The Company accounts for stock-based compensation at fair value. The fair value of stock options is determined at the grant date using the Black-Scholes option pricing model. The fair value of restricted stock units (“RSUs”) is equal to the closing price of the underlying common stock on the grant date. The fair value of an award that is ultimately expected to vest is recognized on a straight-line basis over the requisite service or performance period and is classified in the condensed consolidated statements of operations and comprehensive income in a manner consistent with the classification of the recipient’s compensation. The expected vesting of the Company’s performance-based RSUs is based upon the likelihood that the Company achieves the defined performance goals. The level of achievement of performance goals, if any, is determined by the compensation committee of the Company’s Board of Directors. Stock-based awards to non-employee consultants are expensed at their fair value as services are provided according to the terms of their agreements and are classified in selling, general and administrative expenses in the accompanying condensed consolidated statements of operations and comprehensive income.

In May 2015, the Company’s stockholders approved the 2015 Equity Incentive Plan (the “2015 Plan”) to provide stock-based awards, including nonqualified stock options, incentive stock options, restricted stock and other equity securities, as incentives and rewards for employees, consultants and non-employee directors. In May 2017, the Company’s stockholders amended and restated the 2015 Plan (the “Amended 2015 Plan”), primarily to increase the number of shares available under the plan by 8.0 million shares. All grants in June 2017 or later were made under the Amended 2015 Plan, which continues to permit the grant of stock-based awards, including nonqualified stock options, incentive stock options, restricted stock and other equity securities to employees, consultants and non-employee directors. Members of the Company’s board of directors have received a portion of their annual compensation in the form of equity awards under the 2015 Plan. An aggregate amount of approximately 96,000 and 126,000 RSUs were granted in January 2017 and 2016, respectively. These RSUs vest in full on the first anniversary of the grant date. The estimated aggregate grant date fair value of the RSUs granted to the directors in January 2017 and 2016 was $1.0 million for each year.

During the nine months ended September 30, 2017 and 2016, the Company granted approximately 209,000 and 249,000 stock options, respectively, to its employees, with an estimated aggregate grant date fair value of $0.9 million for each year. Additionally, during the nine months ended September 30, 2017 and 2016, the Company granted 964,000 and 573,000 service-based RSUs, respectively, to its employees, with an estimated aggregate grant date fair value of $8.5 million and $4.0 million, respectively. Employee stock options and service-based RSUs generally vest over a four-year service period, with 25% vesting on the first anniversary of the grant date and the remainder vesting ratably on a quarterly basis thereafter.

In March 2017 and 2016, the Company awarded approximately 1,190,000 and 1,335,000 performance-based RSUs to the Company’s executives and employees (the “Bonus RSUs”). The Company records stock-based compensation expense over the requisite service period related to performance-based RSUs when it is considered probable that the performance conditions will be met. Vesting of the March 2017 and 2016 Bonus RSUs is and was dependent upon the Company’s achievement of defined performance goals over a one-year period (fiscal year 2017 for the March 2017 Bonus RSUs and fiscal year 2016 for the March 2016 Bonus RSUs). Management believes it is probable that certain of the March 2017 Bonus RSUs will vest. The level of achievement, if any, of performance goals will be determined by the compensation committee of the Company’s Board of Directors and, if such goals are achieved, the March 2017 Bonus RSUs will vest, subject to continued employment, through March 2018. Certain of the March 2016 Bonus RSUs vested in March 2017. The estimated aggregate grant date fair value of the March 2017 and 2016 Bonus RSUs was $10.5 million and $9.4 million, respectively.

Additionally, in March 2017 and 2016, the Company awarded approximately 173,000 and 119,000 performance-based RSUs, respectively, to the Company’s executives (the “Performance RSUs”). Vesting of the 2017 and 2016 Performance RSUs is and was dependent upon the Company’s achievement of defined performance goals over a two-year period (fiscal years 2017 and 2018 for the Performance RSUs granted in 2017 and fiscal years 2016 and 2017 for the Performance RSUs granted in 2016). Management believes it is probable that certain of the Performance RSUs will vest. The number of Performance RSUs that will ultimately vest may range from 0% to 150% of the original grant based on the level of achievement of the performance goals. If the Company achieves the performance goals, 50% of the Performance RSUs will vest in March in the year after the performance period ends and the remaining 50% will vest in March of the third year after grant, in each case subject to the executive’s continued service as of the vesting date. The estimated aggregate grant date fair value of the Performance RSUs was $1.5 million for the 2017 grants and $0.8 million for the 2016 grants.

In June 2017 and June 2016, the Company granted approximately 8,000 and 35,000 RSUs, respectively, to non-employee consultants. The RSUs are generally subject to service-based vesting. The RSUs will vest 50% in June of the year after the grant and the remaining 50% will vest quarterly thereafter. The estimated aggregate grant date fair value of the RSUs granted to non-employee consultants during the nine months ended September 30, 2017 and 2016 was $0.1 million and $0.3 million, respectively.