Stock-Based and Other Long Term Incentive Compensation	9 Months Ended
Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based and Other Long Term Incentive Compensation	Stock-Based and Other Long-Term Incentive Compensation During the second quarter of 2018, the Compensation Committee of our Board of Directors (“Compensation Committee”) approved equity-based compensation to executive officers and other key employees, consisting of 917,901 shares of restricted stock units which will primarily vest in equal installments over a three-year period. At September 30, 2018, there remained 1,041,661 shares available for award under the 2015 Employee Equity Incentive Plan (“2015 Plan”). In addition, during the second quarter of 2018, non-employee directors received a grant of 85,578 shares of restricted stock awards which will vest in full on the earlier of the day prior to the next annual meeting of stockholders following the grant date or the first anniversary of the grant date. The weighted average grant-date fair value was $10.58 per share for the restricted stock units and $10.75 per share for the restricted stock awards. Also during the second quarter of 2018, the Compensation Committee approved the issuance of cash-settled awards to certain executive officers, including $1.3 million of time-based cash awards and a target amount of $1.3 million of performance-based cash awards. The time-based cash awards vest in equal installments over a three-year period and the performance-based cash awards will be settled based on the relative ranking of our total shareholder return (“TSR”) as compared to the TSR of our designated peer group over a three-year period. The performance period began June 1, 2018 and ends May 31, 2021, with the ending TSR price being equal to the average closing price of our shares over the 30-calendar days ending May 31, 2021 and the cash payout for each executive ranging from 0% to 150% of target. The performance-based cash awards are accrued as a liability award over the performance period based on the estimated fair value. The fair value of the performance-based cash awards is remeasured each period using a Monte-Carlo valuation model with changes in fair value recognized in the consolidated statements of operations. In connection with the retirement of our Senior Vice President, General Counsel and Chief Administrative Officer on September 30, 2018, we modified certain outstanding stock-based and other incentive awards. During the third quarter of 2018, we modified the vesting conditions of outstanding unvested restricted stock units, performance-based restricted stock units, stock options, and time-based and performance-based cash awards to allow for continued vesting after his retirement date, and to extend the exercise period of all of his outstanding options from 90 days from the date of retirement to the earlier of (a) 2 years from his retirement date or (b) the original expiration date of the award. As a result of the above modifications, we recognized a charge of $1.5 million for the third quarter of 2018.

Stock-Based and Other Long-Term Incentive Compensation

During the second quarter of 2018, the Compensation Committee of our Board of Directors (“Compensation Committee”) approved equity-based compensation to executive officers and other key employees, consisting of 917,901 shares of restricted stock units which will primarily vest in equal installments over a three-year period. At September 30, 2018, there remained 1,041,661 shares available for award under the 2015 Employee Equity Incentive Plan (“2015 Plan”). In addition, during the second quarter of 2018, non-employee directors received a grant of 85,578 shares of restricted stock awards which will vest in full on the earlier of the day prior to the next annual meeting of stockholders following the grant date or the first anniversary of the grant date. The weighted average grant-date fair value was $10.58 per share for the restricted stock units and $10.75 per share for the restricted stock awards.

Also during the second quarter of 2018, the Compensation Committee approved the issuance of cash-settled awards to certain executive officers, including $1.3 million of time-based cash awards and a target amount of $1.3 million of performance-based cash awards. The time-based cash awards vest in equal installments over a three-year period and the performance-based cash awards will be settled based on the relative ranking of our total shareholder return (“TSR”) as compared to the TSR of our designated peer group over a three-year period. The performance period began June 1, 2018 and ends May 31, 2021, with the ending TSR price being equal to the average closing price of our shares over the 30-calendar days ending May 31, 2021 and the cash payout for each executive ranging from 0% to 150% of target. The performance-based cash awards are accrued as a liability award over the performance period based on the estimated fair value. The fair value of the performance-based cash awards is remeasured each period using a Monte-Carlo valuation model with changes in fair value recognized in the consolidated statements of operations.

In connection with the retirement of our Senior Vice President, General Counsel and Chief Administrative Officer on September 30, 2018, we modified certain outstanding stock-based and other incentive awards. During the third quarter of 2018, we modified the vesting conditions of outstanding unvested restricted stock units, performance-based restricted stock units, stock options, and time-based and performance-based cash awards to allow for continued vesting after his retirement date, and to extend the exercise period of all of his outstanding options from 90 days from the date of retirement to the earlier of (a) 2 years from his retirement date or (b) the original expiration date of the award. As a result of the above modifications, we recognized a charge of $1.5 million for the third quarter of 2018.