Stock-Based Compensation	9 Months Ended
Sep. 30, 2020
Stock-Based Compensation [Abstract]
Stock-Based Compensation	Note 9 - Stock-based Compensation We recognize compensation expense for all equity-based compensation awards issued to employees and directors that are expected to vest. Stock compensation is calculated based upon the fair value of awards as of the grant date. During the three months ended September 30, 2020 and 2019, we recognized $0.03 million in stock-based compensation expense and $0.2 million of stock-based compensation expense related to equity awards, respectively. We recognized $0.4 million and $1.2 million of stock-based compensation expense related to equity awards for the nine months ended September 30, 2020 and 2019, respectively, under the fair value method. In addition to the equity-based compensation expense recognized, the Company also recognized $0 and $60 thousand of stock-based compensation related to the change in the fair value of cash-settled restricted stock units (RSUs) during the three months ended September 30, 2020 and 2019, respectively. During the nine months ended September 30, 2020, the Company recorded stock-based compensation income of $6 thousand and income of $88 thousand for the same period ended 2019 for the fair value of cash-settled RSUs, respectively. During the three and nine months ended September 30, 2020, we granted approximately 130,000 and 170,000 time-based RSUs with an aggregate fair value of approximately $0.1 million and $0.2 million, respectively. During the three and nine months ended September 30, 2019, we granted approximately 8,500 and 509,000 time-based RSUs with an aggregate fair value of $20 thousand and $1.4 million, respectively. A portion of the time-based RSUs vest quarterly in equal amounts over the course of eight quarters, and the remainder vest annually in equal amounts over the course of one to three years. The fair value of the time-based RSUs is expensed ratably over the requisite service period, which ranges from one to three years. GSE’s 1995 long-term incentive program ("LTIP") provides for the issuance of performance-vesting and time-vesting restricted stock units to certain executives and employees. Vesting of the performance-vesting restricted stock units ("PRSU") is contingent upon the employee's continued employment and the Company's achievement of certain performance goals during designated performance periods as established by the Compensation Committee of the Company's Board of Directors. We recognize compensation expense, net of estimated forfeitures, for PRSU's on a straight-line basis over the performance period based on the probable outcome of achievement of the financial targets. At the end of each reporting period, we estimate the number of PRSUs that are expected to vest, based on the probability and extent to which the performance goals will be met, and take into account these estimates when calculating the expense for the period. If the number of shares expected to be earned changes during the performance period, we make a cumulative adjustment to compensation expense based on the revised number of shares expected to be earned. During the three months ended September 30, 2020, we did not grant any performance-based RSUs to employees and during the nine months ended September 30, 2020 we granted approximately 512,000 performance-based RSUs with an aggregate fair-value of $0.6 million to key employees. Based upon our current forecasts, we do not expect to achieve the Adjusted EBITDA targets. A cumulative adjustment reversing $0.1 million of expense recognized in the first half of 2020 was recorded in the three months ended September 30, 2020 upon determination that vesting was no longer probable for the revenue and EBITDA targets. During the nine months ended September 30, 2019, we granted approximately 350,000 performance-based RSUs to key employees with an aggregate fair-value of $0.9 million. These awards vest over three years based upon achieving certain financial metrics achieved during fiscal 2021 for revenue and Adjusted EBITDA. A cumulative adjustment reversing $0.2 million of expense recognized in the first half of 2019 was recorded in the three months ended September 30, 2019 upon determination that vesting was no longer probable for the revenue and EBITDA targets. The Company did not grant any stock options for three and nine months ended September 30, 2020 and 2019.

Note 9 - Stock-based Compensation

We recognize compensation expense for all equity-based compensation awards issued to employees and directors that are expected to vest. Stock compensation is calculated based upon the fair value of awards as of the grant date. During the three months ended September 30, 2020 and 2019, we recognized $0.03 million in stock-based compensation expense and $0.2 million of stock-based compensation expense related to equity awards, respectively. We recognized $0.4 million and $1.2 million of stock-based compensation expense related to equity awards for the nine months ended September 30, 2020 and 2019, respectively, under the fair value method. In addition to the equity-based compensation expense recognized, the Company also recognized $0 and $60 thousand of stock-based compensation related to the change in the fair value of cash-settled restricted stock units (RSUs) during the three months ended September 30, 2020 and 2019, respectively. During the nine months ended September 30, 2020, the Company recorded stock-based compensation income of $6 thousand and income of $88 thousand for the same period ended 2019 for the fair value of cash-settled RSUs, respectively.

During the three and nine months ended September 30, 2020, we granted approximately 130,000 and 170,000 time-based RSUs with an aggregate fair value of approximately $0.1 million and $0.2 million, respectively. During the three and nine months ended September 30, 2019, we granted approximately 8,500 and 509,000 time-based RSUs with an aggregate fair value of $20 thousand and $1.4 million, respectively. A portion of the time-based RSUs vest quarterly in equal amounts over the course of eight quarters, and the remainder vest annually in equal amounts over the course of one to three years. The fair value of the time-based RSUs is expensed ratably over the requisite service period, which ranges from one to three years.

GSE’s 1995 long-term incentive program ("LTIP") provides for the issuance of performance-vesting and time-vesting restricted stock units to certain executives and employees. Vesting of the performance-vesting restricted stock units ("PRSU") is contingent upon the employee's continued employment and the Company's achievement of certain performance goals during designated performance periods as established by the Compensation Committee of the Company's Board of Directors. We recognize compensation expense, net of estimated forfeitures, for PRSU's on a straight-line basis over the performance period based on the probable outcome of achievement of the financial targets. At the end of each reporting period, we estimate the number of PRSUs that are expected to vest, based on the probability and extent to which the performance goals will be met, and take into account these estimates when calculating the expense for the period. If the number of shares expected to be earned changes during the performance period, we make a cumulative adjustment to compensation expense based on the revised number of shares expected to be earned.

During the three months ended September 30, 2020, we did not grant any performance-based RSUs to employees and during the nine months ended September 30, 2020 we granted approximately 512,000 performance-based RSUs with an aggregate fair-value of $0.6 million to key employees. Based upon our current forecasts, we do not expect to achieve the Adjusted EBITDA targets. A cumulative adjustment reversing $0.1 million of expense recognized in the first half of 2020 was recorded in the three months ended September 30, 2020 upon determination that vesting was no longer probable for the revenue and EBITDA targets.

During the nine months ended September 30, 2019, we granted approximately 350,000 performance-based RSUs to key employees with an aggregate fair-value of $0.9 million. These awards vest over three years based upon achieving certain financial metrics achieved during fiscal 2021 for revenue and Adjusted EBITDA. A cumulative adjustment reversing $0.2 million of expense recognized in the first half of 2019 was recorded in the three months ended September 30, 2019 upon determination that vesting was no longer probable for the revenue and EBITDA targets.

The Company did not grant any stock options for three and nine months ended September 30, 2020 and 2019.