Share-Based Compensation	3 Months Ended
Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	6. Share-based compensation On May 5, 2021, the Company’s stockholders approved the Great Lakes Dredge & Dock Corporation 2021 Long-Term Incentive Plan (the “Incentive Plan”), which previously had been approved by the Company’s board of directors subject to stockholder approval. The Incentive Plan replaces the 2017 Long-Term Incentive Plan (the “Prior Plan”) and is largely based on the Prior Plan, but with updates to the available shares and other administrative changes. The Incentive Plan permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s employees and directors for up to 1.5 million shares of common stock, plus the number of shares that remained available for future grant under the Prior Plan as of the effectiveness of the Incentive Plan. The Prior Plan permitted the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s employees and directors for up to 3.3 million shares of common stock, plus an additional 1.7 million shares underlying equity awards issued under the 2007 Long-Term Incentive Plan. The Company may also issue share-based compensation as inducement awards to new employees upon approval of the Board of Directors and/or the applicable committee or committees thereof, as may be required. During the three months ended March 31, 2023, the Company granted 945 thousand restricted stock units to certain employees. In addition, all non-employee directors on the Company’s board of directors are paid a portion of their board-related compensation in stock grants or restricted stock units. Compensation cost charged to expense related to share-based compensation arrangements was $237 and $552 for the three months ended March 31, 2023 and 2022, respectively.

Share-Based Compensation

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [Abstract]

6. Share-based compensation

On May 5, 2021, the Company’s stockholders approved the Great Lakes Dredge & Dock Corporation 2021 Long-Term Incentive Plan (the “Incentive Plan”), which previously had been approved by the Company’s board of directors subject to stockholder approval. The Incentive Plan replaces the 2017 Long-Term Incentive Plan (the “Prior Plan”) and is largely based on the Prior Plan, but with updates to the available shares and other administrative changes. The Incentive Plan permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s employees and directors for up to 1.5 million shares of common stock, plus the number of shares that remained available for future grant under the Prior Plan as of the effectiveness of the Incentive Plan.

The Prior Plan permitted the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s employees and directors for up to 3.3 million shares of common stock, plus an additional 1.7 million shares underlying equity awards issued under the 2007 Long-Term Incentive Plan. The Company may also issue share-based compensation as inducement awards to new employees upon approval of the Board of Directors and/or the applicable committee or committees thereof, as may be required.

During the three months ended March 31, 2023, the Company granted 945 thousand restricted stock units to certain employees. In addition, all non-employee directors on the Company’s board of directors are paid a portion of their board-related compensation in stock grants or restricted stock units. Compensation cost charged to expense related to share-based compensation arrangements was $237 and $552 for the three months ended March 31, 2023 and 2022, respectively.