KOSMOS ENERGY LTD. Notes to Consolidated Financial Statements (Continued) 12. Equity-based Compensation (Continued) 2017, 2016 and 2015 was approximately $21.2 million, $14.4 million, and $52.2 million, respectively. The Company granted both restricted stock awards and restricted stock units with service vesting criteria and granted both restricted stock awards and restricted stock units with a combination of market and service vesting criteria under the LTIP. Substantially, all of these awards vest over three or four year periods. Restricted stock awards are issued and included in the number of outstanding shares upon the date of grant and, if such awards are forfeited, they become treasury stock. Upon vesting, restricted stock units become issued and outstanding stock. The following table reflects the outstanding restricted stock awards as of December 31, 2017: Weighted- Market / Service Weighted- Service Vesting Average Vesting Average Restricted Stock Grant-Date Restricted Stock Grant-Date Awards Fair Value Awards Fair Value (In thousands) (In thousands) Outstanding at December 31, 2014: . . . . 3,240 $ 16.95 3,361 $ 13.00 Granted . . . . . . . . . . . . . . . . . . . . . . 660 8.64 — — Forfeited . . . . . . . . . . . . . . . . . . . . . (2) 12.84 (1,554) 13.29 Vested . . . . . . . . . . . . . . . . . . . . . . . (3,088) 17.21 (1,546) 13.30 Outstanding at December 31, 2015: . . . . 810 9.20 261 9.44 Granted . . . . . . . . . . . . . . . . . . . . . . — — — — Forfeited . . . . . . . . . . . . . . . . . . . . . — — (162) 9.44 Vested . . . . . . . . . . . . . . . . . . . . . . . (322) 9.77 (99) 9.44 Outstanding at December 31, 2016: . . . . 488 8.83 — — Granted . . . . . . . . . . . . . . . . . . . . . . — — — — Forfeited . . . . . . . . . . . . . . . . . . . . . — — — — Vested . . . . . . . . . . . . . . . . . . . . . . . (268) 8.97 — — Outstanding at December 31, 2017: . . . . 220 8.64 — — 139