|12 Months Ended
Dec. 31, 2017
|Share-based Compensation [Abstract]
During the years ended December 31, 2017, 2016 and 2015 the Company’s stock-based compensation cost was $10.6 million, $12.3 million and $14.4 million, respectively, of which the Company capitalized $4.2 million, $4.9 million and $5.7 million, respectively, relating to its exploration and development efforts.
The fair value of each option award is estimated on the date of grant using the Black-Scholes option valuation model. Expected volatilities are based on the historical volatility of the market price of Gulfport’s common stock over a period of time ending on the grant date. Based upon the historical experience of the Company, the expected term of options granted is equal to the vesting period plus one year. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. The 2013 Restated Stock Incentive Plan (which amended and restated the 2005 Plan) provides that all options must have an exercise price not less than the fair value of the Company’s common stock on the date of the grant.
No stock options were issued during the years ended December 31, 2017, 2016 and 2015.
The Company has not declared dividends and does not intend to do so in the foreseeable future, and thus did not use a dividend yield. In each case, the actual value that will be realized, if any, depends on the future performance of the common stock and overall stock market conditions. There is no assurance that the value an optionee actually realizes will be at or near the value estimated using the Black-Scholes model.
A summary of the status of stock options and related activity for the years ended December 31, 2017, 2016 and 2015 is presented below:
The following table summarizes restricted stock activity for the twelve months ended December 31, 2017, 2016 and 2015:
Unrecognized compensation expense as of December 31, 2017 related to outstanding stock options and restricted shares was $14.4 million. The expense is expected to be recognized over a weighted average period of 1.46 years.