Incentive Award Plan
9 Months Ended
Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]  
Incentive Award Plan
Incentive Award Plan
On May 11, 2016, the stockholders of the Company approved the Amended Incentive Award Plan, which increased the number of shares of common stock reserved for issuance thereunder by 5.5 million shares. As of September 30, 2016, 5.7 million shares remained available for award under the Amended Incentive Award Plan.
Restricted Shares of Common Stock
During the nine months ended September 30, 2016, the Company granted 0.9 million restricted shares under the Amended Incentive Award Plan to certain executive officers and employees. The Company recorded $11.7 million in deferred compensation associated with these grants, which will be recognized in expense over the service period of the awards. As of September 30, 2016, there were approximately 1.0 million unvested restricted shares outstanding.
Performance Share Awards
During the nine months ended September 30, 2016, the Board of Directors or committee thereof approved an initial target grant of 0.3 million performance shares, net of forfeitures of 0.1 million, to executive officers of the Company. The performance period of this grant runs from January 1, 2016 through December 31, 2018. Potential shares of the Corporation's common stock that each participant is eligible to receive is based on the initial target number of shares granted multiplied by a percentage range between 0% and 250%. Grant date fair value was calculated using the Monte Carlo simulation model, which incorporated stock price correlation, projected dividend yields and other variables over the time horizons matching the performance periods. Stock-based compensation expense associated with unvested performance share awards is recognized on a straight-line basis over the minimum required service period, which is generally three years. Based on the grant date fair value, the Corporation expects to recognize $4.1 million in compensation expense on a straight-line basis over the requisite service period associated with this market-based grant.
Approximately $0.4 million and $0.2 million in dividend rights have been accrued for non-vested performance share awards outstanding as of September 30, 2016 and December 31, 2015, respectively. For outstanding non-vested awards at September 30, 2016, 0.8 million shares would have been released based on the Corporation's TSR relative to the specified peer groups through that date. During the nine months ended September 30, 2016, 0.2 million shares were released at target in connection with qualifying terminations of participants.
Stock-based Compensation Expense
For the three months ended September 30, 2016 and 2015, the Company recognized $3.4 million and $3.5 million, respectively, in stock-based compensation expense, which is included in general and administrative expenses in the accompanying consolidated statements of operations. For the nine months ended September 30, 2016 and 2015, the Company recognized $7.2 million and $10.8 million, respectively, in stock-based compensation expense.
As of September 30, 2016, the remaining unamortized stock-based compensation expense, including amounts relating to the performance share awards, totaled $16.7 million, including $11.2 million related to restricted stock awards and $5.5 million related to performance share awards, which is recognized as the greater of the amount amortized on a straight-line basis over the service period of each applicable award or the amount vested over the vesting periods.