Stock-Based Compensation

9 Months Ended

Sep. 30, 2016

Share-based Compensation [Abstract]

Stock-Based Compensation

Stock-Based Compensation

A summary of restricted stock transactions during the nine months ended September 30, 2016 follows:

	Number of shares
Non-vested stock awards outstanding at January 1, 2016	1,778,275
Awarded:
Time-vesting shares	127,167
Performance-based shares	137,374
Released:
Time-vesting shares	(412,889	)
Performance-based shares	(90,003	)
Forfeitures:
Time-vesting shares	(46,667	)
Performance-based shares	(161,415	)
Non-vested stock awards outstanding at September 30, 2016	1,331,842

The performance-based awards cliff vest at the end of three years. The number of performance-based shares that will ultimately vest is based on the level of market performance achieved, ranging between 0% and 200% of the shares originally awarded, and will be settled in stock. The market performance criteria is the Company's Total Shareholder Return ("TSR"), which includes share price appreciation and dividends paid, during the three-year term of the award measured against the TSR of a peer group of companies.

The time-vesting restricted and deferred stock awards vest ratably over three to five years.

The weighted average grant-date fair value of the 2016 time-vesting stock awards was $51.04 and the performance-based stock awards was $51.18.

The fair value of the performance-based shares awarded in 2016 was calculated using a Monte Carlo valuation model, including a weighted average stock price volatility of 19.8%, an expected term of three years, and a weighted average risk-free interest rate of 1.22%.

At September 30, 2016, unrecognized compensation cost related to outstanding non-vested stock awards was $36. The weighted average period over which the expense is expected to be recognized is 2.0 years. The aggregate market value of the shares released on the vesting dates was $26 for the nine months ended September 30, 2016.