STOCK-BASED COMPENSATION

Total stock-based compensation cost charged to selling, general and administrative expenses for the three and nine months ended September 30, 2016 was $3.0 million and $7.7 million, respectively. Total stock-based compensation cost charged to selling, general and administrative expenses for the three and nine months ended September 30, 2015 was $0.5 million and $6.6 million, respectively. During the three months ended September 30, 2015, the Company reversed $1.4 million of stock based compensation for performance stock awards originally issued in 2014 as management determined it was no longer probable that a portion of the performance targets would be earned. The total income tax benefit recognized in the consolidated statements of operations from stock-based compensation was $0.9 million and $2.3 million for the three and nine months ended September 30, 2016, respectively. The total income tax benefit recognized in the consolidated statements of operations from stock-based compensation was $0.1 million and $1.8 million for the three and nine months ended September 30, 2015, respectively.

Restricted Stock Awards

The following information relates to restricted stock awards that have been granted to employees and directors under the Company's equity incentive plans (the "Plans"). The restricted stock awards are not transferable until vested and the restrictions generally lapse upon the achievement of continued employment over a three-to-five-year period or service as a director until the following annual meeting of shareholders. The fair value of each restricted stock grant is based on the closing price of the Company's common stock on the date of grant and is amortized to expense over its vesting period.

The following table summarizes information about restricted stock awards for the nine months ended September 30, 2016:



Restricted Stock	Number of Shares		Weighted Average Grant-Date Fair Value
Balance at January 1, 2016	362,618		$	55.79
Granted	335,992		$	50.87
Vested	(168,565	)	$	54.06
Forfeited	(46,298	)	$	53.04
Balance at September 30, 2016	483,747		$	53.23

As of September 30, 2016, there was $17.2 million of total unrecognized compensation cost arising from restricted stock awards under the Company's Plans. This cost is expected to be recognized over a weighted average period of 3.0 years. The total fair value of restricted stock vested during the three and nine months ended September 30, 2016 was $1.8 million and $7.9 million, respectively. The total fair value of restricted stock vested during the three and nine months ended September 30, 2015 was $0.6 million and $6.8 million, respectively.

Performance Stock Awards

The following information relates to performance stock awards that have been granted to employees under the Company's Plans. Performance stock awards are subject to performance criteria established by the compensation committee of the Company's board of directors prior to or at the date of grant. The vesting of the performance stock awards is based on achieving such targets typically based on revenue, Adjusted EBITDA margin, return on invested capital percentage and Total Recordable Incident Rate. In addition, performance stock awards include continued service conditions. The fair value of each performance stock award is based on the closing price of the Company's common stock on the date of grant and is amortized to expense over the service period if achievement of performance measures is considered probable.

The following table summarizes information about performance stock awards for the nine months ended September 30, 2016:



Performance Stock	Number of Shares		Weighted Average Grant-Date Fair Value
Balance at January 1, 2016	187,274		$	57.13
Granted	207,624		$	54.21
Vested	(8,420	)	$	61.90
Forfeited	(33,469	)	$	55.96
Balance at September 30, 2016	353,009		$	55.39

As of September 30, 2016, there was $0.2 million of total unrecognized compensation cost arising from unvested performance stock awards deemed probable of vesting under the Company's Plans. No performance awards vested during the three months ended September 30, 2016. The total fair value of performance awards vested during the nine months ended September 30, 2016 was $0.4 million. The total fair value of performance awards vested during the nine months ended September 30, 2015 was $0.3 million. No performance awards vested during the three months ended September 30, 2015.

Common Stock Repurchases

On March 13, 2015, the Company's board of directors authorized the repurchase of up to $300 million of the Company's common stock. During the three and nine months ended September 30, 2016, the Company repurchased and retired a total of 0.1 million shares and 0.3 million shares, respectively, of the Company's common stock for a total cost of $6.2 million and $16.3 million, respectively. During the three and nine months ended September 30, 2015, the Company repurchased and retired a total of 0.8 million shares and 1.3 million shares, respectively, of the Company's common stock for a total cost of $37.6 million and $69.8 million, respectively. Through September 30, 2016, the Company has repurchased and retired a total of 3.7 million shares of the Company's common stock for a total cost of $194.0 million under this program. As of September 30, 2016, an additional $106.0 million remains available for repurchase of shares under the current authorized program.