STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of restricted stock awards

The following table summarizes information about restricted stock awards for the six months ended June 30, 2017:

Restricted Stock	Number of Shares		Weighted Average Grant-Date Fair Value
Balance at January 1, 2017	510,041		$	52.65
Granted	161,250		$	56.15
Vested	(105,064	)	$	54.17
Forfeited	(34,374	)	$	51.50
Balance at June 30, 2017	531,853		$	53.49

Summary of performance stock awards

The following table summarizes information about performance stock awards for the six months ended June 30, 2017:

Performance Stock	Number of Shares		Weighted Average Grant-Date Fair Value
Balance at January 1, 2017	220,882		$	54.69
Granted	588		$	54.44
Vested	(25,168	)	$	54.84
Forfeited	(16,187	)	$	56.24
Balance at June 30, 2017	180,115		$	54.70