EMPLOYEE BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2019

Defined Benefit Plan [Abstract]

Summary of stock option activity

The following table summarizes stock option activity during the six months ended June 30, 2019:

	Options		Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Weighted Average Remaining Life
					(In Millions)
Outstanding at December 31, 2018	2,262,743		$	19.12
Granted	230,713		28.28
Exercised	(76,159	)	4.56
Forfeited/Expired	(120,871	)	19.25
Outstanding at June 30, 2019	2,296,426		$	20.52	$	3	6.4 years
Vested and expected to vest at June 30, 2019	2,296,426		$	20.52	$	3	6.4 years
Exercisable at June 30, 2019	684,628		$	19.03	$	2	3.1 years

Schedule of assumptions used to determine fair value of stock options

These fair values were calculated based on each grant date, using a Monte Carlo simulation with the following assumptions:

	February 27, 2019	February 28, 2018
Expected volatility	48%	46%
Expected dividend yield	0%	0%
Expected life	6.2 years	6.2 years
Expected forfeiture rate	0%	0%
Risk-free interest rate	2.53%	2.72%

Summary of information about stock options by range of exercise prices

The following table summarizes information about our outstanding stock options at June 30, 2019:

	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number of Options	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price		Number of Options	Weighted Average Exercise Price
$16.43 to $19.759	1,246,675	5.7 years	18.15		413,960	16.46
$19.76 to $35.430	1,049,751	7.1 years	23.33		270,668	22.94
	2,296,426	6.4 years	$	20.52	684,628	$	19.03

Summary of restricted stock unit activity

The following table summarizes restricted stock unit activity during the six months ended June 30, 2019: 

	Restricted Stock Units		Weighted Average Grant Date Fair Value Per Unit
Unvested at December 31, 2018	1,884,130		$	32.25
Granted	1,235,876		26.20
Vested	(817,820	)	27.55
Forfeited	(298,680	)	25.02
Unvested at June 30, 2019	2,003,506		$	31.52