EMPLOYEE BENEFIT PLANS (Tables)

3 Months Ended

Mar. 31, 2020

Defined Benefit Plan [Abstract]

Summary of stock option activity

The following table summarizes stock option activity during the three months ended March 31, 2020:

	Options		Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Weighted Average Remaining Life
					(In Millions)
Outstanding at December 31, 2019	1,960,992		$	20.24
Exercised	(27,167	)	19.54
Outstanding at March 31, 2020	1,933,825		$	20.25	$	—	5.9 years
Vested and expected to vest at March 31, 2020	1,933,825		$	20.25	$	—	5.9 years
Exercisable at March 31, 2020	1,242,956		$	18.34	$	—	4.9 years

Schedule of assumptions used to determine fair value of stock options

This fair value was calculated based on each grant date, using a Monte Carlo simulation with the following assumptions:

	March 29, 2019	February 27, 2019
Expected volatility	48%	48%
Expected dividend yield	0%	0%
Expected life	6.2 years	6.2 years
Expected forfeiture rate	0%	0%
Risk-free interest rate	2.26%	2.53%

Summary of information about stock options by range of exercise prices

The following table summarizes information about our outstanding stock options at March 31, 2020:

	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	1,201,289	5.0 years	$	18.12	1,201,289	$	18.12
$19.76 to $35.430	732,536	7.3 years	23.75		41,667	24.83
	1,933,825	5.9 years	$	20.25	1,242,956	$	18.34

Summary of restricted stock unit activity

The following table summarizes restricted stock unit activity during the three months ended March 31, 2020: 

	Restricted Stock Units		Weighted Average Grant Date Fair Value Per Unit
Unvested at December 31, 2019	1,463,499		$	25.08
Granted	1,423,953		29.05
Vested	(394,281	)	25.28
Forfeited	(14,587	)	24.80
Unvested at March 31, 2020	2,478,584		$	27.33