STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Changes in Outstanding Stock Options

Stock options and stock appreciation rights outstanding at December 31, 2019 and changes during the year ended December 31, 2019 is as follows:

	December 31, 2019
	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
	(Shares and intrinsic value in thousands)
Outstanding at January 1, 2019	33,158		$	3.42
Granted	—		—
Exercised	(9,009	)	2.06
Forfeited	(158	)	8.16
Expired	(7	)	23.21
Outstanding at December 31, 2019	23,984		$	3.89	6.4	$	114,687
Exercisable	15,208		$	3.52	6.1	$	78,854

Schedule of Information for Stock Options Outstanding and Exercisable

The following table summarizes the information about stock options and stock appreciation rights outstanding and exercisable at December 31, 2019:

	Awards Outstanding				Awards Exercisable
Range of Exercise Prices	Outstanding at December 31, 2019	Weighted Average Remaining Contractual Life in Years	Weighted Average Exercise Price		Exercisable at December 31, 2019	Weighted Average Remaining Contractual Life in Years	Weighted Average Exercise Price
	(Shares in thousands)
$0.01 to $3.00	9,562	5.5	$	1.84	7,904	5.3	$	1.67
$3.01 to $6.00	12,997	7.1	4.53		6,347	7.1	4.53
$6.01 to $9.00	149	5.1	7.93		141	5	7.89
$9.01 to $12.00	771	7.3	10.64		436	6.8	10.51
$12.01 to $15.00	369	6.5	12.94		244	5.9	13.04
$15.01 to $18.00	—	—	—		—	—	—
$18.01 to $21.00	115	3.2	19.88		115	3.2	19.88
$21.01 to $24.00	21	3.6	22.02		21	3.6	22.02
	23,984	6.4	$	3.89	15,208	6.1	$	3.52

Schedule of Weighted Average Assumptions

The following are the weighted average assumptions used in the Black-Scholes option pricing model:

	Year Ended
	December 31, 2017
Expected volatility	50	%
Risk-free interest rate	2.0	%
Expected term	5.5 years
Dividend yield	—	%

Schedule of Outstanding Unvested RSUs

	RSUs				MSUs				PSUs
	Number of Shares		Weighted Average  Grant Date  Fair Value		Number of Shares (a)		Weighted Average Grant Date Fair Value		Number of Shares (a)		Weighted Average Grant Date Fair Value
	(Shares in thousands)
Unvested at January 1, 2019	4,611		$	16.77	—		$	—	—		$	—
Granted	2,666		13.16		3,979		3.67		923		15.93
Vested	(1,259	)	15.39		(472	)	4.03		—		—
Forfeited	(358	)	9.14		(4	)	4.03		(42	)	16.89
Unvested at December 31, 2019	5,660		$	15.29	3,503		$	3.62	881		$	15.89