PENSION AND POSTRETIREMENT BENEFIT PLANS (Tables)

12 Months Ended

Dec. 31, 2019

Retirement Benefits [Abstract]

Components of pension and postretirement amounts recognized in the balance sheets

	As of December 31,
	2019			2018			2019			2018
	Pension Benefits						Postretirement Benefits
Amounts recognized in the balance sheet:	(in millions)
Accrued liabilities	$	—		$	—		$	(3	)	$	(2	)
Other long-term liabilities	(18		)	(14		)	(113		)	(82		)
	$	(18	)	$	(14	)	$	(116	)	$	(84	)
Amounts recognized in accumulated other comprehensive (loss) income:	$	(6	)	$	(10	)	$	(17	)	$	4

Funding status of plans

	As of December 31,
	2019			2018			2019			2018
	Pension Benefits						Postretirement Benefits
Amounts recognized in the balance sheet:	(in millions)
Accrued liabilities	$	—		$	—		$	(3	)	$	(2	)
Other long-term liabilities	(18		)	(14		)	(113		)	(82		)
	$	(18	)	$	(14	)	$	(116	)	$	(84	)
Amounts recognized in accumulated other comprehensive (loss) income:	$	(6	)	$	(10	)	$	(17	)	$	4

	As of December 31,
	2019			2018			2019			2018
	Pension Benefits						Postretirement Benefits
Changes in the benefit obligation:	(in millions)
Benefit obligation—beginning of year	$	56		$	65		$	84		$	93
Service cost—benefits earned during the period	1			1			4			4
Interest cost on projected benefit obligation	2			2			4			4
Actuarial loss (gain)	11			(2		)	19			(14		)
Cost of special termination benefits	—			—			6			—
Curtailment	—			—			2			—
Benefits paid	(25		)	(10		)	(3		)	(3		)
Benefit obligation—end of year	$	45		$	56		$	116		$	84
Changes in plan assets:
Fair value of plan assets—beginning of year	$	42		$	46		$	—		$	—
Actual gain (loss) on plan assets	7			(2		)	—			—
Employer contributions	3			8			3			3
Benefits paid	(25		)	(10		)	(3		)	(3		)
Fair value of plan assets—end of year	$	27		$	42		$	—		$	—
Unfunded status	$	(18	)	$	(14	)	$	(116	)	$	(84	)

Schedule of defined benefit pension plans with accumulated benefit obligations in excess of plan assets

	2019		2018
	(in millions)
Projected Benefit Obligation	$	45	$	56
Accumulated Benefit Obligation	$	41	$	53
Fair Value of Plan Assets	$	27	$	42

Schedule of Net Benefit Costs [Table Text Block]

	For the years ended December 31,
	2019			2018			2017			2019		2018		2017
	Pension Benefits									Postretirement Benefits
Net periodic benefit costs:	(in millions)
Service cost—benefits earned during the period	$	1		$	1		$	1		$	4	$	4	$	3
Interest cost on projected benefit obligation	2			2			2			4		4		4
Expected return on plan assets	(2		)	(3		)	(3		)	—		—		—
Cost of special termination benefits	—			—			—			6		—		—
Amortization of net actuarial loss	1			2			2			—		—		—
Settlement costs	9			4			5			—		—		—
Net periodic benefit cost	$	11		$	6		$	7		$	14	$	8	$	7

Amounts recognized in other comprehensive income (expense)

	For the years ended December 31,
	2019			2018			2017			2019		2018		2017
	Pension Benefits									Postretirement Benefits
Net periodic benefit costs:	(in millions)
Service cost—benefits earned during the period	$	1		$	1		$	1		$	4	$	4	$	3
Interest cost on projected benefit obligation	2			2			2			4		4		4
Expected return on plan assets	(2		)	(3		)	(3		)	—		—		—
Cost of special termination benefits	—			—			—			6		—		—
Amortization of net actuarial loss	1			2			2			—		—		—
Settlement costs	9			4			5			—		—		—
Net periodic benefit cost	$	11		$	6		$	7		$	14	$	8	$	7

	For the years ended December 31,
	2019			2018			2017			2019			2018		2017
Amounts recognized in other comprehensive income (loss):	Pension Benefits									Postretirement Benefits
	(in millions)
Net actuarial (loss) gain	$	(6	)	$	(3	)	$	(4	)	$	(19	)	$	14	$	(12	)
Settlement costs	9			4			5			(2		)	—		—
Amortization of net actuarial gain/loss	1			2			2			—			—		—
Total recognized in other comprehensive income (loss)	$	4		$	3		$	3		$	(21	)	$	14	$	(12	)

Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost

	For the years ended December 31,
	2019		2018		2019		2018
Benefit Obligation Assumptions:	Pension Benefits				Postretirement Benefits
Discount rate	3.16	%	4.22	%	3.48	%	4.57	%
Rate of compensation increase	4.00	%	4.00	%	—		—
Net Periodic Benefit Cost Assumptions:
Discount rate	4.22	%	3.53	%	4.57	%	3.87	%
Assumed long-term rate of return on assets	6.50	%	6.50	%	—		—
Rate of compensation increase	4.00	%	4.00	%	—		—

Fair values of pension plan assets by asset category

	Fair Value Measurements at December 31, 2019
	Level 1		Level 2		Level 3		Total
Asset Class:	(in millions)
Cash equivalents	$	—	$	—	$	—	$	—
Commingled funds:
Fixed income	—		3		—		3
U.S. equity	—		4		—		4
International equity	—		2		—		2
Mutual funds:
Bond funds	5		—		—		5
Blend funds	2		—		—		2
Value funds	2		—		—		2
Growth funds	2		—		—		2
Guaranteed deposit account	—		—		7		7
Total pension plan assets	$	11	$	9	$	7	$	27

	Fair Value Measurements at December 31, 2018
	Level 1		Level 2		Level 3		Total
Asset Class:	(in millions)
Cash equivalents	$	1	$	—	$	—	$	1
Commingled funds:
Fixed income	—		9		—		9
U.S. equity	—		9		—		9
International equity	—		5		—		5
Mutual funds:
Bond funds	5		—		—		5
Blend funds	2		—		—		2
Value funds	2		—		—		2
Growth funds	2		—		—		2
Guaranteed deposit account	—		—		7		7
Total pension plan assets	$	12	$	23	$	7	$	42

Estimated future undiscounted benefit payments, which reflect expected future service, as appropriate

	Pension Benefits		Postretirement Benefits
For the years ended December 31,	(in millions)
2020	$	10	$	4
2021	$	4	$	5
2022	$	2	$	5
2023	$	3	$	5
2024	$	2	$	5
2025 - 2029	$	11	$	27