LEASES (Details) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
	Jan. 01, 2019	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Operating Lease Cost		$ 7	$ 18
Short-term Lease Cost		6	20
Variable Lease, Cost		1	3
Finance Lease, Right-of-Use Asset, Amortization		0	1
Lease, Cost		14	42
Operating Lease, Payments			18
Finance Lease, Principal Payments			1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 99		105
Operating lease right-of-use assets		93	93	$ 0
Finance Lease, Right-of-Use Asset		12	12
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		6,040	6,040	5,982
Total Lease Assets		99	99
Operating lease liabilities - current		18	18	0
Finance Lease, Liability, Current		1	1
Operating lease liabilities - noncurrent		75	75	0
Finance Lease, Liability, Noncurrent		5	5
Total Lease Liabilities		$ 99	$ 99
Operating Lease, Weighted Average Remaining Lease Term		6 years 4 months 24 days	6 years 4 months 24 days
Finance Lease, Weighted Average Remaining Lease Term		4 years 9 months 18 days	4 years 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent		4.23%	4.23%
Finance Lease, Weighted Average Discount Rate, Percent		4.22%	4.22%
Lessee, Operating Lease, Liability, Payments, Remainder of 2019		$ 5	$ 5
Finance Lease, Liability, Payments, Due 2019		0	0
Lessee, Operating Lease, Liability, Payments, Due 2020		20	20
Finance Lease, Liability, Payments, Due 2020		2	2
Lessee, Operating Lease, Liability, Payments, Due 2021		16	16
Finance Lease, Liability, Payments, Due 2021		2	2
Lessee, Operating Lease, Liability, Payments, Due 2022		15	15
Finance Lease, Liability, Payments, Due 2022		1	1
Lessee, Operating Lease, Liability, Payments, Due 2023		13	13
Finance Lease, Liability, Payments, Due 2023		1	1
Lessee, Operating Lease, Liability, Payments, Due 2024 and thereafter		37	37
Finance Lease, Liability, Payments, Due 2024 and thereafter		1	1
Lessee, Operating Lease, Liability, Payments, Due		106	106
Finance Lease, Liability, Payment, Due		7	7
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		13	13
Finance Lease, Liability, Undiscounted Excess Amount		1	1
Operating Lease, Liability		93	93
Finance Lease, Liability		6	6
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount		$ 15	$ 15
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract		20 years
Lessee, Operating Lease, Liability, Payments, Due 2019				18
Operating Leases, Future Minimum Payments, Due 2020				16
Operating Leases, Future Minimum Payments, Due 2021				14
Operating Leases, Future Minimum Payments, Due 2022				13
Operating Leases, Future Minimum Payments, Due 2023				13
Operating Leases, Future Minimum Payments, Due 2024 and thereafter				37
Operating Leases, Future Minimum Payments Due				$ 111
Minimum [Member]
Lessee, Operating and Finance Leases, Remaining Lease Term			1 year
Maximum [Member]
Lessee, Operating and Finance Leases, Remaining Lease Term			10 years
finance leases [Member]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		$ 6	$ 6