LEASES (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 01, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating Lease Cost		$ 5	$ 7	$ 15	$ 18
Short-term Lease Cost		6	6	17	20
Variable Lease, Cost		2	1	6	3
Finance Lease, Right-of-Use Asset, Amortization		0	0	1	1
Lease, Cost		13	$ 14	39	42
Operating cash flows for operating leases				14	18
Finance Lease, Principal Payments				1	$ 1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 99			8		$ 105
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability				1		0
Operating lease right-of-use assets		81		81		89
Finance Lease, Right-of-Use Asset		12		12		12
Less accumulated depreciation		(5,970)		(5,970)		(5,878)
Total Lease Assets		86		86		95
Operating lease liabilities - current		15		15		16
Finance Lease, Liability, Current		1		1		1
Operating lease liabilities - noncurrent		67		67		74
Finance Lease, Liability, Noncurrent		4		4		5
Total Lease Liabilities		$ 87		$ 87		$ 96
Operating Lease, Weighted Average Remaining Lease Term		5 years 10 months 24 days		5 years 10 months 24 days		6 years 3 months 18 days
Finance Lease, Weighted Average Remaining Lease Term		3 years 7 months 6 days		3 years 7 months 6 days		4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent		3.99%		3.99%		4.13%
Finance Lease, Weighted Average Discount Rate, Percent		4.03%		4.03%		4.22%
Lessee, Operating Lease, Liability, Payments, Remainder of 2020		$ 5		$ 5
Finance Lease, Liability, Payments, Due 2020		0		0
Lessee, Operating Lease, Liability, Payments, Due 2021		17		17
Finance Lease, Liability, Payments, Due 2021		2		2
Lessee, Operating Lease, Liability, Payments, Due 2022		16		16
Finance Lease, Liability, Payments, Due 2022		2		2
Lessee, Operating Lease, Liability, Payments, Due 2023		14		14
Finance Lease, Liability, Payments, Due 2023		1		1
Lessee, Operating Lease, Liability, Payments, Due 2024		14		14
Finance Lease, Liability, Payments, Due 2024		1		1
Lessee, Operating Lease, Liability, Payments, Due 2025 and thereafter		27		27
Finance Lease, Liability, Payments, Due 2025 and thereafter		0		0
Lessee, Operating Lease, Liability, Payments, Due		93		93
Finance Lease, Liability, Payment, Due		6		6
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		11		11
Finance Lease, Liability, Undiscounted Excess Amount		1		1
Operating Lease, Liability		82		82
Finance Lease, Liability		5		5
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount		16		$ 16
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract				20 years
finance leases [Member]
Less accumulated depreciation		$ (7)		$ (7)		$ (6)