LEASES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating Lease, Cost	$ 122	$ 134	$ 362	$ 398
Finance Lease, Right-of-Use Asset, Amortization	16	14	42	31
Finance Lease, Interest Expense	7	6	19	19
Finance Lease, Cost	23	20	61	50
Short-term Lease, Cost	54	51	161	151
Variable Lease, Cost	45	89	157	196
Sublease Income	(2)	0	(4)	(2)
Lease, Cost	242	$ 294	737	793
Operating Lease, Payments			357	398
Finance Lease, Interest Payment on Liability			19	19
Finance Lease, Principal Payments			34	$ 16
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			68		$ 2,476
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability			142		89
Operating lease right-of-use assets	1,809		1,809		2,072
Property	56,132		56,132		54,910
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(35,719)		(35,719)		(33,914)
Total Lease Assets	2,231		2,231		2,391
Operating lease liabilities - current	405		405		421
Finance Lease, Liability, Current	49		49		32
Operating lease liabilities - noncurrent	1,488		1,488		1,739
Finance Lease, Liability, Noncurrent	447		447		363
Total Lease Liabilities	$ 2,389		$ 2,389		$ 2,555
Operating Lease, Weighted Average Remaining Lease Term	7 years 7 months 6 days		7 years 7 months 6 days		8 years
Finance Lease, Weighted Average Remaining Lease Term	11 years 8 months 12 days		11 years 8 months 12 days		12 years 3 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	3.96%		3.96%		4.09%
Finance Lease, Weighted Average Discount Rate, Percent	5.56%		5.56%		6.28%
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 127		$ 127
Finance Lease, Liability, Payments, Remainder of Fiscal Year	25		25
Lessee, Operating Lease, Liability, to be Paid, Year One	443		443
Finance Lease, Liability, to be Paid, Year One	72		72
Lessee, Operating Lease, Liability, Payments, Due Year Two	359		359
Finance Lease, Liability, Payments, Due Year Two	68		68
Lessee, Operating Lease, Liability, Payments, Due Year Three	288		288
Finance Lease, Liability, Payments, Due Year Three	93		93
Lessee, Operating Lease, Liability, Payments, Due Year Four	222		222
Finance Lease, Liability, to be Paid, Year Four	40		40
Lessee, Operating Lease, Liability, Payments, Due Year Five	806		806
Finance Lease, Liability, Payments, Due Year Five	389		389
Lessee, Operating Lease, Liability, Payments, Due	2,245		2,245
Finance Lease, Liability, Payment, Due	687		687
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	352		352
Finance Lease, Liability, Undiscounted Excess Amount	191		191
Operating Lease, Liability	1,893		1,893
Finance lease obligations 2	496		496
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount	56		$ 56
Lessee, Additional Leases Not yet Commenced, Term of Contract			20 years
Residual Value Guarantees [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	807		$ 807		$ 792
Guarantor Obligations, Current Carrying Value	24		24		0
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	807		807		792
Guarantor Obligations, Current Carrying Value	24		24		0
Finance Leases [Member]
Property	620		620		486
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ (198)		$ (198)		(167)
Accounting Standards Update 2016-02 [Member]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability					$ 2,300