LEASES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Lease, Cost	$ 120	$ 139	$ 240	$ 264
Finance Lease, Right-of-Use Asset, Amortization	13	11	26	17
Finance Lease, Interest Expense	6	7	12	13
Finance Lease, Cost	19	18	38	30
Short-term Lease, Cost	53	50	107	100
Variable Lease, Cost	48	63	112	107
Sublease Income	(1)	(1)	(2)	(2)
Lease, Cost	239	$ 269	495	499
Operating Lease, Payments			240	269
Finance Lease, Interest Payment on Liability			12	13
Finance Lease, Principal Payments			21	$ 9
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			49		$ 2,476
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability			43		89
Operating lease right-of-use assets	1,881		1,881		2,072
Property	55,459		55,459		54,910
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(34,841)		(34,841)		(33,914)
Total Lease Assets	2,224		2,224		2,391
Operating lease liabilities - current	388		388		421
Finance Lease, Liability, Current	50		50		32
Operating lease liabilities - noncurrent	1,562		1,562		1,739
Finance Lease, Liability, Noncurrent	365		365		363
Total Lease Liabilities	$ 2,365		$ 2,365		$ 2,555
Operating Lease, Weighted Average Remaining Lease Term	7 years 10 months 24 days		7 years 10 months 24 days		8 years
Finance Lease, Weighted Average Remaining Lease Term	11 years 2 months 12 days		11 years 2 months 12 days		12 years 3 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	4.16%		4.16%		4.09%
Finance Lease, Weighted Average Discount Rate, Percent	6.02%		6.02%		6.28%
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 232		$ 232
Finance Lease, Liability, Payments, Remainder of Fiscal Year	40		40
Lessee, Operating Lease, Liability, Payments, Due Year Two	419		419
Finance Lease, Liability, Payments, Due Year Two	66		66
Lessee, Operating Lease, Liability, Payments, Due Year Three	356		356
Finance Lease, Liability, Payments, Due Year Three	59		59
Lessee, Operating Lease, Liability, Payments, Due Year Four	286		286
Finance Lease, Liability, Payments, Due Year Four	84		84
Lessee, Operating Lease, Liability, Payments, Due Year Five	220		220
Finance Lease, Liability, Payments, Due Year Five	31		31
Lessee, Operating Lease, Liability, Payments, Due after Year Five	808		808
Finance Lease, Liability, Payments, Due after Year Five	310		310
Lessee, Operating Lease, Liability, Payments, Due	2,321		2,321
Finance Lease, Liability, Payment, Due	590		590
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	371		371
Finance Lease, Liability, Undiscounted Excess Amount	175		175
Operating Lease, Liability	1,950		1,950
Finance lease obligations 1	415		415
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount	64		$ 64
Lessee, Additional Leases Not yet Commenced, Term of Contract			20 years
Residual Value Guarantees [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	793		$ 793		$ 792
Guarantor Obligations, Current Carrying Value	0		0		0
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	793		793		792
Guarantor Obligations, Current Carrying Value	0		0		0
Finance Leases [Member]
Property	536		536		486
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ (193)		$ (193)		(167)
Accounting Standards Update 2016-02 [Member]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability					$ 2,300