LEASES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Cost	$ 532
Amortization of right-of-use assets - finance	39
Interest on lease liabilities - finance	25
Total finance lease cost	64
Short-term lease cost	204
Variable lease cost	198
Sublease income	(4)
Total lease cost	994
Operating cash flows for operating leases	544
Operating cash flows for finance leases	25
Financing cash flows for finance leases	34
Operating leases 1	2,476
Finance leases	89
Operating lease right-of-use assets	2,072		$ 0
Property	54,910		53,984
Less accumulated depreciation	33,914		32,566
Total Lease Assets	2,391
Operating lease liabilities - current	421		0
Finance Lease, Liability, Current	32
Operating lease liabilities - noncurrent	1,739		0
Finance Lease, Liability, Noncurrent	363
Total Lease Liabilities	$ 2,555
Weighted-average remaining lease term - Operating leases	8 years
Weighted-average remaining lease term - Finance leases	12 years 3 months 18 days
Weighted-average discount rate - Operating leases	4.09%
Weighted-average discount rate - Finance leases	6.28%
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 492		366
Finance Lease, Liability, Payments, Remainder of Fiscal Year	60
Lessee, Operating Lease, Liability, Payments, Due Year Two	422		329
Finance Lease, Liability, Payments, Due Year Two	55
Lessee, Operating Lease, Liability, Payments, Due Year Three	355		296
Finance Lease, Liability, Payments, Due Year Three	50
Lessee, Operating Lease, Liability, Payments, Due Year Four	285		269
Finance Lease, Liability, Payments, Due Year Four	84
Lessee, Operating Lease, Liability, Payments, Due Year Five	219		227
Finance Lease, Liability, Payments, Due Year Five	29
Lessee, Operating Lease, Liability, Payments, Due after Year Five	803		855
Finance Lease, Liability, Payments, Due after Year Five	310
Lessee, Operating Lease, Liability, Payments, Due	2,576		2,342
Finance Lease, Liability, Payment, Due	588
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	416
Finance Lease, Liability, Undiscounted Excess Amount	193
Lease liability	2,160
Finance Lease, Liability	395
Lessee, Additional Leases Not yet Commenced, Assumptions and Judgment, Amount	$ 71
Lessee, Additional Leases Not yet Commenced, Term of Contract	20 years
Residual Value Guarantees
Maximum future payments	$ 792		885
Recorded liability	0		$ 130
Accounting Standards Update 2016-02
Operating lease right-of-use assets		$ 2,300
Cumulative Effect of New Accounting Principle in Period of Adoption	32	2,300
Lease liability		$ 2,300
Finance Leases [Member]
Property	486
Less accumulated depreciation	$ 167
Maximum
Lessee, Operating and Finance Leases, Remaining Lease Term	50 years