LEASES (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Expense	$ 134	$ 398
Finance Lease, Right-of-Use Asset, Amortization	14	31
Finance Lease, Interest Expense	6	19
Finance Lease, Cost	20	50
Short-term Lease, Cost	51	151
Variable Lease, Cost	89	196
Sublease Income	0	(2)
Lease, Cost	294	793
Operating Lease, Payments		398
Finance Lease, Interest Payment on Liability		19
Finance Lease, Principal Payments		16
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		2,482
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability		99
Operating Lease, Right-of-Use Asset	2,130	2,130		$ 0
Property, Plant and Equipment, Gross	54,890	54,890		53,984
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(33,887)	(33,887)		(32,566)
Total Lease Assets	2,473	2,473
Operating Lease, Liability, Current	418	418		0
Finance Lease, Liability, Current	38	38
Operating Lease, Liability, Noncurrent	1,735	1,735		0
Finance Lease, Liability, Noncurrent	387	387
Total Lease Liabilities	$ 2,578	$ 2,578
Operating Lease, Weighted Average Remaining Lease Term	8 years	8 years
Finance Lease, Weighted Average Remaining Lease Term	12 years 2 months 12 days	12 years 2 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	4.17%	4.17%
Finance Lease, Weighted Average Discount Rate, Percent	6.16%	6.16%
Lessee, Operating Lease, Liability, Payments, Due 2019	$ 132	$ 132		366
Finance Lease, Liability, Payments, Due 2019	22	22
Lessee, Operating Lease, Liability, Payments, Due 2020	472	472		329
Finance Lease, Liability, Payments, Due 2020	62	62
Lessee, Operating Lease, Liability, Payments, Due 2021	391	391		296
Finance Lease, Liability, Payments, Due 2021	57	57
Lessee, Operating Lease, Liability, Payments, Due 2022	329	329		269
Finance Lease, Liability, Payments, Due 2022	51	51
Lessee, Operating Lease, Liability, Payments, Due 2023	265	265		227
Finance Lease, Liability, Payments, Due 2023	78	78
Lessee, Operating Lease, Liability, Payments, Due 2024 and thereafter	990	990		855
Finance Lease, Liability, Payments, Due 2024 and thereafter	348	348
Lessee, Operating Lease, Liability, Payments, Due	2,579	2,579		2,342
Finance Lease, Liability, Payment, Due	618	618
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	426	426
Finance Lease, Liability, Undiscounted Excess Amount	193	193
Operating Lease, Liability	2,153	2,153
Finance lease obligations 1	425	425
Lessor, Operating Lease, Lease Not yet Commenced, Assumption and Judgment, Value of Underlying Asset, Amount	88	$ 88
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract		20 years
Residual Value Guarantees [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	763	$ 763		885
Guarantor Obligations, Current Carrying Value	0	0		$ 130
Finance Leases [Member]
Property, Plant and Equipment, Gross	501	501
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ (158)	$ (158)
Accounting Standards Update 2016-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 2,300
Minimum [Member]
Lessee, Operating and Finance Leases, Remaining Lease Term		1 year
Maximum [Member]
Lessee, Operating and Finance Leases, Remaining Lease Term		50 years