COMMITMENTS AND CONTINGENCIES - LESSOR INFORMATION (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessor, Lease, Description [Line Items]
Property, plant and equipment	$ 49,329	$ 46,615
Accumulated depreciation	(12,877)	(12,176)
Property, plant and equipment, net	36,452	34,439
2020	201
2021	193
2022	193
2023	193
2024	193
Thereafter	2,402
Total undiscounted cash flows	3,375
Fixed lease payments	200	194	$ 193
Variable lease payments	6	72	44
Total revenues from operating leases	206	266	237
Depreciation expense	1,551	1,470	1,368
Assets Leased to Others [Member]
Lessor, Lease, Description [Line Items]
Assets held for sale	0	172
Property, plant and equipment	1,038	1,022
Accumulated depreciation	(179)	(142)
Property, plant and equipment, net	859	880
Depreciation expense	$ 38	$ 72	$ 57