RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Notional Principal or Quantity Information (Details) - Sep. 30, 2023 € in Millions, ¥ in Millions, £ in Millions, $ in Millions, $ in Millions	USD ($) MWh MMBbls Bcf	GBP (£) MWh MMBbls Bcf	EUR (€) MWh MMBbls Bcf	JPY (¥) MWh MMBbls Bcf	CAD ($) MWh MMBbls Bcf
Foreign exchange contracts - forwards - purchase
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
Derivative Notional Amount Outstanding	$ 1,614			¥ 84,800
Foreign exchange contracts - forwards - purchase | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023	114
2024	1,000
2025	500
2026	0
2027	0
Thereafter	0
Foreign exchange contracts - forwards - purchase | Japanese yen
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 | ¥				0
2024 | ¥				0
2025 | ¥				84,800
2026 | ¥				0
2027 | ¥				0
Thereafter | ¥				¥ 0
Foreign exchange contracts - forwards - sell
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
Derivative Notional Amount Outstanding	22,846	£ 127	€ 632
Foreign exchange contracts - forwards - sell | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023	1,593
2024	5,440
2025	4,955
2026	4,325
2027	3,647
Thereafter	$ 2,886
Foreign exchange contracts - forwards - sell | GBP
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 | £		7
2024 | £		30
2025 | £		30
2026 | £		28
2027 | £		32
Thereafter | £		£ 0
Foreign exchange contracts - forwards - sell | Euro
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 | €			27
2024 | €			91
2025 | €			86
2026 | €			85
2027 | €			81
Thereafter | €			€ 262
Interest rate contracts - short-term borrowings
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023					$ 2,656
2024					5,645
2025					1,364
2026					1,097
2027					75
Thereafter					39
Derivative Notional Amount Outstanding					10,876
Interest rate contracts - short-term debt receive
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023					229
2024					946
2025					946
2026					179
2027					0
Thereafter					0
Derivative Notional Amount Outstanding					2,300
Interest rate contracts - long-term debt pay fixed rate
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023					1,726
2024					400
2025					588
2026					0
2027					0
Thereafter					0
Derivative Notional Amount Outstanding					2,714
Interest Rate Contract, Costless Collar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023					0
2024					0
2025					394
2026					11
2027					0
Thereafter					0
Derivative Notional Amount Outstanding					405
Equity contracts
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023					0
2024					33
2025					12
2026					0
2027					0
Thereafter					0
Derivative Notional Amount Outstanding					$ 45
Commodity contracts | Natural gas
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 (bcf / mmbbls) | Bcf	6,000,000	6,000,000	6,000,000	6,000,000	6,000,000
2024 (bcf / mmbbls) | Bcf	45,000,000	45,000,000	45,000,000	45,000,000	45,000,000
2025 (bcf / mmbbls) | Bcf	27,000,000	27,000,000	27,000,000	27,000,000	27,000,000
2026 (bcf / mmbbls) | Bcf	9,000,000	9,000,000	9,000,000	9,000,000	9,000,000
2027 (bcf / mmbbls) | Bcf	7,000,000	7,000,000	7,000,000	7,000,000	7,000,000
Thereafter (bcf / mmbbls) | Bcf	0	0	0	0	0
Derivative Nonmonetary Notional Amount Outstanding | Bcf	94,000,000	94,000,000	94,000,000	94,000,000	94,000,000
Commodity contracts | Crude
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 (bcf / mmbbls) | MMBbls	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
2024 (bcf / mmbbls) | MMBbls	(3,000,000)	(3,000,000)	(3,000,000)	(3,000,000)	(3,000,000)
2025 (bcf / mmbbls) | MMBbls	0	0	0	0	0
2026 (bcf / mmbbls) | MMBbls	0	0	0	0	0
2027 (bcf / mmbbls) | MMBbls	0	0	0	0	0
Thereafter (bcf / mmbbls) | MMBbls	0	0	0	0	0
Derivative Nonmonetary Notional Amount Outstanding | MMBbls	2,000,000	2,000,000	2,000,000	2,000,000	2,000,000
Net sell | Commodity contracts | Power
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2023 (MWH) | MWh	61,000,000	61,000,000	61,000,000	61,000,000	61,000,000
2024 (MWH) | MWh	3,000,000	3,000,000	3,000,000	3,000,000	3,000,000
2025 (MW/H) | MWh	(42,000,000)	(42,000,000)	(42,000,000)	(42,000,000)	(42,000,000)
2026 (MWH) | MWh	(49,000,000)	(49,000,000)	(49,000,000)	(49,000,000)	(49,000,000)
2027 (MW/H) | MWh	(53,000,000)	(53,000,000)	(53,000,000)	(53,000,000)	(53,000,000)
Thereafter (MWH) | MWh	(50,000,000)	(50,000,000)	(50,000,000)	(50,000,000)	(50,000,000)
Total (MWH) | MWh	(33,000,000)	(33,000,000)	(33,000,000)	(33,000,000)	(33,000,000)