RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Notional Principal or Quantity Information (Details) - Sep. 30, 2024 € 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	$ 1,195			¥ 84,800
Foreign exchange contracts - forwards - purchase | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024	695
2025	500
2026	0
2027	0
2028	0
Thereafter	0
Foreign exchange contracts - forwards - purchase | Japanese yen
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 | ¥				0
2025 | ¥				84,800
2026 | ¥				0
2027 | ¥				0
2028 | ¥				0
Thereafter | ¥				¥ 0
Foreign exchange contracts - forwards - sell
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
Derivative Notional Amount Outstanding	20,719	£ 99	€ 625
Foreign exchange contracts - forwards - sell | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024	2,014
2025	5,327
2026	4,697
2027	4,271
2028	3,342
Thereafter	$ 1,068
Foreign exchange contracts - forwards - sell | GBP
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 | £		9
2025 | £		30
2026 | £		28
2027 | £		32
2028 | £		0
Thereafter | £		£ 0
Foreign exchange contracts - forwards - sell | Euro
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 | €			35
2025 | €			126
2026 | €			121
2027 | €			81
2028 | €			67
Thereafter | €			€ 195
Interest rate contracts - short-term borrowings
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					$ 1,900
2025					2,236
2026					1,717
2027					675
2028					49
Thereafter					13
Derivative Notional Amount Outstanding					6,590
Interest rate contracts - short-term debt receive
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					18
2025					0
2026					0
2027					0
2028					0
Thereafter					0
Derivative Notional Amount Outstanding					18
Interest rate contracts - long-term debt pay fixed rate
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					300
2025					4,080
2026					723
2027					0
2028					0
Thereafter					0
Derivative Notional Amount Outstanding					5,103
Interest Rate Contract, Costless Collar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					0
2025					1,858
2026					265
2027					104
2028					6
Thereafter					0
Derivative Notional Amount Outstanding					$ 2,233
Commodity contracts | Natural gas
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (bcf / mmbbls) | Bcf	7,000,000	7,000,000	7,000,000	7,000,000	7,000,000
2025 (bcf / mmbbls) | Bcf	101,000,000	101,000,000	101,000,000	101,000,000	101,000,000
2026 (bcf / mmbbls) | Bcf	60,000,000	60,000,000	60,000,000	60,000,000	60,000,000
2027 (bcf / mmbbls) | Bcf	28,000,000	28,000,000	28,000,000	28,000,000	28,000,000
2028 (bcf / mmbbls) | Bcf	9,000,000	9,000,000	9,000,000	9,000,000	9,000,000
Thereafter (bcf / mmbbls) | Bcf	7,000,000	7,000,000	7,000,000	7,000,000	7,000,000
Derivative Nonmonetary Notional Amount Outstanding | Bcf	212,000,000	212,000,000	212,000,000	212,000,000	212,000,000
Net purchase | Commodity contracts | Crude
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2025 (bcf / mmbbls) | MMBbls	22,000,000	22,000,000	22,000,000	22,000,000	22,000,000
2026 (bcf / mmbbls) | MMBbls	19,000,000	19,000,000	19,000,000	19,000,000	19,000,000
2027 (bcf / mmbbls) | MMBbls	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000
2028 (bcf / mmbbls) | MMBbls	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000
Thereafter (bcf / mmbbls) | MMBbls	2,000,000	2,000,000	2,000,000	2,000,000	2,000,000
Derivative Nonmonetary Notional Amount Outstanding | MMBbls	36,000,000	36,000,000	36,000,000	36,000,000	36,000,000
Net purchase | Commodity contracts | Power
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (MWH) | MWh	151,000,000	151,000,000	151,000,000	151,000,000	151,000,000
2025 (MWH) | MWh	31,000,000	31,000,000	31,000,000	31,000,000	31,000,000
Net sell | Commodity contracts | Crude
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (bcf / mmbbls) | MMBbls	9,000,000	9,000,000	9,000,000	9,000,000	9,000,000
Net sell | Commodity contracts | Power
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2026 (MW/H) | MWh	26,000,000	26,000,000	26,000,000	26,000,000	26,000,000
2027 (MWH) | MWh	(51,000,000)	(51,000,000)	(51,000,000)	(51,000,000)	(51,000,000)
2028 (MW/H) | MWh	(49,000,000)	(49,000,000)	(49,000,000)	(49,000,000)	(49,000,000)
Thereafter (MWH) | MWh	(30,000,000)	(30,000,000)	(30,000,000)	(30,000,000)	(30,000,000)
Total (MWH) | MWh	(7,000,000)	(7,000,000)	(7,000,000)	(7,000,000)	(7,000,000)