RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Notional Principal or Quantity Information (Details) - Mar. 31, 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	$ 1,215			¥ 84,800
Foreign exchange contracts - forwards - purchase | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024	715
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	23,533	£ 115	€ 696
Foreign exchange contracts - forwards - sell | United States dollar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024	5,368
2025	5,327
2026	4,697
2027	4,091
2028	3,162
Thereafter	$ 888
Foreign exchange contracts - forwards - sell | GBP
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 | £		25
2025 | £		30
2026 | £		28
2027 | £		32
2028 | £		0
Thereafter | £		£ 0
Foreign exchange contracts - forwards - sell | Euro
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 | €			106
2025 | €			126
2026 | €			121
2027 | €			81
2028 | €			67
Thereafter | €			€ 195
Interest rate contracts - short-term borrowings
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					$ 4,726
2025					1,904
2026					1,130
2027					75
2028					25
Thereafter					13
Derivative Notional Amount Outstanding					7,873
Interest rate contracts - short-term debt receive
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					708
2025					947
2026					179
2027					0
2028					0
Thereafter					0
Derivative Notional Amount Outstanding					1,834
Interest rate contracts - long-term debt pay fixed rate
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					5,436
2025					588
2026					0
2027					0
2028					0
Thereafter					0
Derivative Notional Amount Outstanding					6,024
Interest Rate Contract, Costless Collar
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024					0
2025					1,382
2026					53
2027					0
2028					0
Thereafter					0
Derivative Notional Amount Outstanding					$ 1,435
Commodity contracts | Natural gas
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (bcf / mmbbls) | Bcf	50,000,000	50,000,000	50,000,000	50,000,000	50,000,000
2025 (bcf / mmbbls) | Bcf	28,000,000	28,000,000	28,000,000	28,000,000	28,000,000
2026 (bcf / mmbbls) | Bcf	18,000,000	18,000,000	18,000,000	18,000,000	18,000,000
2027 (bcf / mmbbls) | Bcf	12,000,000	12,000,000	12,000,000	12,000,000	12,000,000
2028 (bcf / mmbbls) | Bcf	0	0	0	0	0
Thereafter (bcf / mmbbls) | Bcf	0	0	0	0	0
Derivative Nonmonetary Notional Amount Outstanding | Bcf	108,000,000	108,000,000	108,000,000	108,000,000	108,000,000
Commodity contracts | Crude
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (bcf / mmbbls) | MMBbls	13,000,000	13,000,000	13,000,000	13,000,000	13,000,000
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
2028 (bcf / mmbbls) | MMBbls	0	0	0	0	0
Thereafter (bcf / mmbbls) | MMBbls	0	0	0	0	0
Derivative Nonmonetary Notional Amount Outstanding | MMBbls	13,000,000	13,000,000	13,000,000	13,000,000	13,000,000
Net sell | Commodity contracts | Power
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2024 (MWH) | MWh	51,000,000	51,000,000	51,000,000	51,000,000	51,000,000
2025 (MWH) | MWh	(18,000,000)	(18,000,000)	(18,000,000)	(18,000,000)	(18,000,000)
2026 (MW/H) | MWh	(35,000,000)	(35,000,000)	(35,000,000)	(35,000,000)	(35,000,000)
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	(25,000,000)	(25,000,000)	(25,000,000)	(25,000,000)	(25,000,000)