RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - NOTIONAL PRINCIPAL OR QUANTITY INFORMATION (Details) € in Millions, ¥ in Millions, £ in Millions, MWh in Millions, MMBbls in Millions, Bcf in Millions, $ in Millions, $ in Millions	Dec. 31, 2021 USD ($) MWh MMBbls Bcf	Dec. 31, 2021 GBP (£) MWh MMBbls Bcf	Dec. 31, 2021 EUR (€) MWh MMBbls Bcf	Dec. 31, 2021 JPY (¥) MWh MMBbls Bcf	Dec. 31, 2021 CAD ($) MWh MMBbls Bcf	Dec. 31, 2020 USD ($) MWh MMBbls Bcf	Dec. 31, 2020 GBP (£) MWh MMBbls Bcf	Dec. 31, 2020 EUR (€) MWh MMBbls Bcf	Dec. 31, 2020 JPY (¥) MWh MMBbls Bcf	Dec. 31, 2020 CAD ($) MWh MMBbls Bcf
Foreign exchange contracts - United States dollar or GBP or Japanese yen forwards - purchase
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional principal	$ 2,508			¥ 72,500
2022 notional principal	0			0
2023 notional principal	0			0
2024 notional principal	0			0
2025 notional principal	0			0
Thereafter notional principal	0			0
Total notional principal	2,508			¥ 72,500		$ 3,522			¥ 72,500
Foreign exchange contracts - United States dollar or GBP forwards - sell
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional principal	9,245	£ 28	€ 104
2022 notional principal	5,596	29	92
2023 notional principal	4,346	30	91
2024 notional principal	3,174	30	86
2025 notional principal	2,574	28	85
Thereafter notional principal	492	32	343
Total notional principal	$ 25,427	£ 177	€ 801			$ 17,859	£ 265	€ 885
Interest rate contracts - short-term borrowings
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional principal					$ 395
2022 notional principal					47
2023 notional principal					35
2024 notional principal					30
2025 notional principal					26
Thereafter notional principal					64
Total notional principal					597					$ 4,635
Interest rate contract - long term debt - Pay Fixed Rate
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional principal					2,363
2022 notional principal					1,784
2023 notional principal					1,132
2024 notional principal					0
2025 notional principal					0
Thereafter notional principal					0
Total notional principal					5,279					5,396
Equity contracts
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional principal					20
2022 notional principal					26
2023 notional principal					21
2024 notional principal					0
2025 notional principal					0
Thereafter notional principal					0
Total notional principal					$ 67					$ 62
Commodity contracts | Natural gas
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional quantity (in bcf, bbl or mbbl) | Bcf	165	165	165	165	165
2022 notional quantity (in bcf, bbl or mbbl) | Bcf	18	18	18	18	18
2023 notional quantity (in bcf, bbl or mbbl) | Bcf	5	5	5	5	5
2024 notional quantity (in bcf, bbl or mbbl) | Bcf	11	11	11	11	11
2025 notional quantity (in bcf, bbl or mbbl) | Bcf	0	0	0	0	0
Thereafter notional quantity (in bcf, bbl or mbbl) | Bcf	0	0	0	0	0
Total notional quantity (in bcf, bbl or mbbl) | Bcf	199	199	199	199	199	173	173	173	173	173
Commodity contracts | Crude
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional quantity (in bcf, bbl or mbbl) | MMBbls	12	12	12	12	12
2022 notional quantity (in bcf, bbl or mbbl) | MMBbls	0	0	0	0	0
2023 notional quantity (in bcf, bbl or mbbl) | MMBbls	0	0	0	0	0
2024 notional quantity (in bcf, bbl or mbbl) | MMBbls	0	0	0	0	0
2025 notional quantity (in bcf, bbl or mbbl) | MMBbls	0	0	0	0	0
Thereafter notional quantity (in bcf, bbl or mbbl) | MMBbls	0	0	0	0	0
Total notional quantity (in bcf, bbl or mbbl) | MMBbls	12	12	12	12	12	15	15	15	15	15
Commodity contracts | Power | Net sell
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS
2021 notional quantity (MW/H) | MWh	(43)	(43)	(43)	(43)	(43)
2022 notional quantity (MW/H) | MWh	(43)	(43)	(43)	(43)	(43)
2023 notional quantity (MW/H) | MWh	(43)	(43)	(43)	(43)	(43)
2024 notional quantity (MW/H) | MWh	(43)	(43)	(43)	(43)	(43)
2025 notional quantity (MW/H) | MWh	0	0	0	0	0
Thereafter notional quantity (MW/H) | MWh	0	0	0	0	0
Total notional quantity (MW/H) | MWh	(43)	(43)	(43)	(43)	(43)	(35)	(35)	(35)	(35)	(35)