COMMITMENTS AND CONTINGENCIES - OTHER LITIGATION (Details) claim in Thousands, £ in Millions, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 31, 2020 GBP (£)	Mar. 31, 2020 GBP (£)	Jun. 30, 2021 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2021 USD ($)	Nov. 01, 2021 claim lawsuit	Oct. 01, 2014 USD ($)	Oct. 01, 2014 GBP (£)
R B S Sempra Commodities [Member] | HMRC VAT Claim [Member]
Loss Contingencies [Line Items]
VAT tax claim paid upon appeal							$ 138	£ 86
Plaintiffs [Member] | HMRC VAT Claim [Member]
Loss Contingencies [Line Items]
Damages awarded		£ 45			$ 61
Cost and interest assessed	£ 21				$ 28
Energy Future Holdings Corp. [Member] | Subsequent Event [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit						3
Number of proof of claims | claim						28
R B S Sempra Commodities [Member]
Loss Contingencies [Line Items]
Equity losses on investment | $			$ 50	$ 100