OTHER CONTINGENCIES AND COMMITMENTS (GT&S Capital Expenditures 2011-2014 and CZU Lightning Complex Fire Notice of Violations) (Details) $ in Millions		1 Months Ended
	Jun. 23, 2016 USD ($)	Feb. 08, 2021 notice	Jul. 31, 2020 USD ($)
Disallowance of Plant Costs
Loss Contingencies [Line Items]
Gas transmission and storage capital disallowance	$ 696
Permanently disallowed capital	120
Amount subject to audit	$ 576
Capital expenditures for future recovery			$ 512
CZU Lightning Complex Fire Notice of Violations | Subsequent Event
Loss Contingencies [Line Items]
Number of notices issued of violation | notice		5