Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Subtotal	$ 500	$ 499
Alternative revenue programs, net of amortization	9	3
Other accrued (deferred) revenues, net	5	7
Total retail revenues	514	509
Wholesale revenues	47	37
Other operating revenue	12	27
Total Revenues	573	573
Gain on Derivative Instruments, Pretax	16	11
Residential [Member]
Disaggregation of Revenue [Line Items]
Subtotal	279	290
Commercial [Member]
Disaggregation of Revenue [Line Items]
Subtotal	159	154
Industrial [Member]
Disaggregation of Revenue [Line Items]
Subtotal	51	44
Direct Access customers [Member]
Disaggregation of Revenue [Line Items]
Subtotal	$ 11	$ 11