Organization and Basis of Presentation (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	$ 545	$ 503
Change	42
Regulatory transition costs
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	7	10
Change	(3)
Deferred transmission costs
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	27	80
Change	(53)
Deferred generation costs
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	15	8
Change	7
Storm-related costs
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	471	363
Change	108
Other
Regulatory Assets [Line Items]
Regulatory Assets by Source Not Earning a Current Return	25	$ 42
Change	$ (17)