Resolution Of Remaining Chapter 11 Disputed Claims (Changes In The Remaining Net Disputed Claims Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Apr. 12, 2004
Resolution Of Remaining Chapter Eleven Disputed Claims [Line Items]
Escrow for payment of remaining net disputed claims	$ 0	$ 228	$ 1,700
Net disputed claims and customer refunds	236	$ 454
Increase Decrease To Disputed Claims Liability Balance	231
Increase Decrease To Escrow For Payment Of Remaining Net Disputed Claims	161
CAISO And PX [Member]
Resolution Of Remaining Chapter Eleven Disputed Claims [Line Items]
Increase Decrease To Disputed Claims Liability Balance	165
Increase Decrease To Escrow For Payment Of Remaining Net Disputed Claims	$ 66