Resolution Of Remaining Chapter 11 Disputed Claims (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Resolution Of Remaining Chapter Eleven Disputed Claims [Line Items]
Escrow for payment of remaining net disputed claims	$ 320	$ 320
Balance at December 31, 2011	848
Interest accrued	7
Less: electricity supplier settlements	(23)
Balance at March 31, 2012	832
Interest accrued on disputed claims	668
Pacific Gas And Electric Company [Member]
Resolution Of Remaining Chapter Eleven Disputed Claims [Line Items]
Balance at March 31, 2012	832
Remaining disputed claims	658
CAISO And PX [Member]
Resolution Of Remaining Chapter Eleven Disputed Claims [Line Items]
Carrying amounts due from CAISO and PX as of the balance sheet date for disputed claims related to the Chapter 11 Filing	$ 494