Commitments And Contingencies (Environmental Remediation Contingencies) (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Dec. 31, 2010
Pacific Gas And Electric Company [Member] | Remediation At Utility Natural Gas Compressor Site Near Hinkley, CA [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	$ 150,000,000	$ 150,000,000
Remediation At Utility Natural Gas Compressor Site Near Topock, AZ [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	178,000,000	178,000,000
Remediation At Divested Generation Facilities [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	81,000,000	81,000,000
Remediation Costs For Generation And Other Facilities And For Third-Party Disposal Sites [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	140,000,000	140,000,000
Investigation And Or Remediation Costs At Former MGP Sites [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	157,000,000	157,000,000
Remediation Of Decommissioning Fossil Fueled Sites [Member]
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual for remediation	57,000,000	57,000,000
Pacific Gas And Electric Company [Member] | Hinkley Natural Gas Compressor Station [Member]
Long-term Purchase Commitment [Line Items]
Authorized recovery of hazardous waste remediation costs	90.00%	90.00%
Hinkley Natural Gas Compressor Station [Member]
Long-term Purchase Commitment [Line Items]
Gross environmental remediation liability	150,000,000	150,000,000	45,000,000
Utility undiscounted future costs	150,000,000	150,000,000	45,000,000
provision for environmental remediation	106,000,000	132,000,000
Pacific Gas And Electric Company [Member]
Long-term Purchase Commitment [Line Items]
Gross environmental remediation liability	763,000,000	763,000,000	612,000,000
Amount of environmental loss accrual expected to be recovered	364,000,000	364,000,000
Amounts recoverable by Utility as authorized by CPUC and FERC	128,000,000	128,000,000
Recovery of remediation costs for decommissioning fossil-fueled sites		100.00%
Increase in undiscounted future costs in the event other potentially responsible parties are not able to contribute	1,400,000,000	1,400,000,000
Utility undiscounted future costs	$ 763,000,000	$ 763,000,000	$ 612,000,000