Commitments and Contingencies (Environmental Matters) (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Pacific Gas and Electric Company [Member] | Remediation at Utility Natural Gas Compressor Site Near Hinkley, CA [Member]
Amount of environmental loss accrual for remediation	$ 54,000,000
Authorized recovery of hazardous waste remediation costs	90.00%
Remediation at Utility Natural Gas Compressor Site Near Topock, AZ [Member]
Amount of environmental loss accrual for remediation	179,000,000
Remediation at Divested Generation Facilities [Member]
Amount of environmental loss accrual for remediation	83,000,000
Remediation Costs for Generation and Other Facilities and for Third-Party Disposal Sites [Member]
Amount of environmental loss accrual for remediation	141,000,000
Investigation and or Remediation Costs at Former MGP Sites [Member]
Amount of environmental loss accrual for remediation	158,000,000
Remediation of Decommissioning Fossil Fueled Sites [Member]
Amount of environmental loss accrual for remediation	62,000,000
Pacific Gas and Electric Company [Member]
Gross environmental remediation liability	677,000,000	612,000,000
Amount of environmental loss accrual expected to be recovered	365,000,000
Amounts recoverable by Utility as authorized by CPUC and FERC	135,000,000
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	$ 1,300,000,000