Commitments And Contingencies (Class Action Complaint) (Detail) (Pacific Gas And Electric Company [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012
Pacific Gas And Electric Company [Member]
Long Term Purchase Commitment [Line Items]
Alleged utility collection 1997 to 2010	$ 100
Utility spent on capital expenditures 1996 to 2010	95
Utility spent on operations and maintenance 1996 to 2010	$ 39

Utility spent on operations and maintenance 1996 to 2010

No definition available.

Name:	pcg_UtilitySpentOnOperationsAndMaintenance
Namespace Prefix:	pcg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration