Condensed Consolidated Statements Of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Unrecognized prior service credit, income tax	$ 5	$ 5
Unrecognized net gain, income tax	11	6
Unrecognized net transition obligation, income tax	2	2
Transfer to regulatory account, income tax	15	8
Pacific Gas And Electric Company [Member]
Unrecognized prior service credit, income tax	5	5
Unrecognized net gain, income tax	11	6
Unrecognized net transition obligation, income tax	2	2
Transfer to regulatory account, income tax	$ 15	$ 8