Condensed Consolidated Statements Of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Unrecognized prior service credit income tax	$ 5	$ 5
Unrecognized net gain income tax	11	11
Unrecognized net transition obligation income tax	0	2
Transfer to regulatory account of income tax	13	15
Other	4	0
Pacific Gas And Electric Company [Member]
Unrecognized prior service credit income tax	5	5
Unrecognized net gain income tax	10	11
Unrecognized net transition obligation income tax	0	2
Transfer to regulatory account of income tax	$ 13	$ 15