Condensed Consolidated Statements Of Cash Flows (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash Flows from Financing Activities
Net (repayments) issuances of commercial paper, discount	$ 1	$ 1
Pacific Gas And Electric Company [Member]
Cash Flows from Financing Activities
Net (repayments) issuances of commercial paper, discount	$ 1	$ 1