Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended
	Mar. 20, 2012	Mar. 31, 2012	Mar. 31, 2012 Pacific Gas And Electric Company [Member]	Mar. 31, 2011 Pacific Gas And Electric Company [Member]
Stock issued during period for stock options exercised and under 401(K) plan and DRSPP		3,363,617
Cash proceeds from employee stock options exercised		$ 133
Net of fees and commissions		1
Equity distribution agreement amount		219
Sale of common stock in an underwritten public offering	5,900,000
Cash proceeds from sale of common shares in an underwritten public offering	254
Equity contribution			$ 385	$ 65
Common equity ratio percentage		52.00%
Debt and preferred stock ratio percentage		48.00%