Debt (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended							3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Mar. 31, 2014 Pollution Control Bonds Series 2009 A-D [Member]	Mar. 31, 2014 Minimum [Member] Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Mar. 31, 2014 Minimum [Member] Pollution Control Bonds Series 2009 A-D [Member]	Mar. 31, 2014 Maximum [Member] Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Mar. 31, 2014 Maximum [Member] Pollution Control Bonds Series 2009 A-D [Member]	Mar. 31, 2014 Utility [Member]	Feb. 21, 2014 Utility [Member] Due February 15, 2024 [Member]	Feb. 21, 2014 Utility [Member] Due February 15, 2044 [Member]	Mar. 31, 2014 Utility [Member] Due March 1, 2014 [Member]	Feb. 21, 2014 Utility [Member] Due March 1, 2014 [Member]	Feb. 27, 2014 PG&E Corporation [Member] Due March 1, 2019 [Member]	Mar. 31, 2014 PG&E Corporation [Member] Due April 1, 2014 [Member]	Feb. 27, 2014 PG&E Corporation [Member] Due April 1, 2014 [Member]
Debt [Line Items]
Line of Credit termination date	Apr. 01, 2019							Apr. 01, 2019
Debt instrument, interest rate				0.06%	0.05%	0.10%	0.07%		3.75%	4.75%		4.80%	2.40%		5.75%
Debt instrument, face amount		$ 614	$ 309
Senior Notes									450	450			350
Extinguishment of Debt											$ 539			$ 350