Debt (Detail) (USD $) In Millions, unless otherwise specified							3 Months Ended			3 Months Ended			3 Months Ended		3 Months Ended
	Jun. 30, 2014 Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Jun. 30, 2014 Pollution Control Bonds Series 2009 A-D [Member]	Jun. 30, 2014 Minimum [Member] Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Jun. 30, 2014 Minimum [Member] Pollution Control Bonds Series 2009 A-D [Member]	Jun. 30, 2014 Maximum [Member] Pollution Control Bonds Series 1996 C, E, F, And 1997 B [Member]	Jun. 30, 2014 Maximum [Member] Pollution Control Bonds Series 2009 A-D [Member]	Jun. 30, 2014 Utility [Member]	Feb. 21, 2014 Utility [Member] Due February 15, 2024 [Member]	Feb. 21, 2014 Utility [Member] Due February 15, 2044 [Member]	Jun. 30, 2014 Utility [Member] Due March 1, 2014 [Member]	Feb. 21, 2014 Utility [Member] Due March 1, 2014 [Member]	May 12, 2014 Utility [Member] Floating Rate Senior Notes [Member] Due May 11, 2015 [Member]	Jun. 30, 2014 PG&E Corporation [Member]	Feb. 27, 2014 PG&E Corporation [Member] Due March 1, 2019 [Member]	Jun. 30, 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			0.01%	0.01%	0.04%	0.04%		3.75%	4.75%		4.80%			2.40%		5.75%
Debt instrument, face amount	$ 614	$ 309
Senior Notes								450	450			300		350
Extinguishment of Debt										$ 539					$ 350