Regulatory Assets, Liabilities, And Balancing Accounts (Long-Term Regulatory Assets) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets [Line Items]
Total long-term regulatory assets		$ 7,029	$ 6,322
Deferred income taxes regulatory asset recovery maximum (years)		47 years
Weighted average remaining life of Utility retained generation assets (years)		10 years
Environmental compliance costs regulatory asset recovery (years)		32 years
Price risk management regulatory assets recovery (years)		10 years
Recovery of costs related to debt reacquired or redeemed prior to maturity (years)		11 years
Retained Generation Asset Costs		$ 1,200
Pension benefits regulatory assets recovery (years)		Indefinitely
Other regulatory assets recovery (years)		Various
Current regulatory assets		$ 517	444
Pension Plans Defined Benefit [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1]	2,414	2,347
Deferred Income Taxes [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1]	3,054	2,390
Utility Retained Generation [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[2]	411	456
Environmental Compliance Costs [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1]	748	717
Price Risk Management [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1]	138	127
Electromechanical meters [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[3]	0	70
Current regulatory assets		70
Unamortized Loss, Net Of Gain, On Reacquired Debt [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1]	94	113
Other Regulatory Assets ( Liabilities) [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets		$ 170	$ 102

[1] Represents the cumulative differences between amounts recognized for ratemaking purposes and amounts recognized in accordance with GAAP. Pension benefits also includes amounts that otherwise would be recorded to accumulated other comprehensive income/loss in the Consolidated Balance Sheets. (See Note 11 below.)

[2] In connection with the settlement agreement entered into among PG&E Corporation, the Utility, and the CPUC in 2003 to resolve the Utility's proceeding under Chapter 11, the CPUC authorized the Utility to recover $1.2 billion of costs related to the Utility's retained generation assets. The individual components of these regulatory assets are being amortized over the respective lives of the underlying generation facilities, consistent with the period over which the related revenues are recognized.

[3] Represents the expected future recovery of the net book value of electromechanical meters that were replaced with SmartMeter devices. As of December 31, 2015, the remaining balance of $70 million is included in current regulatory assets on the Consolidated Balance Sheets.