Regulatory Assets, Liabilities, And Balancing Accounts (Long-Term Regulatory Assets) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets [Line Items]
Total long-term regulatory assets		$ 7,951	$ 7,029
Deferred income taxes regulatory asset recovery maximum (years)		47 years
Weighted average remaining life of Utility retained generation assets (years)		9 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)		26 years
Retained Generation Asset Costs		$ 1,200
Pension benefits regulatory assets recovery (years)		Indefinitely
Other regulatory assets recovery (years)		Various
Current regulatory assets		$ 423	517
Pension Plans Defined Benefit [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[1],[2]	2,429	2,414
Deferred Income Taxes [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[2]	3,859	3,054
Utility Retained Generation [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[3]	364	411
Environmental Compliance Costs [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[2]	778	748
Price Risk Management [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[2]	92	138
Unamortized Loss, Net Of Gain, On Reacquired Debt [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets	[2]	76	94
Other Regulatory Assets ( Liabilities) [Member]
Regulatory Assets [Line Items]
Total long-term regulatory assets		$ 353	$ 170

[1] Payments into the pension and other benefits plans are based on annual contribution requirements. As these annual requirements continue indefinitely into the future, the Utility expects to continuously recover pension benefits.

[2] 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.)

[3] 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.