Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Feb. 01, 2018	Dec. 31, 2016	Dec. 31, 2015
Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year		$ 21
Decrease of unrecognized tax benefit		20
Provisional Amounts Recorded For New Federal Tax Law		64
2015 GT&S rate base adjustment for new federal tax law		$ 49	$ 61	$ 28	$ 7
New Federal Income Tax Rate	21.00%	35.00%
State [Member]
Net operating loss carryforwards		$ 0
Tax credit carryforward, amount		13
Loss carryforwards, charitable contribution		$ 24
Charitable Contribution Carryforward Expiration Date [Minimum]		Dec. 31, 2020
Charitable Contribution Carryforward Expiration Date [Maximum]		Dec. 31, 2021
Federal [Member]
Net operating loss carryforwards		$ 4,233
Tax credit carryforward, amount		103
Loss carryforwards, charitable contribution		$ 93
Tax Credit Carryforward Expiration Date [Minimum]		Dec. 31, 2029
Tax Credit Carryforward Expiration Date [Maximum]		Dec. 31, 2036
Charitable Contribution Carryforward Expiration Date [Minimum]		Dec. 31, 2019
Charitable Contribution Carryforward Expiration Date [Maximum]		Dec. 31, 2021
Minimum [Member] | State [Member]
Tax credit carryforward expiration date
Minimum [Member] | Federal [Member]
Tax credit carryforward expiration date		Dec. 31, 2031
Maximum [Member] | State [Member]
Tax credit carryforward expiration date
Maximum [Member] | Federal [Member]
Tax credit carryforward expiration date		Dec. 31, 2036
Provisional Deferred Tax Regulatory Liability Recorded For New Federal Tax Law [Member]
Provisional Amounts Recorded For New Federal Tax Law		$ 5,700
Provisional Tax Expense Recorded For New Federal Tax Law [Member]
Provisional Amounts Recorded For New Federal Tax Law		83
Pacific Gas And Electric Company [Member]
Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation		205		199
Income tax regulatory asset		0		1,572
PG&E Corporation [Member]
Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation		274		277
Income tax regulatory asset		$ 0		$ 1,572