Commitments and Contingencies (Wildfire loss accrual) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
2017/2018 Wildfire/Mudslide Events
Loss Contingency Accrual [Roll Forward]
Beginning balance	$ 4,383
Increase in accrued estimated losses to reflect best estimate	1,265	$ 1,297
Amounts paid	(3,914)
Ending balance	1,734	4,383
2017/2018 Wildfire/Mudslide Events | Other Current Liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	2,231
Ending balance	131	2,231
2017/2018 Wildfire/Mudslide Events | Other long-term liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	2,281
Fixed payments to be made under settlement agreements	1,733
Ending balance		2,281
November 2018 Wildfires
Loss Contingency Accrual [Roll Forward]
Litigation settlement		2,212
November 2018 Wildfires | Other long-term liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	2,152
Ending balance	1,603	2,152
Other Wildfire Related Claims
Loss Contingency Accrual [Roll Forward]
Litigation settlement		19
Other Wildfire Related Claims | Other long-term liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	129
Ending balance	$ 130	$ 129