Commitments and Contingencies (Wildfire loss accrual) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
2017/2018 Wildfire/Mudslide Events
Loss Contingency Accrual [Roll Forward]
Beginning balance	$ 4,383
Amounts paid	(2,852)
Ending balance	1,531	$ 4,383
2017/2018 Wildfire/Mudslide Events | Other current liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	2,231
Ending balance	141	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	1,519
Ending balance		2,281
November 2018 - Woolsey Wildfires
Loss Contingency Accrual [Roll Forward]
Litigation settlement		2,212
November 2018 - Woolsey Wildfires | Other long-term liabilities
Loss Contingency Accrual [Roll Forward]
Beginning balance	2,152
Ending balance	1,390	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	$ 129	$ 129