Commitments and Contingencies (Wildfire loss expense) (Details) - 2017/2018 Wildfire/Mudslide Events $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Charge for wildfire-related claims	$ 416
Expected revenue from FERC customers	(26)
Total pre-tax charge	390
Income tax benefit	(109)
Total after-tax charge	$ 281