Commitments and Contingencies - Accrual Roll forward (Details) - USD ($) $ in Millions	12 Months Ended			66 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024
Loss contingency accrual roll forward
Balance, beginning	$ 1,398
Increase in accrued estimated losses	743
Amounts paid	(1,140)	$ (1,224)	$ (1,924)	$ (10,018)
Balance, end	1,001	1,398		1,001
2017/2018 Wildfire/Mudslide Events
Loss contingency accrual roll forward
Balance, beginning	715
Increase in accrued estimated losses	490
Amounts paid	(779)	(1,034)	(1,911)	(9,454)
Balance, end	426	715		426
Other Wildfire Events
Loss contingency accrual roll forward
Balance, beginning	683
Increase in accrued estimated losses	253
Amounts paid	(361)	(190)	$ (13)	(564)
Balance, end	$ 575	$ 683		$ 575