Commitments and Contingencies - PAC - Narrative (Details) naturalGasProducer in Thousands, a in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($) a naturalGasProducer	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Hydroelectric [Line Items]
Capital expenditures required by hydroelectric licenses, period		10 years
PAC
Hydroelectric [Line Items]
Maximum percentage of energy sources for which a share of operating costs and debt service is required		5.00%	5.00%	5.00%
Capital expenditures required by hydroelectric licenses		$ 282
PAC | Minimum | Purchased electricity contracts - commercially operable
Hydroelectric [Line Items]
Purchase commitment period		7 years
PAC | Minimum | Purchased electricity contracts - not commercially operable
Hydroelectric [Line Items]
Purchase commitment period		7 years
PAC | Maximum | Purchased electricity contracts - commercially operable
Hydroelectric [Line Items]
Purchase commitment period		30 years
PAC | Maximum | Purchased electricity contracts - not commercially operable
Hydroelectric [Line Items]
Purchase commitment period		30 years
2020 Wildfires | PAC
Hydroelectric [Line Items]
Number of acres burned | a	0.5
Number of structures destroyed | naturalGasProducer	2
Fire suppression costs	$ 150
Estimate of possible loss		$ 477
Estimated insurance recoveries		246	$ 116
Loss recognized in period		64	$ 0	$ 136
2022 McKinney Fire | PAC
Hydroelectric [Line Items]
Estimate of possible loss		31
Estimated insurance recoveries		103
Klamath Hydroelectric System | PAC
Hydroelectric [Line Items]
Dam removal cost limit		200
Additional dam removal costs, California bond measure		250
Additional contingency funding		45
Hydroelectric dam removal cost funding		$ 450