Commitments and Contingencies - PAC - Narrative (Details) - PAC naturalGasProducer in Thousands, a in Thousands, $ in Millions	1 Months Ended	3 Months Ended
	Sep. 30, 2020 USD ($) a naturalGasProducer	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Apr. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Construction commitment | Subsequent event
Loss Contingencies [Line Items]
Purchase obligation				$ 1,200
Fuel contracts
Loss Contingencies [Line Items]
Purchase obligation		$ 247
Lower Klamath Hydroelectric System
Loss Contingencies [Line Items]
Hydroelectric dam removal cost, total funding		450
Dam removal cost collected		200
Additional dam removal costs, California bond measure		250
Hydroelectric dam removal cost, additional contingency funding		45
2020 Wildfires
Loss Contingencies [Line Items]
Number of acres burned | a	500
Number of structures destroyed | naturalGasProducer	2
Fire suppression costs	$ 150
Estimate of possible loss		877
Expected insurance recoveries		287			$ 246
Loss in period		359	$ 0
2022 McKinney Fire
Loss Contingencies [Line Items]
Estimate of possible loss		31
Expected insurance recoveries		$ 103