Derivative Financial Instruments - Summary of Economic Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative [Line Items]
Total			$ (188)	$ 776
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract
Derivative [Line Items]
Total	$ 164	$ 589	(158)	778
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract \| Operating revenues
Derivative [Line Items]
Total	89	192	(197)	255
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract \| Purchased power and fuel
Derivative [Line Items]
Total	$ 75	$ 397	$ 39	$ 523

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.