Derivative Financial Instruments - Summary of Economic Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative [Line Items]
Total	$ 1,040	$ (356)
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract
Derivative [Line Items]
Total	1,059	(324)
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract \| Operating revenues
Derivative [Line Items]
Total	1,311	(287)
Not Designated as Hedging Instrument, Economic Hedge \| Commodity Contract \| Purchased power and fuel
Derivative [Line Items]
Total	$ (252)	$ (37)

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.