Nuclear Decommissioning Trust Funds - Summary of the Sale Proceeds, Gains, and Losses for Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	5 Months Ended	6 Months Ended
	Jun. 30, 2023	May 17, 2023	Jun. 30, 2024	May 17, 2023	Jun. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Sales proceeds of NDT funds investments	$ 271	$ 243	$ 535	$ 839	$ 1,034
Gross realized gains	0	2	2	7	5
Gross realized losses	$ (2)	$ (2)	$ (3)	$ (12)	$ (6)