Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Nuclear decommissioning trusts - Fixed Income Securities $ in Millions	Dec. 31, 2024 USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 18
Due after one through five years	105
Due after five through ten years	107
Due after ten years	308
Fixed income securities total	$ 538