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, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 12
Due after one through five years	118
Due after five through ten years	95
Due after ten years	273
Fixed income securities total	$ 498