Notes and Debentures Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt	$ 23,425		$ 23,388
Debt, fair value	21,131		22,400
Junior Subordinated Debt
Debt Instrument [Line Items]
Subordinated notes related to financial covenants	500
SEC Debt Shelf Registration
Debt Instrument [Line Items]
Remaining amount of debt securities that may be issued	1,650
Mortgage Bonds
Debt Instrument [Line Items]
Debt	$ 47		$ 47
Five Point Five Percent Debenture Due March 15 2055 | Corporate Debt Securities
Debt Instrument [Line Items]
Debt Instrument issued amount		$ 1,300
Debt instrument interest rate		5.50%