Long-Term Borrowings (Details) - USD ($) $ in Millions		Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net		$ (14)	$ (10)
Unamortized Debt Issuance Expense		(35)	(29)
Long-Term Debt, Current Maturities		0	(350)
Long-Term Debt		$ 3,551	2,961
First Mortgage Bonds, Series due: | Series Due June 15, 2024 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.30%
Face Amount		$ 0	150
First Mortgage Bonds, Series due: | Series Due June 15, 2024 2 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.30%
Face Amount		$ 0	200
First Mortgage Bonds, Series due: | Series Due Aug. 15, 2041 4
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		4.50%
Face Amount		$ 200	200
First Mortgage Bonds, Series due: | Series Due Aug. 15, 2041 2 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		4.50%
Face Amount		$ 100	100
First Mortgage Bonds, Series due: | Series Due Aug. 15, 2041 3 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		4.50%
Face Amount		$ 100	100
First Mortgage Bonds, Series due: | Series Due August 15, 2046 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.40%
Face Amount		$ 300	300
First Mortgage Bonds, Series due: | Series Due August 15, 2047 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.70%
Face Amount		$ 450	450
First Mortgage Bonds, Series due: | Series Due Nov. 15, 2048 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		4.40%
Face Amount		$ 300	300
First Mortgage Bonds, Series due: | Series Due June 15, 2049
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.75%
Face Amount		$ 300	300
First Mortgage Bonds, Series due: | Series due May 1, 2050 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.15%
Face Amount		$ 350	350
First Mortgage Bonds, Series due: | Series due May 1, 2050 2
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		3.15%
Face Amount		$ 250	250
First Mortgage Bonds, Series due: | Series Due June 1, 2052
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		5.15%
Face Amount		$ 200	200
First Mortgage Bonds, Series due: | Series Due Sept. 15, 2053
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)	[1]	6.00%
Face Amount	[1]	$ 100	100
First Mortgage Bonds, Series due: | Series Due June 1, 2054
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)	[2]	6.00%
Face Amount	[2]	$ 600	0
Unsecured Debt [Member] | Senior C and D Due Oct. 1, 2033 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		6.00%
Face Amount		$ 100	100
Unsecured Debt [Member] | Senior F Due Oct. 1, 2036 [Member]
Debt Instrument [Line Items]
Interest Rate, Stated Percentage (in hundredths)		6.00%
Face Amount		$ 250	$ 250

[1] 2023 financing.

[2] 2024 financing