Commitments and Contingencies, Leases (Details) - USD ($)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Maximum Length - Short-Term Leases		12 months
Operating Lease, Weighted Average Discount Rate, Percent		4.40%
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		$ 544,000,000	$ 544,000,000
Operating Lease, Right-of-Use Asset, Accumulated Depreciation		(141,000,000)	(110,000,000)
Operating lease right-of-use assets		403,000,000	434,000,000
Lease, Cost [Abstract]
Operating Lease, Cost	[1]	57,000,000	57,000,000	$ 57,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2024		49,000,000
2025		49,000,000
2026		49,000,000
2027		50,000,000
2028		50,000,000
Thereafter		253,000,000
Total minimum obligation		500,000,000
Interest component of obligation		(97,000,000)
Tax credit carryforward		403,000,000
Less current portion		(32,000,000)	(31,000,000)
Operating Lease, Liability, Noncurrent		371,000,000	403,000,000
Weighted Average Remaining lease term, operating		10
Property, Plant and Equipment, Other Types [Member]
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		44,000,000	44,000,000
Lease, Cost [Abstract]
Operating Lease, Cost	[2]	4,000,000	4,000,000	4,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2024		3,000,000
2025		3,000,000
2026		3,000,000
2027		4,000,000
2028		4,000,000
Thereafter		33,000,000
Total minimum obligation		50,000,000
Interest component of obligation		(12,000,000)
Tax credit carryforward		38,000,000
Purchased Power Agreements
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		500,000,000	500,000,000
Lease, Cost [Abstract]
Operating Lease, Cost		53,000,000	$ 53,000,000	$ 53,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2024	[3],[4]	46,000,000
2025	[3],[4]	46,000,000
2026	[3],[4]	46,000,000
2027	[3],[4]	46,000,000
2028	[3],[4]	46,000,000
Thereafter	[3],[4]	220,000,000
Total minimum obligation	[3],[4]	450,000,000
Interest component of obligation	[3],[4]	(85,000,000)
Tax credit carryforward	[3],[4]	$ 365,000,000

[1] PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in O&M expense.

[2] Includes immaterial short-term lease expense for 2023, 2022 and 2021.

[3] Amounts do not include PPAs accounted for as executory contracts and/or contingent payments, such as energy payments on renewable PPAs.

[4] PPA operating leases contractually expire at various dates through 2033.