Commitments and Contingencies, Leases (Details) - USD ($)		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
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		(207,000,000)	(173,000,000)
Operating lease right-of-use assets		337,000,000	371,000,000
Lease, Cost [Abstract]
Operating Lease, Cost		43,000,000	51,000,000	$ 57,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2026		49,000,000
2027		49,000,000
2028		50,000,000
2029		50,000,000
2030		50,000,000
Thereafter		153,000,000
Total minimum obligation		401,000,000
Interest component of obligation		(64,000,000)
Present value of minimum obligation		337,000,000
Less current portion		(36,000,000)	(34,000,000)
Operating Lease, Liability, Noncurrent		301,000,000	337,000,000
Weighted Average Remaining lease term, operating		8.1
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	[1]	4,000,000	3,000,000	4,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2026		3,000,000
2027		3,000,000
2028		4,000,000
2029		4,000,000
2030		4,000,000
Thereafter		25,000,000
Total minimum obligation		43,000,000
Interest component of obligation		(9,000,000)
Present value of minimum obligation		34,000,000
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		39,000,000	$ 48,000,000	$ 53,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2026	[2],[3]	46,000,000
2027	[2],[3]	46,000,000
2028	[2],[3]	46,000,000
2029	[2],[3]	46,000,000
2030	[2],[3]	46,000,000
Thereafter	[2],[3]	128,000,000
Total minimum obligation	[2],[3]	358,000,000
Interest component of obligation	[2],[3]	(55,000,000)
Present value of minimum obligation	[2],[3]	$ 303,000,000

[1] Includes immaterial short-term lease expense.

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

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