Leases (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2024		Sep. 30, 2023		Sep. 30, 2024		Sep. 30, 2023		Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	$ 13	[1]	$ 14	[1]	$ 41	[2]	$ 43	[2]
Lessee, Operating Lease, Liability, to be Paid	463				463
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(84)				(84)
Operating Lease, Liability	379				379
Operating Lease, Liability, Current	(34)				(34)				$ (32)
Operating lease liabilities	345				345				$ 371
PPAs
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	12		13		38		40
Lessee, Operating Lease, Liability, to be Paid	416				416
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(73)				(73)
Operating Lease, Liability	343				343
Property, Plant and Equipment, Other Types
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	1	[3]	$ 1	[3]	3	[4]	$ 3	[4]
Lessee, Operating Lease, Liability, to be Paid	47				47
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(11)				(11)
Operating Lease, Liability	$ 36				$ 36

[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 operating and maintenance expense and electric fuel and purchased power.

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

[3] Includes immaterial short-term lease expense for 2024 and 2023.

[4] Includes immaterial short-term lease expense for 2024 and 2023.