Regulatory Assets and Liabilities, Regulatory Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024	[1]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		$ 118	$ 142
Regulatory Liability, Noncurrent		772	768
Deferred Income Tax Adjustments and TCJA Refunds
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	[2]	0	0
Regulatory Liability, Noncurrent	[2]	418	436
Plant Removal Costs
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		0	0
Regulatory Liability, Noncurrent		$ 283	267
Deferred Electric Energy Costs | Maximum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		1 year
Contract Valuation Adjustments
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	[3]	$ 79	67
Regulatory Liability, Noncurrent	[3]	$ 0	0
Contract Valuation Adjustments | Maximum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		1 year
Other
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		$ 15	30
Regulatory Liability, Noncurrent		45	36
Deferred Fuel Costs
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		20	41
Regulatory Liability, Noncurrent		0	0
LP&L Departure Payment
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		4	4
Regulatory Liability, Noncurrent		$ 26	$ 29
Regulatory Liability, Amortization Period		8 years

[1] Prior period amounts have been reclassified to conform with current year presentation.

[2] Includes the revaluation of recoverable/regulated plant accumulated deferred income taxes and revaluation impact of non-plant accumulated deferred income taxes due to the TCJA.

[3] Includes the fair value of FTR instruments utilized/intended to offset the impacts of transmission system congestion.