Consolidated Statement of Capitalization - Long-term Debt - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL DEBENTURES		$ 25,801	$ 24,710
Unamortized debt expense		(179)	(179)
Unamortized debt discount		(70)	(70)
Less: Long-term debt due within one year		250	0
TOTAL LONG-TERM DEBT		25,551	24,710
Less: Held for sale project debt, net	[1]	0	59
TOTAL LONG-TERM DEBT EXCLUDING HELD FOR SALE		25,551	24,651
TOTAL CAPITALIZATION		$ 49,741	46,613
Broken Bow II
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[1]	4.82%
TOTAL PROJECT DEBT	[1]	$ 0	59
TOTAL PROJECT DEBT
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		0	59
Debentures
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 25,825	24,675
Debentures | Debenture Series 2016B, 2.90% Due 2026
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.90%
TOTAL PROJECT DEBT		$ 250	250
Debentures | Debenture Series 1997F, 6.50% Due 2027
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.50%
TOTAL PROJECT DEBT		$ 80	80
Debentures | Debenture Series 2017B, 3.125% Due 2027
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.125%
TOTAL PROJECT DEBT		$ 350	350
Debentures | Debenture Series 2017B, 4.825% Due 2027
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[2]	4.254%
TOTAL PROJECT DEBT	[2]	$ 350	350
Debentures | Debenture Series 2018A, 3.80% Due 2028
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.80%
TOTAL PROJECT DEBT		$ 300	300
Debentures | Debenture Series 2018D, 4.00% Due 2028
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.00%
TOTAL PROJECT DEBT		$ 500	500
Debentures | Debenture 2019B, 2.94%, Due 2029
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.94%
TOTAL PROJECT DEBT		$ 44	44
Debentures | Debenture 2020A, 3.35%, Due 2030
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.35%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2020A, 2.02%, Due 2030
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.02%
TOTAL PROJECT DEBT		$ 35	35
Debentures | Debenture 2021A, 2.40%, Due 2031
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.40%
TOTAL PROJECT DEBT		$ 900	900
Debentures | Debenture 2021A, 2.31%, Due 2031
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.31%
TOTAL PROJECT DEBT		$ 45	45
Debentures | Debenture 2022A, 5.70%, Due 2032
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL PROJECT DEBT		$ 100	100
Debentures | Debenture Series 2003A, 5.875% Due 2033
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.875%
TOTAL PROJECT DEBT		$ 175	175
Debentures | Debenture Series 2003C, 5.10% Due 2033
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.10%
TOTAL PROJECT DEBT		$ 200	200
Debentures | Debenture Series 2023A, 5.20% Due 2033
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.20%
TOTAL PROJECT DEBT		$ 500	500
Debentures | Debenture Series 2004B, 5.70% Due 2034
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL PROJECT DEBT		$ 200	200
Debentures | Debenture Series 2023B, 5.50% Due 2034
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2024A, 5.375%, Due 2034
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.375%
TOTAL PROJECT DEBT		$ 400	400
Debentures | Debenture Series 2005A, 5.30% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.30%
TOTAL PROJECT DEBT		$ 350	350
Debentures | Debenture Series 2005 B 5.25% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.25%
TOTAL PROJECT DEBT		$ 125	125
Debentures | Debenture Series 2024 D 5.125% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.125%
TOTAL PROJECT DEBT		$ 450	450
Debentures | Debenture Series 2006A, 5.85% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.85%
TOTAL PROJECT DEBT		$ 400	400
Debentures | Debenture Series 2006B, 6.20% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.20%
TOTAL PROJECT DEBT		$ 400	400
Debentures | Debenture Series 2006E, 5.70% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL PROJECT DEBT		$ 250	250
Debentures | Debenture Series 2007A, 6.30% Due 2037
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.30%
TOTAL PROJECT DEBT		$ 525	525
Debentures | Debenture 2008B, 6.75%, Due 2038
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.75%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2009B, 6.00%, Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.00%
TOTAL PROJECT DEBT		$ 60	60
Debentures | Debenture 2009C, 5.50%, Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2019C, 3.46%, Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.46%
TOTAL PROJECT DEBT		$ 38	38
Debentures | Debenture 2010B, 5.70%, Due 2040
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL PROJECT DEBT		$ 350	350
Debentures | Debenture 2010B, 5.50%, Due 2040
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL PROJECT DEBT		$ 115	115
Debentures | Debenture 2012A, 4.20%, Due 2042
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.20%
TOTAL PROJECT DEBT		$ 400	400
Debentures | Debenture 2013A, 3.95%, Due 2043
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.95%
TOTAL PROJECT DEBT		$ 700	700
Debentures | Debenture 2014A, 4.45%, Due 2044
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL PROJECT DEBT		$ 850	850
Debentures | Debenture 2015A, 4.50%, Due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL PROJECT DEBT		$ 650	650
Debentures | Debenture 2015A, 4.95%, Due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.95%
TOTAL PROJECT DEBT		$ 120	120
Debentures | Debenture Series 2015B, 4.69% due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.69%
TOTAL PROJECT DEBT		$ 100	100
Debentures | Debenture 2016A, 3.85%, Due 2046
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.85%
TOTAL PROJECT DEBT		$ 550	550
Debentures | Debenture Series 2016A. 3.88% Due 2046
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.88%
TOTAL PROJECT DEBT		$ 75	75
Debentures | Debenture Series 2017A, 3.875% Due 2047
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.875%
TOTAL PROJECT DEBT		$ 500	500
Debentures | Debenture Series 2018E, 4.65% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.65%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture Series 2018A, 4.35% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.35%
TOTAL PROJECT DEBT		$ 125	125
Debentures | Debenture Series 2018B, 4.35% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.35%
TOTAL PROJECT DEBT		$ 25	25
Debentures | Debenture 2019A, 4.125%, Due 2049
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.125%
TOTAL PROJECT DEBT		$ 700	700
Debentures | Debenture 2019A, 3.73%, Due 2049
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.73%
TOTAL PROJECT DEBT		$ 43	43
Debentures | Debenture 2020B, 3.95%, Due 2050
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.95%
TOTAL PROJECT DEBT		$ 1,000	1,000
Debentures | Debenture 2020B, 3.24%, Due 2050
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.24%
TOTAL PROJECT DEBT		$ 40	40
Debentures | Debenture 2021B, 3.17%, Due 2051
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.17%
TOTAL PROJECT DEBT		$ 30	30
Debentures | Debenture 2021C, 3.20%, Due 2051
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.20%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2022A, 6.15%, Due 2052
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.15%
TOTAL PROJECT DEBT		$ 700	700
Debentures | Debenture 2023C, 5.90%, Due 2053
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.90%
TOTAL PROJECT DEBT		$ 900	900
Debentures | Debenture 2023A, 6.59%, Due 2053
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.59%
TOTAL PROJECT DEBT		$ 50	50
Debentures | Debenture 2024B, 5.70%, Due 2054
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL PROJECT DEBT		$ 1,000	1,000
Debentures | Debenture 2024A, 5.41%, Due 1954
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.41%
TOTAL PROJECT DEBT		$ 125	125
Debentures | Debenture Series 2014C, 4.625% Due 2054
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.625%
TOTAL PROJECT DEBT		$ 750	750
Debentures | Debenture 2024E, 5.50%, Due 2055
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL PROJECT DEBT		$ 650	650
Debentures | Debenture 2025A, 5.99%, Due 1955
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.99%
TOTAL PROJECT DEBT		$ 250	0
Debentures | Debenture 2025A, 5.75 Percent, Due 2055
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.75%
TOTAL PROJECT DEBT		$ 900	0
Debentures | Debenture Series 2016C, 4.30% Due 2056
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.30%
TOTAL PROJECT DEBT		$ 500	500
Debentures | Debenture Series 2017C, 4.00% Due 2057
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.00%
TOTAL PROJECT DEBT		$ 350	350
Debentures | Debenture Series 2018B, 4.50% Due 2058
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL PROJECT DEBT		$ 700	700
Debentures | Debenture 2019B, 3.70%, Due 2059
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.70%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2020C, 3.00%, Due 2060
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.00%
TOTAL PROJECT DEBT		$ 600	600
Debentures | Debenture 2021B, 3.60%, Due 2061
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.60%
TOTAL PROJECT DEBT		$ 750	750
Tax-Exempt Debt
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 225	225
Tax-Exempt Debt | Tax Exempt Debt Series 2004C, 3.47% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[3]	2.23%
TOTAL PROJECT DEBT	[3]	$ 99	99
Tax-Exempt Debt | Tax-Exempt Debt Series 2005A, 3.40% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[3]	2.20%
TOTAL PROJECT DEBT	[3]	$ 126	$ 126

[1] (c) The sale and transfer of Broken Bow II, including the related debt, was completed in January 2025. See Notes C, W and X.

[2] (a) Rates reset quarterly; December 31, 2025 floating rate equals SOFR+0.52 percent.

[3] (b) Rates reset weekly; December 31, 2025 rates shown