Other Assets and Leases - Tax Equity Investments under the Proportional Amortization Method (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Equity Method Investments
Total proportional amortization method investment	$ 1,925	$ 1,854
Investment, Proportional Amortization Method, Elected, Statement of Financial Position [Extensible Enumeration]	Other assets
Unfunded equity contributions	$ 707	613
Funding period	5 years
Excluded tax equity investments	$ 45	$ 48
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, after Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration]	Provision for income taxes	Provision for income taxes	Provision for income taxes
Low Income Housing
Equity Method Investments
Total proportional amortization method investment	$ 1,897	$ 1,787
Renewable Energy and Other
Equity Method Investments
Total proportional amortization method investment	$ 28	$ 67

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Amount of investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under program not meeting condition for accounting under proportional amortization method.

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