Other Assets - Net Benefits Attributable to Tax Equity Investments under the Proportional Amortization Method (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Equity Method Investments and Joint Ventures [Abstract]
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration]	Provision for income taxes	Provision for income taxes	Provision for income taxes	Provision for income taxes
Income tax credits and other income tax benefits	$ 75	$ 74	$ 227	$ 227
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Provision for income taxes	Provision for income taxes	Provision for income taxes	Provision for income taxes
Proportional amortization	$ (60)	$ (59)	$ (184)	$ (177)
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, after Amortization, Statement of Cash Flows [Extensible Enumeration]	Depreciation and amortization	Depreciation and amortization	Depreciation and amortization	Depreciation and amortization
Net benefits	$ 15	$ 15	$ 43	$ 50

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

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-Name Accounting Standards Codification
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Amount of amortization expense for investment that generates income tax credit and other income tax benefit under tax credit program accounted for using proportional amortization method.

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-Topic 740
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-Name Accounting Standards Codification
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Indicates line item in statement of income or comprehensive income that includes amortization expense for investment that generates income tax credit and other income tax benefit under tax credit program accounted for using proportional amortization method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
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Amount, after amortization expense, of income tax credit and other income tax benefit generated by investment under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under tax credit program not meeting condition for accounting under proportional amortization method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
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