Fair Value Option - Summary of Fair Value and Unpaid Principal Balance (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Commercial loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Commercial loans held for sale, Fair Value	$ 733	$ 626
Commercial loans held for sale, Unpaid Principal Balance	843	721
Fair Value Over (Under) Unpaid Principal Balance	(110)	(95)
Fixed rate long-term debt
Fair Value, Option, Quantitative Disclosures [Line Items]
Fixed rate long-term debt, Fair Value	808	831
Fixed rate long-term debt, Unpaid Principal Balance	785	791
Fair Value Over (Under) Unpaid Principal Balance	23	40
Fixed rate long-term debt \| Structured notes
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt	6,840	7,435
Hybrid instruments, Unpaid Principal Balance	6,815	7,093
Fair Value Over (Under) Unpaid Principal Balance	25	342
Structured deposits
Fair Value, Option, Quantitative Disclosures [Line Items]
Hybrid instruments, structured deposits, Fair Value	3,539	3,570
Hybrid instruments, Unpaid Principal Balance	3,292	3,260
Fair Value Over (Under) Unpaid Principal Balance	$ 247	$ 310

Fair Value Over (Under) Unpaid Principal Balance

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Fixed-rate debt accounted for under fair value option.

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Unpaid Principal Balance Commercial Syndicated Loans Held For Sale Carried At Fair Value

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Unpaid principal balance on fixed-rate debt accounted for under FVO.

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Unpaid Principal Balance On Hybrid Instruments At Fair Value Option

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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