Debt - Schedule of Pledged Assets Related to Secured Borrowings and Repurchase Agreement (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	$ 64,803	$ 64,770
Secured debt	11,556	11,753
Amortized cost	25,974	25,825
Short-term borrowings	4,126	4,695
Secured debt
Pledged Assets related to secured borrowings [Line Items]
Short-term borrowings	4,126	4,695
Asset Pledged as Collateral
Pledged Assets related to secured borrowings [Line Items]
Amortized cost	3,012	3,114
Credit-Linked Notes
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	1,224	1,381
Pledged assets for Federal Home Loan Bank
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	25,900	26,000
Pledged assets for Federal Reserve Bank
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	33,600	33,700
Investment securities
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	3,187	3,292
Consumer \| Consumer automotive
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	37,151	36,807
Consumer \| Consumer mortgage
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	15,342	15,604
Commercial
Pledged Assets related to secured borrowings [Line Items]
Total assets restricted as collateral	$ 7,899	$ 7,686

Secured Debt, Long-Term And Short-Term, Combined Amount

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- Definition

Amount of assets pledged to secure a debt instrument.

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- Definition

Amortized cost excluding accrued interest, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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