Net interest income (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Jun. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Interest income
Deposits with the Federal Reserve and other central banks	$ 892	$ 937	$ 1,188	$ 2,655	$ 3,608
Deposits with banks	81	87	109	252	340
Federal funds sold and securities purchased under resale agreements	3,159	3,176	2,874	9,257	7,938
Loans	1,062	1,032	1,142	3,093	3,322
Securities	1,306	1,281	1,264	3,798	3,713
Trading securities	94	89	75	264	219
Total interest income	6,594	6,602	6,652	19,319	19,140
Interest expense
Deposits	1,813	1,840	2,271	5,375	6,713
Federal funds purchased and securities sold under repurchase agreements	2,829	2,875	2,620	8,314	7,296
Trading liabilities	37	35	22	95	66
Other borrowed funds	2	6	3	12	15
Commercial paper	38	29	21	81	34
Customer payables	180	162	170	499	477
Long-term debt	459	452	497	1,345	1,421
Total interest expense	5,358	5,399	5,604	15,721	16,022
Net interest income	1,236	1,203	1,048	3,598	3,118
Provision for credit losses	(7)	(17)	23	(6)	50
Net interest income after provision for credit losses	$ 1,243	$ 1,220	$ 1,025	$ 3,604	$ 3,068

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Interest income derived from funds deposited with the Federal Reserve and other central banks.

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Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.

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Amount of operating dividend and interest income, including amortization and accretion of premiums and discounts, on securities.

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

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Amount of interest expense on commercial paper.

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Aggregate amount of interest expense on all deposits.

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The aggregate expense incurred on federal funds purchased and securities sold under agreements to repurchase. If amounts recognized as payables under repurchase agreements have been offset against amounts recognized as receivables under reverse repurchase agreements and reported as a net amount on the balance sheet, the income and expense from these agreements may be reported on a net basis.

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Aggregate amount of interest paid or due on all long-term debt.

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Amount of interest expense classified as operating.

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Interest expense incurred during the reporting period on other short-term borrowings.

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Interest expense incurred on short positions arising from sales of securities and other assets, which the entity does not own, to other parties. Trading liabilities includes the fair value of derivative contracts held for trading that are in loss positions.

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Interest income derived from funds deposited with both domestic and foreign financial institutions including funds in money market and other accounts.

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Amount of interest income or expense, including any amortization and accretion (as applicable) of discounts and premiums, including consideration of the provisions for loan, lease, credit, and other related losses.

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Amount of interest income (expense) classified as operating.

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The aggregate interest income earned from (1) the lending of excess federal funds to another commercial bank requiring such for its legal reserve requirements and (2) securities purchased under agreements to resell.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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