Other assets - Components of Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Other Assets [Abstract]
Corporate/bank-owned life insurance	$ 5,349	$ 5,301
Accounts receivable	4,187	3,619
Fails to deliver	3,531	1,371
Software	1,999	1,884
Prepaid pension assets	1,683	1,556
Equity in a joint venture and other investments	1,409	1,259
Qualified affordable housing project investments	1,104	1,145
Renewable energy investments	1,066	1,206
Income taxes receivable	610	599
Assets of consolidated investment management funds	505	487
Prepaid expense	488	477
Federal Reserve Bank stock	470	479
Seed capital	255	215
Fair value of hedging derivatives	238	19
Other	1,904	1,338
Total other assets	24,798	20,955
Federal Home Loan Bank stock, at cost	$ 7	$ 7

Assets of Consolidated Investment Management Funds

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Equity in joint ventures and other investments

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Renewable Energy Investments

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Seed Capital investments

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount of investment in qualified affordable housing projects.

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The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

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Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Federal Reserve Bank stock represents an equity interest in the Federal Reserve Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Carrying amount as of the balance sheet date of income taxes previously overpaid to tax authorities (such as U.S. Federal, state and local tax authorities) representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Also called income tax refund receivable.

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This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Amount of assets classified as other.

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Amount of other miscellaneous assets.

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Carrying amount as of the balance sheet date of expenditures made in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs.

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Amount receivable from broker-dealers and clearing organizations, including, but not limited to, securities failed-to-deliver, certain deposits for securities borrowed, open transactions, good faith and margin deposits, commissions and floor brokerage receivables.

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