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Carrying value as of the balance sheet date of the sum of the obligations to contract holders to provide to them an agreed upon rate of return pursuant to the terms of the underlying contract. These contracts represent lending by the contract holders to the entity in return for a guaranteed (primarily fixed) interest rate until maturity, unless called earlier if the contracts provide that option to the contract holders (usually institutions). There is little or no insurance risk for the entity.

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Commitments, Contingent Liabilities and Guarantees - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2019	Jun. 30, 2018	Sep. 30, 2014	Sep. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2008
Loss Contingencies
Margin account balance held by the brokerage clearing agent	$ 7		$ 7			$ 14
Visa
Loss Contingencies
Fair value of liability	172		172			195
Visa IPO, shares of Visa's Class B common stock received (in shares)																	10.1
Visa Class B shares carryover basis																	$ 0
Escrow deposit	150		150		$ 500	350	$ 600	$ 250	$ 300	$ 600	$ 450	$ 150	$ 1,565	$ 400	$ 800	$ 500	$ 3,000
Residential mortgage loans
Loss Contingencies
Fair value of liability	11		11
Make-whole payments	0	$ 0	0	$ 0
Repurchased outstanding principal	13	16	46	44
Repurchase demand request	16	$ 28	76	$ 72
Outstanding repurchase demand inventory	10		10			25
Secured Debt
Loss Contingencies
Fully and unconditionally guaranteed certain long-term borrowing obligations issued by wholly-owned issuing trust entities	62		62			62
Standby Letters of Credit
Loss Contingencies
Reserve for unfunded commitments	$ 22		$ 22			$ 22
Standby letters of credit as a percentage of total letters of credit	99.00%		99.00%			99.00%
Standby Letters of Credit \| Secured Debt
Loss Contingencies
Standby letters of credit as a percentage of total letters of credit	70.00%		70.00%			67.00%
Variable Rate Demand Note
Loss Contingencies
Total variable rate demand notes	$ 457		$ 457			$ 423
Letters of credit issued related to variable rate demand notes	91		91			102
Variable Rate Demand Note \| Debt Securities
Loss Contingencies
Total variable rate demand notes	16		16			3
Other Liabilities
Loss Contingencies
Reserve for unfunded commitments	189		189			216
Other Liabilities \| Residential mortgage loans
Loss Contingencies
Outstanding balances on residential mortgage loans sold with representation and warranty provisions	$ 8		$ 8			$ 9