Commitments and Contingencies Disclosure [Line Items]

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Number of Investment Funds

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Number of Liable Former Directors

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Obligation to Return Cash or Securities Received as Collateral on standby letters of credit

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Cash collateralization percentage generally required for a securities lending transaction.

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This item represents the amount of securities lending indemnifications collateral.

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This item represents securities lending indemnifications - joint venture

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Standby letters of credit, expiring after One Through Five Years

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The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
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-Name Accounting Standards Codification
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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Number of claims dismissed.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Number of claims settled.

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Amount of damages awarded to the plaintiff in the legal matter.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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Commitments and contingent liabilities - Narrative (Details)											9 Months Ended	28 Months Ended
	Sep. 04, 2025 USD ($)	Jul. 30, 2025 USD ($)	Apr. 07, 2025 USD ($)	Aug. 14, 2024 USD ($)	Aug. 24, 2022 claim	Jun. 07, 2022 USD ($)	May 09, 2022 USD ($)	May 20, 2021 USD ($) claim	Sep. 09, 2020 USD ($) director claim	Dec. 17, 2015 claim	Sep. 30, 2025 USD ($) claim	Feb. 28, 2023 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)	Aug. 21, 2023 investmentFund	Oct. 31, 2022 claim	Dec. 31, 2021 claim	Feb. 28, 2017 claim	May 31, 2016 claim	Dec. 31, 2009 claim	Nov. 30, 2009 claim
Commitments and Contingencies Disclosure [Line Items]
Lending commitment maturing in less than one year											$ 31,600,000,000
Lending commitment maturing in one to five years											22,200,000,000
Lending commitment maturing over five years											266,000,000
Allowance for credit losses on lending related commitments											$ 63,000,000		$ 70,000,000	$ 72,000,000	$ 75,000,000
Collateralization percentage generally required for a securities lending transaction with indemnification against broker default											102.00%
Securities lending indemnifications, secured amount of collateral											$ 650,000,000,000			574,000,000,000
Securities lending indemnifications, joint venture											81,000,000,000			60,000,000,000
Securities lending indemnifications, collateral joint venture											86,000,000,000			64,000,000,000
Unsettled Repurchase Agreements
Commitments and Contingencies Disclosure [Line Items]
Unsettled repurchase and reverse repurchase agreements											0			0
Unsettled Reverse Repurchase Agreements
Commitments and Contingencies Disclosure [Line Items]
Unsettled repurchase and reverse repurchase agreements											$ 84,700,000,000			96,100,000,000
Mortgage-Securitization Trusts Proceedings \| Federal Court
Commitments and Contingencies Disclosure [Line Items]
Number of lawsuits or class actions (claim) \| claim																			2
Mortgage-Securitization Trusts Proceedings \| State Court
Commitments and Contingencies Disclosure [Line Items]
Number of lawsuits or class actions (claim) \| claim											3						2	1
Matters Related to R. Allen Stanford
Commitments and Contingencies Disclosure [Line Items]
Number of lawsuits or class actions (claim) \| claim																				1	2	1
New claims filed, number (in claims) \| claim											3
Brazilian Postalis Litigation
Commitments and Contingencies Disclosure [Line Items]
New claims filed, number (in claims) \| claim										3
Damages awarded, value		$ 185,000,000	$ 3,000,000			$ 2,000,000	$ 20,000,000	$ 3,000,000	$ 50,000,000
Number of investment funds \| investmentFund																4
Damages sought, value									$ 2,000,000
Number of claims dismissed (claim) \| claim					1
Claims settled, number (in claims) \| claim								1	1
Number of liable former Directors \| director									2
German Tax Matters \| Foreign Tax Authority
Commitments and Contingencies Disclosure [Line Items]
Damages sought, value												$ 150,000,000
Off-Channel Business-Related Communications
Commitments and Contingencies Disclosure [Line Items]
Damages awarded, value	$ 500,000			$ 40,000,000
Lawsuits In The Russian Federation
Commitments and Contingencies Disclosure [Line Items]
Damages sought, value											$ 251,000,000
Maximum
Commitments and Contingencies Disclosure [Line Items]
Loss contingency, aggregate range of reasonable loss (up to)											780,000,000
Standby letters of credit
Commitments and Contingencies Disclosure [Line Items]
Standby letters of credit (SBLC) collateralized with cash and securities											218,000,000			173,000,000
SBLC expiring within one year											1,100,000,000
SBLC expiring within one to five years											453,000,000
SBLC expiring over five years											0
Off-balance sheet credit risks											1,582,000,000			1,641,000,000
Commercial letters of credit
Commitments and Contingencies Disclosure [Line Items]
Off-balance sheet credit risks											$ 42,000,000			$ 24,000,000