The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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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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Threshold Of Derivative Liability Position Requiring Cash Collateral

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No definition available.

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Derivative Financial Instruments (Narrative) (Details) $ in Millions, ¥ in Billions, £ in Billions	3 Months Ended		9 Months Ended
	Jan. 31, 2019 JPY (¥)	Jan. 31, 2019 GBP (£)	Oct. 31, 2019 JPY (¥)	Oct. 31, 2019 GBP (£)	Oct. 31, 2019 USD ($)	Jan. 31, 2019 USD ($)
Derivative [Line Items]
Cash collateral held from counterparties					$ 219	$ 220
Threshold of derivative liability position requiring cash collateral					150
Collateral Already Posted, Aggregate Fair Value					$ 0	$ 0
Designated as hedging instrument \| Net investment hedging [Member]
Derivative [Line Items]
Notional amount of nonderivative instruments	¥ 180	£ 1.7	¥ 180	£ 1.7