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Collateralized Transactions (Amounts Related to Collateralized Transactions) (Details) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Permitted To Repledge [Member] |  |  |
Collateralized Transactions [Line Items] |  |  |
Securities lending transactions |  | $ 23,662 | $ 13,768
Agreements to resell | [1] | 11,231 | 11,117
Customer margin assets |  | 30,236 | 17,773
Total collateralized transactions |  | 65,129 | 42,658
Sold Or Repledged [Member] |  |  |
Collateralized Transactions [Line Items] |  |  |
Securities lending transactions |  | 3,041 | 3,621
Agreements to resell | [1] | 11,231 | 11,117
Customer margin assets |  | 9,013 | 7,172
Total collateralized transactions |  | $ 23,285 | $ 21,910
[1] | As of December 31, 2017, $9.2 billion or 82% (as of December 31, 2016, $11.0 billion or 99%) of securities acquired through agreements to resell that are shown as repledged have been deposited in a separate bank account for the exclusive benefit of customers in accordance with SEC Rule 15c3-3.

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- Definition Market value of collateral received in reverse repurchase transactions + References No definition available. + Details
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- Definition Collateralized Transactions [Line Items] + References No definition available. + Details
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- Definition Total market value of collateralized transactions as of the balance sheet date. + References No definition available. + Details
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- Definition Fair value as of the balance sheet date of customer securities accepted as collateral by the entity that it is permitted by contract or custom to sell or re-pledge to counterparties as collateral. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=64858031&loc=SL6224234-111729 + Details
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- Details
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- Details
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