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FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES (Additional Information) (Detail) - USD ($) | Dec. 31, 2018 | Dec. 31, 2017
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Money Market Funds [Member] |  |
Loss Contingencies [Line Items] |  |
Deposits in domestic and foreign financial institutions, including cash investments in money market funds | $ 52,000,000 | $ 150,000,000
US Treasury Securities [Member] |  |
Loss Contingencies [Line Items] |  |
Deposits in domestic and foreign financial institutions, including cash investments in money market funds | $ 1,604,935,976 | $ 1,841,256,955

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- Definition The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition 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. + References No definition available. + Details
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- Details
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- Details
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