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FEES PAID BY THE FUND AND RELATED PARTY TRANSACTIONS - Additional Information (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Fees Paid and Related Party Transactions [Line Items] |  |  |
Percentage of Management Fee in Average Daily Total Net Assets | 0.60% |  |
Licensing fee incurred | $ 8,433 | $ 11,830 | $ 16,158
Investor tax reporting cost | 131,500 | 144,700 | 153,000
Directors' fees and expenses | 13,028 | 13,806 | 14,120
USL and the Related Public Funds, other than USCI, USAG, CPER and USMI |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |
Directors' fees and expenses | $ 556,951 | 521,689 | 536,375
On and after October 20, 2011 |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |
Fee percentage | 0.015% |  |
USL's |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |
Investor tax reporting cost | $ 13,028 | $ 13,806 | $ 14,120

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- Definition Noninterest expense related to directors' fees which are fees paid by an Entity to its directors. Directors' fees may be paid in addition to salary and other benefits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14) -URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260 + Details
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- Definition Amount of general expenses not normally included in Other Operating Costs and Expenses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.6) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
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- Definition It represent the value of license fees and other offering expenses. + References No definition available. + Details
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- Definition Percentage of Management Fee In Average Daily Total Net Assets. + References No definition available. + Details
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