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Fees Paid by the Fund and Related Party Transactions (Additional Information) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fees Paid and Related Party Transactions [Line Items]
USCF Management Fee	USL is contractually obligated to pay USCF a fee, which is paid monthly, equal to 0.60% per annum of average daily total net assets.
Ongoing Registration Fees and Other Offering Expenses	$ 0	$ 1,350	$ 82,385
Licensing fee incurred	10,849	7,910	12,774
Estimated investor tax reporting cost	100,000	169,000	150,000
Estimated directors' fees and expenses	9,808	15,649	19,340
USL and the Related Public Funds, other than USCI, USAG, CPER and USMI
Fees Paid and Related Party Transactions [Line Items]
Estimated directors' fees and expenses	$ 569,303	$ 567,863	$ 555,456
Licensing Agreements | On and after October 20, 2011
Fees Paid and Related Party Transactions [Line Items]
Fee percentage	0.015%

X

- Definition

Costs incurred and are directly related to generating license revenue. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(e))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Balance Type:	debit
Period Type:	duration

X

- Definition

Description of the nature of payments to managing member or general partner for management of the day-to-day business functions of the limited liability company (LLC) or limited partnership (LP), including the fee rate, basis of calculation, relevant accounting period, whether the fee is paid to an entity other than the managing member or general partner, or whether the fee is waived.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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X

- 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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.14)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of general expenses not normally included in Other Operating Costs and Expenses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.6)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Balance Type:	debit
Period Type:	duration

X

- Definition

Base Fee Percentage

+ References

No definition available.

+ Details

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- Definition

Fees Paid and Related Party Transactions [Line Items]

+ References

No definition available.

+ Details

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- Definition

Registration Fees and Other Offering Expenses

+ References

No definition available.

+ Details

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- Details

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- Details

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