XML 39 R24.htm IDEA: XBRL DOCUMENT v3.7.0.1

CONTRACTS AND AGREEMENTS (Brokerage Commissions) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Long Duration Contracts Assumptions By Product And Guarantee [Line Items]
Brokerage commissions	$ 4,709	$ 3,747	$ 8,841	$ 12,416
Brokerage commissions as a percentage of average daily net assets	0.02%	0.02%	0.02%	0.02%
Rebalancing Investments Transaction [Member]
Long Duration Contracts Assumptions By Product And Guarantee [Line Items]
Brokerage commissions			$ 7,074	$ 8,959
Brokerage commissions as a percentage of average daily net assets	80.01%	72.16%	80.01%	72.16%
Trades Necessitated By Creation And Redemption Activity [Member]
Long Duration Contracts Assumptions By Product And Guarantee [Line Items]
Brokerage commissions			$ 1,767	$ 3,457
Brokerage commissions as a percentage of average daily net assets	19.99%	27.84%	19.99%	27.84%

X

- Definition

The amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees.

+ References

No definition available.

+ Details

Name:	us-gaap_FloorBrokerageExchangeAndClearanceFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- 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

Name:	us-gaap_LongDurationContractsAssumptionsByProductAndGuaranteeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of Average Daily Net Assets

+ References

No definition available.

+ Details

Name:	usl_PercentageOfAverageDailyNetAssets
Namespace Prefix:	usl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_NatureOfExpenseAxis=usl_RebalancingInvestmentsTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_NatureOfExpenseAxis=usl_TradesNecessitatedByCreationAndRedemptionActivityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: