XML 40 R25.htm IDEA: XBRL DOCUMENT v3.8.0.1

CONTRACTS AND AGREEMENTS (Brokerage Commissions) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Total commissions accrued to brokers	$ 318	$ 434
Total commissions as annualized percentage of average total net assets	0.02%	0.01%
Rebalancing Investments Transaction [Member]
Total commissions accrued to brokers	$ 185	$ 90
Total commissions as annualized percentage of average total net assets	58.18%	20.74%
Creation And Redemption Activity [Member]
Total commissions accrued to brokers	$ 133	$ 344
Total commissions as annualized percentage of average total net assets	41.82%	79.26%

X

- Definition

Percentage of Average Daily Net Assets

+ References

No definition available.

+ Details

Name:	unl_PercentageOfAverageDailyNetAssets
Namespace Prefix:	unl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Details

Name:	us-gaap_StatementClassOfStockAxis=unl_RebalancingInvestmentsTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=unl_CreationAndRedemptionActivityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: