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Capital Units, Issued

No definition available.

Name:	ung_CapitalUnitsIssued
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Period Type:	instant

Nine character alphanumeric identifier of an entity or issuer and the type of security.

No definition available.

Name:	ung_CommitteeForUniformSecuritiesIdentificationProcedureCusip
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Balance Type:	na
Period Type:	duration

Fee Paid Per Order

No definition available.

Name:	ung_FeePaidPerOrder
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Period Type:	instant

Net asset value per unit.

No definition available.

Name:	ung_NetAssetValuePerUnit
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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Number of Registered Units

No definition available.

Name:	ung_NumberOfRegisteredUnits
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Number of successive valuation days over which the average daily percentage change in the fund's NAV will be considered for achieving the entity's investment objective, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	ung_NumberOfSuccessiveValuationDays
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Number of unit per basket.

No definition available.

Name:	ung_NumberOfUnitPerBasket
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Period Type:	instant

Number of Units Registered in Period

No definition available.

Name:	ung_NumberOfUnitsRegisteredInPeriod
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Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]

No definition available.

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Units Issued During Period, Units, New Issues

No definition available.

Name:	ung_UnitsIssuedDuringPeriodUnitsNewIssues
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Units Issued During Period, Value, New Issues

No definition available.

Name:	ung_UnitsIssuedDuringPeriodValueNewIssues
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Number of capital units or capital shares outstanding. This element is relevant to issuers of face-amount certificates and registered investment companies.

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Balance held at close of period in number of contracts.

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Description of the reverse stock split arrangement. Also provide the retroactive effect given by the reverse split that occurs after the balance sheet date but before the release of financial statements.

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Namespace Prefix:
Data Type:	na
Balance Type:
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Data Type:	na
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