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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.

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The amount of fee paid per order.

No definition available.

Name:	ung_FeePaidPerOrder
Namespace Prefix:	ung_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Net asset value per unit.

No definition available.

Name:	ung_NetAssetValuePerUnit
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Number of shares registered.

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 units per Basket.

No definition available.

Name:	ung_NumberOfUnitsPerBasket
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Period Type:	instant

Number of initially registered shares.

No definition available.

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Period Type:	duration

Organization, Consolidation and Presentation of Financial Statements Disclosure

No definition available.

Name:	ung_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItems
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Data Type:	xbrli:stringItemType
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Number of shares issued during the period.

No definition available.

Name:	ung_UnitsIssuedDuringPeriodUnitsNewIssues
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Period Type:	duration

Amount received from the issuance of new shares during the period.

No definition available.

Name:	ung_UnitsIssuedDuringPeriodValueNewIssues
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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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Data Type:	na
Balance Type:
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Namespace Prefix:
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