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FAIR VALUE OF FINANCIAL INSTRUMENTS - Valuation of UNG's securities using the fair value hierarchy (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Short-Term Investments
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	$ 288,950,000	$ 317,800,000
Exchange-Traded Futures Contracts | United States Contracts
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	(82,506,416)	(144,765,937)
Exchange-Traded Futures Contracts | OTC Commodity Swap Contracts
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	(2,004)
Level 1 | Short-Term Investments
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	288,950,000	317,800,000
Level 1 | Exchange-Traded Futures Contracts | United States Contracts
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	(82,506,416)	$ (144,765,937)
Level 2 | Exchange-Traded Futures Contracts | OTC Commodity Swap Contracts
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair value of securities	$ (2,004)

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- Definition

Line items represents the information pertaining to fair value of financial instruments.

+ References

No definition available.

+ Details

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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