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ORGANIZATION AND BUSINESS (Details) |  | 1 Months Ended | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 04, 2018 $ / shares shares | Apr. 30, 2007 | Apr. 18, 2007 USD ($) $ / shares shares | Jun. 30, 2021 contract $ / shares $ / item | Mar. 31, 2021 $ / shares | Dec. 31, 2020 $ / shares | Jun. 30, 2020 $ / shares | Mar. 31, 2020 $ / shares | Dec. 31, 2019 $ / shares
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Number of successive valuation days |  |  |  | 30 days |  |  |  |  |
Average daily percentage change in the price of the Benchmark Futures Contract considered |  |  |  | 10.00% |  |  |  |  |
Fee paid by Authorized Purchasers for each order placed to create one or more Creation Baskets or to redeem one or more baskets | $ / item |  |  |  | 1,000 |  |  |  |  |
Number of initially registered units on Form S-1 with the U.S. Securities and Exchange Commission |  | 30,000,000 |  |  |  |  |  |  |
Net Asset Value Per Unit | $ / shares |  |  |  | $ 12.75 | $ 9.61 | $ 9.20 | $ 10.25 | $ 12.43 | $ 16.91
Number of units issued | shares |  |  | 200,000 |  |  |  |  |  |
Value of unit issued | $ |  |  | $ 10,001,000 |  |  |  |  |  |
Number of registered units |  |  |  | 2,280,000,000 |  |  |  |  |
Committee For Uniform Securities Identification Procedure Cusip | CUSIP number for UNG’s shares changed to 912318300 |  |  |  |  |  |  |  |
Prior to Reverse Split [Member] |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Net Asset Value Per Unit | $ / shares | $ 5.69 |  | $ 50.00 |  |  |  |  |  |
Issued units | shares | 97,466,476 |  |  |  |  |  |  |  |
Stockholders' Equity, Reverse Stock Split | 1-for-4 reverse share split |  |  |  |  |  |  |  |
Following Reverse Split [Member] |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Net Asset Value Per Unit | $ / shares | $ 22.76 |  |  |  |  |  |  |  |
Capital Units, Outstanding | shares | 24,366,619 |  |  |  |  |  |  |  |
Creation Baskets [Member] |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Number of units per basket | $ / item |  |  |  | 100,000 |  |  |  |  |
Redemption Baskets [Member] |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Number of units per basket | $ / item |  |  |  | 100,000 |  |  |  |  |
Open Commodity Futures Contracts, Long [Member] | United States Contracts | NYMEX Natural Gas Futures Contracts [Member] |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |
Number of Contracts | contract |  |  |  | 7,612 |  |  |  |  |

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