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ORGANIZATION AND BUSINESS (Details) |  | 1 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jan. 04, 2018 $ / shares shares | Feb. 21, 2012 $ / shares shares | Apr. 30, 2007 | Apr. 18, 2007 USD ($) $ / shares shares | Dec. 31, 2019 contract $ / shares $ / item | Dec. 31, 2018 $ / shares | Dec. 31, 2017 $ / shares | [1] | Dec. 31, 2016 $ / shares | [1]
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |  |
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 |  |  |  |  | $ 16.91 |  | $ 24.35 |  | $ 23.34 | $ 37.18
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 | CUSIP number for UNG's shares changed to 912318201 |  |  |  |  |  |  |  |
Operations Commenced Date |  |  |  | Apr. 18, 2007 |  |  |  |  |  |
Reverse unit split ratio | 4 | 4 |  |  |  |  |  |  |  |
Pre-split units of USNG automatically exchanged for one post-split unit | 4 | 4 |  |  |  |  |  |  |  |
Prior to Reverse Split [Member] |  |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |  |
Net Asset Value Per Unit | $ / shares | $ 5.69 | $ 5.51 |  | $ 50.00 |  |  |  |  |  |
Issued units | shares | 97,466,476 | 174,297,828 |  |  |  |  |  |  |  |
Stockholders' Equity, Reverse Stock Split | 1-for-4 reverse share 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 | $ 22.04 |  |  |  |  |  |  |  |
Capital Units, Outstanding | shares | 24,366,619 | 43,574,457 |  |  |  |  |  |  |  |
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 Futures Contracts - Long [Member] | United States Contracts |  |  |  |  |  |  |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure |  |  |  |  |  |  |  |  |  |
Number of Contracts |  |  |  |  | 20,310 | [2] | 12,935 | [3] |  |
Open 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 |  |  |  |  | 20,310 |  |  |  |  |
[1] | On January 4, 2018, there was a 1for4 reverse share split. The Statement of Changes in Partners’ Capital have been adjusted for the period shown to reflect the 1for4 reverse share split on a retroactive basis.
[2] | Collateral amounted to $83,410,316 on open futures contracts.
[3] | Collateral amounted to $100,299,442 on open futures contracts.

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