XML 41 R26.htm IDEA: XBRL DOCUMENT
v3.20.2

CONTRACTS AND AGREEMENTS - Brokerage Commission (Details) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Commissions accrued to brokers | $ 369,980 | $ 290,231 | $ 1,538,224 | $ 812,893
Percentage of commissions accrued | 0.51% | 0.37% | 0.51% | 0.37%
Rebalancing Investments Transaction [Member] |  |  |  |
Commissions accrued to brokers |  |  | $ 1,370,685 | $ 691,311
Percentage of commissions accrued | 89.11% | 85.04% | 89.11% | 85.04%
Creation And Redemption Activity [Member] |  |  |  |
Commissions accrued to brokers |  |  | $ 167,539 | $ 121,582
Percentage of commissions accrued | 10.89% | 14.96% | 10.89% | 14.96%

X
- Definition Percentage of Average Daily Net Assets + References No definition available. + Details
Name: | ung_PercentageOfAverageDailyNetAssets
Namespace Prefix: | ung_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees. + References No definition available. + Details
Name: | us-gaap_FloorBrokerageExchangeAndClearanceFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=ung_RebalancingInvestmentsTransactionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=ung_TradesNecessitatedByCreationAndRedemptionActivityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |