XML 33 R18.htm IDEA: XBRL DOCUMENT
v3.10.0.1

CONTRACTS AND AGREEMENTS (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2018
Contractors [Abstract] |
Brokerage Commissions |
|  | For the nine months ended September 30, 2018 |  |  | For the nine months ended September 30, 2017 |
Total commissions accrued to brokers |  | $ | 1,110,685 |  |  | $ | 1,204,240 |
Total commissions as annualized percentage of average total net assets |  |  | 0.40 | % |  |  | 0.34 | %
Commissions accrued as a result of rebalancing |  | $ | 856,305 |  |  | $ | 998,598 |
Percentage of commissions accrued as a result of rebalancing |  |  | 77.10 | % |  |  | 82.92 | %
Commissions accrued as a result of creation and redemption activity |  | $ | 254,380 |  |  | $ | 205,642 |
Percentage of commissions accrued as a result of creation and redemption activity |  |  | 22.90 | % |  |  | 17.08 | %

X
- Definition Brokerage Commissions + References No definition available. + Details
Name: | ung_BrokerageCommissionsTableTextBlock
Namespace Prefix: | ung_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ContractorsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration