XML 44 R30.htm IDEA: XBRL DOCUMENT
v3.23.3

FINANCIAL HIGHLIGHTS (Details) - $ / shares | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Per Share Operating Performance: |  |  |  |
Net asset value, beginning of period | $ 7.46 | $ 18.45 | $ 14.22 | $ 12.39
Total income (loss) | (0.63) | 4.90 | (7.35) | 11.06
Total expenses | (0.02) | (0.07) | (0.06) | (0.17)
Net increase (decrease) in net asset value | (0.65) | 4.83 | (7.41) | 10.89
Net asset value, end of period | $ 6.81 | $ 23.28 | $ 6.81 | $ 23.28
Total Return | (8.71%) | 26.18% | (52.11%) | 87.89%
Ratios to Average Net Assets |  |  |  |
Total income (loss) | (7.07%) | 21.70% | (39.07%) | 59.23%
Management fees | 0.60% | 0.60% | 0.60% | 0.60%
Total expenses excluding management fees | 0.34% | 0.47% | 0.42% | 0.43%
Net income (loss) | (7.31%) | 21.43% | (39.84%) | 58.45%

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

X
- Definition Per unit of increase (decrease) in net asset value. + References No definition available. + Details
Name: | ung_IncreaseDecreaseInNetAssetValuePerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of management incentive fee. + References No definition available. + Details
Name: | ung_ManagementIncentiveFeePercentage
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per unit of net asset value. + References No definition available. + Details
Name: | ung_NetAssetValuePerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of consolidated net income (loss). + References No definition available. + Details
Name: | ung_PercentageOfConsolidatedNetIncomeLoss
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of total revenue. + References No definition available. + Details
Name: | ung_PercentageOfTotalRevenue
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of rate of return on average asset. + References No definition available. + Details
Name: | ung_RateOfReturnOnAverageAsset
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of total expenses excluding management fees. + References No definition available. + Details
Name: | ung_TotalExpensesExcludingManagementFeesPercent
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per unit of total expenses. + References No definition available. + Details
Name: | ung_TotalExpensesPerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per unit of total income (loss). + References No definition available. + Details
Name: | ung_TotalIncomeLossPerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_IncreaseDecreaseInPartnersCapitalRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration