XML 42 R28.htm IDEA: XBRL DOCUMENT
v3.22.2

FINANCIAL HIGHLIGHTS - Per share performance data and other supplemental financial data (Details) - $ / shares | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Per Share Operating Performance: |  |  |  |  |
Net asset value, beginning of period |  | $ 19.69 | $ 9.61 | $ 12.39 | $ 9.20
Total income (loss) |  | (1.18) | 3.18 | 6.16 | 3.61
Total expenses |  | (0.06) | (0.04) | (0.10) | (0.06)
Net increase (decrease) in net asset value |  | (1.24) | 3.14 | 6.06 | 3.55
Net asset value, end of period |  | $ 18.45 | $ 12.75 | $ 18.45 | $ 12.75
Total Return |  | (6.30%) | 32.67% | 48.91% | 38.59%
Ratios to Average Net Assets |  |  |  |  |
Total income (loss) |  | (10.84%) | 29.45% | 37.08% | 34.79%
Management fees | [1] | 0.60% | 0.60% | 0.60% | 0.60%
Total expenses excluding management fees | [1] | 0.41% | 0.80% | 0.41% | 0.67%
Net income (loss) |  | (11.09%) | 29.10% | 36.58% | 34.16%
[1] | # Annualized.

X
- Definition Average Net Assets [Abstract] + References No definition available. + Details
Name: | ung_AverageNetAssetsAbstract
Namespace Prefix: | ung_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Increase (Decrease) In Net Asset Value Per Unit + References No definition available. + Details
Name: | ung_IncreaseDecreaseInNetAssetValuePerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Management Incentive Fee Percentage + References No definition available. + Details
Name: | ung_ManagementIncentiveFeePercentage
Namespace Prefix: | ung_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net asset value per unit. + 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 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 Represents the 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 Total Expenses, Per Unit + References No definition available. + Details
Name: | ung_TotalExpensesPerUnit
Namespace Prefix: | ung_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total Income (Loss), Per Unit + 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