v3.8.0.1

SUBSEQUENT EVENTS (Details) - $ / shares | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Feb. 07, 2018
Subsequent Event [Line Items] |  |  |  |  |
General partner ownership interest |  | 2.00% | 2.00% | 2.00% |
NuStar Energy common units owned by NuStar GP Holdings |  | 10,214,626 |  |  |
Subsequent Event [Member] |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |
Common unit conversion rate |  |  |  |  | 55.00%
Greehey Unitholders ownership interest |  |  |  |  | 21.00%
Scenario, Plan [Member] | Subsequent Event [Member] |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |
Common limited partner quarterly distribution per unit reset | $ 0.60 |  |  |  |
Common limited partner quarterly distribution per unit annualized reset | $ 2.40 |  |  |  |

X
- Definition Rate applied to the conversion of outstanding common units at the effective time of the merger (percent of acquirer's common unit to be exchanged per acquiree unit). + References No definition available. + Details
Name: | ns_ConversionRateOfCommonUnitsForMerger
Namespace Prefix: | ns_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

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- Definition Expected per unit quarterly distribution annualized to common limited partners to be declared and paid. + References No definition available. + Details
Name: | ns_ExpectedPerUnitQuarterlyDistributionAnnualizedToCommonLimitedPartners
Namespace Prefix: | ns_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected per unit quarterly distribution to common limited partners to be declared and paid. + References No definition available. + Details
Name: | ns_ExpectedPerUnitQuarterlyDistributionToCommonLimitedPartners
Namespace Prefix: | ns_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

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- Definition The general partner ownership interest (ownership percentage) in the limited partnership. Excludes other ownership interests held by the general partner in the limited partnership. + References No definition available. + Details
Name: | ns_GeneralPartnerOwnershipInterest
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage investment held by Greehey Unitholders in NuStar GP, LLC. + References No definition available. + Details
Name: | ns_GreeheyUnitholdersOwnershipPercentage
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Common Limited Partner Units Owned by General Partner + References No definition available. + Details
Name: | ns_NumberofCommonLimitedPartnerUnitsOwnedbyGeneralPartner
Namespace Prefix: | ns_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |