v3.20.2

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS Narrative (Details) - NuStar Energy | 9 Months Ended
--- | ---
Sep. 30, 2020
NuStar Logistics |
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] |
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest | 100.00%
NuPOP |
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] |
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest | 100.00%

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership. + References No definition available. + Details
Name: | us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_OwnershipAxis=ns_NustarLogisticsLpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ns_NustarEnergyLpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=ns_NustarPipelineOperatingPartnershipLpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |