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: