Aggregate storage capacity of tanks acquired in the business combination, in barrels.

No definition available.

Name:	ns_AcquiredStorageCapacity
Namespace Prefix:	ns_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The time frame used to determine environmental costs accrued.

+ References

No definition available.

+ Details

Name:	ns_EnvironmentalRemediationCostsTimePeriodUsed
Namespace Prefix:	ns_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

- Definition

Ownership percentage of entity sold

+ References

No definition available.

+ Details

Name:	ns_OwnershipPercentageofEntitySold
Namespace Prefix:	ns_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tax year that remains open to examination under enacted tax laws

+ References

No definition available.

+ Details

Name:	ns_TaxYearsSubjectToExamination
Namespace Prefix:	ns_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

+ Details

Name:	us-gaap_AssetRetirementObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

+ Details

Name:	us-gaap_UnrecognizedTaxBenefits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ns_LindenAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ns_AxeonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General, Narrative (Details) bbl in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013	Jan. 02, 2015 bbl	Feb. 26, 2014
Business Acquisition [Line Items]
Unrecognized tax benefits	$ 0.0	$ 0.0
Tax years subject to examination	For U.S. federal and state purposes, as well as for our major non-U.S. jurisdictions, tax years subject to examination are 2011 through 2014, according to standard statute of limitations.
Asset retirement obligation	$ 0.6	$ 0.8
Environmental remediation costs, time period used, in years	20 years
Limited Partners Ownership Interest	98.00%	98.00%	98.00%
General Partner Ownership Interest	2.00%	2.00%	2.00%
Linden Acquisition
Business Acquisition [Line Items]
Acquired Storage Capacity \| bbl				4.3
Axeon [Member]
Business Acquisition [Line Items]
Ownership Percentage of Entity Sold					50.00%