v3.8.0.1

PARTNERS' EQUITY Table 4 - General Partner Incentive Distributions (Details) | 12 Months Ended
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Dec. 31, 2017
Common Limited Partner [Member] | Quarterly Distributions Level 1 [Member] |
Distribution Allocation [Line Items] |
Quarterly distribution amount per common unit | Up to $0.60
Percentage of distribution allocated to common unitholders | 98.00%
Common Limited Partner [Member] | Quarterly Distributions Level 2 [Member] |
Distribution Allocation [Line Items] |
Quarterly distribution amount per common unit | Above $0.60 up to $0.66
Percentage of distribution allocated to common unitholders | 90.00%
Common Limited Partner [Member] | Quarterly Distributions Level 3 [Member] |
Distribution Allocation [Line Items] |
Quarterly distribution amount per common unit | Above $0.66
Percentage of distribution allocated to common unitholders | 75.00%
General Partner [Member] | Quarterly Distributions Level 1 [Member] |
Distribution Allocation [Line Items] |
Percentage of distribution allocated to the general partner | 2.00%
General Partner [Member] | Quarterly Distributions Level 2 [Member] |
Distribution Allocation [Line Items] |
Percentage of distribution allocated to the general partner | 10.00%
General Partner [Member] | Quarterly Distributions Level 3 [Member] |
Distribution Allocation [Line Items] |
Percentage of distribution allocated to the general partner | 25.00%

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- Definition Distribution Allocation [Line Items] + References No definition available. + Details
Name: | ns_DistributionAllocationLineItems
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Percentage of the total distribution allocated to the general partner, which includes both the general partner interest and the incentive distributions. + References No definition available. + Details
Name: | ns_PercentageOfDistributionAllocatedToGeneralPartner
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Percentage of the total distribution allocated to the common limited partners. + References No definition available. + Details
Name: | ns_PercentageofDistributionAllocatedtoCommonLimitedPartners
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Threshold (quarterly distribution amount per limited partner unit) that must be met to receive the corresponding percentage of the total distribution. + References No definition available. + Details
Name: | ns_QuarterlyDistributionAmountThresholdPerUnit
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=ns_CommonLimitedPartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | ns_DistributionTargetLevelsAxis=ns_QuarterlyDistributionsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | ns_DistributionTargetLevelsAxis=ns_QuarterlyDistributionsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | ns_DistributionTargetLevelsAxis=ns_QuarterlyDistributionsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_GeneralPartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |