v3.8.0.1

PARTNERS' EQUITY Narrative 1 (Details) $ in Millions | 3 Months Ended
--- | ---
Jun. 30, 2017 USD ($)
Partners' Capital Notes [Abstract] |
Incentive distribution waiver | $ 22.0
Number of periods covered by waiver | 10

X
- Definition Maximum aggregate amount of incentive distribution payments the general partner agrees to forgo. + References No definition available. + Details
Name: | ns_IncentiveDistributionWaiver
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of consecutive quarters covering the incentive distribution waiver period. + References No definition available. + Details
Name: | ns_NumberOfPeriodsCoveredByWaiver
Namespace Prefix: | ns_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PartnersCapitalNotesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration