v3.8.0.1

RELATED PARTY TRANSACTIONS Table 1 - Related Party Transactions (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Related Party Transaction [Line Items] |  |  |
Operating expenses | $ 0 | $ 21,681 | $ 135,565
General and administrative expenses | $ 0 | 10,493 | 66,769
Expenses included in discontinued operations, net of tax |  | $ 0 | $ 2

X
- Definition Related party expenses for managing and administering the affairs of an entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References No definition available. + Details
Name: | ns_RelatedPartyGeneralAndAdministrativeExpense
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Generally recurring related party costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Also excludes general and administrative expense. + References No definition available. + Details
Name: | ns_RelatedPartyOperatingExpenses
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Related party revenue (expenses) in discontinued operations + References No definition available. + Details
Name: | ns_Relatedpartyexpensesindiscontinuedoperations
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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