RELATED PARTY TRANSACTIONS Table 1 (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Related Party Transaction [Line Items]
Operating expenses	$ 0	$ 34,570	$ 21,681	$ 65,857
General and administrative expenses	$ 0	$ 17,707	$ 10,493	$ 35,093

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.

No definition available.

Name:	ns_RelatedPartyOperatingExpenses
Namespace Prefix:	ns_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration