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

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