v3.10.0.1

PARTNERS' EQUITY (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2018
Distributions Made to Limited Partners and General Partner [Line Items] |
Schedule of Changes in Partners' Equity [Table Text Block] | The following table summarizes changes to our partners’ equity, which excludes the Series D Preferred Units, (in thousands of dollars):
Balance as of January 1, 2018 | $ | 2,480,089 |
Net income | 155,320 |
Unit-based compensation | 3,051 |
Other comprehensive income | 18,303 |
Distributions to partners | (204,347 | )
Issuance of common units, including contribution from general partner | 10,204 |
Other | (6,143 | )
Balance as of June 30, 2018 | $ | 2,456,477 |
Schedule of Distribution Waterfall [Table Text Block] | Prior to the Merger, our available cash was distributed based on the percentages shown below:
|  | Percentage of Distribution
Quarterly Distribution Amount per Common Unit |  | Common Unitholders |  | General Partner Including Incentive Distributions
Up to $0.60 |  | 98% |  | 2%
Above $0.60 up to $0.66 |  | 90% |  | 10%
Above $0.66 |  | 75% |  | 25%
Schedule of Distributions To General and Common Limited Partners [Table Text Block] | The following table reflects the allocation of total cash distributions to the general partner and common limited partners applicable to the period in which the distributions were earned:
| Three Months Ended June 30, |  | Six Months Ended June 30,
| 2018 |  | 2017 |  | 2018 |  | 2017
| (Thousands of Dollars, Except Per Unit Data)
General partner interest | $ | — |  |  | $ | 2,302 |  |  | $ | 1,141 |  |  | $ | 4,645 |
General partner incentive distribution | — |  |  | 10,912 |  |  | — |  |  | 23,824 |
Total general partner distribution | — |  |  | 13,214 |  |  | 1,141 |  |  | 28,469 |
Common limited partners’ distribution | 64,205 |  |  | 101,869 |  |  | 120,121 |  |  | 203,782 |
Total cash distributions | $ | 64,205 |  |  | $ | 115,083 |  |  | $ | 121,262 |  |  | $ | 232,251 |
Cash distributions per unit applicable to common limited partners | $ | 0.60 |  |  | $ | 1.095 |  |  | $ | 1.200 |  |  | $ | 2.190 |
Distributions Made to Common Limited and General Partners, by Distribution [Table Text Block] | The following table summarizes information about our quarterly cash distributions to our general partner and common limited partners:
Quarter Ended |  | Cash Distributions Per Unit |  | Total Cash Distributions |  | Record Date |  | Payment Date
|  |  |  | (Thousands of Dollars) |  |  |  |
June 30, 2018 |  | $ | 0.600 |  |  | $ | 64,205 |  |  | August 7, 2018 |  | August 13, 2018
March 31, 2018 |  | $ | 0.600 |  |  | $ | 57,057 |  |  | May 8, 2018 |  | May 14, 2018
December 31, 2017 |  | $ | 1.095 |  |  | $ | 115,267 |  |  | February 8, 2018 |  | February 13, 2018
Schedule of Calculation of Net Income Applicable to General Partner [Table Text Block] | The following table details the calculation of net income applicable to the general partner:
| Three Months Ended June 30, |  | Six Months Ended June 30,
| 2018 |  | 2017 |  | 2018 |  | 2017
| (Thousands of Dollars, Except Percentage Data)
Net income | $ | 29,399 |  |  | $ | 26,250 |  |  | $ | 155,532 |  |  | $ | 84,190 |
Less preferred limited partner interest | 16,245 |  |  | 9,950 |  |  | 32,235 |  |  | 14,763 |
Less general partner incentive distribution | — |  |  | 10,912 |  |  | — |  |  | 23,824 |
Net income after preferred limited partner interest and general partner incentive distribution | 13,154 |  |  | 5,388 |  |  | 123,297 |  |  | 45,603 |
General partner interest allocation | 2 | % |  | 2 | % |  | 2 | % |  | 2 | %
General partner interest allocation of net income | 263 |  |  | 108 |  |  | 2,466 |  |  | 912 |
General partner incentive distribution | — |  |  | 10,912 |  |  | — |  |  | 23,824 |
Net income applicable to general partner | $ | 263 |  |  | $ | 11,020 |  |  | $ | 2,466 |  |  | $ | 24,736 |
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | The balance of and changes in the components included in AOCI were as follows:
| Foreign Currency Translation |  | Cash Flow Hedges |  | Pension and Other Postretirement Benefits |  | Total
| (Thousands of Dollars)
Balance as of January 1, 2018 | $ | (51,603 | ) |  | $ | (24,304 | ) |  | $ | (9,020 | ) |  | $ | (84,927 | )
Other comprehensive (loss) income: |  |  |  |  |  |  |
Other comprehensive (loss) income before reclassification adjustments | (6,379 | ) |  | 22,527 |  |  | — |  |  | 16,148 |
Net gain on pension costs reclassified into other income, net | — |  |  | — |  |  | (407 | ) |  | (407 | )
Net loss on cash flow hedges reclassified into interest expense, net | — |  |  | 2,552 |  |  | — |  |  | 2,552 |
Other | 60 |  |  | — |  |  | (50 | ) |  | 10 |
Other comprehensive (loss) income | (6,319 | ) |  | 25,079 |  |  | (457 | ) |  | 18,303 |
Balance as of June 30, 2018 | $ | (57,922 | ) |  | $ | 775 |  |  | $ | (9,477 | ) |  | $ | (66,624 | )
Preferred Limited Partner [Member] |
Distributions Made to Limited Partners and General Partner [Line Items] |
Distributions Made to Limited Partner, by Distribution [Table Text Block] | The following table summarizes information about our cash distributions on our 8.50% Series A, 7.625% Series B and 9.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units:
Period |  | Cash Distributions Per Unit |  | Total Cash Distributions |  | Record Date |  | Payment Date
|  |  |  | (Thousands of Dollars) |  |  |  |
Series A Preferred Units: |  |  |  |  |  |  |  |
June 15, 2018 - September 14, 2018 |  | $ | 0.53125 |  |  | $ | 4,813 |  |  | September 4, 2018 |  | September 17, 2018
March 15, 2018 - June 14, 2018 |  | $ | 0.53125 |  |  | $ | 4,813 |  |  | June 1, 2018 |  | June 15, 2018
December 15, 2017 - March 14, 2018 |  | $ | 0.53125 |  |  | $ | 4,813 |  |  | March 1, 2018 |  | March 15, 2018
Series B Preferred Units: |  |  |  |  |  |  |  |
June 15, 2018 to September 14, 2018 |  | $ | 0.47657 |  |  | $ | 7,339 |  |  | September 4, 2018 |  | September 17, 2018
March 15, 2018 to June 14, 2018 |  | $ | 0.47657 |  |  | $ | 7,339 |  |  | June 1, 2018 |  | June 15, 2018
December 15, 2017 to March 14, 2018 |  | $ | 0.47657 |  |  | $ | 7,339 |  |  | March 1, 2018 |  | March 15, 2018
Series C Preferred Units: |  |  |  |  |  |  |  |
June 15, 2018 to September 14, 2018 |  | $ | 0.56250 |  |  | $ | 3,881 |  |  | September 4, 2018 |  | September 17, 2018
March 15, 2018 to June 14, 2018 |  | $ | 0.56250 |  |  | $ | 3,881 |  |  | June 1, 2018 |  | June 15, 2018
November 30, 2017 - March 14, 2018 |  | $ | 0.65625 |  |  | $ | 4,528 |  |  | March 1, 2018 |  | March 15, 2018

X
- Definition Tabular disclosure of payment of cash made to common limited and general partners of a limited partnership (LP). + References No definition available. + Details
Name: | ns_DistributionsMadeToCommonLimitedAndGeneralPartnersByDistributionTableTextBlock
Namespace Prefix: | ns_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Distributions Made to Limited Partners and General Partner [Line Items] + References No definition available. + Details
Name: | ns_DistributionsMadeToLimitedPartnersAndGeneralPartnerLineItems
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Calculation of Net Income Applicable to General Partner [Table Text Block] + References No definition available. + Details
Name: | ns_ScheduleOfCalculationOfNetIncomeApplicableToGeneralPartnerTableTextBlock
Namespace Prefix: | ns_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule describing the distribution waterfall. + References No definition available. + Details
Name: | ns_ScheduleOfDistributionWaterfallTableTextBlock
Namespace Prefix: | ns_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Distributions To General and Common Limited Partners [Table Text Block] + References No definition available. + Details
Name: | ns_ScheduleofDistributionsToGeneralandCommonLimitedPartnersTableTextBlock
Namespace Prefix: | ns_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of payment of cash or stock made to limited partner of limited partnership (LP). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 + Details
Name: | us-gaap_DistributionsMadeToLimitedPartnerByDistributionTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of accumulated other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580 + Details
Name: | us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of changes in the separate accounts comprising stockholders' equity (in addition to retained earnings) and of the changes in the number of shares of equity securities during at least the most recent annual fiscal period and any subsequent interim period presented is required to make the financial statements sufficiently informative if both financial position and results of operations are presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 + Details
Name: | us-gaap_ScheduleOfStockholdersEquityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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