v2.4.0.8

INCOME TAXES Narrative (Details) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Tax Disclosures [Line Items] |  |  |
Federal Statutory Income Tax Rate | 35.00% |  |
Valuation Allowance, Amount | $ 12,237,000 | $ 78,000 |
Gain on legal settlement | 0 | 28,738,000 | 0
Income Tax Expense (Benefit) | 12,753,000 | 24,450,000 | 18,555,000
Deferred Tax Liabilities | 40,494,000 | 54,786,000 |
U.S. [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Operating Loss Carryforwards | 80,000,000 |  |
Operating Loss Carryforwards, Expiration Dates | years 2021 through 2033 |  |
Valuation Allowance, Deferred Tax Asset, Change in Amount | 10,300,000 |  |
Foreign [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Operating Loss Carryforwards | 4,700,000 |  |
Operating Loss Carryforwards, Expiration Dates | years 2017 and 2018 |  |
Valuation Allowance, Deferred Tax Asset, Change in Amount | 1,800,000 |  |
Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority |  | 1,000,000 |
Income Tax Examination, Penalties and Interest Expense |  | 2,200,000 |
Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority |  | 1,300,000 |
Income Tax Examination, Penalties and Interest Expense |  | 700,000 |
St. Eustatius |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Holiday, Description | On June 1, 1989, the governments of the Netherlands Antilles and St. Eustatius approved a Free Zone and Profit Tax Agreement retroactive to January 1, 1989, which expired on December 31, 2000. This agreement required a subsidiary of Kaneb, which we acquired on July 1, 2005, to pay the greater of 2% of taxable income, as defined therein, or 500,000 Netherlands Antilles guilders (approximately $0.3 million) per year. The agreement further provided that any amounts paid in order to meet the minimum annual payment were available to offset future tax liabilities under the agreement to the extent that the minimum annual payment is greater than 2% of taxable income. On February 22, 2006, we entered into a revised agreement (the 2005 Tax and Maritime Agreement) with the governments of St. Eustatius and the Netherlands Antilles. The 2005 Tax and Maritime Agreement was effective beginning January 1, 2005 and expires on December 31, 2014. Under the terms of the 2005 Tax and Maritime Agreement, we agreed to make a one-time payment of 5.0 million Netherlands Antilles guilders (approximately $2.8 million) in full and final settlement of all of our liabilities, taxes, fees, levies, charges, or otherwise (including settlement of audits) due or potentially due to St. Eustatius. We further agreed to pay an annual minimum profit tax to St. Eustatius of 1.0 million Netherlands Antilles guilders (approximately $0.6 million), beginning as of January 1, 2005. We agreed to pay the minimum annual profit tax in twelve equal monthly installments. To the extent the minimum annual profit tax exceeds 2% of taxable profit (as defined in the 2005 Tax and Maritime Agreement), we can carry forward that excess to offset future tax liabilities. If the minimum annual profit tax is less than 2% of taxable profit, we agreed to pay that difference. |  |
Grace Energy Corporation Matter |  |  |
Tax Disclosures [Line Items] |  |  |
Gain on legal settlement |  | 28,700,000 |
Income Tax Expense (Benefit) |  | $ 10,100,000 |
Year 1 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2006 |  |
Year 1 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2003 |  |
Year 2 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2007 |  |
Year 2 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2004 |  |
Year 3 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2008 |  |
Year 3 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2005 |  |
Year 4 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2009 |  |
Year 4 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2006 |  |
Year 5 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2010 |  |
Year 5 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2007 |  |
Year 6 [Member] | Canada 1 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2011 |  |
Year 6 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2008 |  |
Year 7 [Member] | Canada 2 [Member] |  |  |
Tax Disclosures [Line Items] |  |  |
Income Tax Examination, Year under Examination | 2009 |  |

X
- Definition The domestic federal statutory tax rate applicable under enacted tax laws. + References No definition available. + Details
Name: | ns_FederalStatutoryIncomeTaxRate
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the amount of income or expense recognized in the period to settle pending or threatened litigation. + References No definition available. + Details
Name: | ns_GainOrLossOnLegalSettlement
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Range of expiration dates (years) of operating loss carryforwards. + References No definition available. + Details
Name: | ns_OperatingLossCarryforwardsExpirationDateRange
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ns_TaxDisclosuresLineItems
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e31931-109318 + Details
Name: | us-gaap_DeferredTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319 + Details
Name: | us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319 + Details
Name: | us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax year being audited in the income tax examination, in CCYY format. + References No definition available. + Details
Name: | us-gaap_IncomeTaxExaminationYearUnderExamination
Namespace Prefix: | us-gaap_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Income Tax Expense (or Benefit) -URI http://asc.fasb.org/extlink&oid=6515339 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A description of the factual circumstances giving rise to an income tax exemption or special reduction received from a taxing jurisdiction. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 11.C) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330215-122817 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28937-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 11 -Section C + Details
Name: | us-gaap_IncomeTaxHolidayDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of the change in the period in the valuation allowance for a specified deferred tax asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e32123-109318 + Details
Name: | us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration