v3.10.0.1

SERIES D CUMULATIVE CONVERTIBLE PREFERRED UNITS Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Jul. 13, 2018 | Jun. 29, 2018 | Jul. 13, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Class of Stock [Line Items] |  |  |  |  |  |  |
Proceeds from issuance of Series D preferred units |  |  |  |  | $ 400,000 | $ 0 |
Series D preferred units outstanding |  |  |  |  | 15,760,441 |  | 0
Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Proceeds from issuance of Series D preferred units |  | $ 400,000 |  |  |  |  |
Series D preferred units outstanding |  | 15,760,441 |  |  |  |  |
Temporary Equity, Stock Issued During Period, Value, New Issues |  | $ 370,700 |  |  |  |  |
Transaction fee percentage |  | 3.50% |  |  |  |  |
Transaction fee |  | $ 20,700 |  |  |  |  |
Unpaid dividend penalty, Per unit dividend increase |  |  |  |  | $ 0.048 |  |
Unpaid Dividend Penalty, Preferred Stock, Conversion Basis |  |  |  |  | each holder of the Series D Preferred Units may elect to convert its Series D Preferred Units into common units on a one-for-one basis |  |
Unpaid Dividend Penalty, Minimum Amount Of Acquisitions or Asset Sales Requiring Consent |  |  |  |  | $ 50,000 |  |
Convertible preferred units, terms of redemption |  |  |  |  | The Partnership may redeem all or any portion of the Series D Preferred Units, in an amount not less than $50.0 million for cash at a redemption price equal to, as applicable: (i) $31.73 per Series D Preferred Unit at any time on or after June 29, 2023 but prior to June 29, 2024; (ii) $30.46 per Series D Preferred Unit at any time on or after June 29, 2024 but prior to June 29, 2025; (iii) $29.19 per Series D Preferred Unit at any time on or after June 29, 2025; plus, in each case, the sum of any unpaid distributions on the applicable Series D Preferred Unit plus the distributions prorated for the number of days elapsed (not to exceed 90) in the period of redemption (Series D Partial Period Distributions). The holders have the option to convert the units prior to such redemption as discussed above. Additionally, at any time on or after June 29, 2028, each holder of Series D Preferred Units will have the right to require the Partnership to redeem all of the Series D Preferred Units held by such holder at a redemption price equal to $29.19 per Series D Preferred Unit plus any unpaid Series D distributions plus the Series D Partial Period Distributions. If a holder of Series D Preferred Units exercises its redemption right, the Partnership may elect to pay up to 50% of such amount in common units (which shall be valued at 93% of a volume-weighted average trading price of the common units; provided, that the common units to be issued do not, in the aggregate, exceed 15% of NuStar Energy’s common equity market capitalization at the time. |  |
Maximum number of days within partial distribution period |  |  |  |  | 90 |  |
Convertible Preferred Stock, Terms of Conversion, Change of Control |  |  |  |  | convert its Series D Preferred Units into common units on a one-for-one basis, plus any unpaid Series D distributions |  |
Change of control redemption amount |  |  |  |  | the sum of (a) $29.82 per Series D Preferred Unit plus (b) any unpaid Series D distributions plus (c) the applicable distribution amount for the distribution periods ending after the change of control event and prior to (but including) the fourth anniversary of the Initial Closing |  |
Temporary equity, accounting treatment |  |  |  |  | The Series D Preferred Units are considered redeemable securities under GAAP due to the existence of redemption provisions at the option of the holders of the Series D Preferred Units and upon a Series D Change of Control (as defined in the partnership agreement), which is outside the Partnership’s control. Therefore, they are presented as temporary equity in the mezzanine section of the consolidated balance sheets. The Series D Preferred Units have been recorded at their issuance date fair value, net of issuance costs. We reassess the presentation of the Series D Preferred Units in our consolidated balance sheets on a quarterly basis. The Series D Preferred Units are subject to accretion from their carrying value at the issuance date to the redemption value, which is based on the redemption right of the Series D Preferred Unit holders that may be exercised at any time on or after June 29, 2028, using the effective interest method over a period of ten years. The accretion will be treated in the same manner as a distribution and deducted from net income to arrive at net income attributable to common units. |  |
Accretion period |  |  |  |  | 10 years |  |
Subsequent Event [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Proceeds from issuance of Series D preferred units | $ 190,000 |  | $ 590,000 |  |  |  |
Issuance of preferred units (temporary equity) (in units) | 7,486,209 |  | 7,486,209 |  |  |  |
Units issued, price per unit | $ 25.38 |  | $ 25.38 |  |  |  |
Series D preferred units outstanding | 23,246,650 |  | 23,246,650 |  |  |  |
Temporary Equity, Stock Issued During Period, Value, New Issues | $ 185,200 |  | $ 555,900 |  |  |  |
Equity issuance costs |  |  | $ 13,400 |  |  |  |
Distribution payment date |  |  |  | Sep. 17, 2018 |  |  |
Distribution date of record |  |  |  | Sep. 04, 2018 |  |  |
Preferred Stock, Distributions, Period - June 29, 2018 to June 28, 2020 [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred units distribution percentage |  |  |  |  | 9.75% |  |
Preferred Stock, Distributions, Period - June 29, 2020 to June 28, 2023 [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred units distribution percentage |  |  |  |  | 10.75% |  |
Preferred Stock, Distributions, Period - June 29, 2023 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred units, dividend payment rate, variable |  |  |  |  | the greater of 13.75% per annum or the common unit distribution rate thereafter |  |
Preferred Stock, Distributions, Period - June 29, 2023 and thereafter [Member] | Minimum [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred units distribution percentage |  |  |  |  | 13.75% |  |
Preferred Stock, Distributions, Period - June 29, 2018 to June 15, 2019 [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Maximim percentage of distributions that may be paid in additional units |  |  |  |  | 50.00% |  |
Preferred Stock Distributions, Period - June 16, 2019 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Required amount of per unit cash dividends to permit dividend paid in kind |  |  |  |  | $ 0.635 |  |
Preferred Stock, Issuer Redemption, Period - June 29, 2023 to June 28, 2024 [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Temporary equity redemption price per unit |  |  |  |  | $31.73 per Series D Preferred Unit plus any unpaid Series D distributions plus the Series D Partial Period Distributions |  |
Preferred Stock, Issuer Redemption, Period - June 29, 2023 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Minimum redemption amount |  |  |  |  | $ 50,000 |  |
Preferred Stock, Issuer Redemption, Period - June 29, 2024 to June 28, 2025 [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Temporary equity redemption price per unit |  |  |  |  | $30.46 per Series D Preferred Unit plus any unpaid Series D distributions plus the Series D Partial Period Distributions |  |
Preferred Stock, Issuer Redemption, Period - June 29, 2025 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Temporary equity redemption price per unit |  |  |  |  | $29.19 per Series D Preferred Unit plus any unpaid Series D distributions plus the Series D Partial Period Distributions |  |
Preferred Stock, Holder Redemption, Period - June 29, 2028 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Temporary equity redemption price per unit |  |  |  |  | $29.19 per Series D Preferred Unit plus any unpaid Series D distributions plus the Series D Partial Period Distributions |  |
Percentage of redemption amount that may be paid in common limited partner units |  |  |  |  | 50.00% |  |
Volume-weighted average trading price percentage of common limited partner units |  |  |  |  | 93.00% |  |
Common limited partners' equity market capitalization, maximum allowable percentage |  |  |  |  | 15.00% |  |
Preferred Stock, Conversion, Period - June 29, 2020 and thereafter [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Convertible preferred units, terms of conversion |  |  |  |  | At any time on or after June 29, 2020, each holder of Series D Preferred Units may convert all or any portion of its Series D Preferred Units into common units on a one-for-one basis (plus any unpaid Series D distributions), subject to anti-dilution adjustments, at any time, but not more than once per quarter, so long as any conversion is for at least $50.0 million based on the Series D Preferred Unit Purchase Price (or such lesser amount representing all of a holder’s Series D Preferred Units). |  |
Minimum conversion amount |  |  |  |  | $ 50,000 |  |
Equity Issuance Date, June 29, 2018 [Member] | Subsequent Event [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred unit distribution declared |  |  |  | $ 0.525 |  |  |
Equity Issuance Date, July 13, 2018 [Member] | Subsequent Event [Member] | Series D Preferred Limited Partner [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred unit distribution declared |  |  |  | $ 0.431 |  |  |

X
- Definition Maximum percentage of Distributions that may be Paid in Additional Units + References No definition available. + Details
Name: | ns_AllowablePercentageOfDistributionPaidInKind
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum Allowable Percentage of Common Equity Market Capitalization For Redemption Paid In Kind with common equity + References No definition available. + Details
Name: | ns_AllowablePercentageofCommonEquityMarketCapitalizationForRedemptionPaidInKind
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum Percentage of Redemption Amount that may be Paid in Kind with common equity + References No definition available. + Details
Name: | ns_AllowablePercentageofRedemptionAmountPaidInKind
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Terms of Conversion upon a Change of Control of preferred equity + References No definition available. + Details
Name: | ns_ConvertiblePreferredStockTermsofConversionChangeofControl
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The redemption terms of preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity. + References No definition available. + Details
Name: | ns_Convertiblepreferredstocktermsofredemption
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Distribution payment date for preferred units + References No definition available. + Details
Name: | ns_Distributionpaymentdatepreferredunits
Namespace Prefix: | ns_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Costs incurred with the issuance of equity. + References No definition available. + Details
Name: | ns_EquityIssuanceCosts
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Maximum Number of Days Within A Partial Distribution Period + References No definition available. + Details
Name: | ns_MaximumNumberofDaysWithinAPartialDistributionPeriod
Namespace Prefix: | ns_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum amount of per unit dividend to be paid in cash before in-kind dividend permitted + References No definition available. + Details
Name: | ns_MinimumPerUnitCashDividendRequiredToPermitDividendInKind
Namespace Prefix: | ns_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity, Accretion to Redemption Value, Period + References No definition available. + Details
Name: | ns_TemporaryEquityAccretiontoRedemptionValuePeriod
Namespace Prefix: | ns_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity, Minimum amount required to be converted it conversion option is elected + References No definition available. + Details
Name: | ns_TemporaryEquityMinimumRequiredConversionAmount
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Temporary Equity, Minimum amount required to be redeemed if redemption option is elected + References No definition available. + Details
Name: | ns_TemporaryEquityMinimumRequiredRedemptionAmount
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount to be paid per share that is classified as temporary equity by entity upon redemption. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. + References No definition available. + Details
Name: | ns_TemporaryEquityRedemptionPricePerPreferredUnit
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount to be paid per share that is classified as temporary equity by entity upon redemption upon a change of control. + References No definition available. + Details
Name: | ns_TemporaryEquityRedemptionPricePerUnitChangeofControl
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Transaction Fee Paid To Purchasers Of Equity Interests, Percentage + References No definition available. + Details
Name: | ns_TransactionFeePaidToPurchasersOfEquityInterestsPercentage
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Transaction Fee Paid to Purchasers of Equity Interests + References No definition available. + Details
Name: | ns_TransactionFeePaidtoPurchasersofEquityInterests
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unpaid Dividend Penalty, Minimum Amount Of Acquisitions or Asset Sales For which consent of the holders holding a majority of the outstanding units is required + References No definition available. + Details
Name: | ns_UnpaidDividendPenaltyMinimumAmountOfAcquisitionsorAssetSalesRequiringConsent
Namespace Prefix: | ns_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unpaid dividend penalty, Per unit dividend increase + References No definition available. + Details
Name: | ns_UnpaidDividendPenaltyPerUnitDividendIncrease
Namespace Prefix: | ns_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unpaid Dividend Penalty, Preferred Stock, Conversion Basis + References No definition available. + Details
Name: | ns_UnpaidDividendPenaltyPreferredStockConversionBasis
Namespace Prefix: | ns_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value Of Redemption Amount Paid In Kind, Percentage of Volume-Weighted Average Trading Price of Common Equity + References No definition available. + Details
Name: | ns_ValueOfRedemptionAmountPaidInKindPercentageofVolumeWeightedAverageTradingPriceofCommonEquity
Namespace Prefix: | ns_
Data Type: | num:percentItemType
Balance Type: | na
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_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Specific terms relevant to convertibility. Includes class of preferred stock and number of shares convertible into, exercise (or conversion) price or rates, dates relevant to conversion timing and events relevant to conversion. Describe also any beneficial conversion features. where convertible preferred stock with a nondetachable conversion feature is in-the-money at commitment date. For contingently convertible preferred stock, discuss the circumstances of the contingency, including the events or changes in circumstance that would cause the contingency to be met and any of the significant features necessary to understand the conversion rights and the timing of those rights. Include also an events or changes in circumstance, if any, that could adjust or change the contingency, conversion price, or number of shares, including significant terms of those changes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21521-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21538-112644 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_ConvertiblePreferredStockTermsOfConversion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date of record for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format. + 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_DistributionMadeToLimitedPartnerDateOfRecord
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per unit of ownership amount of cash distributions declared to unit-holder of a limited partnership (LP). + References Reference 1: 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 2: 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 Reference 3: 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 + Details
Name: | us-gaap_DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of basis of dividend, such as adjustable rate. Excludes percentage rate dividend payments or fixed dollar amounts per share. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockDividendPaymentRateVariable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow from issuance of callable preferred stock which is identified as being convertible to another type of financial security at the option of the issuer or the holder. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfRedeemableConvertiblePreferredStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Per share or per unit amount of equity securities issued. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of the accounting treatment if the carrying value of the redeemable stock that is classified as temporary equity is different from the redemption amount. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (27) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=65877616&loc=d3e177068-122764 + Details
Name: | us-gaap_TemporaryEquityAccountingTreatment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_TemporaryEquitySharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_TemporaryEquitySharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Value of new stock classified as temporary equity issued during the period. + References No definition available. + Details
Name: | us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockDistributionsPeriodAxis=ns_PreferredStockDistributionsPeriodJune292018toJune282020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockDistributionsPeriodAxis=ns_PreferredStockDistributionsPeriodJune292020toJune282023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockDistributionsPeriodAxis=ns_PreferredStockDistributionsPeriodJune292023andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockDistributionsPeriodAxis=ns_PreferredStockDistributionsPeriodJune292018toJune152019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockDistributionsPeriodAxis=ns_PreferredStockDistributionsPeriodJune162019andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockRedemptionPeriodAxis=ns_PreferredStockIssuerRedemptionOptionPeriodJune292023toJune282024Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockRedemptionPeriodAxis=ns_PreferredStockIssuerRedemptionOptionPeriodJune292023andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockRedemptionPeriodAxis=ns_PreferredStockIssuerRedemptionOptionPeriodJune292024toJune282025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockRedemptionPeriodAxis=ns_PreferredStockIssuerRedemptionOptionPeriodJune292025andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockRedemptionPeriodAxis=ns_PreferredStockHolderRedemptionOptionPeriodJune292028andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_PreferredStockConversionPeriodAxis=ns_PreferredStockConversionPeriodJune292020andthereafterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_EquityIssuanceDateAxis=ns_EquityIssuanceDateJune292018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ns_EquityIssuanceDateAxis=ns_EquityIssuanceDateJuly132018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |