Name:	nsh_EquityMethodInvestmentSummarizedFinancialInformationGoodwill
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Sum of equity method investee's carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

No definition available.

Name:	nsh_EquityMethodInvestmentSummarizedFinancialInformationLongTermDebtNoncurrent
Namespace Prefix:	nsh_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Equity method investee's tangible assets that are held for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment.

No definition available.

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Namespace Prefix:	nsh_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of assets reported by an equity method investment of the entity.

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.(g))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33912-111571

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 28

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph bb

-Article 1

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph g

-Subparagraph 1, 2

-Article 4

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph w

-Article 1

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- Details

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssetsAbstract
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Data Type:	xbrli:stringItemType
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The amount of current assets reported by an equity method investment of the entity.

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of current liabilities reported by an equity method investment of the entity.

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of equity, excluding noncontrolling interest, attributable to the equity method investment of the entity.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of liabilities reported by an equity method investment of the entity.

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of liabilities and equity reported by an equity method investment of the entity.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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The amount of noncurrent assets reported by an equity method investment of the entity.

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of noncurrent liabilities reported by an equity method investment of the entity.