The carrying amounts assigned to equity method investment for additional ownership percentage

No definition available.

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Namespace Prefix:	nhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Increase in dollar amount invested into equity method investment

+ References

No definition available.

+ Details

Name:	nhc_IncreaseInLimitedPartnershipInterest
Namespace Prefix:	nhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase in ownership percentage invested into equity method investment

+ References

No definition available.

+ Details

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Namespace Prefix:	nhc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of equity method locations prior to assignment

+ References

No definition available.

+ Details

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Namespace Prefix:	nhc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

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

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ 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 210.5-02.12)

-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 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33749-111570

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Note 16 - Equity Method Investment in Caris HealthCare, L.P. (Detail) (USD $)	1 Months Ended
	Jun. 30, 2012	Jan. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Caris [Member]
Equity Method Investment, Ownership Percentage			75.10%
Equity Method Investments			$ 38,463,000	$ 19,215,000
Increase in Limited Partnership Interest Percentage	7.50%	2.70%
Increase in Limited Partnership Interest	7,500,000
Solaris Hospice [Member] \| Reclassified Carrying Values which was Previously Recorded Goodwill [Member]
Assignment Of Hospice Business		2,945,000
Solaris Hospice [Member]
Number of Equity Method Entities		8
Assignment Of Hospice Business		$ 4,311,000