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

The amount of annual base rent expense from lessee's financing leases.

No definition available.

Name:	nhc_LesseeFinanceLeaseAnnualBaseRentExpense
Namespace Prefix:	nhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage applied to the increase in facility rent expense over the base year under lessee's operating leases.

No definition available.

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

The amount of annual base rent expense from lessee's operating leases.

No definition available.

Name:	nhc_LesseeOperatingLeaseAnnualBaseRentExpense
Namespace Prefix:	nhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of additional lease options.

No definition available.

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

Number of Assisted Living Centers under lease agreements with NHI

No definition available.

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

Number of facilities that comprise the finance lease obligation at the balance sheet date.

No definition available.

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

Number of finance leases in existence at the balance sheet date.

No definition available.

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

Number of Independent Living Centers under lease agreements with NHI

No definition available.

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

Number of lease agreements with NHI

No definition available.

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

Number of Skilled Nursing Centers under lease agreements with NHI

No definition available.

Name:	nhc_NumberOfSkilledNursingCentersLeasedFromNHI
Namespace Prefix:	nhc_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant

Represents the number of skilled nursing facilities that the company subleases.

No definition available.

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

Term of lessee's finance lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

Name:	us-gaap_LesseeFinanceLeaseRenewalTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Name:	us-gaap_LesseeFinanceLeaseTermOfContract1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

Amount of operating lease expense. Excludes sublease income.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918638-209977