No definition available.

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

Number of skilled nursing centers operated or managed as of the balance sheet date.

No definition available.

Name:	nhc_NumberOfSkilledNursingCenters
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

Amount of insurance premium revenue recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_HealthCareOrganizationPremiumRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Revenue, comprised of base and incentive revenue derived from the management of joint ventures, managing third-party properties, or another entity's operations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_ManagementFeesRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The cash inflow from the amounts received by the insured under the terms of an insurance contract settlement. This element pertains only to insurance proceeds related to operating activities. It excludes insurance settlements classified as investing cash flows, for example, insurance settlements related to fixed assets.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 16

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3337-108585

Name:	us-gaap_ProceedsFromInsuranceSettlementOperatingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

No definition available.

Name:	us-gaap_UnbilledReceivablesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	us-gaap_HealthCareOrganizationRevenueSourcesAxis=nhc_NationalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_HealthCareOrganizationRevenueSourcesAxis=nhc_OtherNursingCentersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfMalpracticeInsuranceTypeAndTierIdentifierAxis=nhc_ProfessionalLiabilityInsuranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfMalpracticeInsuranceTypeAndTierIdentifierAxis=nhc_WorkersCompensationPremiumRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=nhc_AccountingAndFinancialServicesProvidedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: