Name:	nhc_EquityInterestsOfDomesticSubsidiariesPledgedPercentage
Namespace Prefix:	nhc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents percentage of non-voting equity interests of foreign subsidiaries pledged as collateral for borrowings under credit agreement.

No definition available.

Name:	nhc_NonVotingEquityInterestsOfForeignSubsidiariesPledgedPercentage
Namespace Prefix:	nhc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	nhc_Note1075000000RevolvingCreditFacilityDetailsLineItems
Namespace Prefix:	nhc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents percentage of maximum voting equity interests of foreign subsidiaries pledged as collateral for borrowings under credit agreement.

No definition available.

Name:	nhc_VotingEquityInterestsOfForeignSubsidiariesPledgedPercentage
Namespace Prefix:	nhc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

No definition available.

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682