Note 1 - Description of Business (Details Textual)	Sep. 30, 2025
Number of Skilled Nursing Facilities	80
Number of Beds	10,329
Number of Assisted Living Facilities	26
Number of Independent Living Facilities	9
Number of Behavioral Health Hospitals	3
Number of Homecare Programs	34
Number of Hospice Agencies	33
Number of States in which Entity Operates	9

Number of assisted living facilities in which company operates as of the Balance Sheet date.

No definition available.

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

Number of licensed skilled nursing beds that are operated or managed as of the balance sheet date.

No definition available.

The number of behavioral health hospitals.

No definition available.

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

Number of homecare Programs in which the company operates as of the Balance Sheet date.

No definition available.

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

Represents the number of hospice agencies operated or managed by the reporting entity as of the specified date.

No definition available.

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

Number of independent living facilities in which the company operates as of the Balance Sheet date.

No definition available.

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

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

No definition available.

Name:	nhc_NumberOfSkilledNursingFacilities1
Namespace Prefix:	nhc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant