Note 2 - Acquisition of White Oak Senior Living (Details Textual) - White Oak Senior Living Portfolio [Member]		12 Months Ended
Aug. 01, 2024 USD ($)	Dec. 31, 2024 USD ($)
Business Combination, Consideration Transferred	$ 221,400,000
Number of Healthcare Operations	22
Number of Skilled Nursing Ficilitiess	15
Number of Assisted Living Facilities	2
Number of Independent Living Facilities	4
Number of Licensed Skilled Nursing Beds	1,928
Number of Assisted Living Units	48
Number of Independent Living Units	302
Number of Assisted Living and Independent Living Units	2,278
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual		$ 96,065,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual		4,974,000
Business Combination, Acquisition Related Costs		$ 3,266,000

The number of assisted living and independent living units.

No definition available.

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The number of assisted living units.

+ References

No definition available.

+ Details

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Namespace Prefix:	nhc_
Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

The number of healthcare operations.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The number of independent living units.

+ References

No definition available.

+ Details

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

- Definition

The number of licensed skilled nursing beds.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479405/805-10-25-23

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 8
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479637/805-30-30-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 7
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479637/805-30-30-7

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

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

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