Note 4 - Other Revenues (Details Textual)	3 Months Ended
Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Number of Assisted Living Facilities	25
Number of Skilled Nursing Centers	75
Insurance Services Revenue, Total	$ 1,382,000	$ 1,524,000
Workers Compensation Revenue [Member]
Insurance Services Revenue, Total	779,000	847,000
Professional Liability Insurance [Member]
Insurance Services Revenue, Total	$ 603,000	$ 677,000
National [Member]
Number of Skilled Nursing Centers	5	5
Property Management Fee Revenue	$ 1,537,000	$ 1,854,000
FLORIDA
Number of Assisted Living Facilities	4

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

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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

Revenue from insurance services, including net premiums earned, gain on sale of insurance block, agency management fees and insurance contract fees and commissions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.1,4)
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

+ Details

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- Definition

The amount of revenue derived from managing real estate properties.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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