Interim Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Net patient revenues	$ 235,090,000			$ 234,827,000			$ 706,465,000	$ 697,173,000
Other revenues	11,977,000			11,499,000			36,038,000	34,256,000
Net operating revenues	247,067,000			246,326,000			742,503,000	731,429,000
Costs and expenses:
Salaries, wages and benefits	152,175,000			149,188,000			441,441,000	434,749,000
Other operating	66,730,000			64,507,000			203,760,000	192,268,000
Facility rent	10,167,000			10,190,000			30,602,000	30,691,000
Depreciation and amortization	10,663,000			10,437,000			31,515,000	31,176,000
Interest	764,000			1,170,000			2,644,000	3,663,000
Total costs and expenses	240,499,000			235,492,000			709,962,000	692,547,000
Income from operations	6,568,000			10,834,000			32,541,000	38,882,000
Other income:
Non–operating income	6,663,000			8,467,000			20,936,000	11,056,000
Unrealized gains on marketable equity securities	9,312,000			3,486,000			16,096,000	417,000
Income before income taxes	22,543,000			22,787,000			69,573,000	50,355,000
Income tax provision	(3,167,000)			(1,700,000)			(15,284,000)	(9,792,000)
Net income	19,376,000			21,087,000			54,289,000	40,563,000
Net loss attributable to noncontrolling interest	85,000	$ 29,000	$ 38,000	55,000	$ 86,000	$ 108,000	152,000	249,000
Net income attributable to National HealthCare Corporation	$ 19,461,000	$ 13,711,000	$ 21,269,000	$ 21,142,000	$ 22,461,000	$ (2,791,000)	$ 54,441,000	$ 40,812,000
Earnings per share attributable to National HealthCare Corporation stockholders:
Basic (in dollars per share)	$ 1.27			$ 1.39			$ 3.57	$ 2.68
Diluted (in dollars per share)	$ 1.27			$ 1.39			$ 3.55	$ 2.68
Basic (in shares)	15,275,709			15,225,654			15,267,250	15,221,217
Diluted (in shares)	15,373,617			15,242,086			15,350,308	15,230,692
Dividends declared per common share (in dollars per share)	$ 0.52			$ 0.50			$ 1.54	$ 1.48