Note 7 - Business Segments - Summary of Financial Information by Reporting Segment (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues and grant income:
Net patient revenues	$ 260,247,000	$ 254,817,000	$ 776,661,000	$ 708,648,000
Other revenues	10,596,000	11,491,000	33,584,000	33,916,000
Net operating revenues and grant income	270,843,000	276,737,000	821,185,000	790,868,000
Government stimulus income	0	10,429,000	10,940,000	48,304,000
Costs and expenses:
Salaries, wages, and benefits	173,198,000	170,235,000	518,828,000	483,263,000
Other operating	72,883,000	73,109,000	218,279,000	204,211,000
Rent	10,294,000	10,204,000	30,770,000	30,437,000
Depreciation and amortization	10,253,000	10,229,000	30,011,000	30,521,000
Interest	137,000	198,000	451,000	657,000
Total costs and expenses	266,765,000	263,975,000	798,339,000	749,089,000
Income/(loss) from operations	4,078,000	12,762,000	22,846,000	41,779,000
Non-operating income (loss)	2,731,000	3,399,000	8,451,000	15,245,000
Unrealized losses on marketable equity securities	(11,056,000)	(23,797,000)	(11,479,000)	(23,227,000)
Income/(loss) before income taxes	(4,247,000)	(7,636,000)	19,818,000	128,999,000
Gain on acquisition of equity method investment	0	0	0	95,202,000
Inpatient Services Segment [Member]
Revenues and grant income:
Net patient revenues	228,138,000	222,884,000	680,776,000	644,986,000
Other revenues	(198,000)	128,000	15,000	324,000
Net operating revenues and grant income	227,940,000	233,441,000	691,731,000	693,614,000
Government stimulus income		10,429,000	10,940,000	48,304,000
Costs and expenses:
Salaries, wages, and benefits	144,047,000	141,318,000	435,322,000	407,534,000
Other operating	66,522,000	64,755,000	192,791,000	185,860,000
Rent	8,088,000	7,998,000	24,498,000	24,129,000
Depreciation and amortization	9,198,000	9,300,000	27,120,000	27,790,000
Interest	137,000	198,000	451,000	657,000
Total costs and expenses	227,992,000	223,569,000	680,182,000	645,970,000
Income/(loss) from operations	(52,000)	9,872,000	11,549,000	47,644,000
Non-operating income (loss)	0	0	0	0
Unrealized losses on marketable equity securities	0	0	0	0
Income/(loss) before income taxes	(52,000)	9,872,000	11,549,000	47,644,000
Gain on acquisition of equity method investment				0
Homecare Services Segment [Member]
Revenues and grant income:
Net patient revenues	32,109,000	31,933,000	95,885,000	63,662,000
Other revenues	0	0	0	0
Net operating revenues and grant income	32,109,000	31,933,000	95,885,000	63,662,000
Government stimulus income		0	0	0
Costs and expenses:
Salaries, wages, and benefits	19,581,000	18,771,000	58,007,000	39,922,000
Other operating	6,310,000	5,618,000	19,848,000	10,291,000
Rent	575,000	594,000	1,759,000	1,478,000
Depreciation and amortization	248,000	118,000	472,000	299,000
Interest	0	0	0	0
Total costs and expenses	26,714,000	25,101,000	80,086,000	51,990,000
Income/(loss) from operations	5,395,000	6,832,000	15,799,000	11,672,000
Non-operating income (loss)	0	0	0	0
Unrealized losses on marketable equity securities	0	0	0	0
Income/(loss) before income taxes	5,395,000	6,832,000	15,799,000	11,672,000
Gain on acquisition of equity method investment				0
Other Segments [Member]
Revenues and grant income:
Net patient revenues	0	0	0	0
Other revenues	10,794,000	11,363,000	33,569,000	33,592,000
Net operating revenues and grant income	10,794,000	11,363,000	33,569,000	33,592,000
Government stimulus income		0	0	0
Costs and expenses:
Salaries, wages, and benefits	9,570,000	10,146,000	25,499,000	35,807,000
Other operating	51,000	2,736,000	5,640,000	8,060,000
Rent	1,631,000	1,612,000	4,513,000	4,830,000
Depreciation and amortization	807,000	811,000	2,419,000	2,432,000
Interest	0	0	0	0
Total costs and expenses	12,059,000	15,305,000	38,071,000	51,129,000
Income/(loss) from operations	(1,265,000)	(3,942,000)	(4,502,000)	(17,537,000)
Non-operating income (loss)	2,731,000	3,399,000	8,451,000	15,245,000
Unrealized losses on marketable equity securities	(11,056,000)	(23,797,000)	(11,479,000)	(23,227,000)
Income/(loss) before income taxes	$ (9,590,000)	$ (24,340,000)	$ (7,530,000)	69,683,000
Gain on acquisition of equity method investment				$ 95,202,000