Note 6 - Business Segments - Summary of Financial Information by Reporting Segment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Net patient revenues	$ 1,251,759,000	$ 1,087,614,000	$ 1,029,085,000
Other revenues	46,178,000	53,930,000	45,196,000
Government grant income	9,445,000	0	11,457,000
Net operating revenues and grant income	1,307,382,000	1,141,544,000	1,085,738,000
Costs and Expenses:
Salaries, wages and benefits	810,930,000	712,344,000	686,169,000
Other operating	321,390,000	288,183,000	289,372,000
Facility rent	43,182,000	41,525,000	40,977,000
Depreciation and amortization	41,985,000	42,034,000	40,489,000
Interest	4,135,000	324,000	563,000
Total costs and expenses	1,221,622,000	1,084,410,000	1,053,842,000
Income (loss) before non-operating income	85,760,000	57,134,000	31,896,000
Non-operating income (loss)	19,690,000	16,660,000	11,141,000
Unrealized gains on marketable equity securities	30,958,000	14,944,000	(15,806,000)
Income before income taxes	136,408,000	88,738,000	27,231,000
Recovery of assets	0	0	(3,728,000)
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Revenues:
Net patient revenues	0	0	0
Other revenues	44,863,000	52,789,000	45,060,000
Government grant income	9,445,000		0
Net operating revenues and grant income	54,308,000	52,789,000	45,060,000
Costs and Expenses:
Salaries, wages and benefits	57,189,000	42,455,000	27,774,000
Other operating	14,596,000	10,095,000	11,698,000
Facility rent	7,100,000	6,811,000	6,124,000
Depreciation and amortization	3,260,000	3,076,000	3,276,000
Interest	0	0	0
Total costs and expenses	82,145,000	62,437,000	45,144,000
Income (loss) before non-operating income	(27,837,000)	(9,648,000)	(84,000)
Non-operating income (loss)	19,690,000	16,660,000	11,141,000
Unrealized gains on marketable equity securities	30,958,000	14,944,000	(15,806,000)
Income before income taxes	22,811,000	21,956,000	(4,749,000)
Recovery of assets			(3,728,000)
Inpatient Services Segment [Member] | Operating Segments [Member]
Revenues:
Net patient revenues	1,111,300,000	956,077,000	900,231,000
Other revenues	1,315,000	1,141,000	136,000
Government grant income	0		11,457,000
Net operating revenues and grant income	1,112,615,000	957,218,000	911,824,000
Costs and Expenses:
Salaries, wages and benefits	668,029,000	589,279,000	580,707,000
Other operating	280,867,000	254,559,000	251,355,000
Facility rent	33,787,000	32,542,000	32,526,000
Depreciation and amortization	37,988,000	38,172,000	36,522,000
Interest	4,135,000	324,000	563,000
Total costs and expenses	1,024,806,000	914,876,000	901,673,000
Income (loss) before non-operating income	87,809,000	42,342,000	10,151,000
Non-operating income (loss)	0	0	0
Unrealized gains on marketable equity securities	0	0	0
Income before income taxes	87,809,000	42,342,000	10,151,000
Recovery of assets			0
Homecare Services Segment [Member] | Operating Segments [Member]
Revenues:
Net patient revenues	140,459,000	131,537,000	128,854,000
Other revenues	0	0	0
Government grant income	0		0
Net operating revenues and grant income	140,459,000	131,537,000	128,854,000
Costs and Expenses:
Salaries, wages and benefits	85,712,000	80,610,000	77,688,000
Other operating	25,927,000	23,529,000	26,319,000
Facility rent	2,295,000	2,172,000	2,327,000
Depreciation and amortization	737,000	786,000	691,000
Interest	0	0	0
Total costs and expenses	114,671,000	107,097,000	107,025,000
Income (loss) before non-operating income	25,788,000	24,440,000	21,829,000
Non-operating income (loss)	0	0	0
Unrealized gains on marketable equity securities	0	0	0
Income before income taxes	$ 25,788,000	$ 24,440,000	21,829,000
Recovery of assets			$ 0