Note 6 - Business Segments - Summary of Financial Information by Reporting Segment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Other revenues	$ 11,488,000	$ 11,610,000	$ 22,757,000	$ 22,894,000
Net operating revenues	242,142,000	238,695,000	485,103,000	477,233,000
Costs and expenses:
Salaries, wages and benefits	145,466,000	142,684,000	285,561,000	280,739,000
Other operating	62,589,000	62,094,000	127,761,000	125,272,000
Rent	10,272,000	10,079,000	20,501,000	20,167,000
Depreciation and amortization	10,397,000	10,481,000	20,739,000	20,776,000
Interest	1,253,000	1,219,000	2,493,000	2,277,000
Total costs and expenses	229,977,000	226,557,000	457,055,000	449,231,000
Income (loss) from operations	12,165,000	12,138,000	28,048,000	28,002,000
Non-operating income	5,654,000	5,189,000	2,589,000	9,957,000
Unrealized gains on marketable equity securities	12,448,000		(3,069,000)
Income before income taxes	30,267,000	17,327,000	27,568,000	37,959,000
Net Patient Revenues [Member]
Revenues:
Net patient revenues	230,654,000	227,085,000	462,346,000	454,339,000
Inpatient Services Segment [Member]
Revenues:
Other revenues	181,000	225,000	451,000	451,000
Net operating revenues	215,798,000	211,282,000	432,419,000	422,948,000
Costs and expenses:
Salaries, wages and benefits	128,115,000	125,614,000	251,495,000	245,238,000
Other operating	56,069,000	55,227,000	113,904,000	111,392,000
Rent	8,267,000	8,257,000	16,524,000	16,424,000
Depreciation and amortization	9,571,000	9,396,000	19,032,000	18,605,000
Interest	383,000	436,000	780,000	886,000
Total costs and expenses	202,405,000	198,930,000	401,735,000	392,545,000
Income (loss) from operations	13,393,000	12,352,000	30,684,000	30,403,000
Non-operating income
Unrealized gains on marketable equity securities
Income before income taxes	13,393,000	12,352,000	30,684,000	30,403,000
Inpatient Services Segment [Member] | Net Patient Revenues [Member]
Revenues:
Net patient revenues	215,617,000	211,057,000	431,968,000	422,497,000
Homecare Services Segment [Member]
Revenues:
Other revenues
Net operating revenues	15,037,000	16,028,000	30,378,000	31,842,000
Costs and expenses:
Salaries, wages and benefits	8,611,000	8,615,000	16,642,000	16,442,000
Other operating	4,740,000	5,058,000	10,019,000	10,193,000
Rent	485,000	499,000	973,000	987,000
Depreciation and amortization	44,000	39,000	82,000	80,000
Interest
Total costs and expenses	13,880,000	14,211,000	27,716,000	27,702,000
Income (loss) from operations	1,157,000	1,817,000	2,662,000	4,140,000
Non-operating income
Unrealized gains on marketable equity securities
Income before income taxes	1,157,000	1,817,000	2,662,000	4,140,000
Homecare Services Segment [Member] | Net Patient Revenues [Member]
Revenues:
Net patient revenues	15,037,000	16,028,000	30,378,000	31,842,000
Other Segments [Member]
Revenues:
Other revenues	11,307,000	11,385,000	22,306,000	22,443,000
Net operating revenues	11,307,000	11,385,000	22,306,000	22,443,000
Costs and expenses:
Salaries, wages and benefits	8,740,000	8,455,000	17,424,000	19,059,000
Other operating	1,780,000	1,809,000	3,838,000	3,687,000
Rent	1,520,000	1,323,000	3,004,000	2,756,000
Depreciation and amortization	782,000	1,046,000	1,625,000	2,091,000
Interest	870,000	783,000	1,713,000	1,391,000
Total costs and expenses	13,692,000	13,416,000	27,604,000	28,984,000
Income (loss) from operations	(2,385,000)	(2,031,000)	(5,298,000)	(6,541,000)
Non-operating income	5,654,000	5,189,000	2,589,000	9,957,000
Unrealized gains on marketable equity securities	12,448,000		(3,069,000)
Income before income taxes	15,717,000	3,158,000	(5,778,000)	3,416,000
Other Segments [Member] | Net Patient Revenues [Member]
Revenues:
Net patient revenues