Note 3 - Coronavirus Pandemic (Details Textual) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2020	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Proceeds from Medicare Accelerated and Advance Payment Program			$ 51,253,000
Contract with Customer, Liability, Current	$ 138,000			$ 138,000		$ 15,022,000
Revenue from Contract with Customer, Including Assessed Tax	260,247,000	$ 254,817,000		776,661,000	$ 708,648,000
Supplemental Medicaid Payments [Member]
Revenue from Contract with Customer, Including Assessed Tax	4,773,000	5,053,000		15,312,000	16,102,000
Other Noncurrent Liabilities [Member]
Accrued Payroll Taxes	10,545,000			10,545,000		$ 10,545,000
Provider Relief Fund Under CARES Act [Member]
Government Assistance, Amount	$ 0	$ 10,429,000		$ 10,940,000	$ 48,304,000