Note 3 - Coronavirus Pandemic (Details Textual) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Proceeds from Medicare Accelerated and Advance Payment Program			$ 51,253,000
Contract with Customer, Liability, Current	$ 586,000			$ 586,000		$ 15,022,000
Revenue from Contract with Customer, Including Assessed Tax	260,077,000	$ 236,976,000		516,414,000	$ 453,831,000
Supplemental Medicaid Payments [Member]
Revenue from Contract with Customer, Including Assessed Tax	5,001,000	7,094,000		10,539,000	11,049,000
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	$ 320,000	$ 15,126,000		$ 10,940,000	$ 37,875,000