Note 13 - Discontinued Operations (Details Textual) - USD ($)		3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 25, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent, Total		$ (50,000)	$ (469,000)			$ (848,000)	$ (469,000)
Discontinued Operation, Tax Effect of Discontinued Operation, State Tax Assessment						937,000
Discontinued Operation, Current Income Tax						58,000
Discontinued Operation, Tax Effect of Discontinued Operation, Total						$ (147,000)
MidCap Agreement [Member] | MidCap Financial [Member]
Extinguishment of Debt, Amount	$ 32,300,000
Debt Instrument, Prepayment and Exit Fees	2,300,000
Laboratory Services Business [Member]
Proceeds from Divestiture of Businesses	170,000,000
Disposal Group, Including Discontinued Operation, Consideration	$ 27,900,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total				$ 146,000,000.0
Proceeds from Funds Placed in Escrow					$ 4,500,000