Note 2 - Fair Value Measurement - Financial Assets and Liabilities on Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets	$ 52,380	$ 63,873
Liabilities	13,562	17,242
Contingent Consideration Liabilities [Member]
Liabilities	6,692
Long-Term Debt [Member]
Liabilities	6,870	7,215
Money Market Funds [Member]
Assets	52,380	63,873
Contingent Consideration Liabilities [Member]
Liabilities		10,027
Fair Value, Inputs, Level 1 [Member]
Assets	52,380	63,873
Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Contingent Consideration Liabilities [Member]
Liabilities	0
Fair Value, Inputs, Level 1 [Member] | Long-Term Debt [Member]
Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets	52,380	63,873
Fair Value, Inputs, Level 1 [Member] | Contingent Consideration Liabilities [Member]
Liabilities		0
Fair Value, Inputs, Level 2 [Member]
Assets	0	0
Liabilities	6,870	7,215
Fair Value, Inputs, Level 2 [Member] | Contingent Consideration Liabilities [Member]
Liabilities	0
Fair Value, Inputs, Level 2 [Member] | Long-Term Debt [Member]
Liabilities	6,870	7,215
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Contingent Consideration Liabilities [Member]
Liabilities		0
Fair Value, Inputs, Level 3 [Member]
Assets	0	0
Liabilities	6,692	10,027
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration Liabilities [Member]
Liabilities	6,692
Fair Value, Inputs, Level 3 [Member] | Long-Term Debt [Member]
Liabilities	0	0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Assets	$ 0	0
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration Liabilities [Member]
Liabilities		$ 10,027