Note 3 - Investments and Fair Value Measurements - Fair Value Hierarchy for Cash Equivalents, Marketable Securities and Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Nov. 17, 2021	Dec. 31, 2020
Contingent Consideration	$ 720		$ 720
Financial instrument liability	825	$ 900
Total liabilities	1,545		2,675
Convertible Notes Payable [Member]
Convertible note payable			1,955
Fair Value, Inputs, Level 1 [Member]
Contingent Consideration	0
Financial instrument liability	0
Total liabilities	0		0
Fair Value, Inputs, Level 1 [Member] | Convertible Notes Payable [Member]
Convertible note payable			0
Fair Value, Inputs, Level 2 [Member]
Contingent Consideration	0
Financial instrument liability	0
Total liabilities	0		0
Fair Value, Inputs, Level 2 [Member] | Convertible Notes Payable [Member]
Convertible note payable			0
Fair Value, Inputs, Level 3 [Member]
Contingent Consideration	720		720
Financial instrument liability	825
Total liabilities	$ 1,545		2,675
Fair Value, Inputs, Level 3 [Member] | Convertible Notes Payable [Member]
Convertible note payable			$ 1,955