Note 3 - Fair Value - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021		Dec. 31, 2020
Cash and cash equivalents	$ 59,779	[1]	$ 16,363
Restricted cash	1,153		1,166
Short-term investments	57,972		0
Long-term investments	30,142		0
Total assets measured at fair value	149,046		17,529
Contingent consideration	4,949		3,936
Total liabilities measured at fair value	4,949		4,191
Warrant liabilities	0		255
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	59,779	[1]	16,363
Restricted cash	1,153		1,166
Short-term investments	0
Long-term investments	0
Total assets measured at fair value	60,932		17,529
Contingent consideration	0		0
Total liabilities measured at fair value	0		0
Warrant liabilities			0
Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	[1]	0
Restricted cash	0		0
Short-term investments	57,972
Long-term investments	30,142
Total assets measured at fair value	88,114		0
Contingent consideration	0		0
Total liabilities measured at fair value	0		0
Warrant liabilities			0
Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	[1]	0
Restricted cash	0		0
Short-term investments	0
Long-term investments	0
Total assets measured at fair value	0		0
Contingent consideration	4,949		3,936
Total liabilities measured at fair value	$ 4,949		4,191
Warrant liabilities			$ 255

[1] Includes investments that are readily convertible to cash with original maturities of 90 days or less.