Note 3 - Fair Value - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Cash and cash equivalents	$ 165,245	$ 16,363
Restricted cash	1,149	1,166
Total assets measured at fair value	166,394	17,529
Contingent consideration	4,193	3,936
Total liabilities measured at fair value	4,193	4,191
Warrant liabilities	0	255
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	165,245	16,363
Restricted cash	1,149	1,166
Total assets measured at fair value	166,394	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	0
Restricted cash	0	0
Total assets measured at fair value	0	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	0
Restricted cash	0	0
Total assets measured at fair value	0	0
Contingent consideration	4,193	3,936
Total liabilities measured at fair value	$ 4,193	4,191
Warrant liabilities		$ 255