Note 4 - Fair Value - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 15,603	$ 9,598
Restricted cash	627	969
Total assets measured at fair value	16,230	10,567
Contingent consideration	2,278	1,084
Warrant liabilities	187	2,388
Total liabilities measured at fair value	2,465	3,472
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	15,603	9,598
Restricted cash	627	969
Total assets measured at fair value	16,230	10,567
Contingent consideration	0	0
Warrant liabilities	0	0
Total liabilities measured at fair value	0	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
Warrant liabilities	0	0
Total liabilities measured at fair value	0	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	2,278	1,084
Warrant liabilities	187	2,388
Total liabilities measured at fair value	$ 2,465	$ 3,472