Note 5 - Revenue from Contracts with Customers - Revenue by Sales Channel (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues	$ 99,702	$ 88,830	$ 196,458	$ 175,093
Sales Channel, Directly to Consumer [Member]
Revenues	58,782	51,805	116,734	101,810
Sales Channel, Through Intermediary [Member]
Revenues	$ 40,920	$ 37,025	$ 79,724	$ 73,283