Note 9 - Shareholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	6 Months Ended
	Apr. 06, 2022	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021
Proceeds from Issuance of Common Stock			$ 30,000	$ 0
Stock Issued During Period, Exercise Of Warrants, Shares (in shares)		520,335
HGC NEXT INV LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)	4,618,226
Share Price (in dollars per share)	$ 6.496
Proceeds from Issuance of Common Stock	$ 30,000