Note 10 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Feb. 03, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 13, 2023
Proceeds from Issuance of Common Stock		$ 75.0	$ 30.0
Private Placement, Tranche 1 [Member]
Equity Offering, Maximum Shares to be Issued (in shares)				8,026,165
Equity Offering, Price Per Share (in dollars per share)				$ 4.9837
Equity Offering, Maximum Amount				$ 40.0
Private Placement, Tranche 2 [Member]
Equity Offering, Maximum Shares to be Issued (in shares)				22,072,103
Equity Offering, Price Per Share (in dollars per share)				$ 4.9837
Equity Offering, Maximum Amount				$ 110.0
Private Placement, Tranche 3 [Member]
Equity Offering, Maximum Amount				$ 69.4
Equity Offering, Maximum Percentage of Outstanding Common Stock				17.50%
HGC NEXT INV LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)	5,835,277
Share Price (in dollars per share)	$ 5.998
Proceeds from Issuance of Common Stock	$ 35.0