Note 14 - Subsequent Events (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Mar. 23, 2022	Dec. 31, 2021	Dec. 31, 2020
Proceeds from Issuance of Common Stock		$ 32,459	$ 14,767
Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)	6,857,140
Shares Issued, Price Per Share (in dollars per share)	$ 1.75
Proceeds from Issuance of Common Stock, Gross	$ 12,000
Proceeds from Issuance of Common Stock	$ 11,800
Subsequent Event [Member] | Keith Brackpool [Member]
Stock Issued During Period, Shares, New Issues (in shares)	1,142,857
Subsequent Event [Member] | Geoffrey Grant [Member]
Stock Issued During Period, Shares, New Issues (in shares)	285,714
Subsequent Event [Member] | Heerema International Group Services S.A. [Member]
Stock Issued During Period, Shares, New Issues (in shares)	2,857,142
Subsequent Event [Member] | Keith Brackpool, Geoffrey Grant, and Heerema International Group Services S.A. [Member]
Common Stock Ownership, Percent	35.40%