Note 12 - Properties and Equipment, Accrued Expenses, Other Current Liabilities, and Other Liabilities (Details Textual) $ in Millions		1 Months Ended	3 Months Ended
	Mar. 07, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022
Number of Vessels			183
Number of Vessels, Held for Sale			3	8
Down Payment To Start Construction On Crew Boats			$ 3.6
Solstad Offshore ASA [Member]
Number Of Offshore Supply Vessels	37
Expected Payments to Acquire Property, Plant, and Equipment	$ 577.0
Alucat Crew Boats [Member]
Number of Vessels			6
Expected cost of Boats			$ 14.1
Subsequent Event [Member]
Number of Ocean Going Tugs, Contracted To Build		2
Down Payments To Start Construction On Tugboats		$ 2.3
Expected cost of Boats		$ 9.2