Note 1 - Nature of Operations and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Property, Plant and Equipment [Table Text Block]

(In Thousands)	December 31,		December 31,
	2022		2021
Properties and equipment:
Vessels and related equipment	$	1,070,821	$	898,649
Other properties and equipment		35,819		19,625
		1,106,640		918,274
Less accumulated depreciation and amortization		309,985		230,234
Net properties and equipment	$	796,655	$	688,040

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

(In Thousands, except per share and incremental "in-the-money" data)	Year Ended December 31,
	2022			2021			2020
Net loss available to common shareholders	$	(21,749	)	$	(128,969	)	$	(196,242	)
Weighted average outstanding shares of common stock, basic		44,132			41,009			40,355
Dilutive effect of options, warrants and stock awards		—			—			—
Weighted average common stock and equivalents		44,132			41,009			40,355
Loss per share, basic	$	(0.49	)	$	(3.14	)	$	(4.86	)
Loss per share, diluted	$	(0.49	)	$	(3.14	)	$	(4.86	)
Additional information:
Incremental "in-the-money" options, warrants, and restricted stock units outstanding at the end of the period (A)		1,863,233			2,345,948			2,235,310

Financing Receivable, Allowance for Credit Loss [Table Text Block]

	Trade			Due
(In Thousands)	and			from
	Other Receivables			Affiliate
Balance at January 1, 2020	$	70		$	20,083
Cumulative effect adjustment upon adoption of standard		163			—
Current period provision for expected credit losses		1,283			52,981
Other		—			(1,264	)
Balance at December 31, 2021	$	1,516		$	71,800
Current period provision for expected credit losses		838			400
Write offs		(406	)		—
Other		—			256
Balance at December 31, 2021	$	1,948		$	72,456
Current period provision for expected credit losses		414			—
Acquisition of Sonatide joint venture		—			(59,678	)
Other		—			(1,080	)
Balance at December 31, 2022	$	2,362		$	11,698