Note 14 - Segment and Geographic Distribution of Operations - Segment Reporting Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue	$ 647,684	$ 371,033	$ 397,038
Corporate expenses	620,976	466,049	583,840
Gain (loss) on asset dispositions, net	250	(2,901)	7,591
Affiliate credit loss impairment expense	0	(400)	(52,981)
Affiliate guarantee obligation	0	0	(2,000)
Long-lived asset impairments and other	(714)	(15,643)	(74,109)
Operating loss	26,708	(95,016)	(186,802)
Depreciation and amortization	119,160	114,544	116,709
Property Plant And Equipment Additions	16,637	8,951	14,900
Total Assets	1,297,656	1,095,780	1,251,177
Vessel [Member]
Revenue	641,404	361,569	386,174
Product and Service, Other [Member]
Revenue	6,280	9,464	10,864
Operating Segments [Member]
Gross Profit	80,755	(39,164)	(29,670)
Operating Segments [Member] | Vessel [Member]
Gross Profit	76,605	(46,397)	(37,128)
Operating Segments [Member] | Product and Service, Other [Member]
Revenue	6,280	9,464	10,864
Gross Profit	4,150	7,233	7,458
Operating Segments [Member] | Americas [Member]
Depreciation and amortization	29,920	30,856	32,079
Property Plant And Equipment Additions	4,468	0	2,842
Total Assets	309,985	278,394	338,649
Operating Segments [Member] | Americas [Member] | Vessel [Member]
Revenue	146,871	102,151	126,676
Gross Profit	12,016	(11,270)	4,944
Operating Segments [Member] | Asia Pacific [Member]
Depreciation and amortization	5,960	4,484	4,076
Property Plant And Equipment Additions	317	(42)	1,497
Total Assets	148,684	28,564	43,222
Operating Segments [Member] | Asia Pacific [Member] | Vessel [Member]
Revenue	64,231	18,142	14,348
Gross Profit	3,726	4,896	2,076
Operating Segments [Member] | Middle East [Member]
Depreciation and amortization	24,236	21,508	20,168
Property Plant And Equipment Additions	3,911	0	1,132
Total Assets	197,054	154,723	183,200
Operating Segments [Member] | Middle East [Member] | Vessel [Member]
Revenue	110,375	84,395	82,785
Gross Profit	(1,093)	(6,070)	(8,011)
Operating Segments [Member] | Europe and Mediterranean [Member]
Depreciation and amortization	27,734	28,163	29,222
Property Plant And Equipment Additions	1,302	764	1,059
Total Assets	282,670	293,760	302,214
Operating Segments [Member] | Europe and Mediterranean [Member] | Vessel [Member]
Revenue	129,578	80,914	83,602
Gross Profit	18,844	(16,968)	(8,629)
Operating Segments [Member] | West Africa [Member]
Depreciation and amortization	28,534	26,196	27,787
Property Plant And Equipment Additions	2,923	6,341	6,028
Total Assets	285,965	223,988	242,825
Operating Segments [Member] | West Africa [Member] | Vessel [Member]
Revenue	190,349	75,967	78,763
Gross Profit	43,112	(16,985)	(27,508)
Corporate, Non-Segment [Member]
Corporate expenses	(53,583)	(36,908)	(35,633)
Depreciation and amortization	2,776	3,337	3,377
Property Plant And Equipment Additions	3,716	1,888	2,342
Total Assets	$ 73,298	$ 116,351	$ 141,067