Note 14 - Segment Information, Geographical Data and Major Customers - Segment Reporting Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue	$ 1,345,835	$ 1,009,985	$ 647,684
Total vessel operating costs	693,107	556,515	397,301
General and Administrative Expense	110,817	95,283	101,921
Depreciation and amortization	242,770	180,331	119,160
Additions to properties and equipment	27,580	45,852	16,637
Total assets	2,074,904	2,062,774	1,297,656
Costs of other operating revenues	3,555	4,342	2,130
Corporate expenses	1,034,487	827,770	620,976
Gain on asset dispositions, net	15,762	8,701	250
Long-lived asset impairments and other	0	0	(714)
Operating income	311,348	182,215	26,708
Operating Segments [Member]
Revenue	1,345,835	1,009,985	647,684
Crew costs	416,276	329,473	242,364
Repair and maintenance	98,376	78,716	51,256
Insurance	11,027	9,297	6,765
Fuel, lube and supplies	65,371	60,548	43,729
Other	102,057	78,481	53,187
Total vessel operating costs	693,107	556,515	397,301
General and Administrative Expense	56,131	51,850	51,114
Depreciation and amortization	239,676	178,110	116,384
Operating profit	353,366	219,168	80,755
Additions to properties and equipment	23,766	40,684	12,921
Total assets	1,875,706	1,869,843	1,224,358
Costs of other operating revenues	3,555	4,342	2,130
Operating Segments [Member] | Americas [Member]
Crew costs	87,545	86,328	56,767
Repair and maintenance	20,677	17,295	12,706
Insurance	2,034	1,891	1,439
Fuel, lube and supplies	13,635	13,175	9,655
Other	24,391	19,232	13,442
Total vessel operating costs	148,282	137,921	94,009
General and Administrative Expense	14,046	15,105	10,926
Depreciation and amortization	44,822	41,215	29,920
Operating profit	54,779	42,964	12,016
Additions to properties and equipment	5,980	2,916	4,468
Total assets	350,126	418,151	309,985
Operating Segments [Member] | Asia Pacific [Member]
Crew costs	88,968	41,940	29,433
Repair and maintenance	13,999	9,212	3,077
Insurance	1,197	794	516
Fuel, lube and supplies	8,834	5,251	4,139
Other	10,311	7,751	5,081
Total vessel operating costs	123,309	64,948	42,246
General and Administrative Expense	8,544	8,147	12,299
Depreciation and amortization	18,606	10,669	5,960
Operating profit	59,869	38,471	3,726
Additions to properties and equipment	2,157	7,839	317
Total assets	173,587	167,085	148,684
Operating Segments [Member] | Middle East [Member]
Crew costs	53,390	53,416	44,944
Repair and maintenance	17,595	16,187	12,210
Insurance	1,882	1,784	1,412
Fuel, lube and supplies	10,019	12,092	10,531
Other	24,076	17,127	9,015
Total vessel operating costs	106,962	100,606	78,112
General and Administrative Expense	11,320	9,254	9,120
Depreciation and amortization	30,135	26,566	24,236
Operating profit	3,770	(1,051)	(1,093)
Additions to properties and equipment	1,260	3,016	3,911
Total assets	180,286	191,927	197,054
Operating Segments [Member] | Europe and Mediterranean [Member]
Crew costs	109,178	78,613	49,709
Repair and maintenance	28,288	17,029	9,239
Insurance	3,171	2,218	1,442
Fuel, lube and supplies	14,650	11,697	6,026
Other	18,864	13,758	8,426
Total vessel operating costs	174,151	123,315	74,842
General and Administrative Expense	12,726	10,063	8,158
Depreciation and amortization	92,331	63,152	27,734
Operating profit	53,873	33,687	18,844
Additions to properties and equipment	11,069	7,320	1,302
Total assets	659,158	671,626	282,670
Operating Segments [Member] | West Africa [Member]
Crew costs	77,195	69,176	61,511
Repair and maintenance	17,817	18,993	14,024
Insurance	2,743	2,610	1,956
Fuel, lube and supplies	18,233	18,333	13,378
Other	24,415	20,613	17,223
Total vessel operating costs	140,403	129,725	108,092
General and Administrative Expense	9,495	9,281	10,611
Depreciation and amortization	53,782	36,508	28,534
Operating profit	176,432	98,447	43,112
Additions to properties and equipment	3,300	19,593	2,923
Total assets	512,549	421,054	285,965
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Additions to properties and equipment	3,814	5,168	3,716
Total assets	199,198	192,931	73,298
Corporate expenses	(57,780)	(45,654)	(53,583)
Vessel [Member]
Revenue	1,337,637	998,993	641,404
Vessel [Member] | Operating Segments [Member]
Revenue	1,337,637	998,993	641,404
Vessel [Member] | Operating Segments [Member] | Americas [Member]
Revenue	261,929	237,205	146,871
Vessel [Member] | Operating Segments [Member] | Asia Pacific [Member]
Revenue	210,328	122,235	64,231
Vessel [Member] | Operating Segments [Member] | Middle East [Member]
Revenue	152,187	135,375	110,375
Vessel [Member] | Operating Segments [Member] | Europe and Mediterranean [Member]
Revenue	333,081	230,217	129,578
Vessel [Member] | Operating Segments [Member] | West Africa [Member]
Revenue	380,112	273,961	190,349
Product and Service, Other [Member]
Revenue	8,198	10,992	6,280
Product and Service, Other [Member] | Operating Segments [Member]
Revenue	$ 8,198	$ 10,992	$ 6,280