v3.26.1
Note 13 - Segment and Geographic Distribution of Operations - Segment Reporting Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Revenue $ 342,287 $ 341,431 $ 668,509 $ 674,875  
Total vessel operating costs 180,746 167,354 346,933 332,333  
General and administrative 34,845 31,213 68,404 60,307  
Depreciation and amortization 66,412 64,314 133,031 129,746  
Additions to properties and equipment 14,923 6,855 29,808 26,219  
Total assets 2,366,260 2,074,372 2,366,260 2,074,372 $ 2,386,911
Costs of other operating revenues 1,072 3,108 1,833 4,538  
Corporate expenses 279,759 260,509 546,997 518,906  
Gain on asset dispositions, net 3,316 5,480 3,204 8,018  
Operating income 62,528 80,922 121,512 155,969  
Operating Segments [Member]          
Revenue 342,287 341,431 668,509 674,875  
Crew costs 105,225 99,476 204,112 196,589  
Repair and maintenance 28,953 23,937 53,757 45,891  
Insurance 2,939 1,640 5,599 4,674  
Fuel, lube and supplies 21,046 15,107 37,500 29,485  
Other 22,583 27,194 45,965 55,694  
Total vessel operating costs 180,746 167,354 346,933 332,333  
General and administrative 15,556 14,955 30,542 30,063  
Depreciation and amortization 65,292 63,391 130,597 127,874  
Operating profit 79,621 92,623 158,604 180,067  
Additions to properties and equipment 13,704 5,143 27,008 22,668  
Total assets 1,726,875 1,860,104 1,726,875 1,860,104  
Costs of other operating revenues 1,072 3,108 1,833 4,538  
Operating Segments [Member] | Americas [Member]          
Crew costs 17,972 19,652 37,701 37,092  
Repair and maintenance 5,706 4,830 10,934 9,096  
Insurance 429 351 891 922  
Fuel, lube and supplies 3,252 2,215 6,139 4,832  
Other 5,276 5,965 10,840 16,094  
Total vessel operating costs 32,635 33,013 66,505 68,036  
General and administrative 4,143 3,785 7,894 7,327  
Depreciation and amortization 9,806 11,718 21,144 23,110  
Operating profit 7,385 20,242 16,952 25,137  
Additions to properties and equipment 1,268 353 2,734 2,286  
Total assets 309,457 397,790 309,457 397,790  
Operating Segments [Member] | Asia Pacific [Member]          
Crew costs 17,630 18,518 33,497 38,849  
Repair and maintenance 3,136 3,365 6,093 5,635  
Insurance 283 176 537 500  
Fuel, lube and supplies 3,048 1,789 5,561 3,556  
Other 2,095 2,317 3,849 4,435  
Total vessel operating costs 26,192 26,165 49,537 52,975  
General and administrative 2,442 2,050 4,667 4,470  
Depreciation and amortization 6,207 5,703 11,731 11,021  
Operating profit 13,107 11,778 28,577 25,458  
Additions to properties and equipment (102) 375 444 967  
Total assets 167,986 153,018 167,986 153,018  
Operating Segments [Member] | Middle East [Member]          
Crew costs 17,314 13,302 32,841 26,582  
Repair and maintenance 4,514 4,261 8,370 8,361  
Insurance 852 343 1,615 872  
Fuel, lube and supplies 3,548 3,250 6,232 5,289  
Other 4,044 4,661 8,119 9,249  
Total vessel operating costs 30,272 25,817 57,177 50,353  
General and administrative 2,316 2,847 4,593 5,784  
Depreciation and amortization 9,711 7,657 19,470 14,923  
Operating profit 6,184 3,894 12,812 12,457  
Additions to properties and equipment 2,596 329 6,939 1,183  
Total assets 208,277 180,769 208,277 180,769  
Operating Segments [Member] | Europe and Mediterranean [Member]          
Crew costs 34,312 29,342 66,011 56,453  
Repair and maintenance 9,419 5,736 16,985 12,447  
Insurance 810 417 1,509 1,265  
Fuel, lube and supplies 5,229 2,153 9,880 5,300  
Other 5,981 6,187 11,747 10,925  
Total vessel operating costs 55,751 43,835 106,132 86,390  
General and administrative 3,401 3,385 7,163 7,048  
Depreciation and amortization 26,075 22,833 50,832 47,442  
Operating profit 26,849 29,227 34,894 36,605  
Additions to properties and equipment 8,454 584 13,666 1,898  
Total assets 652,900 628,740 652,900 628,740  
Operating Segments [Member] | West Africa [Member]          
Crew costs 17,997 18,662 34,062 37,613  
Repair and maintenance 6,178 5,745 11,375 10,352  
Insurance 565 353 1,047 1,115  
Fuel, lube and supplies 5,969 5,700 9,688 10,508  
Other 5,187 8,064 11,410 14,991  
Total vessel operating costs 35,896 38,524 67,582 74,579  
General and administrative 3,254 2,888 6,225 5,434  
Depreciation and amortization 13,493 15,480 27,420 31,378  
Operating profit 24,612 26,017 61,842 77,630  
Additions to properties and equipment 1,488 3,502 3,225 16,334  
Total assets 388,255 499,787 388,255 499,787  
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]          
Additions to properties and equipment 1,219 1,712 2,800 3,551  
Total assets 639,385 214,268 639,385 214,268  
Corporate expenses (20,409) (17,181) (40,296) (32,116)  
Vessel [Member]          
Revenue 339,731 336,858 663,149 667,557  
Vessel [Member] | Operating Segments [Member]          
Revenue 339,731 336,858 663,149 667,557  
Vessel [Member] | Operating Segments [Member] | Americas [Member]          
Revenue 53,969 68,758 112,495 123,610  
Vessel [Member] | Operating Segments [Member] | Asia Pacific [Member]          
Revenue 47,948 45,696 94,512 93,924  
Vessel [Member] | Operating Segments [Member] | Middle East [Member]          
Revenue 48,483 40,215 94,052 83,517  
Vessel [Member] | Operating Segments [Member] | Europe and Mediterranean [Member]          
Revenue 112,076 99,280 199,021 177,485  
Vessel [Member] | Operating Segments [Member] | West Africa [Member]          
Revenue 77,255 82,909 163,069 189,021  
Product and Service, Other [Member]          
Revenue 2,556 4,573 5,360 7,318  
Product and Service, Other [Member] | Operating Segments [Member]          
Revenue $ 2,556 $ 4,573 $ 5,360 $ 7,318