v3.26.1
Segment Data (Details)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Segment
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Segment Reporting Information [Line Items]          
Number of reportable segments | Segment     2    
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]     srt:ChiefExecutiveOfficerMember    
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description     The CODM evaluates the performance of the Company’s segments based on the contributions to operating income of the respective segments, and before income taxes, interest, gains or losses on disposition of assets, other nonoperating income, noncontrolling interests, accounting changes, and nonrecurring items. The CODM uses segment operating income to allocate resources for each segment during the annual budget and forecasting process. The CODM considers budget-to-actual variances on a monthly basis for segment operating income when making decisions about allocating capital and personnel to the segments. The CODM also uses segment operating income to assess the performance for each segment by comparing the results and return on invested capital of each segment.    
Revenues [Abstract]          
Revenues $ 922,399 $ 855,455 $ 1,766,498 $ 1,641,114  
Earnings before taxes on income 118,407 123,928 223,111 224,271  
Total assets 6,220,267   6,220,267   $ 6,008,045
Marine Transportation [Member]          
Revenues [Abstract]          
Revenues 536,974 492,562 1,034,157 968,711  
Distribution and Services [Member]          
Revenues [Abstract]          
Revenues 385,425 362,893 732,341 672,403  
Other [Member]          
Other Assets [Abstract]          
General corporate assets 169,442   169,442   187,616
Investment in affiliates 2,535   2,535   3,188
Total other assets 171,977   171,977   190,804
Reportable Segments [Member]          
Revenues [Abstract]          
Revenues 922,399 855,455 1,766,498 1,641,114  
Earnings before taxes on income 125,953 134,487 238,954 243,662  
Total assets 6,220,267   6,220,267   6,008,045
Reportable Segments [Member] | Marine Transportation [Member]          
Revenues [Abstract]          
Revenues 536,974 492,562 1,034,157 968,711  
Earnings before taxes on income 87,802 99,052 177,457 185,636  
Total assets 4,823,614   4,823,614   4,705,692
Reportable Segments [Member] | Distribution and Services [Member]          
Revenues [Abstract]          
Revenues 385,425 362,893 732,341 672,403  
Earnings before taxes on income 38,151 35,435 61,497 58,026  
Total assets 1,224,676   1,224,676   1,111,549
Reportable Segments [Member] | Other [Member]          
Revenues [Abstract]          
Total assets 171,977   171,977   $ 190,804
Intersegment Eliminations [Member]          
Revenues [Abstract]          
Revenues 9,600 11,300 17,400 22,500  
Earnings before taxes on income $ 1,000 $ 1,100 $ 1,700 $ 2,200