v3.26.1
Revenues (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Abstract]        
Revenues by major source $ 922,399 $ 855,455 $ 1,766,498 $ 1,641,114
Revenue recognized     89,600 94,700
Marine Transportation [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 536,974 492,562 1,034,157 968,711
Marine Transportation [Member] | Inland Transportation [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 431,894 397,141 826,019 789,640
Marine Transportation [Member] | Coastal Transportation [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 105,080 95,421 208,138 179,071
Distribution and Services [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 385,425 362,893 732,341 672,403
Distribution and Services [Member] | Commercial and Industrial [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 193,886 173,606 355,532 333,834
Distribution and Services [Member] | Power Generation [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source 151,317 140,739 303,071 245,241
Distribution and Services [Member] | Oil and Gas [Member]        
Disaggregation of Revenue [Abstract]        
Revenues by major source $ 40,222 $ 48,548 $ 73,738 $ 93,328