v3.26.1
Revenue - Schedule of Disaggregation of Revenue (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        
Revenues $ 213,600 $ 180,676 $ 401,274 $ 373,219
Throughput and storage        
Disaggregation of Revenue        
Revenues [1] 23,743 22,404 46,180 43,953
Sulfur services        
Disaggregation of Revenue        
Revenues 4,253 4,073 8,627 8,296
Terminalling and storage segment        
Disaggregation of Revenue        
Revenues 23,743 22,404 46,180 43,953
Terminalling and storage segment | Throughput and storage        
Disaggregation of Revenue        
Revenues 23,743 22,404 46,180 43,953
Transportation segment        
Disaggregation of Revenue        
Revenues 56,639 53,826 109,446 106,811
Transportation segment | Land transportation        
Disaggregation of Revenue        
Revenues 42,292 38,942 81,204 77,621
Transportation segment | Inland marine transportation        
Disaggregation of Revenue        
Revenues 13,187 12,678 25,736 24,680
Transportation segment | Offshore marine transportation        
Disaggregation of Revenue        
Revenues 1,160 2,206 2,506 4,510
Sulfur services segment        
Disaggregation of Revenue        
Revenues 50,070 44,128 100,894 92,832
Sulfur services segment | Sulfur product sales        
Disaggregation of Revenue        
Revenues 12,522 8,894 23,326 18,606
Sulfur services segment | Fertilizer product sales        
Disaggregation of Revenue        
Revenues 33,295 31,161 68,941 65,930
Sulfur services segment | Sulfur services        
Disaggregation of Revenue        
Revenues 4,253 4,073 8,627 8,296
Specialty products segment        
Disaggregation of Revenue        
Revenues 83,148 60,318 144,754 129,623
Specialty products segment | Natural gas liquids product sales        
Disaggregation of Revenue        
Revenues 48,932 32,976 83,345 75,096
Specialty products segment | Lubricant product sales        
Disaggregation of Revenue        
Revenues $ 34,216 $ 27,342 $ 61,409 $ 54,527
[1] Related Party Transactions Included Above
Three Months EndedSix Months Ended
June 30,June 30,
2026202520262025
Revenues:*    
Terminalling and storage$18,982 $18,221 $37,738 $35,483 
Transportation7,883 7,320 15,926 15,290 
Product Sales817 1,040 1,800 2,340 
Costs and expenses:*
Cost of products sold: (excluding depreciation and amortization)
Specialty products10,137 7,277 18,067 13,287 
Sulfur services3,318 3,187 6,606 6,308 
Expenses:
Operating expenses27,286 27,823 54,582 55,388 
Selling, general and administrative7,753 8,135 16,020 16,027