v3.26.3
Business Segments - Schedule of Financial Information of Partnership's Operating Segments (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Segment Reporting          
Total consolidated revenues $ 231,727 $ 168,717 $ 633,001 $ 541,936  
Depreciation and amortization 13,133 12,336 39,056 37,790  
(Gain) loss on sale or disposition of property, plant and equipment 39 (395) (4,947) (1,487)  
Operating income 10,188 6,894 37,465 36,179  
Segment assets 564,297 510,122 564,297 510,122 $ 522,418
Capital expenditures and plant turnaround costs 12,311 11,044 40,466 22,667  
Operating Segments          
Segment Reporting          
Total consolidated revenues 238,123 174,706 652,003 560,025  
Direct product costs 118,845 69,412 296,247 226,681  
Manufacturing costs (plant, labor, transportation, and other) 13,681 11,555 44,310 32,810  
Segment gross margin 105,597 93,739 311,446 300,534  
Employment related expenses 28,434 28,224 85,353 85,323  
Driver pay 12,305 11,305 36,995 34,891  
Pass-through expenses 9,860 6,465 25,115 20,088  
Utilities, materials, and supplies 4,737 4,483 14,404 13,448  
Repairs and maintenance 6,364 5,620 17,904 17,333  
Insurance related expenses 6,011 6,300 18,864 18,085  
Lease expenses 7,280 6,672 21,480 18,746  
Other segment expenses 7,246 5,836 19,757 20,138  
Depreciation and amortization 13,133 12,336 39,056 37,790  
(Gain) loss on sale or disposition of property, plant and equipment 39 (396) (4,947) (1,487)  
Total costs and expenses 95,409 86,845 273,981 264,355  
Operating income 10,188 6,894 37,465 36,179  
Elimination of intersegment revenues          
Segment Reporting          
Total consolidated revenues (6,396) (5,989) (19,002) (18,089)  
Indirect selling, general and administrative          
Segment Reporting          
Employment related expenses 2,908 3,036 8,666 9,295  
Insurance related expenses 29 13 61 105  
Other segment expenses 703 818 2,055 3,079  
Total costs and expenses 3,640 3,867 10,782 12,479  
Operating income (3,640) (3,867) (10,782) (12,479)  
Terminalling and storage          
Segment Reporting          
Total consolidated revenues 24,008 23,930 70,188 67,883  
Terminalling and storage | Operating Segments          
Segment Reporting          
Total consolidated revenues 25,911 25,799 76,018 73,441  
Direct product costs 0 0 0 0  
Manufacturing costs (plant, labor, transportation, and other) 0 0 0 0  
Segment gross margin 25,911 25,799 76,018 73,441  
Employment related expenses 7,213 6,727 20,854 19,863  
Driver pay 0 0 0 0  
Pass-through expenses 0 0 0 0  
Utilities, materials, and supplies 3,865 3,563 11,761 10,783  
Repairs and maintenance 1,410 883 3,610 3,188  
Insurance related expenses 1,675 1,558 4,976 4,589  
Lease expenses 1,279 1,111 3,616 3,343  
Other segment expenses 2,202 2,235 6,305 5,872  
Depreciation and amortization 5,079 5,143 15,158 16,123  
(Gain) loss on sale or disposition of property, plant and equipment 45 2 (4,414) (7)  
Total costs and expenses 22,768 21,222 61,866 63,754  
Operating income 3,143 4,577 14,152 9,687  
Segment assets 156,328 155,876 156,328 155,876 156,111
Capital expenditures and plant turnaround costs 3,503 2,808 18,032 5,655  
Terminalling and storage | Elimination of intersegment revenues          
Segment Reporting          
Total consolidated revenues (1,903) (1,869) (5,830) (5,558)  
Transportation segment          
Segment Reporting          
Total consolidated revenues 56,629 49,709 166,075 156,520  
Transportation segment | Operating Segments          
Segment Reporting          
Total consolidated revenues 61,073 53,790 179,133 168,966  
Direct product costs 0 0 0 0  
Manufacturing costs (plant, labor, transportation, and other) 0 0 0 0  
Segment gross margin 61,073 53,790 179,133 168,966  
Employment related expenses 14,908 15,012 44,922 45,448  
Driver pay 12,305 11,305 36,995 34,891  
Pass-through expenses 8,606 5,650 22,746 17,632  
Utilities, materials, and supplies 572 656 1,711 1,851  
Repairs and maintenance 4,854 4,618 14,045 13,594  
Insurance related expenses 4,112 4,489 13,048 12,734  
Lease expenses 5,879 5,424 17,509 14,979  
Other segment expenses 2,639 1,324 6,986 6,031  
Depreciation and amortization 3,203 2,907 9,303 8,755  
(Gain) loss on sale or disposition of property, plant and equipment (6) (383) (507) (1,460)  
Total costs and expenses 57,072 51,002 166,758 154,455  
Operating income 4,001 2,788 12,375 14,511  
Segment assets 156,831 159,937 156,831 159,937 165,129
Capital expenditures and plant turnaround costs 1,134 2,217 6,728 7,116  
Transportation segment | Elimination of intersegment revenues          
Segment Reporting          
Total consolidated revenues (4,444) (4,081) (13,058) (12,446)  
Sulfur services segment          
Segment Reporting          
Total consolidated revenues 61,588 32,635 162,482 125,467  
Sulfur services segment | Operating Segments          
Segment Reporting          
Total consolidated revenues 61,588 32,635 162,482 125,467  
Direct product costs 42,112 16,878 101,176 66,302  
Manufacturing costs (plant, labor, transportation, and other) 8,358 7,237 26,004 19,126  
Segment gross margin 11,118 8,520 35,302 40,039  
Employment related expenses 1,990 2,105 6,290 6,489  
Driver pay 0 0 0 0  
Pass-through expenses 1,254 815 2,369 2,456  
Utilities, materials, and supplies 259 235 816 726  
Repairs and maintenance 95 118 235 541  
Insurance related expenses 155 195 650 535  
Lease expenses 110 117 307 351  
Other segment expenses 1,629 1,211 3,892 4,420  
Depreciation and amortization 4,190 3,531 12,437 10,644  
(Gain) loss on sale or disposition of property, plant and equipment 0 (2) (25) (3)  
Total costs and expenses 9,682 8,325 26,971 26,159  
Operating income 1,436 195 8,331 13,880  
Segment assets 146,416 127,554 146,416 127,554 132,397
Capital expenditures and plant turnaround costs 7,367 5,496 15,030 8,824  
Sulfur services segment | Elimination of intersegment revenues          
Segment Reporting          
Total consolidated revenues 0 0 0 0  
Specialty Products          
Segment Reporting          
Total consolidated revenues 89,502 62,443 234,256 192,066  
Specialty Products | Operating Segments          
Segment Reporting          
Total consolidated revenues 89,551 62,482 234,370 192,151  
Direct product costs 76,733 52,534 195,071 160,379  
Manufacturing costs (plant, labor, transportation, and other) 5,323 4,318 18,306 13,684  
Segment gross margin 7,495 5,630 20,993 18,088  
Employment related expenses 1,415 1,344 4,621 4,228  
Driver pay 0 0 0 0  
Pass-through expenses 0 0 0 0  
Utilities, materials, and supplies 41 29 116 88  
Repairs and maintenance 5 1 14 10  
Insurance related expenses 40 45 129 122  
Lease expenses 12 20 48 73  
Other segment expenses 73 248 519 736  
Depreciation and amortization 661 755 2,158 2,268  
(Gain) loss on sale or disposition of property, plant and equipment 0 (13) (1) (17)  
Total costs and expenses 2,247 2,429 7,604 7,508  
Operating income 5,248 3,201 13,389 10,580  
Segment assets 104,722 66,755 104,722 66,755 $ 68,781
Capital expenditures and plant turnaround costs 307 523 676 1,072  
Specialty Products | Elimination of intersegment revenues          
Segment Reporting          
Total consolidated revenues $ (49) $ (39) $ (114) $ (85)