v3.26.1
Business Segments - Schedule of Financial Information of Partnership's Operating Segments (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting        
Total consolidated revenues $ 213,600 $ 180,676 $ 401,274 $ 373,219
Depreciation and amortization 13,052 12,638 25,923 25,454
(Gain) loss on sale or disposition of property, plant and equipment (4,653) (613) (4,986) (1,092)
Total costs and expenses 198,995 166,406 378,983 345,026
Operating income 19,258 14,883 27,277 29,285
Segment assets - as of June 30, 2026 547,433 515,632 547,433 515,632
Capital expenditures and plant turnaround costs 14,164 6,015 28,155 11,623
Operating Segments        
Segment Reporting        
Total consolidated revenues 220,238 186,398 413,880 385,319
Direct product costs 96,529 72,822 177,402 157,269
Manufacturing costs (plant, labor, transportation, and other) 16,853 10,655 30,629 21,255
Segment gross margin 106,856 102,921 205,849 206,795
Employment related expenses 27,850 28,584 56,918 57,100
Driver pay 12,963 11,504 24,689 23,585
Pass-through expenses 8,494 6,661 15,255 13,623
Utilities, materials, and supplies 4,680 4,441 9,669 8,965
Repairs and maintenance 5,641 5,610 11,540 11,715
Insurance related expenses 6,250 6,082 12,853 11,785
Lease expenses 7,096 6,136 14,201 12,074
Other segment expenses 6,225 6,995 12,510 14,301
Depreciation and amortization 13,052 12,638 25,923 25,454
(Gain) loss on sale or disposition of property, plant and equipment (4,653) (613) (4,986) (1,092)
Total costs and expenses 87,598 88,038 178,572 177,510
Operating income 19,258 14,883 27,277 29,285
Elimination of intersegment revenues        
Segment Reporting        
Total consolidated revenues (6,638) (5,722) (12,606) (12,100)
Indirect selling, general and administrative        
Segment Reporting        
Employment related expenses 2,964 3,165 5,759 6,259
Insurance related expenses 25 3 32 92
Other segment expenses 674 769 1,351 2,261
Total costs and expenses 3,663 3,937 7,142 8,612
Operating income (3,663) (3,937) (7,142) (8,612)
Terminalling and storage        
Segment Reporting        
Total consolidated revenues 23,743 22,404 46,180 43,953
Terminalling and storage | Operating Segments        
Segment Reporting        
Total consolidated revenues 25,719 24,228 50,107 47,642
Direct product costs 0 0 0 0
Manufacturing costs (plant, labor, transportation, and other) 0 0 0 0
Segment gross margin 25,719 24,228 50,107 47,642
Employment related expenses 6,654 6,584 13,641 13,137
Driver pay 0 0 0 0
Pass-through expenses 0 0 0 0
Utilities, materials, and supplies 3,793 3,587 7,896 7,220
Repairs and maintenance 1,094 905 2,200 2,305
Insurance related expenses 1,642 1,560 3,301 3,031
Lease expenses 1,197 1,075 2,337 2,231
Other segment expenses 1,858 2,114 4,103 3,637
Depreciation and amortization 5,125 5,411 10,079 10,980
(Gain) loss on sale or disposition of property, plant and equipment (4,450) (8) (4,459) (9)
Total costs and expenses 16,913 21,228 39,098 42,532
Operating income 8,806 3,000 11,009 5,110
Segment assets - as of June 30, 2026 161,643 159,001 161,643 159,001
Capital expenditures and plant turnaround costs 4,313 1,925 14,529 2,847
Terminalling and storage | Elimination of intersegment revenues        
Segment Reporting        
Total consolidated revenues (1,976) (1,824) (3,927) (3,689)
Transportation segment        
Segment Reporting        
Total consolidated revenues 56,639 53,826 109,446 106,811
Transportation segment | Operating Segments        
Segment Reporting        
Total consolidated revenues 61,257 57,701 118,060 115,176
Direct product costs 0 0 0 0
Manufacturing costs (plant, labor, transportation, and other) 0 0 0 0
Segment gross margin 61,257 57,701 118,060 115,176
Employment related expenses 14,753 15,183 30,013 30,436
Driver pay 12,963 11,504 24,689 23,585
Pass-through expenses 7,997 5,884 14,140 11,982
Utilities, materials, and supplies 590 587 1,139 1,196
Repairs and maintenance 4,501 4,481 9,191 8,976
Insurance related expenses 4,350 4,296 8,937 8,246
Lease expenses 5,784 4,920 11,631 9,555
Other segment expenses 2,304 2,313 4,347 4,707
Depreciation and amortization 3,062 2,916 6,100 5,848
(Gain) loss on sale or disposition of property, plant and equipment (184) (600) (501) (1,078)
Total costs and expenses 56,120 51,484 109,686 103,453
Operating income 5,137 6,217 8,374 11,723
Segment assets - as of June 30, 2026 164,321 162,974 164,321 162,974
Capital expenditures and plant turnaround costs 3,876 2,077 5,594 4,899
Transportation segment | Elimination of intersegment revenues        
Segment Reporting        
Total consolidated revenues (4,618) (3,875) (8,614) (8,365)
Sulfur services segment        
Segment Reporting        
Total consolidated revenues 50,070 44,128 100,894 92,832
Sulfur services segment | Operating Segments        
Segment Reporting        
Total consolidated revenues 50,070 44,128 100,894 92,832
Direct product costs 28,882 22,604 59,064 49,424
Manufacturing costs (plant, labor, transportation, and other) 8,389 6,707 17,646 11,889
Segment gross margin 12,799 14,817 24,184 31,519
Employment related expenses 2,070 2,221 4,300 4,384
Driver pay 0 0 0 0
Pass-through expenses 497 777 1,115 1,641
Utilities, materials, and supplies 254 236 558 491
Repairs and maintenance 42 215 140 424
Insurance related expenses 191 179 495 339
Lease expenses 100 110 196 235
Other segment expenses 1,176 1,555 2,263 3,208
Depreciation and amortization 4,120 3,556 8,247 7,113
(Gain) loss on sale or disposition of property, plant and equipment (19) (1) (25) (1)
Total costs and expenses 8,431 8,848 17,289 17,834
Operating income 4,368 5,969 6,895 13,685
Segment assets - as of June 30, 2026 141,256 128,266 141,256 128,266
Capital expenditures and plant turnaround costs 5,790 1,587 7,663 3,328
Sulfur services segment | Elimination of intersegment revenues        
Segment Reporting        
Total consolidated revenues 0 0 0 0
Specialty Products        
Segment Reporting        
Total consolidated revenues 83,148 60,318 144,754 129,623
Specialty Products | Operating Segments        
Segment Reporting        
Total consolidated revenues 83,192 60,341 144,819 129,669
Direct product costs 67,647 50,218 118,338 107,845
Manufacturing costs (plant, labor, transportation, and other) 8,464 3,948 12,983 9,366
Segment gross margin 7,081 6,175 13,498 12,458
Employment related expenses 1,409 1,431 3,205 2,884
Driver pay 0 0 0 0
Pass-through expenses 0 0 0 0
Utilities, materials, and supplies 43 31 76 58
Repairs and maintenance 4 9 9 10
Insurance related expenses 42 44 88 77
Lease expenses 15 31 37 53
Other segment expenses 213 244 446 488
Depreciation and amortization 745 755 1,497 1,513
(Gain) loss on sale or disposition of property, plant and equipment 0 (4) (1) (4)
Total costs and expenses 2,471 2,541 5,357 5,079
Operating income 4,610 3,634 8,141 7,379
Segment assets - as of June 30, 2026 80,213 65,391 80,213 65,391
Capital expenditures and plant turnaround costs 185 426 369 549
Specialty Products | Elimination of intersegment revenues        
Segment Reporting        
Total consolidated revenues $ (44) $ (23) $ (65) $ (46)