Business Segments - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Total assets:
Total assets	$ 554,757	$ 509,375
Terminalling and storage
Total assets:
Total assets	192,058	171,320
Transportation
Total assets:
Total assets	166,448	161,506
Sulfur services
Total assets:
Total assets	116,748	103,779
Specialty products
Total assets:
Total assets	$ 79,503	$ 72,770