Revenue Recognition (Disaggregated Revenue) (Details) - USD ($)		3 Months Ended		6 Months Ended
	Feb. 28, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Disaggregation of Revenue [Line Items]
Total revenues		$ 377,348,000	$ 430,179,000	$ 775,659,000	$ 864,626,000
Other Assets		6,498,000		6,498,000		$ 5,174,000
Accrued Liabilities		33,400,000		33,400,000		41,618,000
Other Long-Term Liabilities		73,350,000		73,350,000		$ 82,164,000
Proceeds from disposal of discontinued operations, net of cash divested				996,642,000	0
Alkali Business
Disaggregation of Revenue [Line Items]
Proceeds from disposal of discontinued operations, net of cash divested	$ 1,000,000,000
Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues		221,700,000	197,094,000	424,736,000	395,945,000
Product sales
Disaggregation of Revenue [Line Items]
Total revenues		137,885,000	212,659,000	312,148,000	425,368,000
Sulfur services
Disaggregation of Revenue [Line Items]
Total revenues		17,763,000	20,426,000	38,775,000	43,313,000
Offshore pipeline transportation
Disaggregation of Revenue [Line Items]
Total revenues		125,370,000	99,024,000	234,257,000	201,014,000
Offshore pipeline transportation | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues		125,370,000	99,024,000	234,257,000	201,014,000
Offshore pipeline transportation | Product sales
Disaggregation of Revenue [Line Items]
Total revenues		0	0	0	0
Offshore pipeline transportation | Sulfur services
Disaggregation of Revenue [Line Items]
Total revenues		0	0	0	0
Marine transportation
Disaggregation of Revenue [Line Items]
Total revenues		79,617,000	81,871,000	160,261,000	165,445,000
Marine transportation | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues		79,617,000	81,871,000	160,261,000	165,445,000
Marine transportation | Product sales
Disaggregation of Revenue [Line Items]
Total revenues		0	0	0	0
Marine transportation | Sulfur services
Disaggregation of Revenue [Line Items]
Total revenues		0	0	0	0
Onshore transportation and services
Disaggregation of Revenue [Line Items]
Total revenues		172,361,000	249,284,000	381,141,000	498,167,000
Onshore transportation and services | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues		16,713,000	16,199,000	30,218,000	29,486,000
Onshore transportation and services | Product sales
Disaggregation of Revenue [Line Items]
Total revenues		137,885,000	212,659,000	312,148,000	425,368,000
Onshore transportation and services | Sulfur services
Disaggregation of Revenue [Line Items]
Total revenues		$ 17,763,000	$ 20,426,000	$ 38,775,000	$ 43,313,000