Business Segment Information (Schedule of Total Assets and Total Growth and Maintenance Capital Expenditures by Reportable Segment) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Assets	$ 7,037,692	$ 7,018,778
Capital Expenditures	$ 471,062	$ 703,502
Offshore Pipeline Transportation
Segment Reporting Information [Line Items]
Costs incurred, percentage	1	1
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 6,999,885	$ 6,949,515
Capital Expenditures	459,018	691,329
Operating Segments | Offshore Pipeline Transportation
Segment Reporting Information [Line Items]
Assets	2,748,296	2,580,032
Capital Expenditures	255,640	410,237
Operating Segments | Soda and Sulfur Services
Segment Reporting Information [Line Items]
Assets	2,597,039	2,705,350
Capital Expenditures	95,343	219,393
Operating Segments | Marine Transportation
Segment Reporting Information [Line Items]
Assets	641,082	645,020
Capital Expenditures	91,752	42,681
Operating Segments | Onshore Facilities and Transportation
Segment Reporting Information [Line Items]
Assets	1,013,468	1,019,113
Capital Expenditures	16,283	19,018
Other assets
Segment Reporting Information [Line Items]
Assets	37,807	69,263
Capital Expenditures	$ 12,044	$ 12,173