Business Segment Information (Schedule of Segment Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Total Segment Margin	$ 151,108	$ 207,897	$ 500,519	$ 617,644
Revenues	714,297	807,618	2,240,663	2,402,892
Offshore pipeline transportation
Segment Reporting Information [Line Items]
Revenues	101,119	106,297	302,133	289,151
Soda and sulfur services
Segment Reporting Information [Line Items]
Revenues	370,065	423,575	1,161,007	1,331,078
Onshore facilities and transportation
Segment Reporting Information [Line Items]
Revenues	164,617	197,526	533,582	541,874
Marine transportation
Segment Reporting Information [Line Items]
Revenues	78,496	80,220	243,941	240,789
Operating Segments
Segment Reporting Information [Line Items]
Total Segment Margin	151,108	207,897	500,519	617,644
Capital expenditures	137,277	205,183	348,452	419,553
Revenues	714,297	807,618	2,240,663	2,402,892
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Total Segment Margin	72,149	109,267	256,086	300,505
Capital expenditures	74,461	149,489	193,875	293,187
Revenues	101,119	101,985	302,133	284,839
Operating Segments | Soda and sulfur services
Segment Reporting Information [Line Items]
Total Segment Margin	38,188	61,957	125,181	217,319
Capital expenditures	30,280	36,502	66,986	83,109
Revenues	372,146	425,913	1,167,325	1,337,897
Operating Segments | Onshore facilities and transportation
Segment Reporting Information [Line Items]
Total Segment Margin	9,703	9,547	25,278	21,242
Capital expenditures	2,112	6,696	15,325	10,714
Revenues	162,536	199,500	527,264	539,367
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Total Segment Margin	31,068	27,126	93,974	78,578
Capital expenditures	30,424	12,496	72,266	32,543
Revenues	78,496	80,220	243,941	240,789
Intersegment
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Intersegment | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Revenues	0	4,312	0	4,312
Intersegment | Soda and sulfur services
Segment Reporting Information [Line Items]
Revenues	(2,081)	(2,338)	(6,318)	(6,819)
Intersegment | Onshore facilities and transportation
Segment Reporting Information [Line Items]
Revenues	2,081	(1,974)	6,318	2,507
Intersegment | Marine transportation
Segment Reporting Information [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0