Business Segment Information (Schedule of Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total consolidated assets	$ 6,169,539	$ 5,905,801
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Total consolidated assets	2,214,924	2,103,140
Operating Segments | Sodium Minerals and Sulfur Services [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	2,230,163	2,132,588
Operating Segments | Onshore Facilities and Transportation [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	974,464	923,064
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Total consolidated assets	692,303	703,030
Other assets
Segment Reporting Information [Line Items]
Total consolidated assets	$ 57,685	$ 43,979