Business Segment Information (Schedule of Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total consolidated assets	$ 6,586,460	$ 6,365,992
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Total consolidated assets	2,299,586	2,290,488
Operating Segments | Sodium Minerals and Sulfur Services [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	2,561,391	2,358,086
Operating Segments | Onshore Facilities and Transportation [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	997,869	981,354
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Total consolidated assets	657,582	681,231
Other assets
Segment Reporting Information [Line Items]
Total consolidated assets	$ 70,032	$ 54,833