Business Segment Information (Schedule of Total Assets and Total Growth and Maintenance Capital Expenditures by Reportable Segment) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Reporting Information [Line Items]
Assets	$ 4,838,538		$ 7,037,692
Assets held for discontinued operations	0		2,207,420
Capital Expenditures	$ 93,817	$ 181,160
Costs incurred, percentage	1	1
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 4,797,221		4,790,616
Capital Expenditures	93,163	$ 175,072
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Assets	2,769,350		2,748,296
Capital Expenditures	59,136	119,414
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Assets	629,719		641,082
Capital Expenditures	29,452	41,842
Operating Segments | Onshore transportation and services
Segment Reporting Information [Line Items]
Assets	1,398,152		1,401,238
Capital Expenditures	4,575	13,816
Other assets
Segment Reporting Information [Line Items]
Assets	41,317		$ 39,656
Other
Segment Reporting Information [Line Items]
Capital Expenditures	$ 654	$ 6,088