Business Segment Information (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	3
Segment Reporting Information [Line Items]
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]
Capital Expenditures	$ 93,163	$ 175,072
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Capital Expenditures	59,136	119,414
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Capital Expenditures	29,452	41,842
Operating Segments | Onshore transportation and services
Segment Reporting Information [Line Items]
Capital Expenditures	4,575	13,816
Other
Segment Reporting Information [Line Items]
Capital Expenditures	$ 654	$ 6,088