Business Segment Information (Schedule of Segment Information) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 377,348,000	$ 430,179,000	$ 775,659,000	$ 864,626,000
Total Segment Margin	135,869,000	137,916,000	257,264,000	285,183,000
Income (loss) from continuing operations before income taxes	10,356,000	(3,976,000)	(26,061,000)	8,186,000
Net income attributable to noncontrolling interests	(10,417,000)	(7,357,000)	(19,186,000)	(14,960,000)
Corporate general and administrative expenses	15,068,000	19,405,000	56,744,000	34,616,000
Depreciation, amortization and accretion	59,011,000	53,940,000	118,022,000	106,103,000
Interest expense, net	60,754,000	64,539,000	130,792,000	126,873,000
Adjustment to include distributable cash generated by equity investees not included in income and exclude equity in investees net income	5,595,000	4,879,000	11,687,000	11,687,000
Unrealized gains on derivative transactions excluding fair value hedges, net of changes in inventory value	(133,000)	(289,000)	(204,000)	(42,000)
Other non-cash items	(4,229,000)	(2,474,000)	(6,951,000)	(4,601,000)
Loss on extinguishment of debt (Note 10)	8,935,000	1,429,000	9,779,000	1,429,000
Differences in timing of cash receipts for certain contractual arrangements	(9,071,000)	7,820,000	$ (17,358,000)	$ 15,892,000
Costs incurred, percentage			1	1
Offshore pipeline transportation
Segment Reporting Information [Line Items]
Revenues	125,370,000	99,024,000	$ 234,257,000	$ 201,014,000
Marine transportation
Segment Reporting Information [Line Items]
Revenues	79,617,000	81,871,000	160,261,000	165,445,000
Onshore transportation and services
Segment Reporting Information [Line Items]
Revenues	172,361,000	249,284,000	381,141,000	498,167,000
Operating Segments
Segment Reporting Information [Line Items]
Revenues	377,348,000		775,659,000
Segment Operating Expenses	(146,505,000)	(151,779,000)	(298,339,000)	(303,692,000)
Segment Product Costs	(92,479,000)	(159,155,000)	(220,170,000)	(319,543,000)
Other Segment Items	(2,495,000)	18,671,000	114,000	43,792,000
Total Segment Margin	135,869,000	137,916,000	257,264,000	285,183,000
Operating Segments | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Revenues	125,128,000		234,015,000
Segment Operating Expenses	(35,979,000)	(29,892,000)	(68,915,000)	(57,710,000)
Segment Product Costs	0	0	0	0
Other Segment Items	(1,797,000)	16,999,000	(1,200,000)	40,633,000
Total Segment Margin	87,594,000	86,131,000	164,142,000	183,937,000
Operating Segments | Marine transportation
Segment Reporting Information [Line Items]
Revenues	79,617,000		160,261,000
Segment Operating Expenses	(49,977,000)	(50,602,000)	(100,866,000)	(103,010,000)
Segment Product Costs	0	0	0	0
Other Segment Items	177,000	274,000	443,000	471,000
Total Segment Margin	29,817,000	31,543,000	59,838,000	62,906,000
Operating Segments | Onshore transportation and services
Segment Reporting Information [Line Items]
Segment Operating Expenses	(60,549,000)	(71,285,000)	(128,558,000)	(142,972,000)
Segment Product Costs	(92,479,000)	(159,155,000)	(220,170,000)	(319,543,000)
Other Segment Items	(875,000)	1,398,000	871,000	2,688,000
Total Segment Margin	18,458,000	$ 20,242,000	33,284,000	$ 38,340,000
Operating Segments | Onshore transportation and services
Segment Reporting Information [Line Items]
Revenues	172,603,000		381,383,000
Intersegment
Segment Reporting Information [Line Items]
Revenues	0		0
Intersegment | Offshore pipeline transportation
Segment Reporting Information [Line Items]
Revenues	242,000		242,000
Intersegment | Marine transportation
Segment Reporting Information [Line Items]
Revenues	0		0
Intersegment | Onshore transportation and services
Segment Reporting Information [Line Items]
Revenues	$ (242,000)		$ (242,000)