v3.26.1
Business Segment Information (Schedule of Segment Information) (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting Information [Line Items]        
Revenues $ 531,995,000 $ 377,348,000 $ 978,550,000 $ 775,659,000
Total Segment Margin 169,482,000 135,869,000 325,922,000 257,264,000
Offshore pipeline transportation        
Segment Reporting Information [Line Items]        
Revenues 160,147,000 125,370,000 307,428,000 234,257,000
Marine transportation        
Segment Reporting Information [Line Items]        
Revenues 80,943,000 79,617,000 160,988,000 160,261,000
Onshore transportation and services        
Segment Reporting Information [Line Items]        
Revenues 290,905,000 172,361,000 510,134,000 381,141,000
Operating Segments        
Segment Reporting Information [Line Items]        
Revenues 531,995,000 377,348,000 978,550,000 775,659,000
Segment Operating Expenses (162,699,000) (146,505,000) (316,115,000) (298,339,000)
Segment Product Costs (198,716,000) (92,479,000) (338,809,000) (220,170,000)
Other Segment Items (1,098,000) (2,495,000) 2,296,000 114,000
Total Segment Margin 169,482,000 135,869,000 325,922,000 257,264,000
Operating Segments | Offshore pipeline transportation        
Segment Reporting Information [Line Items]        
Revenues 157,508,000 125,128,000 304,924,000 234,015,000
Segment Operating Expenses (41,904,000) (35,979,000) (85,074,000) (68,915,000)
Segment Product Costs 0 0 0 0
Other Segment Items (2,618,000) (1,797,000) 359,000 (1,200,000)
Total Segment Margin 115,625,000 87,594,000 222,713,000 164,142,000
Operating Segments | Marine transportation        
Segment Reporting Information [Line Items]        
Revenues 80,943,000 79,617,000 160,988,000 160,261,000
Segment Operating Expenses (55,499,000) (49,977,000) (107,620,000) (100,866,000)
Segment Product Costs 0 0 0 0
Other Segment Items 205,000 177,000 198,000 443,000
Total Segment Margin 25,649,000 29,817,000 53,566,000 59,838,000
Operating Segments | Onshore transportation and services        
Segment Reporting Information [Line Items]        
Revenues 293,544,000 172,603,000 512,638,000 381,383,000
Operating Segments | Onshore transportation and services        
Segment Reporting Information [Line Items]        
Segment Operating Expenses (65,296,000) (60,549,000) (123,421,000) (128,558,000)
Segment Product Costs (198,716,000) (92,479,000) (338,809,000) (220,170,000)
Other Segment Items 1,315,000 (875,000) 1,739,000 871,000
Total Segment Margin 28,208,000 18,458,000 49,643,000 33,284,000
Intersegment        
Segment Reporting Information [Line Items]        
Revenues 0 0 0 0
Intersegment | Offshore pipeline transportation        
Segment Reporting Information [Line Items]        
Revenues 2,639,000 242,000 2,504,000 242,000
Intersegment | Marine transportation        
Segment Reporting Information [Line Items]        
Revenues 0 0 0 0
Intersegment | Onshore transportation and services        
Segment Reporting Information [Line Items]        
Revenues $ (2,639,000) $ (242,000) $ (2,504,000) $ (242,000)