Segment Information - Schedule of Balance Sheet Information by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 25,292,990	$ 22,204,367
Total assets	28,249,522	25,194,465
Operating Segments
Segment Reporting Information [Line Items]
Property, plant and equipment, net	25,292,990	22,204,367
Total assets	34,193,451	30,510,435
Operating Segments | Distribution
Segment Reporting Information [Line Items]
Property, plant and equipment, net	18,765,128	16,372,659
Total assets	27,296,805	24,328,877
Operating Segments | Pipeline and Storage
Segment Reporting Information [Line Items]
Property, plant and equipment, net	6,527,862	5,831,708
Total assets	6,896,646	6,181,558
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total assets	$ (5,943,929)	$ (5,315,970)