Segment Information - Balance Sheet Information by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 17,240,239	$ 15,063,970
Total assets	22,192,989	19,608,662
Operating Segments | Distribution
Segment Reporting Information [Line Items]
Property, plant and equipment, net	12,723,532	11,232,649
Total assets	21,424,586	18,847,266
Operating Segments | Pipeline and Storage
Segment Reporting Information [Line Items]
Property, plant and equipment, net	4,516,707	3,831,321
Total assets	4,797,206	4,076,844
Eliminations
Segment Reporting Information [Line Items]
Property, plant and equipment, net	0	0
Total assets	$ (4,028,803)	$ (3,315,448)