Property, Plant and Equipment - (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment
Utility	$ 3,938.1	$ 3,616.3
Non-utility	6,134.9	5,345.8
Total property, plant and equipment	10,073.0	8,962.1
Distribution
Property, Plant and Equipment
Utility	3,366.2	3,106.6
Transmission
Property, Plant and Equipment
Utility	106.0	97.1
General and other
Property, Plant and Equipment
Utility	389.3	281.7
Work in process
Property, Plant and Equipment
Utility	76.6	130.9
Non-utility	101.7	57.9
Land
Property, Plant and Equipment
Non-utility	183.5	191.4
Buildings and improvements
Property, Plant and Equipment
Non-utility	403.8	364.9
Transportation equipment
Property, Plant and Equipment
Non-utility	258.3	257.1
Equipment, primarily cylinders and tanks
Property, Plant and Equipment
Non-utility	3,455.2	3,375.4
Electric generation
Property, Plant and Equipment
Non-utility	326.9	319.5
Pipeline and related assets
Property, Plant and Equipment
Non-utility	1,150.2	473.0
Other
Property, Plant and Equipment
Non-utility	$ 255.3	$ 306.6

Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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