Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Public Utilities, Inventory
Total inventories	$ 241	$ 230
Non-utility LPG and natural gas
Public Utilities, Inventory
Total inventories	164	150
Gas Utility natural gas
Public Utilities, Inventory
Total inventories	20	27
Materials, supplies and other
Public Utilities, Inventory
Total inventories	$ 57	$ 53

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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