Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=116637345&loc=SL114874292-224272

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-Name Accounting Standards Codification
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Summary of Significant Accounting Policies - Schedule of Inter-Company Transactions (Details) - Affiliated Entity - Spire Missouri - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Spire Marketing Inc \| Regulated Operation
Related Party Transaction [Line Items]
Purchases of natural gas from Spire Marketing Inc.	$ 13.3	$ 29.2	$ 32.8	$ 69.0
Sales of natural gas to Spire Marketing Inc.				1.4
Spire STL Pipeline LLC \| Unregulated Operation
Related Party Transaction [Line Items]
Transportation services received from	7.9		11.8
Spire NGL Inc. \| Unregulated Operation
Related Party Transaction [Line Items]
Transportation services received from	$ 0.2	$ 0.2	$ 0.5	$ 0.5