XML 42 R30.htm IDEA: XBRL DOCUMENT

Note 1 - Summary of Significant Accounting Policies - Transactions With Affiliates (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Spire Missouri [Member] \| Spire Marketing Incorporation [Member]
Purchases of natural gas from Spire Marketing Inc.	$ 28.5	$ 18.2
Spire Missouri [Member] \| Spire S T L Pipeline L L C [Member]
Transportation services received	8.1	8.1
Spire Alabama Inc [Member] \| Spire Marketing Incorporation [Member]
Purchases of natural gas from Spire Marketing Inc.	$ 1.1	$ 0.0