Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Operating Revenues	$ 669.1	$ 756.6
Operating Expenses:
Natural gas	270.0	367.0
Operation and maintenance	129.3	130.7
Depreciation and amortization	72.3	67.0
Taxes, other than income taxes	48.7	52.7
Total Operating Expenses	520.3	617.4
Operating Income	148.8	139.2
Interest Expense, Net	48.0	50.6
Other Income, Net	0.6	17.5
Income Before Income Taxes	101.4	106.1
Income Tax expense	20.1	21.0
Net Income (Loss)	81.3	85.1
Provision for preferred dividends	3.7	3.7
Income allocated to participating securities	0.1	0.1
Net Income Available to Common Shareholders	$ 77.5	$ 81.3
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)	57.7	53.5
Diluted (in shares)	57.9	53.6
Basic Earnings Per Common Share (in dollars per share)	$ 1.34	$ 1.52
Diluted Earnings Per Common Share (in dollars per share)	$ 1.34	$ 1.52
Spire Alabama Inc [Member]
Operating Revenues	$ 120.4	$ 142.1
Operating Expenses:
Natural gas	32.7	55.8
Operation and maintenance	31.9	34.2
Depreciation and amortization	17.8	17.9
Taxes, other than income taxes	8.6	10.2
Total Operating Expenses	91.0	118.1
Operating Income	29.4	24.0
Interest Expense, Net	7.8	9.3
Other Income, Net	(0.7)	0.3
Income Before Income Taxes	20.9	15.0
Income Tax expense	5.2	3.9
Net Income (Loss)	$ 15.7	$ 11.1