Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating Revenues	$ 756.6	$ 814.0
Operating Expenses:
Natural gas	367.0	419.2
Operation and maintenance	130.7	132.1
Depreciation and amortization	67.0	62.1
Taxes, other than income taxes	52.7	50.4
Total Operating Expenses	617.4	663.8
Operating Income	139.2	150.2
Interest Expense, Net	50.6	43.6
Other Income, Net	17.5	6.0
Income Before Income Taxes	106.1	112.6
Income Tax Expense	21.0	21.6
Net Income	85.1	91.0
Provision for preferred dividends	3.7	3.7
Income allocated to participating securities	0.1	0.1
Net Income Available to Common Shareholders	$ 81.3	$ 87.2
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)	53.5	52.4
Diluted (in shares)	53.6	52.6
Basic Earnings Per Common Share (in dollars per share)	$ 1.52	$ 1.66
Diluted Earnings Per Common Share (in dollars per share)	$ 1.52	$ 1.66
Operating Revenues	$ 756.6	$ 814.0
Spire Alabama Inc [Member]
Operating Revenues	142.1	152.4
Operating Expenses:
Natural gas	55.8	69.4
Operation and maintenance	34.2	35.1
Depreciation and amortization	17.9	17.0
Taxes, other than income taxes	10.2	10.6
Total Operating Expenses	118.1	132.1
Operating Income	24.0	20.3
Interest Expense, Net	9.3	8.3
Other Income, Net	0.3	0.4
Income Before Income Taxes	15.0	12.4
Income Tax Expense	3.9	3.2
Net Income	11.1	9.2
Weighted Average Number of Common Shares Outstanding:
Operating Revenues	$ 142.1	$ 152.4