Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Operating Revenues		$ 814.0	$ 814.0	$ 555.4	$ 555.4
Operating Expenses:
Natural gas		419.2	419.2	249.2	249.2
Operation and maintenance		132.1	132.1	116.4	116.4
Depreciation and amortization		62.1	62.1	56.9	56.9
Taxes, other than income taxes		50.4	50.4	37.6	37.6
Total Operating Expenses		663.8	663.8	460.1	460.1
Operating Income		150.2	150.2	95.3	95.3
Interest Expense, Net			43.6		28.6
Other Income, Net			6.0		7.4
Income Before Income Taxes			112.6		74.1
Income Tax Expense			21.6		18.4
Net Income		91.0	91.0	55.7	55.7
Provision for preferred dividends		3.7	3.7	3.7	3.7
Income allocated to participating securities		0.1	0.1	0.1	0.1
Net Income Available to Common Shareholders		87.2	87.2	51.9	51.9
Other Comprehensive Income, Net of Tax		(2.4)		(3.9)
Comprehensive Income		88.6		51.8
Operating Revenues		$ 814.0	$ 814.0	$ 555.4	$ 555.4
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)		52.4	52.4	51.6	51.6
Diluted (in shares)		52.6	52.6	51.7	51.7
Basic Earnings Per Common Share (in dollars per share)		$ 1.66	$ 1.66	$ 1.01	$ 1.01
Diluted Earnings Per Common Share (in dollars per share)		$ 1,660,000	$ 1.66	$ 1,010,000.00	$ 1.01
Operating Revenues		$ 814.0	$ 814.0	$ 555.4	$ 555.4
Spire Missouri [Member]
Operating Revenues		541.2		347.9
Operating Expenses:
Natural gas		316.7		156.3
Operation and maintenance		77.1		66.3
Depreciation and amortization		38.6		34.2
Taxes, other than income taxes		36.4		25.7
Total Operating Expenses		468.8		282.5
Operating Income		72.4		65.4
Interest Expense, Net		22.0		14.5
Other Income, Net		5.0		5.9
Income Before Income Taxes		55.4		56.8
Income Tax Expense		8.1		11.5
Net Income	[1]	47.3		45.3
Other Comprehensive Income, Net of Tax	[1]	0.1		0.1
Comprehensive Income		47.4		45.4
Operating Revenues		541.2		347.9
Weighted Average Number of Common Shares Outstanding:
Operating Revenues		541.2		347.9
Spire Alabama Inc [Member]
Operating Revenues		152.4		126.6
Operating Expenses:
Natural gas		69.4		45.5
Operation and maintenance		35.1		34.5
Depreciation and amortization		17.0		16.5
Taxes, other than income taxes		10.6		9.0
Total Operating Expenses		132.1		105.5
Operating Income		20.3		21.1
Interest Expense, Net		8.3		5.1
Other Income, Net		0.4		0.4
Income Before Income Taxes		12.4		16.4
Income Tax Expense		3.2		4.2
Net Income		9.2		12.2
Operating Revenues		152.4		126.6
Weighted Average Number of Common Shares Outstanding:
Operating Revenues		$ 152.4		$ 126.6

[1] Accumulated other comprehensive income (loss)