Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended				9 Months Ended
	Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Operating Revenues	$ 448.0		$ 327.8		$ 1,884.3		$ 1,945.3
Operating Expenses:
Natural gas	203.3		96.9		844.5		897.2
Operation and maintenance	102.3		112.0		331.9		342.6
Depreciation and amortization	60.4		53.1		176.2		155.4
Taxes, other than income taxes	44.1		32.6		153.3		126.6
Total Operating Expenses	410.1		294.6		1,505.9		1,521.8
Operating Income	37.9		33.2		378.4		423.5
Interest Expense, Net	29.3		26.9		85.4		78.4
Other (Expense) Income, Net	(12.1)		(1.0)		(8.1)		5.1
(Loss) income Before Income Taxes	(3.5)		5.3		284.9		350.2
Income Tax (Benefit) Expense	(2.1)		0.0		57.0		68.6
Net (Loss) Income	(1.4)		5.3		227.9		281.6
Provision for preferred dividends	3.7		3.7		11.1		11.1
Income allocated to participating securities	0.0		0.1		0.3		0.5
Net (Loss) Income Available to Common Shareholders	(5.1)		1.5		216.5		270.0
Other Comprehensive Income, Net of Tax	18.5		(3.4)		28.6		43.1
Comprehensive (Loss) Income	17.1		1.9		256.5		324.7
Operating Revenues	$ 448.0		$ 327.8		$ 1,884.3		$ 1,945.3
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)	52.2		51.6		51.9		51.6
Diluted (in shares)	52.3		51.7		52.0		51.7
Basic (Loss) Earnings Per Common Share (in dollars per share)	$ (0.10)		$ 0.03		$ 4.17		$ 5.24
Diluted (Loss) Earnings Per Common Share (in dollars per share)	$ (0.10)		$ 0.03		$ 4.16		$ 5.23
Operating Revenues	$ 448.0		$ 327.8		$ 1,884.3		$ 1,945.3
Spire Missouri [Member]
Operating Revenues	236.7		192.1		1,155.8		1,338.5
Operating Expenses:
Natural gas	94.7		55.6		538.8		754.6
Operation and maintenance	59.5		64.3		190.1		190.0
Depreciation and amortization	37.3		31.6		107.4		93.0
Taxes, other than income taxes	32.3		22.2		111.0		86.2
Total Operating Expenses	223.8		173.7		947.3		1,123.8
Operating Income	12.9		18.4		208.5		214.7
Interest Expense, Net	14.7		12.7		43.4		36.1
Other (Expense) Income, Net	(9.7)		(2.6)		(6.2)		0.9
(Loss) income Before Income Taxes	(11.5)		3.1		158.9		179.5
Income Tax (Benefit) Expense	(3.1)		0.0		23.8		26.7
Net (Loss) Income	(8.4)		3.1	[1]	135.1	[1]	152.8
Other Comprehensive Income, Net of Tax	0.2	[1]	0.1		0.4	[1]	0.3
Comprehensive (Loss) Income	(8.2)		3.2		135.5		153.1
Operating Revenues	236.7		192.1		1,155.8		1,338.5
Weighted Average Number of Common Shares Outstanding:
Operating Revenues	236.7		192.1		1,155.8		1,338.5
Spire Alabama Inc [Member]
Operating Revenues	115.7		93.3		446.4		429.5
Operating Expenses:
Natural gas	41.0		24.1		138.6		129.0
Operation and maintenance	29.2		31.9		96.6		98.4
Depreciation and amortization	16.9		16.1		50.1		46.3
Taxes, other than income taxes	8.6		7.9		32.1		30.8
Total Operating Expenses	95.7		80.0		317.4		304.5
Operating Income	20.0		13.3		129.0		125.0
Interest Expense, Net	5.2		5.2		15.0		15.2
Other (Expense) Income, Net	(0.7)		0.6		(0.2)		2.0
(Loss) income Before Income Taxes	14.1		8.7		113.8		111.8
Income Tax (Benefit) Expense	3.6		2.2		28.7		28.3
Net (Loss) Income	10.5		6.5		85.1		83.5
Operating Revenues	115.7		93.3		446.4		429.5
Weighted Average Number of Common Shares Outstanding:
Operating Revenues	$ 115.7		$ 93.3		$ 446.4		$ 429.5

[1] Accumulated other comprehensive income (loss)