CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income (Loss)	$ 5.3	$ (92.3)	$ 281.6	$ 108.3
Cash flow hedging derivative instruments:
Net hedging (loss) gain arising during the period	(4.2)	1.4	56.5	(20.8)
Amounts reclassified into net income	(0.3)	(0.3)	(1.0)	(2.8)
Net (loss) gain on cash flow hedging derivative instruments	(4.5)	1.1	55.5	(23.6)
Net gain (loss) on defined benefit pension and other postretirement plans	0.1		0.3	(0.1)
Net unrealized loss on available for sale securities			(0.1)
Other Comprehensive (Loss) Income, Before Tax	(4.4)	1.1	55.7	(23.7)
Income Tax (Benefit) Expense Related to Items of Other Comprehensive Income	(1.0)	0.1	12.6	(5.4)
Other Comprehensive (Loss) Income, Net of Tax	(3.4)	1.0	43.1	(18.3)
Comprehensive Income (Loss)	1.9	(91.3)	324.7	90.0
Operating Revenues	327.8	321.1	1,945.3	1,603.5
Operating Expenses:
Natural gas	96.9	72.9	897.2	631.9
Operation and maintenance	112.0	124.9	342.6	347.2
Depreciation and amortization	53.1	50.1	155.4	146.8
Taxes, other than income taxes	32.6	31.1	126.6	122.7
Total Operating Expenses	294.6	427.6	1,521.8	1,397.2
Operating Income (Loss)	33.2	(106.5)	423.5	206.3
Interest Expense, Net	26.9	26.4	78.4	80.3
Other (Expense) Income, Net	(1.0)	13.0	5.1	(0.8)
Income (Loss) Before Income Taxes	5.3	(119.9)	350.2	125.2
Income Tax (Benefit) Expense		(27.6)	68.6	16.9
Spire Missouri
Net Income (Loss)	3.1	6.5	152.8	129.0
Cash flow hedging derivative instruments:
Other Comprehensive (Loss) Income, Net of Tax	0.1	0.1	0.3
Comprehensive Income (Loss)	3.2	6.6	153.1	129.0
Operating Revenues	192.1	203.9	1,338.5	1,035.4
Operating Expenses:
Natural gas	55.6	68.9	754.6	478.3
Operation and maintenance	64.3	75.6	190.0	191.9
Depreciation and amortization	31.6	29.7	93.0	88.0
Taxes, other than income taxes	22.2	22.7	86.2	85.5
Total Operating Expenses	173.7	196.9	1,123.8	843.7
Operating Income (Loss)	18.4	7.0	214.7	191.7
Interest Expense, Net	12.7	11.9	36.1	37.8
Other (Expense) Income, Net	(2.6)	11.8	0.9	(8.1)
Income (Loss) Before Income Taxes	$ 3.1	6.9	179.5	145.8
Income Tax (Benefit) Expense		$ 0.4	$ 26.7	$ 16.8