CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Revenues:
Gas Utility	$ 541.9	$ 472.3
Gas Marketing and other	19.9	22.8
Total Operating Revenues	561.8	495.1
Gas Utility
Natural and propane gas	240.8	193.8
Operation and maintenance	97.9	99.4
Depreciation and amortization	40.3	37.7
Taxes, other than income taxes	36.7	33.4
Total Gas Utility Operating Expenses	415.7	364.3
Gas Marketing and other	41.0	41.7
Total Operating Expenses	456.7	406.0
Operating Income	105.1	89.1
Other Income	2.2	0.5
Interest Charges:
Interest on long-term debt	20.7	19.1
Other interest charges	3.7	3.0
Total Interest Charges	24.4	22.1
Income Before Income Taxes	82.9	67.5
Income Tax (Benefit) Expense	(33.1)	22.3
Net Income	$ 116.0	$ 45.2
Weighted Average Number of Shares Outstanding:
Basic (in shares)	48.2	45.5
Diluted (in shares)	48.4	45.7
Basic Earnings Per Share of Common Stock (in dollars per share)	$ 2.40	$ 0.99
Diluted Earnings Per Share of Common Stock (in dollars per share)	2.39	0.99
Dividends Declared Per Share of Common Stock (in dollars per share)	$ 0.5625	$ 0.525
Spire Missouri
Operating Revenues:
Gas Utility	$ 392.3	$ 363.6
Total Operating Revenues	392.3	363.6
Gas Utility
Natural and propane gas	206.2	191.3
Operation and maintenance	60.3	60.5
Depreciation and amortization	24.8	22.7
Taxes, other than income taxes	26.2	24.6
Total Operating Expenses	317.5	299.1
Operating Income	74.8	64.5
Other Income	1.2	0.1
Interest Charges:
Interest on long-term debt	9.9	8.3
Other interest charges	1.7	1.4
Total Interest Charges	11.6	9.7
Income Before Income Taxes	64.4	54.9
Income Tax (Benefit) Expense	(25.0)	16.9
Net Income	89.4	38.0
Spire Alabama
Operating Revenues:
Gas Utility	120.8	86.7
Total Operating Revenues	120.8	86.7
Gas Utility
Natural and propane gas	49.0	16.8
Operation and maintenance	31.8	31.2
Depreciation and amortization	12.8	12.3
Taxes, other than income taxes	8.2	6.6
Total Operating Expenses	101.8	66.9
Operating Income	19.0	19.8
Other Income	0.4	0.4
Interest Charges:
Interest on long-term debt	2.9	2.8
Other interest charges	1.1	0.8
Total Interest Charges	4.0	3.6
Income Before Income Taxes	15.4	16.6
Income Tax (Benefit) Expense	65.0	6.3
Net Income	$ (49.6)	$ 10.3