CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net Income	$ 116.0	$ 45.2
Cash flow hedging derivative instruments:
Net hedging gains arising during the period	0.1	11.5
Reclassification adjustment for (gains) losses included in net income	(0.4)	0.2
Net unrealized (losses) gains on cash flow hedging derivative instruments	(0.3)	11.7
Net gains on defined benefit pension and other postretirement plans	0.1	0.1
Net unrealized losses on available for sale securities	(0.1)	(0.1)
Other Comprehensive (Loss) Income, Before Tax	(0.3)	11.7
Income Tax (Benefit) Expense Related to Items of Other Comprehensive Income	(0.1)	4.3
Other Comprehensive (Loss) Income, Net of Tax	(0.2)	7.4
Comprehensive Income	115.8	52.6
Spire Missouri
Net Income	89.4	38.0
Cash flow hedging derivative instruments:
Other Comprehensive (Loss) Income, Net of Tax	0.0	0.2
Comprehensive Income	$ 89.4	$ 38.2