Interim Financial Information (Unaudited) (Tables)

12 Months Ended

Sep. 30, 2020

Quarterly Financial Information [Line Items]

Schedule of Quarterly Financial Information

Three Months Ended	Dec. 31		March 31		June 30			Sept. 30
Fiscal Year 2020
Total Operating Revenues	$	566.9	$	715.5	$	321.1		$	251.9
Operating Income (Loss)		102.3		210.5		(106.5	)		0.1
Net Income (Loss)		67.0		133.6		(92.3	)		(19.7	)
Basic Earnings (Loss) Per Share of Common Stock	$	1.24	$	2.55	$	(1.87	)	$	(0.45	)
Diluted Earnings (Loss) Per Share of Common Stock	$	1.24	$	2.54	$	(1.87	)	$	(0.45	)
Fiscal Year 2019
Total Operating Revenues	$	602.0	$	803.5	$	321.3		$	225.6
Operating Income (Loss)		105.1		209.5		13.3			(25.6	)
Net Income (Loss)		67.3		154.6		(3.0	)		(34.3	)
Basic Earnings (Loss) Per Share of Common Stock	$	1.33	$	3.05	$	(0.09	)	$	(0.75	)
Diluted Earnings (Loss) Per Share of Common Stock	$	1.32	$	3.04	$	(0.09	)	$	(0.74	)

Spire Missouri

Quarterly Financial Information [Line Items]

Schedule of Quarterly Financial Information

Three Months Ended	Dec. 31		March 31		June 30		Sept. 30
Fiscal Year 2020
Total Operating Revenues	$	374.0	$	457.5	$	203.9	$	158.2
Operating Income		67.0		117.7		7.0		13.9
Net Income		48.0		74.5		6.5		1.2
Fiscal Year 2019
Total Operating Revenues	$	413.2	$	556.6	$	191.4	$	130.6
Operating Income (Loss)		71.4		102.4		12.2		(11.2	)
Net Income (Loss)		51.2		80.0		1.1		(17.3	)

Spire Alabama

Quarterly Financial Information [Line Items]

Schedule of Quarterly Financial Information

Three Months Ended	Dec. 31		March 31		June 30		Sept. 30
Fiscal Year 2020
Total Operating Revenues	$	126.2	$	185.5	$	81.2	$	62.1
Operating Income (Loss)		20.9		81.2		9.3		(8.5	)
Net Income (Loss)		13.2		57.8		3.6		(8.9	)
Fiscal Year 2019
Total Operating Revenues	$	133.5	$	180.4	$	90.8	$	60.8
Operating Income (Loss)		17.1		79.6		11.1		(12.3	)
Net Income (Loss)		10.3		56.7		5.6		(12.3	)