Revenue (Tables)

6 Months Ended

Mar. 31, 2021

Revenue From Contract With Customer [Abstract]

Schedule of Revenue Disaggregated by Source and Customer Type

The following tables show revenue disaggregated by source and customer type.

	Three Months Ended March 31,						Six Months Ended March 31,
	2021			2020			2021			2020
Spire
Gas Utility:
Residential	$	537.6		$	471.9		$	887.5		$	840.3
Commercial & industrial		369.2			156.8			472.2			279.3
Transportation		34.2			32.5			66.4			63.5
Off-system & other incentive		130.6			9.3			139.9			18.7
Other customer revenue		(11.9	)		3.2			(9.7	)		5.6
Total revenue from contracts with customers		1,059.7			673.7			1,556.3			1,207.4
Changes in accrued revenue under alternative revenue programs		(6.6	)		5.3			(5.0	)		2.3
Total Gas Utility operating revenues		1,053.1			679.0			1,551.3			1,209.7
Gas Marketing		33.4			33.3			58.2			65.6
Other		15.6			14.7			32.3			25.8
Total before eliminations		1,102.1			727.0			1,641.8			1,301.1
Intersegment eliminations (see Note 9, Information by Operating Segment)		2.8			(11.5	)		(24.3	)		(18.7	)
Total Operating Revenues	$	1,104.9		$	715.5		$	1,617.5		$	1,282.4

Spire Missouri
Residential	$	365.4		$	331.1	$	628.4		$	607.0
Commercial & industrial		304.0			99.2		373.9			180.0
Transportation		9.9			9.7		18.9			18.7
Off-system & other incentive		128.5			9.3		135.9			18.7
Other customer revenue		(17.5	)		0.9		(14.6	)		1.4
Total revenue from contracts with customers		790.3			450.2		1,142.5			825.8
Changes in accrued revenue under alternative revenue programs		0.6			7.3		3.9			5.7
Total Operating Revenues	$	790.9		$	457.5	$	1,146.4		$	831.5

Spire Alabama
Residential	$	144.8		$	120.5		$	214.0		$	194.8
Commercial & industrial		53.2			46.2			77.5			77.5
Transportation		21.7			19.9			42.2			39.5
Off-system & other incentive		1.9			—			3.9			—
Other customer revenue		3.9			1.7			2.0			3.3
Total revenue from contracts with customers		225.5			188.3			339.6			315.1
Changes in accrued revenue under alternative revenue programs		(2.9	)		(2.8	)		(3.4	)		(3.4	)
Total Operating Revenues	$	222.6		$	185.5		$	336.2		$	311.7

Schedule of Gross Receipts Taxes

The expense amounts (shown in the table below) are reported gross in the “Taxes, other than income taxes” line in the statements of income, and corresponding revenues are reported in “Operating Revenues.”

	Three Months Ended March 31,				Six Months Ended March 31,
	2021		2020		2021		2020
Spire	$	42.2	$	37.9	$	63.9	$	62.5
Spire Missouri		28.6		26.2		43.8		43.4
Spire Alabama		11.8		9.9		17.1		16.1