Note 6 - Financing (Tables)

6 Months Ended

Mar. 31, 2023

Notes Tables

Schedule of Short-Term Debt [Table Text Block]

	Spire (Parent Only)			Spire Missouri						Spire Alabama			Spire
	CP			Term			Spire			Spire			Consol-
	Program			Loan			Note			Note			idated
Six Months Ended March 31, 2023
Highest borrowings outstanding	$	1,282.0		$	250.0		$	656.9		$	274.0		$	1,482.0
Lowest borrowings outstanding		354.4			—			3.8			76.7			554.4
Weighted average borrowings		922.7			111.0			383.6			134.9			1,033.7
Weighted average interest rate		4.6	%		5.4	%		4.5	%		4.6	%		4.7	%
As of March 31, 2023
Borrowings outstanding	$	361.0		$	200.0		$	60.7		$	121.3		$	561.0
Weighted average interest rate		5.3	%		5.6	%		5.3	%		5.3	%		5.4	%
As of September 30, 2022
Borrowings outstanding	$	1,037.5		$	—		$	445.3		$	260.9		$	1,037.5
Weighted average interest rate		3.3	%		0.0	%		3.3	%		3.3	%		3.3	%
As of March 31, 2022
Borrowings outstanding	$	607.1		$	—		$	277.2		$	156.6		$	607.1
Weighted average interest rate		0.9	%		0.0	%		0.9	%		0.9	%		0.9	%

Summary Of Capitalized Interest [Table Text Block]

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Spire	$	1.9	$	1.0	$	3.5	$	2.1
Spire Missouri		0.6		0.1		1.1		0.1
Spire Alabama		0.6		0.8		1.3		1.6