Financing (Tables)

3 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Schedule of Short-term Borrowings

Information about short-term borrowings, including Spire Missouri’s and Spire Alabama’s borrowings from Spire, is presented in the following table. As of December 31, 2021, $421.9 of Spire’s CP Program borrowings was used to support lending to the Utilities.

	Spire (Parent Only)			Spire Missouri						Spire Alabama			Spire
	CP			Term			Spire			Spire			Consol-
	Program			Loan			Note			Note			idated
Three Months Ended December 31, 2021
Highest borrowings outstanding	$	746.8		$	250.0		$	412.0		$	176.7		$	996.8
Lowest borrowings outstanding		408.0			250.0			101.6			38.4			658.0
Weighted average borrowings		558.6			250.0			253.6			73.6			808.6
Weighted average interest rate		0.2	%		0.7	%		0.2	%		0.2	%		0.4	%
As of December 31, 2021
Borrowings outstanding	$	596.0		$	250.0		$	180.4		$	173.7		$	846.0
Weighted average interest rate		0.4	%		0.7	%		0.4	%		0.4	%		0.5	%
As of September 30, 2021
Borrowings outstanding	$	422.0		$	250.0		$	240.9		$	49.0		$	672.0
Weighted average interest rate		0.2	%		0.7	%		0.2	%		0.2	%		0.4	%
As of December 31, 2020
Borrowings outstanding	$	696.1		$	—		$	393.7		$	27.0		$	696.1
Weighted average interest rate		0.3	%	n/a				0.3	%		0.3	%		0.3	%

Summary Capitalized Interest

Interest expense shown on the statements of income is net of the capitalized interest amounts shown in the following table.

	Three Months Ended December 31,
	2021		2020
Spire	$	1.1	$	0.9
Spire Missouri		—		—
Spire Alabama		0.8		0.6