Financing (Tables)

6 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Schedule of Short-term Borrowings

Information about Spire’s consolidated short-term borrowings and about Spire Missouri’s and Spire Alabama’s borrowings from Spire is presented in the following table. As of March 31, 2021, $398.1 of Spire’s short-term borrowings were used to support lending to the Utilities.

	Spire (Parent Only)								Spire Missouri									Spire Alabama						Spire
	Credit		Term			CP			Credit			Term			Spire			Credit			Spire			Consol-
	Facility		Loan			Program			Facility			Loan			Note			Facility			Note			idated
Six Months Ended March 31, 2021
Weighted average borrowings	$	—	$	63.5		$	606.9		$	—		$	11.0		$	360.8		$	—		$	59.6		$	681.4
Lowest borrowings outstanding		—		—			403.5			—			—			277.2			—			—			455.5
Highest borrowings outstanding		—		150.0			775.0			—			250.0			441.9			—			152.2			850.5
Weighted average interest rate	n/a			1.1	%		0.3	%	n/a				0.8	%		0.3	%	n/a				0.2	%		0.4	%
As of March 31, 2021
Borrowings outstanding	$	—	$	—		$	403.5		$	—		$	250.0		$	369.4		$	—		$	—		$	653.5
Weighted average interest rate	n/a		n/a				0.2	%	n/a				0.8	%		0.2	%	n/a			n/a				0.4	%
As of September 30, 2020
Borrowings outstanding	$	—	$	150.0		$	498.0		$	—		$	—		$	301.2		$	—		$	121.3		$	648.0
Weighted average interest rate	n/a			1.1	%		0.2	%	n/a			n/a				0.2	%	n/a				0.2	%		0.6	%
As of March 31, 2020
Borrowings outstanding	$	—	$	150.0		$	175.5		$	185.1		$	—		$	39.6		$	50.0		$	33.0		$	560.6
Weighted average interest rate	n/a			2.1	%		1.8	%		1.8	%	n/a				1.9	%		1.9	%		1.9	%		1.9	%

Summary Capitalized Interest

Interest expense shown on Spire’s consolidated statements of income and Spire Missouri’s statements of comprehensive income is net of the capitalized interest amounts shown in the following table.

	Three Months Ended March 31,				Six Months Ended March 31,
	2021		2020		2021		2020
Spire	$	1.1	$	1.4	$	2.0	$	3.6
Spire Missouri		0.1		0.3		0.1		0.6
Spire Alabama		0.7		0.4		1.3		1.0

Schedule of Variable Stock Purchase Contract Settlement Rates

Each stock purchase contract obligates the holder to purchase, and Spire to issue and deliver, on March 1, 2024, for a price of fifty dollars in cash, a variable number of shares of its common stock as follows (subject to anti-dilution adjustments).

If the applicable market value* per share of Spire common stock is:	Number of shares to be purchased per stock purchase contract is:
Equal to or greater than $78.6906 (“threshold appreciation price”)	0.6354 (“minimum settlement rate”)
Less than $78.6906, but greater than $64.24	$50.00 ÷ applicable market value*
Less than or equal to $64.24 (“reference price”)	0.7783 (“maximum settlement rate”)

*Based on the volume-weighted average price of Spire common stock during the 20 trading days before settlement.