Regulatory Matters (Tables)

3 Months Ended

Dec. 31, 2024

Regulated Operations [Abstract]

Schedule of Regulatory Assets and Liabilities

The following regulatory assets and regulatory liabilities were reflected in the balance sheets of the Company, Spire Missouri and Spire Alabama as of December 31, 2024, September 30, 2024, and December 31, 2023.

	December 31,		September 30,		December 31,
Spire	2024		2024		2023
Regulatory Assets:
Current:
Unamortized purchased gas adjustments	$	12.2	$	28.9	$	207.0
Other		77.4		86.5		49.4
Total Current Regulatory Assets		89.6		115.4		256.4
Noncurrent:
Pension and postretirement benefit costs		248.4		237.5		255.3
Cost of removal		676.1		668.2		640.8
Future income taxes due from customers		152.4		150.7		145.6
Energy efficiency		61.3		61.0		57.5
Unamortized purchased gas adjustments		—		1.2		20.3
Other		150.2		133.2		147.4
Total Noncurrent Regulatory Assets		1,288.4		1,251.8		1,266.9
Total Regulatory Assets	$	1,378.0	$	1,367.2	$	1,523.3
Regulatory Liabilities:
Current:
Unamortized purchased gas adjustments	$	39.2	$	42.3	$	—
Other		11.8		7.2		7.1
Total Current Regulatory Liabilities		51.0		49.5		7.1
Noncurrent:
Deferred taxes due to customers		110.7		114.2		124.5
Pension and postretirement benefit costs		253.2		232.9		188.2
Accrued cost of removal		136.7		133.6		130.3
Unamortized purchased gas adjustments		40.4		17.2		23.7
Other		36.2		37.6		20.5
Total Noncurrent Regulatory Liabilities		577.2		535.5		487.2
Total Regulatory Liabilities	$	628.2	$	585.0	$	494.3

	December 31,		September 30,		December 31,
Spire Missouri	2024		2024		2023
Regulatory Assets:
Current:
Unamortized purchased gas adjustments	$	11.8	$	28.1	$	194.1
Other		44.9		55.9		18.8
Total Current Regulatory Assets		56.7		84.0		212.9
Noncurrent:
Future income taxes due from customers		144.5		142.7		137.3
Pension and postretirement benefit costs		179.7		166.5		185.5
Energy efficiency		61.3		61.0		57.5
Unamortized purchased gas adjustments		—		1.2		20.3
Cost of removal		97.0		97.0		97.0
Other		137.2		119.6		133.2
Total Noncurrent Regulatory Assets		619.7		588.0		630.8
Total Regulatory Assets	$	676.4	$	672.0	$	843.7
Regulatory Liabilities:
Current:
Unamortized purchased gas adjustments	$	17.4	$	10.2	$	—
Total Current Regulatory Liabilities		17.4		10.2		—
Noncurrent:
Deferred taxes due to customers		98.6		101.8		111.6
Pension and postretirement benefit costs		218.0		196.6		160.2
Accrued cost of removal		96.8		94.5		93.4
Unamortized purchased gas adjustments		40.4		17.2		23.7
Other		32.2		33.2		15.6
Total Noncurrent Regulatory Liabilities		486.0		443.3		404.5
Total Regulatory Liabilities	$	503.4	$	453.5	$	404.5

Spire Alabama
Regulatory Assets:
Current:
Unamortized purchased gas adjustments	$	—	$	—	$	12.2
Other		17.4		19.2		18.8
Total Current Regulatory Assets		17.4		19.2		31.0
Noncurrent:
Future income taxes due from customers		1.7		1.8		1.9
Pension and postretirement benefit costs		66.1		68.2		66.0
Cost of removal		579.1		571.2		543.7
Other		0.4		0.8		1.0
Total Noncurrent Regulatory Assets		647.3		642.0		612.6
Total Regulatory Assets	$	664.7	$	661.2	$	643.6
Regulatory Liabilities:
Current:
Unamortized purchased gas adjustments	$	20.7	$	30.9	$	—
Other		7.0		2.9		—
Total Current Regulatory Liabilities		27.7		33.8		—
Noncurrent:
Pension and postretirement benefit costs		24.2		25.1		17.3
Other		2.7		3.2		3.4
Total Noncurrent Regulatory Liabilities		26.9		28.3		20.7
Total Regulatory Liabilities	$	54.6	$	62.1	$	20.7

Schedule of Regulatory Assets Not Earning Return

A portion of the Company’s and Spire Missouri’s regulatory assets are not earning a return, as shown in the table below:

	December 31,		September 30,		December 31,
	2024		2024		2023
Spire
Pension and postretirement benefit costs	$	129.8	$	129.7	$	134.0
Future income taxes due from customers		150.7		148.9		143.6
Unamortized purchased gas adjustments		11.8		29.3		214.4
Other		143.1		132.5		117.0
Total Regulatory Assets Not Earning a Return	$	435.4	$	440.4	$	609.0
Spire Missouri
Pension and postretirement benefit costs	$	129.8	$	129.7	$	134.0
Future income taxes due from customers		144.5		142.7		137.3
Unamortized purchased gas adjustments		11.8		29.3		214.4
Other		143.1		132.5		117.0
Total Regulatory Assets Not Earning a Return	$	429.2	$	434.2	$	602.7