Note 15 - Regulatory Matters (Tables)

12 Months Ended

Sep. 30, 2024

Notes Tables

Schedule of Regulatory Assets and Liabilities [Table Text Block]

	Spire				Spire Missouri				Spire Alabama
September 30	2024		2023		2024		2023		2024		2023
Regulatory Assets:
Current:
Unamortized purchased gas adjustments	$	28.9	$	293.2	$	28.1	$	269.4	$	—	$	21.7
Other		86.5		55.1		55.9		23.7		19.2		19.9
Total Current Regulatory Assets		115.4		348.3		84.0		293.1		19.2		41.6
Noncurrent:
Future income taxes due from customers		150.7		144.5		142.7		136.2		1.8		2.0
Pension and postretirement benefit costs		237.5		261.0		166.5		189.1		68.2		67.8
Cost of removal		668.2		633.2		97.0		97.0		571.2		536.2
Unamortized purchased gas adjustments		1.2		23.0		1.2		23.0		—		—
Energy efficiency		61.0		56.3		61.0		56.3		—		—
Other		133.2		131.2		119.6		116.0		0.8		0.9
Total Noncurrent Regulatory Assets		1,251.8		1,249.2		588.0		617.6		642.0		606.9
Total Regulatory Assets	$	1,367.2	$	1,597.5	$	672.0	$	910.7	$	661.2	$	648.5
Regulatory Liabilities:
Current:
Unamortized purchased gas adjustments	$	42.3	$	—	$	10.2	$	—	$	30.9	$	—
Other		7.2		7.3		—		—		2.9		—
Total Current Regulatory Liabilities		49.5		7.3		10.2		—		33.8		—
Noncurrent:
Deferred taxes due to customers		114.2		128.0		101.8		114.8		—		—
Pension and postretirement benefit costs		232.9		185.2		196.6		156.5		25.1		17.9
Accrued cost of removal		133.6		126.6		94.5		90.4		—		—
Unamortized purchased gas adjustments		17.2		11.2		17.2		11.2		—		—
Other		37.6		21.4		33.2		16.5		3.2		3.3
Total Noncurrent Regulatory Liabilities		535.5		472.4		443.3		389.4		28.3		21.2
Total Regulatory Liabilities	$	585.0	$	479.7	$	453.5	$	389.4	$	62.1	$	21.2

Schedule of Regulatory Assets Not Earning Return [Table Text Block]

	Spire				Spire Missouri
September 30	2024		2023		2024		2023
Pension and postretirement benefit costs	$	129.7	$	133.4	$	129.7	$	133.4
Future income taxes due from customers		148.9		142.5		142.7		136.2
Unamortized purchase gas adjustments		29.3		292.4		29.3		292.4
Other		132.5		104.2		132.5		104.2
Total Regulatory Assets Not Earning a Return	$	440.4	$	672.5	$	434.2	$	666.2