Regulatory Matters (Tables)

12 Months Ended

Sep. 30, 2019

Regulated Operations [Abstract]

Schedule of Regulatory Assets and Liabilities

The following regulatory assets and regulatory liabilities were reflected in the Balance Sheets as of September 30, 2019 and 2018. Unamortized Purchased Gas Adjustments are also included below, which are reported separately in the current assets and liabilities sections of each balance sheet.

	Spire				Spire Missouri				Spire Alabama
September 30	2019		2018		2019		2018		2019		2018
Regulatory Assets:
Current:
Pension and postretirement benefit costs	$	30.1	$	30.2	$	21.9	$	21.9	$	7.3	$	7.3
Unamortized purchased gas adjustments		18.2		8.2		—		1.0		17.7		6.4
Other		30.3		34.4		7.5		7.8		8.9		12.5
Total Current Regulatory Assets		78.6		72.8		29.4		30.7		33.9		26.2
Noncurrent:
Future income taxes due from customers		108.8		96.3		102.9		94.4		—		—
Pension and postretirement benefit costs		416.6		364.9		333.3		292.5		77.2		64.8
Cost of removal		150.9		133.4		—		—		150.9		133.4
Unamortized purchased gas adjustments		9.1		—		9.1		—		—		—
Energy efficiency		35.0		32.8		35.0		32.8		—		—
Other		47.2		42.4		27.2		21.4		3.1		3.3
Total Noncurrent Regulatory Assets		767.6		669.8		507.5		441.1		231.2		201.5
Total Regulatory Assets	$	846.2	$	742.6	$	536.9	$	471.8	$	265.1	$	227.7
Regulatory Liabilities:
Current:
Pension and postretirement benefit costs	$	5.8	$	—	$	3.6	$	—	$	2.2	$	—
Refundable negative salvage		—		2.2		—		—		—		2.2
Unamortized purchased gas adjustments		26.2		2.9		25.4		1.9		—		—
Other		28.8		30.6		23.3		14.8		1.2		5.4
Total Current Regulatory Liabilities		60.8		35.7		52.3		16.7		3.4		7.6
Noncurrent:
Deferred taxes due to customers		179.8		178.3		162.5		161.1		—		—
Pension and postretirement benefit costs		142.3		27.8		119.1		—		19.1		27.8
Accrued cost of removal		41.6		63.6		15.7		39.8		—		—
Unamortized purchased gas adjustments		—		4.7		—		4.7		—		—
Other		35.3		80.2		29.2		69.3		3.9		3.5
Total Noncurrent Regulatory Liabilities		399.0		354.6		326.5		274.9		23.0		31.3
Total Regulatory Liabilities	$	459.8	$	390.3	$	378.8	$	291.6	$	26.4	$	38.9

Schedule of Regulatory Assets Not Earning a Return

A portion of the Company’s regulatory assets are not earning a return and are shown in the schedule below:

	Spire				Spire Missouri
September 30	2019		2018		2019		2018
Pension and postretirement benefit costs	$	211.1	$	148.4	$	211.1	$	148.4
Future income taxes due from customers		108.8		96.3		102.9		94.4
Other		14.3		15.1		14.3		15.1
Total Regulatory Assets Not Earning a Return	$	334.2	$	259.8	$	328.3	$	257.9