Spire Missouri 10-Q 2 Feb 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Dec. 31, 2021	Jan. 28, 2022
Entity Information [Line Items]
Entity Registrant Name	Spire Inc
Entity Central Index Key	0001126956
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		51,750,217
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Entity Shell Company	false
Entity File Number	1-16681
Entity Tax Identification Number	74-2976504
Entity Address, Address Line One	700 Market Street
Entity Address, City or Town	St. Louis
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63101
City Area Code	314
Local Phone Number	342-0500
Entity Incorporation, State or Country Code	MO
Document Quarterly Report	true
Document Transition Report	false
Spire Missouri Inc
Entity Information [Line Items]
Entity Registrant Name	Spire Missouri Inc
Entity Central Index Key	0000057183
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		24,577
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Entity Shell Company	false
Entity File Number	1-1822
Entity Tax Identification Number	43-0368139
Entity Address, Address Line One	700 Market Street
Entity Address, City or Town	St. Louis
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63101
City Area Code	314
Local Phone Number	342-0500
Entity Incorporation, State or Country Code	MO
Spire Alabama Inc
Entity Information [Line Items]
Entity Registrant Name	Spire Alabama Inc
Entity Central Index Key	0000003146
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		1,972,052
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Entity Shell Company	false
Entity File Number	2-38960
Entity Tax Identification Number	63-0022000
Entity Address, Address Line One	605 Richard Arrington Blvd N
Entity Address, City or Town	Birmingham
Entity Address, State or Province	AL
Entity Address, Postal Zip Code	35203
City Area Code	205
Local Phone Number	326-8100
Entity Incorporation, State or Country Code	AL
Common Stock $1.00 par value
Entity Information [Line Items]
Trading Symbol	SR
Title of each class	Common Stock $1.00 par value
Name of each exchange on which registered	NYSE
Depositary Shares, each representing a 1/1,000th interest in a share of 5.90% Series A Cumulative Redeemable Perpetual Preferred Stock, par value $25.00 per share
Entity Information [Line Items]
Trading Symbol	SR.PRA
Title of each class	Depositary Shares
Name of each exchange on which registered	NYSE

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Revenues	$ 555.4	$ 512.6
Operating Expenses:
Natural gas	249.2	181.2
Operation and maintenance	116.4	111.6
Depreciation and amortization	56.9	50.8
Taxes, other than income taxes	37.6	36.1
Total Operating Expenses	460.1	379.7
Operating Income	95.3	132.9
Interest Expense, Net	28.6	25.7
Other Income, Net	7.4	4.3
Income Before Income Taxes	74.1	111.5
Income Tax Expense	18.4	22.6
Net Income	55.7	88.9
Provision for preferred dividends	3.7	3.7
Income allocated to participating securities	0.1	0.1
Net Income Available to Common Shareholders	$ 51.9	$ 85.1
Weighted Average Number of Common Shares Outstanding:
Basic	51.6	51.5
Diluted	51.7	51.6
Basic Earnings Per Common Share	$ 1.01	$ 1.65
Diluted Earnings Per Common Share	$ 1.01	$ 1.65
Spire Alabama
Operating Revenues	$ 126.6	$ 113.6
Operating Expenses:
Natural gas	45.5	35.1
Operation and maintenance	34.5	32.8
Depreciation and amortization	16.5	15
Taxes, other than income taxes	9	8.2
Total Operating Expenses	105.5	91.1
Operating Income	21.1	22.5
Interest Expense, Net	5.1	4.7
Other Income, Net	0.4	0.7
Income Before Income Taxes	16.4	18.5
Income Tax Expense	4.2	4.8
Net Income	$ 12.2	$ 13.7

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net Income	$ 55.7	$ 88.9
Cash flow hedging derivative instruments:
Net hedging (loss) gain arising during the period	(4.8)	17.2
Amounts reclassified into net income	(0.3)	(0.3)
Net (loss) gain on cash flow hedging derivative instruments	(5.1)	16.9
Net gain on defined benefit pension and other postretirement plans	0.1
Net unrealized loss on available for sale securities	(0.1)
Other Comprehensive (Loss) Income, Before Tax	(5.1)	16.9
Income Tax (Benefit) Expense Related to Items of Other Comprehensive Income	(1.2)	3.8
Other Comprehensive (Loss) Income, Net of Tax	(3.9)	13.1
Comprehensive Income	51.8	102
Operating Revenues	555.4	512.6
Operating Expenses:
Natural gas	249.2	181.2
Operation and maintenance	116.4	111.6
Depreciation and amortization	56.9	50.8
Taxes, other than income taxes	37.6	36.1
Total Operating Expenses	460.1	379.7
Operating Income	95.3	132.9
Interest Expense, Net	28.6	25.7
Other Income, Net	7.4	4.3
Income Before Income Taxes	74.1	111.5
Income Tax Expense	18.4	22.6
Net Income	55.7	88.9
Spire Missouri
Net Income	45.3	56.6
Cash flow hedging derivative instruments:
Other Comprehensive (Loss) Income, Net of Tax	0.1	0.1
Comprehensive Income	45.4	56.7
Operating Revenues	347.9	355.5
Operating Expenses:
Natural gas	156.3	161.6
Operation and maintenance	66.3	62.9
Depreciation and amortization	34.2	30.4
Taxes, other than income taxes	25.7	25.1
Total Operating Expenses	282.5	280
Operating Income	65.4	75.5
Interest Expense, Net	14.5	11.7
Other Income, Net	5.9	2.7
Income Before Income Taxes	56.8	66.5
Income Tax Expense	11.5	9.9
Net Income	$ 45.3	$ 56.6

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Utility Plant	$ 7,329.2	$ 7,225	$ 6,860.2
Less: Accumulated depreciation and amortization	2,204.4	2,169.3	2,113.3
Net Utility Plant	5,124.8	5,055.7	4,746.9
Non-utility Property (net of accumulated depreciation and amortization of $36.7, $32.1 and $22.2 at December 31, 2021, September 30, 2021, and December 31, 2020, respectively)	474.2	471.1	448.7
Other Investments	90.4	83.1	74.8
Total Other Property and Investments	564.6	554.2	523.5
Current Assets:
Cash and cash equivalents	8.2	4.3	3.5
Accounts receivable:
Utility	476.2	338.4	281.5
Other	304.2	288.2	170.4
Allowance for credit losses	(31.4)	(30.3)	(28.9)
Delayed customer billings	11.4	9.2	13.6
Inventories:
Natural gas	284.8	267.7	145.9
Propane gas	8.7	8.7	10.7
Materials and supplies	32.1	28.6	27.9
Regulatory assets	265.7	306.5	70.5
Prepayments	25.5	29	30.8
Other	49.9	66.2	44.1
Total Current Assets	1,435.3	1,316.5	770
Deferred Charges and Other Assets:
Goodwill	1,171.6	1,171.6	1,171.6
Regulatory assets	1,089.9	993.5	1,079.2
Other	264.3	264.9	224.4
Total Deferred Charges and Other Assets	2,525.8	2,430	2,475.2
Total Assets	9,650.5	9,356.4	8,515.6
Capitalization:
Preferred stock ($25.00 par value per share; 10.0 million depositary shares authorized, issued and outstanding at December 31, 2021, September 30, 2021, and December 31, 2020)	242	242	242
Common stock (par value $1.00 per share; 70.0 million shares authorized; 51.7 million, 51.7 million, and 51.7 million shares issued and outstanding at December 31, 2021, September 30, 2021, and December 31, 2020, respectively)	51.7	51.7	51.7
Paid-in capital and common stock	1,516.9	1,517.9	1,550
Retained earnings	859.5	843	771.2
Accumulated other comprehensive (loss) income	(0.3)	3.6	(28.1)
Total Shareholders' Equity	2,669.8	2,658.2	2,586.8
Temporary equity	9.8	9.8	5.3
Long-term debt (less current portion)	3,206.8	2,939.1	2,517.6
Total Capitalization	5,886.4	5,607.1	5,109.7
Current Liabilities:
Current portion of long-term debt	31.2	55.8	110.8
Notes payable	846	672	696.1
Accounts payable	427.5	409.9	260.8
Advance customer billings	31.3	32.1	43.2
Wages and compensation accrued	29.9	59.5	26.7
Customer deposits	29.4	28.9	30.9
Taxes accrued	47.2	78.8	41.2
Regulatory liabilities	4.1	34.6	95.5
Other	274.1	236.7	241.5
Total Current Liabilities	1,720.7	1,608.3	1,546.7
Deferred Credits and Other Liabilities:
Deferred income taxes	615.6	612.3	541.9
Pension and postretirement benefit costs	222.5	235.9	289.2
Asset retirement obligations	524.8	519.6	545.6
Regulatory liabilities	531.8	620.9	357.3
Other	148.7	152.3	125.2
Total Deferred Credits and Other Liabilities	2,043.4	2,141	1,859.2
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	9,650.5	9,356.4	8,515.6
Spire Missouri
ASSETS
Utility Plant	4,347.8	4,266.6	4,012.8
Less: Accumulated depreciation and amortization	927.4	905.1	851.5
Net Utility Plant	3,420.4	3,361.5	3,161.3
Other Investments	68.9	60.2	59
Accounts receivable:
Utility	377.4	279	195.4
Associated companies	3.7	4.7	2.3
Other	36.3	57.5	23.6
Allowance for credit losses	(23.8)	(22.6)	(21.4)
Delayed customer billings	4.7	2.4	5.1
Inventories:
Natural gas	186.6	176.7	88.3
Propane gas	8.7	8.7	10.7
Materials and supplies	16.2	15	16.1
Regulatory assets	236.9	276.3	32.1
Prepayments	18.4	19.7	20.9
Other	0	0.1	0
Total Current Assets	865.1	817.5	373.1
Deferred Charges and Other Assets:
Goodwill	210.2	210.2	210.2
Regulatory assets	560.5	483.1	550.4
Other	126.2	125.6	96.1
Total Deferred Charges and Other Assets	896.9	818.9	856.7
Total Assets	5,251.3	5,058.1	4,450.1
Capitalization:
Paid-in capital and common stock	765.1	765.1	765.1
Retained earnings	862.3	817	729.5
Accumulated other comprehensive (loss) income	(4.1)	(4.2)	(2.8)
Total Shareholders' Equity	1,623.3	1,577.9	1,491.8
Long-term debt (less current portion)	1,637	1,338.4	1,092.2
Total Capitalization	3,260.3	2,916.3	2,584
Current Liabilities:
Notes payable	250	250	0
Notes payable ? associated companies	180.4	240.9	393.7
Accounts payable	117	89.7	82.6
Accounts payable ? associated companies	11.6	10.2	7.1
Advance customer billings	20	19.7	29.8
Wages and compensation accrued	21	40.3	19.5
Customer deposits	8	8	9
Taxes accrued	15.4	41.2	13.4
Regulatory liabilities	0.2	17.1	83.4
Other	89.2	47.4	82.6
Total Current Liabilities	712.8	764.5	721.1
Deferred Credits and Other Liabilities:
Deferred income taxes	477.5	480	449.4
Pension and postretirement benefit costs	147.9	159.5	198.7
Asset retirement obligations	144.8	143.4	155
Regulatory liabilities	447.2	538.8	288.2
Other	60.8	55.6	53.7
Total Deferred Credits and Other Liabilities	1,278.2	1,377.3	1,145
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	5,251.3	5,058.1	4,450.1
Spire Alabama
ASSETS
Utility Plant	2,604.8	2,586.5	2,487.4
Less: Accumulated depreciation and amortization	1,137.9	1,124.8	1,122.8
Net Utility Plant	1,466.9	1,461.7	1,364.6
Accounts receivable:
Utility	84.6	49.8	69.6
Associated companies	1.3	0.6	0.7
Other	7.5	6.4	6.1
Allowance for credit losses	(6.7)	(6.6)	(6.2)
Delayed customer billings	6.5	6.7	8.5
Inventories:
Natural gas	44.7	35.5	23.8
Materials and supplies	12.8	10.8	9.2
Regulatory assets	14.6	18.8	22.7
Prepayments	3.6	5.4	5.5
Other	0	0	0.1
Total Current Assets	168.9	127.4	140
Deferred Charges and Other Assets:
Regulatory assets	501.7	483.3	498.2
Deferred income taxes	30	34.2	54.5
Other	63.2	63.9	53.5
Total Deferred Charges and Other Assets	594.9	581.4	606.2
Total Assets	2,230.7	2,170.5	2,110.8
Capitalization:
Paid-in capital and common stock	322.9	328.9	339.9
Retained earnings	556.8	552.6	509
Total Shareholders' Equity	879.7	881.5	848.9
Long-term debt (less current portion)	571.3	571.2	571
Total Capitalization	1,451	1,452.7	1,419.9
Current Liabilities:
Current portion of long-term debt	0	50	50
Notes payable ? associated companies	173.7	49	27
Accounts payable	58.1	52.3	40
Accounts payable ? associated companies	3.6	6	5.3
Advance customer billings	10.2	11.2	12.5
Wages and compensation accrued	4.1	9.3	4.2
Customer deposits	18.8	18.4	19.2
Taxes accrued	27.3	30.4	24.7
Regulatory liabilities	0.8	13.4	6.9
Other	19.4	17.3	22.5
Total Current Liabilities	316	257.3	212.3
Deferred Credits and Other Liabilities:
Pension and postretirement benefit costs	65.1	66.7	73.8
Asset retirement obligations	366.4	362.8	378
Regulatory liabilities	25.3	23.4	18.4
Other	6.9	7.6	8.4
Total Deferred Credits and Other Liabilities	463.7	460.5	478.6
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	$ 2,230.7	$ 2,170.5	$ 2,110.8

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Non-utility property, accumulated depreciation and amortization	$ 36.7	$ 32.1	$ 22.2
Capitalization:
Common stock, par value (in dollars per share)	$ 1	$ 1	$ 1
Common stock, authorized (in shares)	70,000,000	70,000,000	70,000,000
Common stock, issued (in shares)	51,700,000	51,700,000	51,700,000
Common stock, outstanding (in shares)	51,700,000	51,700,000	51,700,000
Spire Missouri
Capitalization:
Common stock, par value (in dollars per share)	$ 1	$ 1	$ 1
Common stock, authorized (in shares)	50,000,000	50,000,000	50,000,000
Common stock, issued (in shares)	24,577	24,577	24,577
Common stock, outstanding (in shares)	24,577	24,577	24,577
Spire Alabama
Capitalization:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, authorized (in shares)	3,000,000	3,000,000	3,000,000
Common stock, issued (in shares)	2,000,000	2,000,000	2,000,000
Common stock, outstanding (in shares)	2,000,000	2,000,000	2,000,000
Depositary Shares
Capitalization:
Preferred stock, par value (in dollars per share)	$ 25	$ 25	$ 25
Preferred stock, depositary shares authorized (in shares)	10,000,000	10,000,000	10,000,000
Preferred stock, depositary shares outstanding (in shares)	10,000,000	10,000,000	10,000,000
Preferred stock, depositary shares issued (in shares)	10,000,000	10,000,000	10,000,000

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Spire Missouri	Spire Alabama	Common Stock	Common StockSpire Missouri	Common StockSpire Alabama	Preferred Stock	Paid-in Capital	Paid-in CapitalSpire Missouri	Paid-in CapitalSpire Alabama	Retained Earnings	Retained EarningsSpire Missouri	Retained EarningsSpire Alabama	AOCI	[1]	AOCISpire Missouri	[1]
BALANCE at Sep. 30, 2020	$ 2,522.3	$ 1,435.1	$ 851.7	$ 51.6	$ 0.1		$ 242	$ 1,549.2	$ 765	$ 350.9	$ 720.7	$ 672.9	$ 500.8	$ (41.2)		$ (2.9)
BALANCE (in shares) at Sep. 30, 2020				51,611,789	24,577	1,972,052
Stockholders' Equity Rollforward
Net Income	88.9	56.6	13.7								88.9	56.6	13.7
Dividend reinvestment plan	0.4							0.4
Dividend reinvestment plan (in shares)				6,698
Stock-based compensation costs	1.4							1.4
Stock issued under stock-based compensation plans				$ 0.1				(0.1)
Stock issued under stock-based compensation plans (in shares)				55,161
Employees’ tax withholding for stock-based compensation	(0.9)							(0.9)
Employee's tax withholding for stock-based compensation (in shares)				(14,175)
Temporary equity adjustment to redemption value	(0.9)										(0.9)
Return of capital to Spire			(11)							(11)
Dividends declared on common stock	(33.8)		(5.5)								(33.8)		(5.5)
Dividends declared on preferred stock	(3.7)										(3.7)
Other comprehensive income (loss), net of tax	13.1	0.1												13.1		0.1
BALANCE at Dec. 31, 2020	2,586.8	1,491.8	848.9	$ 51.7	$ 0.1		242	1,550	765	339.9	771.2	729.5	509	(28.1)		(2.8)
BALANCE (in shares) at Dec. 31, 2020				51,659,473	24,577	1,972,052
BALANCE at Sep. 30, 2021	2,658.2	1,577.9	881.5	$ 51.7	$ 0.1		242	1,517.9	765	328.9	843	817	552.6	3.6		(4.2)
BALANCE (in shares) at Sep. 30, 2021				51,684,883	24,577	1,972,052
Stockholders' Equity Rollforward
Net Income	55.7	45.3	12.2								55.7	45.3	12.2
Dividend reinvestment plan	0.4							0.4
Dividend reinvestment plan (in shares)				6,233
Stock-based compensation costs	0.3							0.3
Stock issued under stock-based compensation plans (in shares)				77,976
Employees’ tax withholding for stock-based compensation	(1.7)							(1.7)
Employee's tax withholding for stock-based compensation (in shares)				(26,611)
Temporary equity adjustment to redemption value	0.1										0.1
Return of capital to Spire			(6)							(6)
Dividends declared on common stock	(35.6)		(8)								(35.6)		(8)
Dividends declared on preferred stock	(3.7)										(3.7)
Other comprehensive income (loss), net of tax	(3.9)	0.1												(3.9)		0.1
BALANCE at Dec. 31, 2021	$ 2,669.8	$ 1,623.3	$ 879.7	$ 51.7	$ 0.1		$ 242	$ 1,516.9	$ 765	$ 322.9	$ 859.5	$ 862.3	$ 556.8	$ (0.3)		$ (4.1)
BALANCE (in shares) at Dec. 31, 2021				51,742,481	24,577	1,972,052
[1]	Accumulated other comprehensive income (loss)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement Of Stockholders Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 0.685	$ 0.65
Dividends declared on preferred stock (in dollars per depositary share)	$ 0.36875	$ 0.36875

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 55.7	$ 88.9
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	56.9	50.8
Deferred income taxes and investment tax credits	18.4	21.8
Changes in assets and liabilities:
Accounts receivable	(152.8)	(169.6)
Inventories	(20.5)	9.5
Regulatory assets and liabilities	(187.3)	11.2
Accounts payable	42.9	43.9
Delayed/advance customer billings, net	(2.9)	(5.8)
Taxes accrued	(31.4)	(30.2)
Other assets and liabilities	(9.6)	(15.4)
Other	0.7	2.5
Net cash (used in) provided by operating activities	(229.9)	7.6
Investing Activities:
Capital expenditures	(145.7)	(163.6)
Other	2.6	0
Net cash used in investing activities	(143.1)	(163.6)
Financing Activities:
Issuance of long-term debt	300	150
Repayment of long-term debt	(55.8)	(5.4)
Issuance of short-term debt, net	174	48.1
Issuance of common stock	0.4	0.4
Dividends paid on common stock	(34.6)	(32.2)
Dividends paid on preferred stock	(3.7)	(3.7)
Other	(3.4)	(1.8)
Net cash provided by financing activities	376.9	155.4
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	3.9	(0.6)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	11.3	4.1
Cash, Cash Equivalents, and Restricted Cash at End of Period	15.2	3.5
Supplemental disclosure of cash (paid) received for:
Interest, net of amounts capitalized	(23.3)	(15.5)
Income taxes	(0.2)	0.1
Spire Missouri
Operating Activities:
Net Income	45.3	56.6
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	34.2	30.4
Deferred income taxes and investment tax credits	11.5	9.9
Changes in assets and liabilities:
Accounts receivable	(74.9)	(88.7)
Inventories	(11.1)	6.3
Regulatory assets and liabilities	(161.3)	7.2
Accounts payable	38.3	24.3
Delayed/advance customer billings, net	(2)	(5.6)
Taxes accrued	(25.8)	(25.7)
Other assets and liabilities	3.8	(8.6)
Other	0.2	0.2
Net cash (used in) provided by operating activities	(141.8)	6.3
Investing Activities:
Capital expenditures	(96.3)	(99.1)
Other	0.4	0.3
Net cash used in investing activities	(95.9)	(98.8)
Financing Activities:
Issuance of long-term debt	300	0
Repayments to Spire, net	(60.6)	92.5
Other	(1.7)	0
Net cash provided by financing activities	237.7	92.5
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	0	0
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	0	0
Cash, Cash Equivalents, and Restricted Cash at End of Period	0	0
Supplemental disclosure of cash (paid) received for:
Interest, net of amounts capitalized	(15.3)	(9.6)
Income taxes	0	0
Spire Alabama
Operating Activities:
Net Income	12.2	13.7
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	16.5	15
Deferred income taxes and investment tax credits	4.2	4.8
Changes in assets and liabilities:
Accounts receivable	(36.5)	(37.8)
Inventories	(11.1)	(2.1)
Regulatory assets and liabilities	(21.4)	2.9
Accounts payable	15.8	10.4
Delayed/advance customer billings, net	(0.9)	(0.1)
Taxes accrued	(3.2)	(3.3)
Other assets and liabilities	(2)	(0.9)
Other	(0.2)	0.1
Net cash (used in) provided by operating activities	(26.6)	2.7
Investing Activities:
Capital expenditures	(34.7)	(40.9)
Other	0.6	0
Net cash used in investing activities	(34.1)	(40.9)
Financing Activities:
Issuance of long-term debt	0	150
Repayment of long-term debt	(50)	0
Return of capital to Spire	(6)	(11)
Repayments to Spire, net	124.7	(94.4)
Dividends paid on common stock	(8)	(5.5)
Other	0	(0.9)
Net cash provided by financing activities	60.7	38.2
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	0	0
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	0	0
Cash, Cash Equivalents, and Restricted Cash at End of Period	0	0
Supplemental disclosure of cash (paid) received for:
Interest, net of amounts capitalized	(5.2)	(3.6)
Income taxes	$ 0	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES BASIS OF PRESENTATION – These notes are an integral part of the accompanying unaudited financial statements of Spire Inc. (“Spire” or the “Company”) presented on a consolidated basis, Spire Missouri Inc. (“Spire Missouri”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri, Spire Alabama and Spire EnergySouth Inc. (“Spire EnergySouth”) are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth (Spire Gulf Inc. and Spire Mississippi Inc.) are collectively referred to as the “Utilities.” The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information with the instructions to Form 10-Q and Rule 10-01 of Regulation S‑X. Accordingly, they do not include all the disclosures required for complete financial statements. In the opinion of management, the accompanying unaudited financial statements include all adjustments necessary for the fair presentation of the results of operations for the periods presented. This Form 10-Q should be read in conjunction with the Notes to Financial Statements contained in Spire, Spire Missouri and Spire Alabama’s combined Annual Report on Form 10-K for the fiscal year ended September 30, 2021. The consolidated financial position, results of operations, and cash flows of Spire include the accounts of the Company and all its subsidiaries. Transactions and balances between consolidated entities have been eliminated from the consolidated financial statements of Spire. In compliance with GAAP, transactions between Spire Missouri and Spire Alabama and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements. NATURE OF OPERATIONS – Spire has two reportable segments: Gas Utility and Gas Marketing. The Gas Utility segment consists of the regulated natural gas distribution operations of the Company and is the core business segment of Spire in terms of revenue and earnings. The Gas Utility segment is comprised of the operations of: Spire Missouri, serving St. Louis, Kansas City, and other areas in Missouri; Spire Alabama, serving central and northern Alabama; and the subsidiaries of Spire EnergySouth, serving the Mobile, Alabama area and south-central Mississippi. The Gas Marketing segment includes Spire’s largest gas-related business, Spire Marketing Inc. (“Spire Marketing”), which provides non-regulated natural gas services throughout the United States (U.S.). The activities of the Company’s other subsidiaries are reported as Other and are described in Note 9 , Information by Operating Segment. Spire Missouri and Spire Alabama each have a single reportable segment. Nearly all the Company’s earnings are derived from its Gas Utility segment. Due to the seasonal nature of the Utilities’ business and the Spire Missouri rate design, earnings are typically concentrated during the heating season of November through April each fiscal year. As a result, the interim statements of income for Spire, Spire Missouri and Spire Alabama are not necessarily indicative of annual results or representative of succeeding quarters of the fiscal year. REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, Regulated Operations . This topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. As authorized by the Missouri Public Service Commission (MoPSC), the Mississippi Public Service Commission (MSPSC) and the Alabama Public Service Commission (APSC), the Purchased Gas Adjustment (PGA) clauses and Gas Supply Adjustment (GSA) riders allow the Utilities to pass through to customers the cost of purchased gas supplies. Regulatory assets and liabilities related to the PGA clauses and the GSA riders are both labeled Unamortized Purchased Gas Adjustments herein. See additional information about regulatory assets and liabilities in Note 4 , Regulatory Matters. DERIVATIVES – In the course of their business, certain subsidiaries of Spire enter into commitments associated with the purchase or sale of natural gas. Certain of their derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of FASB ASC Topic 815, Derivatives and Hedging . Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded gross. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of Spire Marketing’s wholesale purchase and sale transactions are classified as trading activities for financial reporting purposes, with income and expenses presented on a net basis in natural gas expenses in the Condensed Consolidated Statements of Income. TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire. As reflected in their separate financial statements, Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest. Spire Missouri and Spire Alabama also participated in normal intercompany shared services transactions. Spire Missouri’s and Spire Alabama’s other transactions with affiliates are presented below: Three Months Ended December 31, 2021 2020 Spire Missouri Purchases of natural gas from Spire Marketing Inc. $ 18.2 $ 10.7 Transportation services received from Spire STL Pipeline LLC 8.1 8.1 Sales of natural gas to Spire Marketing Inc. — 1.1 Transportation services received from Spire NGL Inc. — 0.3 Spire Alabama Purchases of natural gas from Spire Marketing Inc. $ — $ 4.8 RESTRICTED CASH – In Spire’s statement of cash flows for the period ended December 31, 2021, total Cash, Cash Equivalents, and Restricted Cash included $7.0 of restricted cash reported in “Other Investments” on the Company’s balance sheet as of December 31, 2021 and September 30, 2021 (in addition to amounts shown as “Cash and cash equivalents”). This restricted cash has been segregated and invested in debt securities in a trust account based on collateral requirements for reinsurance at Spire’s risk management company. ACCRUED CAPITAL EXPENDITURES – Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid. December 31, September 30, December 31, 2021 2021 2020 Spire $ 33.5 $ 59.5 $ 40.9 Spire Missouri 27.2 37.1 23.1 Spire Alabama 1.2 13.6 4.2 ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Accounts receivable are written off when they are deemed to be uncollectible. An allowance for expected credit losses is estimated and updated based on relevant data and trends such as accounts receivable aging, historical write-off experience, current write-off trends, economic conditions, and the impact of weather and availability of customer payment assistance on collection trends. For the Utilities, net write-offs as a percentage of revenue has historically been the best predictor of base net write-off experience over time. Management judgment is applied in the development of the allowance due to the complexity of variables and subjective nature of certain relevant factors. The accounts receivable of Spire’s non-utility businesses are evaluated separately from those of the Utilities. The allowance for credit losses for those other businesses is based on a continuous evaluation of the individual counterparty risk and is not significant for the periods presented. Activity in the allowance for credit losses is shown in the following table. Spire Spire Missouri Spire Alabama Three Months Ended December 31, 2021 2020 2021 2020 2021 2020 Allowance at beginning of period $ 30.3 $ 24.9 $ 22.6 $ 18.1 $ 6.6 $ 5.5 Provision for expected credit losses 1.5 4.1 2.1 3.3 (0.5 ) 0.7 Write-offs, net of recoveries (0.4 ) (0.1 ) (0.9 ) — 0.6 — Allowance at end of period $ 31.4 $ 28.9 $ 23.8 $ 21.4 $ 6.7 $ 6.2

Revenue

Revenue	3 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue	2. REVENUE The following tables show revenue disaggregated by source and customer type. Three Months Ended December 31, 2021 2020 Spire Gas Utility: Residential $ 342.0 $ 349.9 Commercial and industrial 103.8 103.0 Transportation 31.2 32.2 Off-system and other incentive 4.8 9.3 Other customer revenue 3.6 2.2 Total revenue from contracts with customers 485.4 496.6 Changes in accrued revenue under alternative revenue programs 18.1 1.6 Total Gas Utility operating revenues 503.5 498.2 Gas Marketing 47.9 24.8 Other 16.6 16.7 Total before eliminations 568.0 539.7 Intersegment eliminations (see Note 9, Information by Operating Segment) (12.6 ) (27.1 ) Total Operating Revenues $ 555.4 $ 512.6 Spire Missouri Residential $ 247.1 $ 263.0 Commercial and industrial 68.2 69.9 Transportation 9.2 9.0 Off-system and other incentive 4.5 7.4 Other customer revenue 2.3 2.9 Total revenue from contracts with customers 331.3 352.2 Changes in accrued revenue under alternative revenue programs 16.6 3.3 Total Operating Revenues $ 347.9 $ 355.5 Spire Alabama Residential $ 80.1 $ 69.2 Commercial and industrial 26.0 24.3 Transportation 19.4 20.5 Off-system and other incentive 0.4 2.0 Other customer revenue 0.8 (1.9 ) Total revenue from contracts with customers 126.7 114.1 Changes in accrued revenue under alternative revenue programs (0.1 ) (0.5 ) Total Operating Revenues $ 126.6 $ 113.6 Gross receipts taxes associated with the Company’s natural gas utility services are imposed on the Company, Spire Missouri, and Spire Alabama and billed to its customers. The expense amounts (shown in the table below) are reported gross in the “Taxes, other than income taxes” line in the statements of income, and corresponding revenues are reported in “Operating Revenues.” Three Months Ended December 31, 2021 2020 Spire $ 21.9 $ 21.7 Spire Missouri 14.9 15.2 Spire Alabama 5.7 5.3

Earnings Per Common Share

Earnings Per Common Share	3 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Common Share	3. EARNINGS PER COMMON SHARE Three Months Ended December 31, 2021 2020 Basic Earnings Per Common Share: Net Income $ 55.7 $ 88.9 Less: Provision for preferred dividends 3.7 3.7 Income allocated to participating securities 0.1 0.1 Income Available to Common Shareholders $ 51.9 $ 85.1 Weighted Average Common Shares Outstanding (in millions) 51.6 51.5 Basic Earnings Per Common Share $ 1.01 $ 1.65 Diluted Earnings Per Common Share: Net Income $ 55.7 $ 88.9 Less: Provision for preferred dividends 3.7 3.7 Income allocated to participating securities 0.1 0.1 Income Available to Common Shareholders $ 51.9 $ 85.1 Weighted Average Common Shares Outstanding (in millions) 51.6 51.5 Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)* 0.1 0.1 Weighted Average Diluted Common Shares (in millions) 51.7 51.6 Diluted Earnings Per Common Share $ 1.01 $ 1.65 * Calculation excludes certain outstanding common shares (shown in millions by period at the right) attributable to stock units subject to performance or market conditions and restricted stock, which could have a dilutive effect in the future 0.2 0.2

Regulatory Matters

Regulatory Matters	3 Months Ended
	Dec. 31, 2021
Regulated Operations [Abstract]
Regulatory Matters	4. REGULATORY MATTERS As explained in Note 1 , Summary of Significant Accounting Policies, the Utilities account for regulated operations in accordance with FASB ASC Topic 980, Regulated Operations December 31, September 30, December 31, Spire 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 31.1 $ 30.6 Unamortized purchased gas adjustments 242.4 243.5 8.4 Other 23.3 31.9 31.5 Total Current Regulatory Assets 265.7 306.5 70.5 Noncurrent: Pension and postretirement benefit costs 335.9 313.8 428.6 Cost of removal 444.5 431.9 417.4 Future income taxes due from customers 135.5 132.9 125.4 Energy efficiency 52.0 47.6 41.4 Unamortized purchased gas adjustments 27.3 — 3.8 Other 94.7 67.3 62.6 Total Noncurrent Regulatory Assets 1,089.9 993.5 1,079.2 Total Regulatory Assets $ 1,355.6 $ 1,300.0 $ 1,149.7 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 5.8 $ 5.8 Unamortized purchased gas adjustments — 11.0 54.8 Other 4.1 17.8 34.9 Total Current Regulatory Liabilities 4.1 34.6 95.5 Noncurrent: Deferred taxes due to customers 155.5 127.5 136.0 Pension and postretirement benefit costs 172.2 159.3 163.7 Accrued cost of removal 35.3 36.2 28.6 Unamortized purchased gas adjustments 155.0 284.3 14.8 Other 13.8 13.6 14.2 Total Noncurrent Regulatory Liabilities 531.8 620.9 357.3 Total Regulatory Liabilities $ 535.9 $ 655.5 $ 452.8 December 31, September 30, December 31, Spire Missouri 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 21.9 $ 21.9 Unamortized purchased gas adjustments 235.2 242.8 — Other 1.7 11.6 10.2 Total Current Regulatory Assets 236.9 276.3 32.1 Noncurrent: Future income taxes due from customers 126.9 124.2 116.6 Pension and postretirement benefit costs 241.6 226.0 324.6 Energy efficiency 52.0 47.6 41.4 Unamortized purchased gas adjustments 27.3 — 3.8 Cost of removal 34.9 34.9 18.3 Other 77.8 50.4 45.7 Total Noncurrent Regulatory Assets 560.5 483.1 550.4 Total Regulatory Assets $ 797.4 $ 759.4 $ 582.5 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 3.6 $ 3.6 Unamortized purchased gas adjustments — — 54.3 Other 0.2 13.5 25.5 Total Current Regulatory Liabilities 0.2 17.1 83.4 Noncurrent: Deferred taxes due to customers 138.2 110.2 118.6 Pension and postretirement benefit costs 142.6 131.4 146.1 Accrued cost of removal 3.3 4.9 — Unamortized purchased gas adjustments 155.0 284.3 14.8 Other 8.1 8.0 8.7 Total Noncurrent Regulatory Liabilities 447.2 538.8 288.2 Total Regulatory Liabilities $ 447.4 $ 555.9 $ 371.6 December 31, September 30, December 31, Spire Alabama 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 8.2 $ 7.7 Unamortized purchased gas adjustments 4.1 — 8.3 Other 10.5 10.6 6.7 Total Current Regulatory Assets 14.6 18.8 22.7 Noncurrent: Pension and postretirement benefit costs 88.7 82.9 95.7 Cost of removal 409.6 397.0 399.1 Future income taxes due from customers 2.2 2.2 2.2 Other 1.2 1.2 1.2 Total Noncurrent Regulatory Assets 501.7 483.3 498.2 Total Regulatory Assets $ 516.3 $ 502.1 $ 520.9 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 2.2 $ 2.2 Unamortized purchased gas adjustments — 10.2 — Other 0.8 1.0 4.7 Total Current Regulatory Liabilities 0.8 13.4 6.9 Noncurrent: Pension and postretirement benefit costs 21.6 19.8 14.7 Other 3.7 3.6 3.7 Total Noncurrent Regulatory Liabilities 25.3 23.4 18.4 Total Regulatory Liabilities $ 26.1 $ 36.8 $ 25.3 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, 2021 2021 2020 Spire Pension and postretirement benefit costs $ 163.4 $ 165.7 $ 229.7 Future income taxes due from customers 133.3 130.7 123.2 Unamortized purchased gas adjustments 262.5 242.8 — Other 107.4 86.0 12.4 Total Regulatory Assets Not Earning a Return $ 666.6 $ 625.2 $ 365.3 Spire Missouri Pension and postretirement benefit costs $ 163.4 $ 165.7 $ 229.7 Future income taxes due from customers 126.9 124.2 116.6 Unamortized purchased gas adjustments 262.5 242.8 — Other 107.4 86.0 12.4 Total Regulatory Assets Not Earning a Return $ 660.2 $ 618.7 $ 358.7 Like all the Company’s regulatory assets, these regulatory assets are expected to be recovered from customers in future rates. The recovery period for the future income taxes due from customers and pension and other postretirement benefit costs could be 20 years or longer, based on current Internal Revenue Service guidelines and average remaining service life of active participants, respectively. For the PGA assets, the recovery period is normally approximately one year, but it will be three years for a portion of these assets due to the Filing Adjustment Factor discussed below. The other items not earning a return are expected to be recovered over a period not to exceed 15 years, consistent with precedent set by the MoPSC. Spire Alabama does not have any regulatory assets that are not earning a return. Spire Missouri The MoPSC approved compliance tariffs with an effective date of December 23, 2021, in Spire Missouri’s general rate case GR-2021-0108. These new tariffs are designed to increase Spire Missouri’s aggregate annual gross base rate revenues by $72.2, which includes $24.9 incremental and $47.3 already being collected through the Infrastructure System Replacement Surcharge (ISRS). The decision, as reflected in the amended report and order dated November 12, 2021, diverged from prior MoPSC precedent in that it (1) included short-term debt in Spire Missouri’s capital structure for the first time and (2) revised its long-standing position regarding Spire Missouri’s compliance with the FERC Uniform System of Accounts (USOA) on the capitalization of prudently incurred non-operational overheads. The amended report and order requires Spire Missouri to cease capitalization of these overhead costs at the time new rates go into effect until a MoPSC staff audit of their revised interpretation of compliance with the USOA framework can be completed. On November 19, 2021, Spire Missouri filed a motion for rehearing of the amended report and order on various issues, including this revised interpretation and the short-term debt issue referenced above. Although Spire Missouri believes that the portions of the amended report and order addressing capitalized overheads lacks the clarity needed to quantify the impact of the issue with adequate precision, it is working with the MoPSC staff to facilitate the ordered audit of capitalized overheads on an expedited basis, including the quantification of the overheads subject to the order, and interpretation of what portion of these costs may be deferred into a regulatory asset until capitalization resumes. On January 12, 2022, the MoPSC denied Spire Missouri’s application for rehearing. Without additional assurance of recovery through a regulatory asset, Spire Missouri anticipates that the change in overhead capitalization methods ordered by the MoPSC will have a material adverse impact on its net income in 2022 and future periods until the completion of a future rate case providing for the resumption of such capitalization. The estimated pre-tax impact of shifting prudently incurred overhead costs from capital to O&M expense is in the range of $20 to $30 annually, beginning with $1.0 in the first quarter of fiscal 2022 since the December 23 effective date. On January 5, 2022, Spire Missouri filed a 60-day notice of intent to initiate a new general rate case proceeding which is intended to address this net income disparity along with other matters. In mid-February 2021, the central U.S. experienced a period of unusually severe cold weather (“Winter Storm Uri”), and Spire Missouri implemented an Operational Flow Order (OFO) to preserve the integrity of its distribution system. During this time, Spire Missouri was required to purchase additional natural gas supply, both to ensure adequate supply for its firm utility customers, and to cover the shortfall created when third-party marketers failed to deliver natural gas supply to its city gates on behalf of their customers. In accordance with its tariffs, Spire Missouri invoiced the cost of gas and associated penalties totaling $195.8 to non-compliant marketers pursuant to the MoPSC-approved OFO tariff and recorded accounts receivable. Recoveries collected, including $3.2 collected to date, will be an offset to cost of natural gas for firm utility customers through the Purchased Gas Adjustment (PGA) and Actual Cost Adjustment (ACA). The three largest counterparties did not remit payment when due, so Spire Missouri filed suit against them in federal court to recover the invoiced amounts. Those suits remain pending. Some marketers have filed complaints with the MoPSC requesting review of the transactions between them and Spire; at this time, the Company has no reason to believe the MoPSC will not follow the tariff and has determined collection is probable. Evidentiary hearings of those complaints are scheduled for March 2022. The MoPSC has also opened a working case to investigate the effects of Winter Storm Uri on all Missouri utilities. Spire Missouri is not subject to any upstream OFO penalties on any interstate pipelines. As a result of the significant net deferred gas costs and average inventory cost in the second quarter of fiscal 2021, primarily due to Winter Storm Uri, Spire Missouri filed for and received MoPSC approval for an adjustment to the PGA tariff to increase a Filing Adjustment Factor credit for three years. This credit will allow Spire Missouri to help mitigate rate impacts of Winter Storm Uri costs and the increased gas market from 2020 to 2021. All gas costs will eventually be recovered through the PGA or ACA mechanisms and carrying costs will be applied per the terms of the tariff. On December 23, 2021, Spire Missouri filed a new ISRS case, its first under the ISRS statute amendments of 2020, seeking accelerated recovery of $11.3 in annual revenue for eligible pipe replacement. The effective date for the new ISRS rates is expected to be late in the third quarter of fiscal 2022. On December 22, 2021, Spire Missouri filed an application with the MoPSC for approval of $ 800.0 in new financing authority over three years. Spire Missouri’s current financing authority order was entered on July 29, 2020, and authorized up to $ 660.0 of new equity and debt financing , of which $ 55.0 remains unused. Spire Alabama On October 26, 2021, Spire Alabama made its annual Rate Stabilization and Equalization (RSE) rate filing with the APSC, presenting the utility’s budget for the fiscal year ending September 30, 2022, including net income and a calculation of allowed return on average common equity (ROE). Following a regulatory review, adjusted rates became effective January 1, 2022. Spire Alabama filed a GSA rate increase effective December 1, 2021, primarily attributable to higher natural gas prices. Spire In addition to those discussed above for Spire Missouri and Spire Alabama, Spire is affected by the following regulatory matters. I n October 2021, Spire Gulf made its annual RSE rate filing with the APSC based on its budget for fiscal 2022 and an allowed ROE of 9.95%. New rates designed to provide increased annual revenues of $1.0 became effective January 3, 2022. On August 23, 2021, Spire Mississippi filed its Rate Stabilization Adjustment Rider (RSA) for the rate year ended June 30, 2021, which reflected an increase to annual revenue totaling $1.1. This RSA filing is being reviewed by the Mississippi Public Utilities Staff. In August 2018, the FERC approved an order issuing a Certificate of Public Convenience and Necessity for the Spire STL Pipeline (“August 2018 Order”). In November 2018, the FERC issued a Notice to Proceed, and in November 2019, Spire STL Pipeline received FERC authorization to place the pipeline into service. Also, in November 2019, the FERC issued an Order on Rehearing of the August 2018 Order dismissing or denying the outstanding requests for rehearing filed by several parties, dismissing the request for stay filed by one party, and noting the withdrawal of the request for rehearing by another party. In January 2020, two of the rehearing parties filed petitions for review of the FERC’s orders with the U.S. Court of Appeals for the District of Columbia Circuit. On June 22, 2021, that court issued an order vacating the Certificate of Public Convenience and Necessity and remanding the matter back to the FERC for further action. On September 14, 2021, and December 3, 2021, the FERC issued temporary certificates to allow the pipeline to continue operating while it considers approval of a new permanent certificate. On December 15, 2021, the FERC issued a notice of intent to prepare a supplemental environmental impact statement (EIS) with the final EIS not anticipated until October 7, 2022. Spire STL Pipeline will continue to pursue all legal and regulatory avenues to ensure access to reliable, affordable and safe delivery of energy for eastern Missouri. While there is no impairment at this time, if the pipeline is taken out of service, the Company’s financial condition and results of operations may be adversely impacted by impairment of Spire STL Pipeline’s assets, currently carried at over $270, and other effects. If Spire Missouri is unable to obtain sufficient pipeline capacity to meet its customers’ annual and seasonal natural gas demands, Spire Missouri’s financial condition and results of operations may be adversely impacted. On October 9, 2020, Spire Storage West LLC (“Spire Storage”) filed with the FERC an Abbreviated Application for an Amendment of Certificate of Public Convenience and Necessity, Reaffirmation of Market-Based Rate Authority, and Related Authorizations pursuant to Section 7(c) of the Natural Gas Act. The FERC has also issued a notice to prepare an EIS for this project, the final EIS of which is now not anticipated until March 15, 2022. The application, which requests authorization to expand capacity and increase pipeline connectivity at certain of Spire Storage’s natural gas storage facilities in Wyoming, remains pending.

Financing

Financing	3 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Financing	5. FINANCING Short-term Spire utilizes a commercial paper program (“CP Program”) pursuant to which Spire may issue short-term, unsecured commercial paper notes. Amounts available under the CP Program may be borrowed, repaid and re-borrowed from time to time, with the aggregate face or principal amount of the notes outstanding under the CP Program at any time not to exceed $975.0. The notes may have maturities of up to 365 days from date of issue. On March 23, 2021, Spire Missouri entered into a loan agreement with several banks for a $250.0, 364-day unsecured term loan with an interest rate based on LIBOR plus 65 basis points. The loan carries no prepayment penalty and has the same covenants as the revolving credit facility. 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 % Long-term The long-term debt agreements of Spire, Spire Missouri and Spire Alabama contain customary financial covenants and default provisions. As of December 31, 2021, there were no events of default under these financial covenants. 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 On December 7, 2021, pursuant to its registration statement on Form S-3 filed with the SEC, Spire Missouri issued $300.0 of first mortgage bonds due December 2, 2024, secured equally with all its other first mortgage bonds. Interest is payable quarterly in arrears at a floating rate based on the compounded secured overnight financing rate plus 50 basis points, with a maximum rate of the lesser of 8% or the maximum rate then permitted by applicable law.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	6. FAIR VALUE OF FINANCIAL INSTRUMENTS The carrying amounts of cash and cash equivalents, notes receivable, and short-term debt approximate fair value due to the short maturity of these instruments. The fair values of long-term debt are estimated based on market prices for similar issues. Refer to Note 7 , Fair Value Measurements, for information on financial instruments measured at fair value on a recurring basis. The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis are shown in the following tables, classified according to the fair value hierarchy. There were no such instruments classified as Level 3 (significant unobservable inputs) as of December 31, 2021, September 30, 2021, and December 31, 2020. Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Spire As of December 31, 2021 Cash and cash equivalents $ 8.2 $ 8.2 $ 8.2 $ — Notes payable 846.0 846.0 — 846.0 Long-term debt, including current portion 3,238.0 3,594.4 — 3,594.4 As of September 30, 2021 Cash and cash equivalents $ 4.3 $ 4.3 $ 4.3 $ — Notes payable 672.0 672.0 — 672.0 Long-term debt, including current portion 2,994.9 3,375.9 — 3,375.9 As of December 31, 2020 Cash and cash equivalents $ 3.5 $ 3.5 $ 3.5 $ — Notes payable 696.1 696.1 — 696.1 Long-term debt, including current portion 2,628.4 3,119.5 — 3,119.5 Spire Missouri As of December 31, 2021 Notes payable $ 250.0 $ 250.0 $ — $ 250.0 Notes payable – associated companies 180.4 180.4 — 180.4 Long-term debt 1,637.0 1,830.5 — 1,830.5 As of September 30, 2021 Notes payable $ 250.0 $ 250.0 $ — $ 250.0 Notes payable – 240.9 240.9 — 240.9 Long-term debt 1,338.4 1,540.4 — 1,540.4 As of December 31, 2020 Notes payable – $ 393.7 $ 393.7 $ — $ 393.7 Long-term debt 1,092.2 1,329.0 — 1,329.0 Spire Alabama As of December 31, 2021 Notes payable – $ 173.7 $ 173.7 $ — $ 173.7 Long-term debt, including current portion 571.3 653.6 — 653.6 As of September 30, 2021 Notes payable – $ 49.0 $ 49.0 $ — $ 49.0 Long-term debt 621.2 707.5 — 707.5 As of December 31, 2020 Notes payable – $ 27.0 $ 27.0 $ — $ 27.0 Long-term debt 621.0 742.9 — 742.9

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. FAIR VALUE MEASUREMENTS The information presented below categorizes the assets and liabilities in the balance sheets that are accounted for at fair value on a recurring basis in periods subsequent to initial recognition. The mutual funds included in Level 1 are valued based on exchange-quoted market prices of individual securities. Derivative instruments included in Level 1 are valued using quoted market prices on the New York Mercantile Exchange (NYMEX) or the Intercontinental Exchange (ICE). Derivative instruments classified in Level 2 include physical commodity derivatives that are valued using broker or dealer quotation services whose prices are derived principally from, or are corroborated by, observable market inputs. Also included in Level 2 are certain derivative instruments that have values that are similar to, and correlate with, quoted prices for exchange-traded instruments in active markets. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. There were no Level 3 balances as of December 31, 2021, September 30, 2021, and December 31, 2020. The Company’s and the Utilities’ policy is to recognize transfers between the levels of the fair value hierarchy, if any, as of the beginning of the interim reporting period in which circumstances change or events occur to cause the transfer. The mutual funds are included in “Other Investments” on the Company’s balance sheets and in “Other Property and Investments” on Spire Missouri’s balance sheets. Derivative assets and liabilities, including receivables and payables associated with cash margin requirements, are presented net in the balance sheets when a legally enforceable netting agreement exists between the Company, Spire Missouri, or Spire Alabama and the counterparty to a derivative contract. Spire Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of December 31, 2021 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 24.8 $ — $ — $ — $ 24.8 NYMEX/ICE natural gas contracts 2.4 — — (2.4 ) — Gas Marketing: NYMEX/ICE natural gas contracts — 67.0 — (67.0 ) — Natural gas commodity contracts — 40.4 — (2.3 ) 38.1 Other: U.S. stock/bond mutual funds 24.6 — — — 24.6 Interest rate swaps 9.4 — — (5.6 ) 3.8 Total $ 61.2 $ 107.4 $ — $ (77.3 ) $ 91.3 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 8.6 $ — $ — $ (8.6 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 40.2 — (40.2 ) — Natural gas commodity contracts — 77.9 — (2.3 ) 75.6 Other: Interest rate swaps 7.3 — — (5.6 ) 1.7 Total $ 15.9 $ 118.1 $ — $ (56.7 ) $ 77.3 Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of September 30, 2021 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 23.8 $ — $ — $ — $ 23.8 NYMEX/ICE natural gas contracts 104.0 — — (104.0 ) — Gas Marketing: NYMEX/ICE natural gas contracts — 114.7 — (93.7 ) 21.0 Natural gas commodity contracts — 35.2 — (5.5 ) 29.7 Other: U.S. stock/bond mutual funds 26.2 — — — 26.2 Interest rate swaps 12.6 — — (5.2 ) 7.4 Total $ 166.6 $ 149.9 $ — $ (208.4 ) $ 108.1 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 0.3 $ — $ — $ (0.3 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 62.0 — (62.0 ) — Natural gas commodity contracts — 96.7 — (5.5 ) 91.2 Other: Interest rate swaps 5.7 — — (5.2 ) 0.5 Total $ 6.0 $ 158.7 $ — $ (73.0 ) $ 91.7 As of December 31, 2020 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 23.4 $ — $ — $ — $ 23.4 Gasoline and heating oil contracts 0.4 — — (0.4 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.3 21.5 — (12.4 ) 9.4 Natural gas commodity contracts — 14.9 — — 14.9 Other: U.S. stock/bond mutual funds 14.2 — — — 14.2 Interest rate swaps — 7.0 — — 7.0 Total $ 38.3 $ 43.4 $ — $ (12.8 ) $ 68.9 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 4.9 $ — $ — $ (4.9 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 9.2 — (9.2 ) — Natural gas commodity contracts — 12.2 — — 12.2 Other: Interest rate swaps — 44.0 — — 44.0 Total $ 4.9 $ 65.4 $ — $ (14.1 ) $ 56.2 Spire Missouri Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of December 31, 2021 ASSETS U.S. stock/bond mutual funds $ 24.8 $ — $ — $ — $ 24.8 NYMEX/ICE natural gas contracts 2.4 — — (2.4 ) — Total $ 27.2 $ — $ — $ (2.4 ) $ 24.8 LIABILITIES NYMEX/ICE natural gas contracts $ 8.6 $ — $ — $ (8.6 ) $ — As of September 30, 2021 ASSETS U.S. stock/bond mutual funds $ 23.8 $ — $ — $ — $ 23.8 NYMEX/ICE natural gas contracts 104.0 — — (104.0 ) — Total $ 127.8 $ — $ — $ (104.0 ) $ 23.8 LIABILITIES NYMEX/ICE natural gas contracts $ 0.3 $ — $ — $ (0.3 ) $ — As of December 31, 2020 ASSETS U.S. stock/bond mutual funds $ 23.4 $ — $ — $ — $ 23.4 Gasoline and heating oil contracts 0.4 — — (0.4 ) — Total $ 23.8 $ — $ — $ (0.4 ) $ 23.4 LIABILITIES NYMEX/ICE natural gas contracts $ 4.9 $ — $ — $ (4.9 ) $ —

Pension Plans and Other Postret

Pension Plans and Other Postretirement Benefits	3 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Pension Plans and Other Postretirement Benefits	8. PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS Pension Plans Spire and the Utilities maintain pension plans for their employees. Spire Missouri has non-contributory, defined benefit, trusteed forms of pension plans covering the majority of its employees. Plan assets consist primarily of corporate and U.S. government obligations and a growth segment consisting of exposure to equity markets, commodities, real estate and inflation-indexed securities, achieved through derivative instruments. Spire Alabama has non-contributory, defined benefit, trusteed forms of pension plans covering the majority of its employees. Qualified plan assets are comprised of mutual and commingled funds consisting of U.S. equities with varying strategies, global equities, alternative investments, and fixed income investments. The net periodic pension cost includes components shown in the following tables. The components other than the service costs and regulatory adjustment are presented in “Other Income, Net” in the income statement, except for Spire Alabama’s losses on lump-sum settlements. Such losses are capitalized in regulatory balances and amortized over the remaining actuarial life of individuals in the plan, and that amortization is presented in “Other Income, Net.” Three Months Ended December 31, 2021 2020 Spire Service cost – benefits earned during the period $ 5.4 $ 5.6 Interest cost on projected benefit obligation 5.1 5.2 Expected return on plan assets (8.2 ) (8.0 ) Amortization of prior service credit (1.1 ) (0.8 ) Amortization of actuarial loss 3.7 4.0 Subtotal 4.9 6.0 Regulatory adjustment 10.6 9.6 Net pension cost $ 15.5 $ 15.6 Spire Missouri Service cost – benefits earned during the period $ 3.9 $ 3.9 Interest cost on projected benefit obligation 3.5 3.5 Expected return on plan assets (6.0 ) (5.6 ) Amortization of prior service credit (0.5 ) (0.2 ) Amortization of actuarial loss 2.8 2.9 Subtotal 3.7 4.5 Regulatory adjustment 8.5 7.6 Net pension cost $ 12.2 $ 12.1 Spire Alabama Service cost – benefits earned during the period $ 1.4 $ 1.5 Interest cost on projected benefit obligation 1.1 1.2 Expected return on plan assets (1.4 ) (1.6 ) Amortization of prior service credit (0.6 ) (0.6 ) Amortization of actuarial loss 0.9 1.1 Subtotal 1.4 1.6 Regulatory adjustment 1.9 1.8 Net pension cost $ 3.3 $ 3.4 Pursuant to the provisions of Spire Missouri’s and Spire Alabama’s pension plans, pension obligations may be satisfied by monthly annuities, lump-sum cash payments, or special termination benefits. Lump-sum payments are recognized as settlements (which can result in gains or losses) only if the total of such payments exceeds the sum of service and interest costs in a specific year. Special termination benefits, when offered, are also recognized as settlements which can result in The funding policy of the Utilities is to contribute an amount not less than the minimum required by government funding standards, nor more than the maximum deductible amount for federal income tax purposes. Fiscal 2022 contributions to Spire Missouri’s pension plans through December 31, 2021 were $13.7 to the qualified trusts and none to non-qualified plans. There were $ 2.6 Contributions to the qualified trusts of Spire Missouri’s pension plans for the remainder of fiscal 2022 are anticipated to be $23.9. Contributions to Spire Alabama’s pension plans for the remainder of fiscal 2022 are anticipated to be $11.8. Other Postretirement Benefits Spire and the Utilities provide certain life insurance benefits at retirement. Spire Missouri plans provide for medical insurance after early retirement until age 65. For retirements prior to January 1, 2015, certain Spire Missouri plans provided medical insurance after retirement until death. The Spire Alabama plans provide medical insurance upon retirement until death for certain retirees depending on the type of employee and the date the employee was originally hired. The net periodic postretirement benefit cost includes components shown in the following tables. The components other than the service costs and regulatory adjustment are presented in “Other Income, Net” in the income statement, except in the event Spire Alabama incurs losses on lump-sum settlements. Any such losses are capitalized in regulatory balances and amortized over the remaining actuarial life of individuals in the plan, and that amortization is presented in “Other Income, Net.” Three Months Ended December 31, 2021 2020 Spire Service cost – benefits earned during the period $ 1.9 $ 1.8 Interest cost on accumulated postretirement benefit obligation 1.5 1.4 Expected return on plan assets (4.2 ) (4.0 ) Amortization of prior service cost 0.3 0.3 Amortization of actuarial gain (0.6 ) (0.4 ) Subtotal (1.1 ) (0.9 ) Regulatory adjustment 3.2 3.4 Net postretirement benefit cost $ 2.1 $ 2.5 Spire Missouri Service cost – benefits earned during the period $ 1.6 $ 1.6 Interest cost on accumulated postretirement benefit obligation 1.1 1.1 Expected return on plan assets (2.8 ) (2.7 ) Amortization of prior service cost 0.2 0.2 Amortization of actuarial gain (0.5 ) (0.4 ) Subtotal (0.4 ) (0.2 ) Regulatory adjustment 3.6 3.8 Net postretirement benefit cost $ 3.2 $ 3.6 Spire Alabama Service cost – benefits earned during the period $ 0.3 $ 0.2 Interest cost on accumulated postretirement benefit obligation 0.4 0.3 Expected return on plan assets (1.3 ) (1.2 ) Amortization of prior service cost 0.1 0.1 Subtotal (0.5 ) (0.6 ) Regulatory adjustment (0.5 ) (0.4 ) Net postretirement benefit income $ (1.0 ) $ (1.0 ) Missouri and Alabama state laws provide for the recovery in rates of costs accrued pursuant to GAAP provided that such costs are funded through an independent, external funding mechanism. The Utilities have established Voluntary Employees’ Beneficiary Association (VEBA) and Rabbi Trusts as external funding mechanisms. The assets of the VEBA and Rabbi Trusts consist primarily of money market securities and mutual funds invested in stocks and bonds. The Utilities’ funding policy is to contribute amounts to the trusts equal to the periodic benefit cost calculated pursuant to GAAP as recovered in rates. There have been no

Information by Operating Segmen

Information by Operating Segment	3 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Information by Operating Segment	9. INFORMATION BY OPERATING SEGMENT The Company has two reportable segments: Gas Utility and Gas Marketing. The Gas Utility segment is the aggregation of the operations of the Utilities. The Gas Marketing segment includes the results of Spire Marketing, a subsidiary engaged in the non-regulated marketing of natural gas and related activities, including utilizing natural gas storage contracts for providing natural gas sales. Other components of the Company’s consolidated information include: • unallocated corporate items, including certain debt and associated interest costs; • Spire STL Pipeline, a subsidiary of Spire providing interstate natural gas pipeline transportation services; • Spire Storage, a subsidiary of Spire providing interstate natural gas storage services; and • Spire’s subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities. Accounting policies are described in Note 1 , Summary of Significant Accounting Policies. Intersegment transactions include sales of natural gas from Spire Marketing to Spire Missouri, Spire Alabama and Spire Storage, sales of natural gas from Spire Missouri to Spire Marketing, propane transportation services provided by Spire NGL Inc to Spire Missouri, and natural gas transportation services provided by Spire STL Pipeline to Spire Missouri. Management evaluates the performance of the operating segments based on the computation of net economic earnings. Net economic earnings exclude from reported net income the after-tax impacts of fair value accounting and timing adjustments associated with energy-related transactions, the impacts of acquisition, divestiture and restructuring activities, and the largely non-cash impacts of impairments and other non-recurring or unusual items such as certain regulatory, legislative, or GAAP standard-setting actions. Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended December 31, 2021 Operating Revenues: Revenues from external customers $ 503.5 $ 47.9 $ 4.0 $ — $ 555.4 Intersegment revenues — — 12.6 (12.6 ) — Total Operating Revenues 503.5 47.9 16.6 (12.6 ) 555.4 Operating Expenses: Natural gas 210.2 48.0 — (9.0 ) 249.2 Operation and maintenance 107.3 2.7 10.0 (3.6 ) 116.4 Depreciation and amortization 54.6 0.3 2.0 — 56.9 Taxes, other than income taxes 37.0 — 0.6 — 37.6 Total Operating Expenses 409.1 51.0 12.6 (12.6 ) 460.1 Operating Income (Loss) $ 94.4 $ (3.1 ) $ 4.0 $ — $ 95.3 Net Economic Earnings (Loss) $ 67.2 $ 0.5 $ (5.1 ) $ — $ 62.6 Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended December 31, 2020 Operating Revenues: Revenues from external customers $ 497.2 $ 10.7 $ 4.7 $ — $ 512.6 Intersegment revenues 1.0 14.1 12.0 (27.1 ) — Total Operating Revenues 498.2 24.8 16.7 (27.1 ) 512.6 Operating Expenses: Natural gas 204.3 0.7 — (23.8 ) 181.2 Operation and maintenance 103.0 3.3 8.6 (3.3 ) 111.6 Depreciation and amortization 48.6 0.3 1.9 — 50.8 Taxes, other than income taxes 35.5 0.2 0.4 — 36.1 Total Operating Expenses 391.4 4.5 10.9 (27.1 ) 379.7 Operating Income $ 106.8 $ 20.3 $ 5.8 $ — $ 132.9 Net Economic Earnings (Loss) $ 76.4 $ 3.3 $ (2.8 ) $ — $ 76.9 The following table reconciles the Company’s net economic earnings to net income. Three Months Ended December 31, 2021 2020 Net Income $ 55.7 $ 88.9 Adjustments, pre-tax: Fair value and timing adjustments 3.7 (16.0 ) Income tax adjustments 3.2 4.0 Net Economic Earnings $ 62.6 $ 76.9 The Company’s total assets by segment were as follows: December 31, September 30, December 31, 2021 2021 2020 Total Assets: Gas Utility $ 7,882.1 $ 7,615.4 $ 6,932.3 Gas Marketing 424.4 466.1 204.8 Other 2,417.6 2,351.7 2,462.3 Eliminations (1,073.6 ) (1,076.8 ) (1,083.8 ) Total Assets $ 9,650.5 $ 9,356.4 $ 8,515.6

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. COMMITMENTS AND CONTINGENCIES Commitments The Company and the Utilities have entered into contracts with various counterparties, expiring on dates through 2039, for the storage, transportation, and supply of natural gas. Minimum payments required under the contracts in place at December 31, 2021, are estimated at $1,840.4, $1,422.4, and $310.3 for the Company, Spire Missouri, and Spire Alabama, respectively. Additional contracts are generally entered into prior to or during the heating season of November through April. The Utilities recover their costs from customers in accordance with their PGA clauses or GSA riders. Contingencies The Company and the Utilities account for contingencies, including environmental liabilities, in accordance with accounting standards under the loss contingency guidance of ASC Topic 450, Contingencies In addition to matters noted below, the Company and the Utilities are involved in other litigation, claims, and investigations arising in the normal course of business. Management, after discussion with counsel, believes the final outcome will not have a material effect on the statements of income, balance sheets, and statements of cash flows of the Company, Spire Missouri, or Spire Alabama. However, there is uncertainty in the valuation of pending claims and prediction of litigation results. The Company and the Utilities own and operate natural gas distribution, transmission, and storage facilities, the operations of which are subject to various environmental laws, regulations, and interpretations. While environmental issues resulting from such operations arise in the ordinary course of business, such issues have not materially affected the Company’s or Utilities’ financial position and results of operations. As environmental laws, regulations, and their interpretations change, the Company or the Utilities may incur additional environmental liabilities that may result in additional costs, which may be material. In the natural gas industry, many gas distribution companies have incurred environmental liabilities associated with sites they or their predecessor companies formerly owned or operated where manufactured gas operations took place. The Utilities each have former manufactured gas plant (MGP) operations in their respective service territories, some of which are discussed under the Spire Missouri and Spire Alabama headings below. To the extent costs are incurred associated with environmental remediation activities, the Utilities would request authority from their respective regulators to defer such costs (less any amounts received from insurance proceeds or as contributions from other potentially responsible parties (PRPs)) and collect them through future rates. To date, costs incurred for all Spire MGP sites for investigation, remediation and monitoring have not been material. However, the amount of costs relative to future remedial actions at these and other sites is unknown and may be material. The actual future costs that Spire Missouri and Spire Alabama may incur could be materially higher or lower depending upon several factors, including whether remediation will be required, final selection and regulatory approval of any remedial actions, changing technologies and government regulations, the ultimate ability of other PRPs to pay, and any insurance recoveries. In 2020, Spire retained an outside consultant to conduct probabilistic cost modeling of its former MGP sites in Missouri and Alabama. The purpose of this analysis was to develop an estimated range of probabilistic future liability for each of their MGP sites. That analysis, completed in March 2021, provided a range of demonstrated possible future expenditures to investigate, monitor and remediate the former MGP sites. Spire Missouri and Spire Alabama have recorded their best estimates of the probable expenditures that relate to these matters. The amount remains immaterial, and Spire Missouri, Spire Alabama and the Company do not expect potential liabilities that may arise from remediating these sites to have a material impact on their future financial condition or results of operations. Spire Missouri Spire Missouri has identified three former MGP sites in the city of St. Louis, Missouri (the “City”) where costs have been incurred and claims have been asserted. Spire Missouri has enrolled two of the sites in the Missouri Department of Natural Resources (MoDNR) Brownfields/Voluntary Cleanup Program (BVCP). The third site is the result of an assertion by the United States Environmental Protection Agency (EPA). In conjunction with redevelopment of the Carondelet Coke site, Spire Missouri and another former owner of the site entered into an agreement (the “Remediation Agreement”) with the City development agencies, the developer, and an environmental consultant that obligates one of the City agencies and the environmental consultant to remediate the site and obtain a No Further Action (NFA) letter from the MoDNR. The Remediation Agreement also provides for a release of Spire Missouri and the other former site owner from certain liabilities related to the past and current environmental condition of the site and requires the developer and the environmental consultant to maintain certain insurance coverage, including remediation cost containment, premises pollution liability, and professional liability. The operative provisions of the Remediation Agreement were triggered on December 20, 2010, on which date Spire Missouri and the other former site owner, as full consideration under the Remediation Agreement, paid a small percentage of the cost of remediation of the site. The property was divided into seven parcels, and MoDNR NFA letters have been received for six of the parcels. Remediation is ongoing on the last parcel. In a letter dated June 29, 2011, the Attorney General for the State of Missouri informed Spire Missouri that the MoDNR had completed an investigation of the second site, Station A. The Attorney General requested that Spire Missouri participate in the follow up investigations of the site. In a letter dated January 10, 2012, Spire Missouri stated that it would participate in future environmental response activities at the site in conjunction with other PRPs. Accordingly, Spire Missouri entered into a cost sharing agreement for remedial investigation with other PRPs. MoDNR never approved the agreement, so no remedial investigation took place. Additionally, in correspondence dated November 30, 2016, Region 7 of the EPA has asserted that Spire Missouri is liable under Section 107(a) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) for alleged coal gas waste contamination at a third site, Station B. Spire Missouri and the site owner notified the EPA that information and data provided by the EPA to date does not rise to the level of documenting a threat to the public health or environment. As such, in March 2017 Spire Missouri requested more information from the EPA. Spire Missouri never received a response from the EPA. Spire Missouri has notified its insurers that it seeks reimbursement for costs incurred in the past and future potential liabilities associated with these MGP sites. While some of the insurers have denied coverage and reserved their rights, Spire Missouri retains the right to seek potential reimbursements from them. On March 10, 2015, Spire Missouri received a Section 104(e) information request under CERCLA from EPA Region 7 regarding the former Thompson Chemical/Superior Solvents site in the City. In turn, Spire Missouri issued a Freedom of Information Act (FOIA) request to the EPA on April 3, 2015, to identify the basis of the inquiry. The FOIA response from the EPA was received on July 15, 2015, and a response was provided to the EPA on August 15, 2015. Spire Missouri has received no further inquiry from the EPA regarding this matter. In its western service area, Spire Missouri has six owned MGP sites enrolled in the BVCP, including Joplin MGP #1, St. Joseph MGP #1, Kansas City Coal Gas Station B, Kansas City Station A Railroad area, Kansas City Coal Gas Station A, and Independence MGP #2. Source removal has been conducted at all the owned sites since 2003 with the exception of Joplin. On September 15, 2016, a request was made with the MoDNR for a restrictive covenant use limitation with respect to Joplin. Remediation efforts at the six sites are at various stages of completion, ranging from groundwater monitoring and sampling following source removal activities to the aforementioned request for the Joplin site. As part of its participation in the BVCP, Spire Missouri communicates regularly with the MoDNR with respect to its remediation efforts and monitoring activities at these sites. On May 11, 2015, MoDNR approved the next phase of investigation at the Kansas City Station A Railroad area. Spire Alabama Spire Alabama is in the chain of title of nine former MGP sites, four of which it still owns, and five former manufactured gas distribution sites, one of which it still owns. In 2012, Spire Alabama responded to an EPA Request for Information Pursuant to Section 104 of CERCLA relating to the 35th Avenue Superfund Site located in North Birmingham, Jefferson County, Alabama. Spire Alabama was identified as a PRP under CERCLA for the cleanup of the site or costs the EPA incurs in cleaning up the site. At this point, Spire Alabama has not been provided information that would allow it to determine the extent, if any, of its potential liability with respect to the 35th Avenue Superfund Site and vigorously denies its inclusion as a PRP. Spire In addition to those discussed above for Spire Missouri and Spire Alabama, Spire is aware of the following contingent matters. Spire Marketing, along with many natural gas industry participants, faced the unprecedented effects of Winter Storm Uri in February 2021. Numerous natural gas producers and midstream operators were unable to deliver natural gas to market as they experienced wellhead freeze-offs, power outages and equipment failure due to the extreme weather. These events resulted in supply curtailments, and related notices of force majeure to excuse performance, from and to certain counterparties. Further, these events have made Spire Marketing subject to various commercial disputes (including regarding force majeure) and a regulatory dispute regarding tariff obligations as a shipper on an interstate pipeline. As such, Spire Marketing has recorded an estimate of potential liabilities for damages based on communications with counterparties to date and the facts and circumstances surrounding each transaction. It is expected that the estimate will change as new facts emerge or settlements are reached, and it is possible that final settlement amounts may materially differ from the current estimate.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION – These notes are an integral part of the accompanying unaudited financial statements of Spire Inc. (“Spire” or the “Company”) presented on a consolidated basis, Spire Missouri Inc. (“Spire Missouri”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri, Spire Alabama and Spire EnergySouth Inc. (“Spire EnergySouth”) are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth (Spire Gulf Inc. and Spire Mississippi Inc.) are collectively referred to as the “Utilities.” The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information with the instructions to Form 10-Q and Rule 10-01 of Regulation S‑X. Accordingly, they do not include all the disclosures required for complete financial statements. In the opinion of management, the accompanying unaudited financial statements include all adjustments necessary for the fair presentation of the results of operations for the periods presented. This Form 10-Q should be read in conjunction with the Notes to Financial Statements contained in Spire, Spire Missouri and Spire Alabama’s combined Annual Report on Form 10-K for the fiscal year ended September 30, 2021. The consolidated financial position, results of operations, and cash flows of Spire include the accounts of the Company and all its subsidiaries. Transactions and balances between consolidated entities have been eliminated from the consolidated financial statements of Spire. In compliance with GAAP, transactions between Spire Missouri and Spire Alabama and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements.
Regulated Operations	REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, Regulated Operations . This topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. As authorized by the Missouri Public Service Commission (MoPSC), the Mississippi Public Service Commission (MSPSC) and the Alabama Public Service Commission (APSC), the Purchased Gas Adjustment (PGA) clauses and Gas Supply Adjustment (GSA) riders allow the Utilities to pass through to customers the cost of purchased gas supplies. Regulatory assets and liabilities related to the PGA clauses and the GSA riders are both labeled Unamortized Purchased Gas Adjustments herein. See additional information about regulatory assets and liabilities in Note 4 , Regulatory Matters.
Derivatives	DERIVATIVES – In the course of their business, certain subsidiaries of Spire enter into commitments associated with the purchase or sale of natural gas. Certain of their derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of FASB ASC Topic 815, Derivatives and Hedging . Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded gross. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of Spire Marketing’s wholesale purchase and sale transactions are classified as trading activities for financial reporting purposes, with income and expenses presented on a net basis in natural gas expenses in the Condensed Consolidated Statements of Income.
Transactions with Affiliates	TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire. As reflected in their separate financial statements, Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest. Spire Missouri and Spire Alabama also participated in normal intercompany shared services transactions. Spire Missouri’s and Spire Alabama’s other transactions with affiliates are presented below: Three Months Ended December 31, 2021 2020 Spire Missouri Purchases of natural gas from Spire Marketing Inc. $ 18.2 $ 10.7 Transportation services received from Spire STL Pipeline LLC 8.1 8.1 Sales of natural gas to Spire Marketing Inc. — 1.1 Transportation services received from Spire NGL Inc. — 0.3 Spire Alabama Purchases of natural gas from Spire Marketing Inc. $ — $ 4.8
Restricted Cash	RESTRICTED CASH – In Spire’s statement of cash flows for the period ended December 31, 2021, total Cash, Cash Equivalents, and Restricted Cash included $7.0 of restricted cash reported in “Other Investments” on the Company’s balance sheet as of December 31, 2021 and September 30, 2021 (in addition to amounts shown as “Cash and cash equivalents”). This restricted cash has been segregated and invested in debt securities in a trust account based on collateral requirements for reinsurance at Spire’s risk management company.
Accrued Capital Expenditures	ACCRUED CAPITAL EXPENDITURES – Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid. December 31, September 30, December 31, 2021 2021 2020 Spire $ 33.5 $ 59.5 $ 40.9 Spire Missouri 27.2 37.1 23.1 Spire Alabama 1.2 13.6 4.2
Accounts Receivable and Allowance For Credit Losses	ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Accounts receivable are written off when they are deemed to be uncollectible. An allowance for expected credit losses is estimated and updated based on relevant data and trends such as accounts receivable aging, historical write-off experience, current write-off trends, economic conditions, and the impact of weather and availability of customer payment assistance on collection trends. For the Utilities, net write-offs as a percentage of revenue has historically been the best predictor of base net write-off experience over time. Management judgment is applied in the development of the allowance due to the complexity of variables and subjective nature of certain relevant factors. The accounts receivable of Spire’s non-utility businesses are evaluated separately from those of the Utilities. The allowance for credit losses for those other businesses is based on a continuous evaluation of the individual counterparty risk and is not significant for the periods presented. Activity in the allowance for credit losses is shown in the following table. Spire Spire Missouri Spire Alabama Three Months Ended December 31, 2021 2020 2021 2020 2021 2020 Allowance at beginning of period $ 30.3 $ 24.9 $ 22.6 $ 18.1 $ 6.6 $ 5.5 Provision for expected credit losses 1.5 4.1 2.1 3.3 (0.5 ) 0.7 Write-offs, net of recoveries (0.4 ) (0.1 ) (0.9 ) — 0.6 — Allowance at end of period $ 31.4 $ 28.9 $ 23.8 $ 21.4 $ 6.7 $ 6.2

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Inter-Company Transactions	Spire Missouri’s and Spire Alabama’s other transactions with affiliates are presented below Three Months Ended December 31, 2021 2020 Spire Missouri Purchases of natural gas from Spire Marketing Inc. $ 18.2 $ 10.7 Transportation services received from Spire STL Pipeline LLC 8.1 8.1 Sales of natural gas to Spire Marketing Inc. — 1.1 Transportation services received from Spire NGL Inc. — 0.3 Spire Alabama Purchases of natural gas from Spire Marketing Inc. $ — $ 4.8
Schedule of Capital Expenditures Excluded from Statement of Cash Flow	Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid. December 31, September 30, December 31, 2021 2021 2020 Spire $ 33.5 $ 59.5 $ 40.9 Spire Missouri 27.2 37.1 23.1 Spire Alabama 1.2 13.6 4.2
Schedule of Allowance for Credit Losses	Spire Spire Missouri Spire Alabama Three Months Ended December 31, 2021 2020 2021 2020 2021 2020 Allowance at beginning of period $ 30.3 $ 24.9 $ 22.6 $ 18.1 $ 6.6 $ 5.5 Provision for expected credit losses 1.5 4.1 2.1 3.3 (0.5 ) 0.7 Write-offs, net of recoveries (0.4 ) (0.1 ) (0.9 ) — 0.6 — Allowance at end of period $ 31.4 $ 28.9 $ 23.8 $ 21.4 $ 6.7 $ 6.2

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Revenue Disaggregated by Source and Customer Type	The following tables show revenue disaggregated by source and customer type. Three Months Ended December 31, 2021 2020 Spire Gas Utility: Residential $ 342.0 $ 349.9 Commercial and industrial 103.8 103.0 Transportation 31.2 32.2 Off-system and other incentive 4.8 9.3 Other customer revenue 3.6 2.2 Total revenue from contracts with customers 485.4 496.6 Changes in accrued revenue under alternative revenue programs 18.1 1.6 Total Gas Utility operating revenues 503.5 498.2 Gas Marketing 47.9 24.8 Other 16.6 16.7 Total before eliminations 568.0 539.7 Intersegment eliminations (see Note 9, Information by Operating Segment) (12.6 ) (27.1 ) Total Operating Revenues $ 555.4 $ 512.6 Spire Missouri Residential $ 247.1 $ 263.0 Commercial and industrial 68.2 69.9 Transportation 9.2 9.0 Off-system and other incentive 4.5 7.4 Other customer revenue 2.3 2.9 Total revenue from contracts with customers 331.3 352.2 Changes in accrued revenue under alternative revenue programs 16.6 3.3 Total Operating Revenues $ 347.9 $ 355.5 Spire Alabama Residential $ 80.1 $ 69.2 Commercial and industrial 26.0 24.3 Transportation 19.4 20.5 Off-system and other incentive 0.4 2.0 Other customer revenue 0.8 (1.9 ) Total revenue from contracts with customers 126.7 114.1 Changes in accrued revenue under alternative revenue programs (0.1 ) (0.5 ) Total Operating Revenues $ 126.6 $ 113.6
Schedule of Gross Receipts Taxes	The expense amounts (shown in the table below) are reported gross in the “Taxes, other than income taxes” line in the statements of income, and corresponding revenues are reported in “Operating Revenues.” Three Months Ended December 31, 2021 2020 Spire $ 21.9 $ 21.7 Spire Missouri 14.9 15.2 Spire Alabama 5.7 5.3

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	3 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	Three Months Ended December 31, 2021 2020 Basic Earnings Per Common Share: Net Income $ 55.7 $ 88.9 Less: Provision for preferred dividends 3.7 3.7 Income allocated to participating securities 0.1 0.1 Income Available to Common Shareholders $ 51.9 $ 85.1 Weighted Average Common Shares Outstanding (in millions) 51.6 51.5 Basic Earnings Per Common Share $ 1.01 $ 1.65 Diluted Earnings Per Common Share: Net Income $ 55.7 $ 88.9 Less: Provision for preferred dividends 3.7 3.7 Income allocated to participating securities 0.1 0.1 Income Available to Common Shareholders $ 51.9 $ 85.1 Weighted Average Common Shares Outstanding (in millions) 51.6 51.5 Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)* 0.1 0.1 Weighted Average Diluted Common Shares (in millions) 51.7 51.6 Diluted Earnings Per Common Share $ 1.01 $ 1.65 * Calculation excludes certain outstanding common shares (shown in millions by period at the right) attributable to stock units subject to performance or market conditions and restricted stock, which could have a dilutive effect in the future 0.2 0.2

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
	Dec. 31, 2021
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, 2021, September 30, 2021, and December 31, 2020. December 31, September 30, December 31, Spire 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 31.1 $ 30.6 Unamortized purchased gas adjustments 242.4 243.5 8.4 Other 23.3 31.9 31.5 Total Current Regulatory Assets 265.7 306.5 70.5 Noncurrent: Pension and postretirement benefit costs 335.9 313.8 428.6 Cost of removal 444.5 431.9 417.4 Future income taxes due from customers 135.5 132.9 125.4 Energy efficiency 52.0 47.6 41.4 Unamortized purchased gas adjustments 27.3 — 3.8 Other 94.7 67.3 62.6 Total Noncurrent Regulatory Assets 1,089.9 993.5 1,079.2 Total Regulatory Assets $ 1,355.6 $ 1,300.0 $ 1,149.7 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 5.8 $ 5.8 Unamortized purchased gas adjustments — 11.0 54.8 Other 4.1 17.8 34.9 Total Current Regulatory Liabilities 4.1 34.6 95.5 Noncurrent: Deferred taxes due to customers 155.5 127.5 136.0 Pension and postretirement benefit costs 172.2 159.3 163.7 Accrued cost of removal 35.3 36.2 28.6 Unamortized purchased gas adjustments 155.0 284.3 14.8 Other 13.8 13.6 14.2 Total Noncurrent Regulatory Liabilities 531.8 620.9 357.3 Total Regulatory Liabilities $ 535.9 $ 655.5 $ 452.8 December 31, September 30, December 31, Spire Missouri 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 21.9 $ 21.9 Unamortized purchased gas adjustments 235.2 242.8 — Other 1.7 11.6 10.2 Total Current Regulatory Assets 236.9 276.3 32.1 Noncurrent: Future income taxes due from customers 126.9 124.2 116.6 Pension and postretirement benefit costs 241.6 226.0 324.6 Energy efficiency 52.0 47.6 41.4 Unamortized purchased gas adjustments 27.3 — 3.8 Cost of removal 34.9 34.9 18.3 Other 77.8 50.4 45.7 Total Noncurrent Regulatory Assets 560.5 483.1 550.4 Total Regulatory Assets $ 797.4 $ 759.4 $ 582.5 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 3.6 $ 3.6 Unamortized purchased gas adjustments — — 54.3 Other 0.2 13.5 25.5 Total Current Regulatory Liabilities 0.2 17.1 83.4 Noncurrent: Deferred taxes due to customers 138.2 110.2 118.6 Pension and postretirement benefit costs 142.6 131.4 146.1 Accrued cost of removal 3.3 4.9 — Unamortized purchased gas adjustments 155.0 284.3 14.8 Other 8.1 8.0 8.7 Total Noncurrent Regulatory Liabilities 447.2 538.8 288.2 Total Regulatory Liabilities $ 447.4 $ 555.9 $ 371.6 December 31, September 30, December 31, Spire Alabama 2021 2021 2020 Regulatory Assets: Current: Pension and postretirement benefit costs $ — $ 8.2 $ 7.7 Unamortized purchased gas adjustments 4.1 — 8.3 Other 10.5 10.6 6.7 Total Current Regulatory Assets 14.6 18.8 22.7 Noncurrent: Pension and postretirement benefit costs 88.7 82.9 95.7 Cost of removal 409.6 397.0 399.1 Future income taxes due from customers 2.2 2.2 2.2 Other 1.2 1.2 1.2 Total Noncurrent Regulatory Assets 501.7 483.3 498.2 Total Regulatory Assets $ 516.3 $ 502.1 $ 520.9 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ — $ 2.2 $ 2.2 Unamortized purchased gas adjustments — 10.2 — Other 0.8 1.0 4.7 Total Current Regulatory Liabilities 0.8 13.4 6.9 Noncurrent: Pension and postretirement benefit costs 21.6 19.8 14.7 Other 3.7 3.6 3.7 Total Noncurrent Regulatory Liabilities 25.3 23.4 18.4 Total Regulatory Liabilities $ 26.1 $ 36.8 $ 25.3
Schedule of Regulatory Assets Not Earning a 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, 2021 2021 2020 Spire Pension and postretirement benefit costs $ 163.4 $ 165.7 $ 229.7 Future income taxes due from customers 133.3 130.7 123.2 Unamortized purchased gas adjustments 262.5 242.8 — Other 107.4 86.0 12.4 Total Regulatory Assets Not Earning a Return $ 666.6 $ 625.2 $ 365.3 Spire Missouri Pension and postretirement benefit costs $ 163.4 $ 165.7 $ 229.7 Future income taxes due from customers 126.9 124.2 116.6 Unamortized purchased gas adjustments 262.5 242.8 — Other 107.4 86.0 12.4 Total Regulatory Assets Not Earning a Return $ 660.2 $ 618.7 $ 358.7

Financing (Tables)

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

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on Recurring Basis	The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis are shown in the following tables, classified according to the fair value hierarchy. There were no such instruments classified as Level 3 (significant unobservable inputs) as of December 31, 2021, September 30, 2021, and December 31, 2020. Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Spire As of December 31, 2021 Cash and cash equivalents $ 8.2 $ 8.2 $ 8.2 $ — Notes payable 846.0 846.0 — 846.0 Long-term debt, including current portion 3,238.0 3,594.4 — 3,594.4 As of September 30, 2021 Cash and cash equivalents $ 4.3 $ 4.3 $ 4.3 $ — Notes payable 672.0 672.0 — 672.0 Long-term debt, including current portion 2,994.9 3,375.9 — 3,375.9 As of December 31, 2020 Cash and cash equivalents $ 3.5 $ 3.5 $ 3.5 $ — Notes payable 696.1 696.1 — 696.1 Long-term debt, including current portion 2,628.4 3,119.5 — 3,119.5 Spire Missouri As of December 31, 2021 Notes payable $ 250.0 $ 250.0 $ — $ 250.0 Notes payable – associated companies 180.4 180.4 — 180.4 Long-term debt 1,637.0 1,830.5 — 1,830.5 As of September 30, 2021 Notes payable $ 250.0 $ 250.0 $ — $ 250.0 Notes payable – 240.9 240.9 — 240.9 Long-term debt 1,338.4 1,540.4 — 1,540.4 As of December 31, 2020 Notes payable – $ 393.7 $ 393.7 $ — $ 393.7 Long-term debt 1,092.2 1,329.0 — 1,329.0 Spire Alabama As of December 31, 2021 Notes payable – $ 173.7 $ 173.7 $ — $ 173.7 Long-term debt, including current portion 571.3 653.6 — 653.6 As of September 30, 2021 Notes payable – $ 49.0 $ 49.0 $ — $ 49.0 Long-term debt 621.2 707.5 — 707.5 As of December 31, 2020 Notes payable – $ 27.0 $ 27.0 $ — $ 27.0 Long-term debt 621.0 742.9 — 742.9

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Spire Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of December 31, 2021 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 24.8 $ — $ — $ — $ 24.8 NYMEX/ICE natural gas contracts 2.4 — — (2.4 ) — Gas Marketing: NYMEX/ICE natural gas contracts — 67.0 — (67.0 ) — Natural gas commodity contracts — 40.4 — (2.3 ) 38.1 Other: U.S. stock/bond mutual funds 24.6 — — — 24.6 Interest rate swaps 9.4 — — (5.6 ) 3.8 Total $ 61.2 $ 107.4 $ — $ (77.3 ) $ 91.3 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 8.6 $ — $ — $ (8.6 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 40.2 — (40.2 ) — Natural gas commodity contracts — 77.9 — (2.3 ) 75.6 Other: Interest rate swaps 7.3 — — (5.6 ) 1.7 Total $ 15.9 $ 118.1 $ — $ (56.7 ) $ 77.3 Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of September 30, 2021 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 23.8 $ — $ — $ — $ 23.8 NYMEX/ICE natural gas contracts 104.0 — — (104.0 ) — Gas Marketing: NYMEX/ICE natural gas contracts — 114.7 — (93.7 ) 21.0 Natural gas commodity contracts — 35.2 — (5.5 ) 29.7 Other: U.S. stock/bond mutual funds 26.2 — — — 26.2 Interest rate swaps 12.6 — — (5.2 ) 7.4 Total $ 166.6 $ 149.9 $ — $ (208.4 ) $ 108.1 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 0.3 $ — $ — $ (0.3 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 62.0 — (62.0 ) — Natural gas commodity contracts — 96.7 — (5.5 ) 91.2 Other: Interest rate swaps 5.7 — — (5.2 ) 0.5 Total $ 6.0 $ 158.7 $ — $ (73.0 ) $ 91.7 As of December 31, 2020 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 23.4 $ — $ — $ — $ 23.4 Gasoline and heating oil contracts 0.4 — — (0.4 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.3 21.5 — (12.4 ) 9.4 Natural gas commodity contracts — 14.9 — — 14.9 Other: U.S. stock/bond mutual funds 14.2 — — — 14.2 Interest rate swaps — 7.0 — — 7.0 Total $ 38.3 $ 43.4 $ — $ (12.8 ) $ 68.9 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 4.9 $ — $ — $ (4.9 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts — 9.2 — (9.2 ) — Natural gas commodity contracts — 12.2 — — 12.2 Other: Interest rate swaps — 44.0 — — 44.0 Total $ 4.9 $ 65.4 $ — $ (14.1 ) $ 56.2
Spire Missouri
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Spire Missouri Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Effects of Netting and Cash Margin Receivables /Payables Total As of December 31, 2021 ASSETS U.S. stock/bond mutual funds $ 24.8 $ — $ — $ — $ 24.8 NYMEX/ICE natural gas contracts 2.4 — — (2.4 ) — Total $ 27.2 $ — $ — $ (2.4 ) $ 24.8 LIABILITIES NYMEX/ICE natural gas contracts $ 8.6 $ — $ — $ (8.6 ) $ — As of September 30, 2021 ASSETS U.S. stock/bond mutual funds $ 23.8 $ — $ — $ — $ 23.8 NYMEX/ICE natural gas contracts 104.0 — — (104.0 ) — Total $ 127.8 $ — $ — $ (104.0 ) $ 23.8 LIABILITIES NYMEX/ICE natural gas contracts $ 0.3 $ — $ — $ (0.3 ) $ — As of December 31, 2020 ASSETS U.S. stock/bond mutual funds $ 23.4 $ — $ — $ — $ 23.4 Gasoline and heating oil contracts 0.4 — — (0.4 ) — Total $ 23.8 $ — $ — $ (0.4 ) $ 23.4 LIABILITIES NYMEX/ICE natural gas contracts $ 4.9 $ — $ — $ (4.9 ) $ —

Pension Plans and Other Postr_2

Pension Plans and Other Postretirement Benefits (Tables)	3 Months Ended
	Dec. 31, 2021
Pension Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	The net periodic pension cost includes components shown in the following tables. The components other than the service costs and regulatory adjustment are presented in “Other Income, Net” in the income statement, except for Spire Alabama’s losses on lump-sum settlements. Such losses are capitalized in regulatory balances and amortized over the remaining actuarial life of individuals in the plan, and that amortization is presented in “Other Income, Net.” Three Months Ended December 31, 2021 2020 Spire Service cost – benefits earned during the period $ 5.4 $ 5.6 Interest cost on projected benefit obligation 5.1 5.2 Expected return on plan assets (8.2 ) (8.0 ) Amortization of prior service credit (1.1 ) (0.8 ) Amortization of actuarial loss 3.7 4.0 Subtotal 4.9 6.0 Regulatory adjustment 10.6 9.6 Net pension cost $ 15.5 $ 15.6 Spire Missouri Service cost – benefits earned during the period $ 3.9 $ 3.9 Interest cost on projected benefit obligation 3.5 3.5 Expected return on plan assets (6.0 ) (5.6 ) Amortization of prior service credit (0.5 ) (0.2 ) Amortization of actuarial loss 2.8 2.9 Subtotal 3.7 4.5 Regulatory adjustment 8.5 7.6 Net pension cost $ 12.2 $ 12.1 Spire Alabama Service cost – benefits earned during the period $ 1.4 $ 1.5 Interest cost on projected benefit obligation 1.1 1.2 Expected return on plan assets (1.4 ) (1.6 ) Amortization of prior service credit (0.6 ) (0.6 ) Amortization of actuarial loss 0.9 1.1 Subtotal 1.4 1.6 Regulatory adjustment 1.9 1.8 Net pension cost $ 3.3 $ 3.4
Other Postretirement Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	The net periodic postretirement benefit cost includes components shown in the following tables. The components other than the service costs and regulatory adjustment are presented in “Other Income, Net” in the income statement, except in the event Spire Alabama incurs losses on lump-sum settlements. Any such losses are capitalized in regulatory balances and amortized over the remaining actuarial life of individuals in the plan, and that amortization is presented in “Other Income, Net.” Three Months Ended December 31, 2021 2020 Spire Service cost – benefits earned during the period $ 1.9 $ 1.8 Interest cost on accumulated postretirement benefit obligation 1.5 1.4 Expected return on plan assets (4.2 ) (4.0 ) Amortization of prior service cost 0.3 0.3 Amortization of actuarial gain (0.6 ) (0.4 ) Subtotal (1.1 ) (0.9 ) Regulatory adjustment 3.2 3.4 Net postretirement benefit cost $ 2.1 $ 2.5 Spire Missouri Service cost – benefits earned during the period $ 1.6 $ 1.6 Interest cost on accumulated postretirement benefit obligation 1.1 1.1 Expected return on plan assets (2.8 ) (2.7 ) Amortization of prior service cost 0.2 0.2 Amortization of actuarial gain (0.5 ) (0.4 ) Subtotal (0.4 ) (0.2 ) Regulatory adjustment 3.6 3.8 Net postretirement benefit cost $ 3.2 $ 3.6 Spire Alabama Service cost – benefits earned during the period $ 0.3 $ 0.2 Interest cost on accumulated postretirement benefit obligation 0.4 0.3 Expected return on plan assets (1.3 ) (1.2 ) Amortization of prior service cost 0.1 0.1 Subtotal (0.5 ) (0.6 ) Regulatory adjustment (0.5 ) (0.4 ) Net postretirement benefit income $ (1.0 ) $ (1.0 )

Information by Operating Segm_2

Information by Operating Segment (Tables)	3 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Operating Segment Information	Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended December 31, 2021 Operating Revenues: Revenues from external customers $ 503.5 $ 47.9 $ 4.0 $ — $ 555.4 Intersegment revenues — — 12.6 (12.6 ) — Total Operating Revenues 503.5 47.9 16.6 (12.6 ) 555.4 Operating Expenses: Natural gas 210.2 48.0 — (9.0 ) 249.2 Operation and maintenance 107.3 2.7 10.0 (3.6 ) 116.4 Depreciation and amortization 54.6 0.3 2.0 — 56.9 Taxes, other than income taxes 37.0 — 0.6 — 37.6 Total Operating Expenses 409.1 51.0 12.6 (12.6 ) 460.1 Operating Income (Loss) $ 94.4 $ (3.1 ) $ 4.0 $ — $ 95.3 Net Economic Earnings (Loss) $ 67.2 $ 0.5 $ (5.1 ) $ — $ 62.6 Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended December 31, 2020 Operating Revenues: Revenues from external customers $ 497.2 $ 10.7 $ 4.7 $ — $ 512.6 Intersegment revenues 1.0 14.1 12.0 (27.1 ) — Total Operating Revenues 498.2 24.8 16.7 (27.1 ) 512.6 Operating Expenses: Natural gas 204.3 0.7 — (23.8 ) 181.2 Operation and maintenance 103.0 3.3 8.6 (3.3 ) 111.6 Depreciation and amortization 48.6 0.3 1.9 — 50.8 Taxes, other than income taxes 35.5 0.2 0.4 — 36.1 Total Operating Expenses 391.4 4.5 10.9 (27.1 ) 379.7 Operating Income $ 106.8 $ 20.3 $ 5.8 $ — $ 132.9 Net Economic Earnings (Loss) $ 76.4 $ 3.3 $ (2.8 ) $ — $ 76.9 December 31, September 30, December 31, 2021 2021 2020 Total Assets: Gas Utility $ 7,882.1 $ 7,615.4 $ 6,932.3 Gas Marketing 424.4 466.1 204.8 Other 2,417.6 2,351.7 2,462.3 Eliminations (1,073.6 ) (1,076.8 ) (1,083.8 ) Total Assets $ 9,650.5 $ 9,356.4 $ 8,515.6
Schedule of Reconciliation of Consolidated Net Economic Earnings to Consolidated Net Income	The following table reconciles the Company’s net economic earnings to net income. Three Months Ended December 31, 2021 2020 Net Income $ 55.7 $ 88.9 Adjustments, pre-tax: Fair value and timing adjustments 3.7 (16.0 ) Income tax adjustments 3.2 4.0 Net Economic Earnings $ 62.6 $ 76.9

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	3 Months Ended
	Dec. 31, 2021USD ($)ReportingUnit	Dec. 31, 2021USD ($)operating-segment	Sep. 30, 2021USD ($)
Accounting Policies [Abstract]
Number of reportable segments	2	2
Restricted cash	$ 7	$ 7	$ 7

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Inter-Company Transactions (Details) - Affiliated Entity - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Spire Missouri | Spire Marketing Inc | Regulated Operation
Related Party Transaction [Line Items]
Purchases of natural gas from related party	$ 18.2	$ 10.7
Sales of natural gas to Spire Marketing Inc.		1.1
Spire Missouri | Spire STL Pipeline LLC | Unregulated Operation
Related Party Transaction [Line Items]
Transportation services received	$ 8.1	8.1
Spire Missouri | Spire NGL Inc. | Unregulated Operation
Related Party Transaction [Line Items]
Transportation services received		0.3
Spire Alabama | Spire Marketing Inc | Regulated Operation
Related Party Transaction [Line Items]
Purchases of natural gas from related party		$ 4.8

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Accrued Capital Expenditures (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	$ 33.5	$ 40.9	$ 59.5
Spire Missouri
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	27.2	23.1	37.1
Spire Alabama
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	$ 1.2	$ 4.2	$ 13.6

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Schedule of Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Allowance at beginning of period	$ 30.3	$ 24.9
Provision for expected credit losses	1.5	4.1
Write-offs, net of recoveries	(0.4)	(0.1)
Allowance at end of period	31.4	28.9
Spire Missouri
Accounts Notes And Loans Receivable [Line Items]
Allowance at beginning of period	22.6	18.1
Provision for expected credit losses	2.1	3.3
Write-offs, net of recoveries	(0.9)
Allowance at end of period	23.8	21.4
Spire Alabama
Accounts Notes And Loans Receivable [Line Items]
Allowance at beginning of period	6.6	5.5
Provision for expected credit losses	(0.5)	0.7
Write-offs, net of recoveries	0.6
Allowance at end of period	$ 6.7	$ 6.2

Revenue - Schedule of Revenue D

Revenue - Schedule of Revenue Disaggregated by Source and Customer Type (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2021	Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 3.2
Total operating revenues		$ 555.4	$ 512.6
Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues		(12.6)	(27.1)
Gas Utility | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		503.5	498.2
Gas Marketing | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		47.9	24.8
Spire
Disaggregation Of Revenue [Line Items]
Total operating revenues		555.4	512.6
Spire | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		568	539.7
Spire | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues		(12.6)	(27.1)
Spire | Gas Utility | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		485.4	496.6
Changes in accrued revenue under alternative revenue programs		18.1	1.6
Total operating revenues		503.5	498.2
Spire | Gas Utility | Operating Segments | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues		342	349.9
Spire | Gas Utility | Operating Segments | Commercial And Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues		103.8	103
Spire | Gas Utility | Operating Segments | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues		31.2	32.2
Spire | Gas Utility | Operating Segments | Off System And Other Incentive
Disaggregation Of Revenue [Line Items]
Total operating revenues		4.8	9.3
Spire | Gas Utility | Operating Segments | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues		3.6	2.2
Spire | Gas Marketing | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		47.9	24.8
Spire | Other | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues		$ 16.6	$ 16.7

Revenue - Schedule of Operating

Revenue - Schedule of Operating Revenue Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 555.4	$ 512.6
Spire Missouri
Disaggregation Of Revenue [Line Items]
Total operating revenues	331.3	352.2
Changes in accrued revenue under alternative revenue programs	16.6	3.3
Total operating revenues	347.9	355.5
Spire Missouri | Commercial And Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues	68.2	69.9
Spire Missouri | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues	247.1	263
Spire Missouri | Off System And Other Incentive
Disaggregation Of Revenue [Line Items]
Total operating revenues	4.5	7.4
Spire Missouri | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues	9.2	9
Spire Missouri | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues	2.3	2.9
Spire Alabama
Disaggregation Of Revenue [Line Items]
Total operating revenues	126.7	114.1
Changes in accrued revenue under alternative revenue programs	(0.1)	(0.5)
Total operating revenues	126.6	113.6
Spire Alabama | Commercial And Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues	26	24.3
Spire Alabama | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues	80.1	69.2
Spire Alabama | Off System And Other Incentive
Disaggregation Of Revenue [Line Items]
Total operating revenues	0.4	2
Spire Alabama | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues	19.4	20.5
Spire Alabama | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 0.8	$ (1.9)

Revenue - Schedule of Gross Rec

Revenue - Schedule of Gross Receipts Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	$ 21.9	$ 21.7
Spire Missouri
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	14.9	15.2
Spire Alabama
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	$ 5.7	$ 5.3

Earnings Per Common Share - Sch

Earnings Per Common Share - Schedule of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Basic Earnings Per Common Share:
Net Income	$ 55.7	$ 88.9
Less: Provision for preferred dividends	3.7	3.7
Income allocated to participating securities	0.1	0.1
Net Income Available to Common Shareholders	$ 51.9	$ 85.1
Weighted Average Common Shares Outstanding (in millions)	51.6	51.5
Basic Earnings Per Common Share	$ 1.01	$ 1.65
Diluted Earnings Per Common Share:
Net Income	$ 55.7	$ 88.9
Less: Provision for preferred dividends	3.7	3.7
Income allocated to participating securities	0.1	0.1
Income Available to Common Shareholders	$ 51.9	$ 85.1
Weighted Average Common Shares Outstanding (in millions)	51.6	51.5
Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)	0.1	0.1
Weighted Average Diluted Common Shares (in millions)	51.7	51.6
Diluted Earnings Per Common Share	$ 1.01	$ 1.65

Earnings Per Common Share - S_2

Earnings Per Common Share - Schedule of Basic and Diluted Earnings Per Common Share (Parenthetical) (Details) - shares shares in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restricted Stock and Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding common shares excluded from calculation of diluted EPS (in shares)	0.2	0.2

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Regulatory Assets and Liabilities, Reflected in Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	$ 265.7	$ 306.5	$ 70.5
Regulatory assets, non current	1,089.9	993.5	1,079.2
Total Regulatory Assets	1,355.6	1,300	1,149.7
Regulatory liabilities, current	4.1	34.6	95.5
Regulatory liabilities, non current	531.8	620.9	357.3
Total Regulatory Liabilities	535.9	655.5	452.8
Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	236.9	276.3	32.1
Regulatory assets, non current	560.5	483.1	550.4
Total Regulatory Assets	797.4	759.4	582.5
Regulatory liabilities, current	0.2	17.1	83.4
Regulatory liabilities, non current	447.2	538.8	288.2
Total Regulatory Liabilities	447.4	555.9	371.6
Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	14.6	18.8	22.7
Regulatory assets, non current	501.7	483.3	498.2
Total Regulatory Assets	516.3	502.1	520.9
Regulatory liabilities, current	0.8	13.4	6.9
Regulatory liabilities, non current	25.3	23.4	18.4
Total Regulatory Liabilities	26.1	36.8	25.3
Pension and Other Postretirement Benefits
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	0	31.1	30.6
Regulatory assets, non current	335.9	313.8	428.6
Pension and Other Postretirement Benefits | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	0	21.9	21.9
Regulatory assets, non current	241.6	226	324.6
Pension and Other Postretirement Benefits | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current		8.2	7.7
Regulatory assets, non current	88.7	82.9	95.7
Unamortized Purchased Gas Adjustments
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	242.4	243.5	8.4
Regulatory assets, non current	27.3	0	3.8
Unamortized Purchased Gas Adjustments | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	235.2	242.8	0
Regulatory assets, non current	27.3	0	3.8
Unamortized Purchased Gas Adjustments | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	4.1	0	8.3
Other
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	23.3	31.9	31.5
Regulatory assets, non current	94.7	67.3	62.6
Other | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	1.7	11.6	10.2
Regulatory assets, non current	77.8	50.4	45.7
Other | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	10.5	10.6	6.7
Regulatory assets, non current	1.2	1.2	1.2
Future Income Taxes Due from Customers
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	135.5	132.9	125.4
Future Income Taxes Due from Customers | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	126.9	124.2	116.6
Future Income Taxes Due from Customers | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	2.2	2.2	2.2
Accrued Cost of Removal
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	444.5	431.9	417.4
Accrued Cost of Removal | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	34.9	34.9	18.3
Accrued Cost of Removal | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	409.6	397	399.1
Energy Efficiency
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	52	47.6	41.4
Energy Efficiency | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	52	47.6	41.4
Pension and Other Postretirement Benefits
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0	5.8	5.8
Regulatory liabilities, non current	172.2	159.3	163.7
Pension and Other Postretirement Benefits | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0	3.6	3.6
Regulatory liabilities, non current	142.6	131.4	146.1
Pension and Other Postretirement Benefits | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current		2.2	2.2
Regulatory liabilities, non current	21.6	19.8	14.7
Unamortized Purchased Gas Adjustments
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0	11	54.8
Regulatory liabilities, non current	155	284.3	14.8
Unamortized Purchased Gas Adjustments | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0	0	54.3
Regulatory liabilities, non current	155	284.3	14.8
Unamortized Purchased Gas Adjustments | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current		10.2	0
Other
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	4.1	17.8	34.9
Regulatory liabilities, non current	13.8	13.6	14.2
Other | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0.2	13.5	25.5
Regulatory liabilities, non current	8.1	8	8.7
Other | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	0.8	1	4.7
Regulatory liabilities, non current	3.7	3.6	3.7
Deferred Taxes Due to Customers
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	155.5	127.5	136
Deferred Taxes Due to Customers | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	138.2	110.2	118.6
Accrued Cost of Removal
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	35.3	36.2	28.6
Accrued Cost of Removal | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	$ 3.3	$ 4.9	$ 0

Regulatory Matters - Schedule_2

Regulatory Matters - Schedule of Regulatory Assets Not Earning a Return (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 666.6	$ 625.2	$ 365.3
Pension and Other Postretirement Benefits
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	163.4	165.7	229.7
Future Income Taxes Due from Customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	133.3	130.7	123.2
Unamortized Purchased Gas Adjustments
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	262.5	242.8
Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	107.4	86	12.4
Spire Missouri
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	660.2	618.7	358.7
Spire Missouri | Pension and Other Postretirement Benefits
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	163.4	165.7	229.7
Spire Missouri | Future Income Taxes Due from Customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	126.9	124.2	116.6
Spire Missouri | Unamortized Purchased Gas Adjustments
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	262.5	242.8
Spire Missouri | Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 107.4	$ 86	$ 12.4

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) - USD ($)	Jan. 03, 2022	Dec. 23, 2021	Aug. 23, 2021	Oct. 31, 2021	Feb. 28, 2021	Dec. 31, 2021	Dec. 31, 2020	Jan. 12, 2022	Dec. 22, 2021	Jul. 29, 2020
Public Utilities, General Disclosures [Line Items]
Remaining recovery period for certain regulatory assets for which no return on investment during recovery period is provided (in years)						20 years
Remaining recovery period for regulatory assets for which no return on investment during recovery period is provided (in years)						15 years
Natural gas					$ 195,800,000	$ 249,200,000	$ 181,200,000
Incremental gross revenue					$ 3,200,000
Spire STL Pipeline LLC
Public Utilities, General Disclosures [Line Items]
Impairment of assets						270,000,000
Spire Missouri
Public Utilities, General Disclosures [Line Items]
Natural gas						156,300,000	$ 161,600,000
Regulatory preferred stock and debt securities issuance, amount authorized										$ 660,000,000
Regulatory preferred stock and debt securities issuance, remaining authorized amount										$ 55,000,000
Spire Gulf
Public Utilities, General Disclosures [Line Items]
Approved return rate on equity				9.95%
Spire Mississippi
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), annualized revenue			$ 1,100,000
Subsequent Event | Spire Gulf
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), annualized revenue	$ 1,000,000
Infrastructure System Replacement Surcharge | Spire Missouri
Public Utilities, General Disclosures [Line Items]
Regulated operating revenue pipe replacement		$ 11,300,000
MoPSC
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount		72,200,000
Requested rate increase		24,900,000
Estimated pre-tax impact, annually						$ 1,000,000
MoPSC | Spire Missouri
Public Utilities, General Disclosures [Line Items]
Financing authority pending approval									$ 800,000,000
MoPSC | Subsequent Event | Minimum
Public Utilities, General Disclosures [Line Items]
Estimated pre-tax impact, annually								$ 20,000,000
MoPSC | Subsequent Event | Maximum
Public Utilities, General Disclosures [Line Items]
Estimated pre-tax impact, annually								$ 30,000,000
MoPSC | Infrastructure System Replacement Surcharge
Public Utilities, General Disclosures [Line Items]
Requested rate increase		$ 47,300,000

Financing - Additional Informat

Financing - Additional Information (Details) - USD ($)	Dec. 07, 2021	Mar. 23, 2021	Dec. 31, 2021
Spire
Debt Instrument And Equity Units [Line Items]
Stated Interest rate			0.40%
Spire Missouri
Debt Instrument And Equity Units [Line Items]
Stated Interest rate			0.70%
Spire Missouri | Bonds due December 2, 2024
Debt Instrument And Equity Units [Line Items]
Interest rate	0.50%
Long-term debt	$ 300,000,000
Stated Interest rate	8.00%
Debt instrument, maturity date	Dec. 2, 2024
Debt instrument, payment terms			Interest is payable quarterly
Commercial Paper Notes
Debt Instrument And Equity Units [Line Items]
Debt amount			$ 975,000,000
Debt term			365 days
Commercial Paper Notes | Spire
Debt Instrument And Equity Units [Line Items]
Short-term borrowings used to support lending to Utilities			$ 421,900,000
Stated Interest rate			0.20%
Unsecured Term Loan | Spire Missouri
Debt Instrument And Equity Units [Line Items]
Debt amount		$ 250,000,000
Debt term		364 days
Prepayment penalty		$ 0
Unsecured Term Loan | Spire Missouri | LIBOR
Debt Instrument And Equity Units [Line Items]
Interest rate		0.65%

Financing -Schedule of Short-te

Financing -Schedule of Short-term Borrowings (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Spire Alabama | Spire Note
Short-term Debt [Line Items]
Highest borrowings outstanding	$ 176.7
Lowest borrowings outstanding	38.4
Weighted average borrowings	$ 73.6
Weighted average interest rate	0.20%
Borrowings outstanding	$ 173.7	$ 49	$ 27
Weighted average interest rate	0.40%	0.20%	0.30%
Spire Missouri
Short-term Debt [Line Items]
Highest borrowings outstanding	$ 250
Lowest borrowings outstanding	250
Weighted average borrowings	$ 250
Weighted average interest rate	0.70%
Borrowings outstanding	$ 250	$ 250
Weighted average interest rate	0.70%	0.70%
Spire Missouri | Spire Note
Short-term Debt [Line Items]
Highest borrowings outstanding	$ 412
Lowest borrowings outstanding	101.6
Weighted average borrowings	$ 253.6
Weighted average interest rate	0.20%
Borrowings outstanding	$ 180.4	$ 240.9	$ 393.7
Weighted average interest rate	0.40%	0.20%	0.30%
Spire
Short-term Debt [Line Items]
Highest borrowings outstanding	$ 996.8
Lowest borrowings outstanding	658
Weighted average borrowings	$ 808.6
Weighted average interest rate	0.40%
Borrowings outstanding	$ 846	$ 672	$ 696.1
Weighted average interest rate	0.50%	0.40%	0.30%
Spire | Commercial Paper Notes
Short-term Debt [Line Items]
Highest borrowings outstanding	$ 746.8
Lowest borrowings outstanding	408
Weighted average borrowings	$ 558.6
Weighted average interest rate	0.20%
Borrowings outstanding	$ 596	$ 422	$ 696.1
Weighted average interest rate	0.40%	0.20%	0.30%

Financing - Summary of Net of C

Financing - Summary of Net of Capitalized Interest (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Spire Alabama
Debt Instrument [Line Items]
Interest expense, net	$ 0.8	$ 0.6
Spire
Debt Instrument [Line Items]
Interest expense, net	$ 1.1	$ 0.9

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Quoted Prices in Active Markets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 8.2	$ 4.3	$ 3.5
Significant Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	846	672	696.1
Long-term debt, including current portion	3,594.4	3,375.9	3,119.5
Significant Observable Inputs (Level 2) | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	250	250
Notes payable – associated companies	180.4	240.9	393.7
Long-term debt, including current portion	1,830.5	1,540.4	1,329
Significant Observable Inputs (Level 2) | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable – associated companies	173.7	49	27
Long-term debt, including current portion	653.6	707.5	742.9
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	8.2	4.3	3.5
Notes payable	846	672	696.1
Long-term debt, including current portion	3,238	2,994.9	2,628.4
Carrying Amount | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	250	250
Notes payable – associated companies	180.4	240.9	393.7
Long-term debt, including current portion	1,637	1,338.4	1,092.2
Carrying Amount | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable – associated companies	173.7	49	27
Long-term debt, including current portion	571.3	621.2	621
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	8.2	4.3	3.5
Notes payable	846	672	696.1
Long-term debt, including current portion	3,594.4	3,375.9	3,119.5
Fair Value | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	250	250
Notes payable – associated companies	180.4	240.9	393.7
Long-term debt, including current portion	1,830.5	1,540.4	1,329
Fair Value | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable – associated companies	173.7	49	27
Long-term debt, including current portion	$ 653.6	$ 707.5	$ 742.9

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Effects of netting and cash margin receivables/payables	$ (77.3)	$ (208.4)	$ (12.8)
Derivative asset after the effects of netting	91.3	108.1	68.9
LIABILITIES
Effects of netting and cash margin receivables/payables	(56.7)	(73)	(14.1)
Derivative liability after the effects of netting	77.3	91.7	56.2
Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables	(2.4)	(104)	(0.4)
Derivative asset after the effects of netting	24.8	23.8	23.4
U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables	0	0	0
Derivative asset after the effects of netting	24.8	23.8	23.4
NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables	(2.4)	(104)
Derivative asset after the effects of netting	0	0
LIABILITIES
Effects of netting and cash margin receivables/payables	(8.6)	(0.3)	(4.9)
Derivative liability after the effects of netting	0	0	0
Gasoline And Heating Oil Contracts | Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables			(0.4)
Derivative asset after the effects of netting			0
Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(2.4)
Derivative asset after the effects of netting	0
Other | U.S. stock/bond mutual funds
ASSETS
Effects of netting and cash margin receivables/payables	0	0	0
Derivative asset after the effects of netting	24.6	26.2	14.2
Other | Interest Rate Swap
ASSETS
Effects of netting and cash margin receivables/payables	(5.6)	(5.2)	0
Derivative asset after the effects of netting	3.8	7.4	7
LIABILITIES
Effects of netting and cash margin receivables/payables	(5.6)	(5.2)	0
Derivative liability after the effects of netting	1.7	0.5	44
Gas Utility | Operating Segments | U.S. stock/bond mutual funds
ASSETS
Effects of netting and cash margin receivables/payables	0	0	0
Derivative asset after the effects of netting	24.8	23.8	23.4
Gas Utility | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables		(104)
Derivative asset after the effects of netting		0
LIABILITIES
Effects of netting and cash margin receivables/payables	(8.6)	(0.3)	(4.9)
Derivative liability after the effects of netting	0	0	0
Gas Utility | Operating Segments | Gasoline And Heating Oil Contracts
ASSETS
Effects of netting and cash margin receivables/payables			(0.4)
Derivative asset after the effects of netting			0
Gas Marketing | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(67)	(93.7)	(12.4)
Derivative asset after the effects of netting	0	21	9.4
LIABILITIES
Effects of netting and cash margin receivables/payables	(40.2)	(62)	(9.2)
Derivative liability after the effects of netting	0	0	0
Gas Marketing | Operating Segments | Natural gas commodity contracts
ASSETS
Effects of netting and cash margin receivables/payables	(2.3)	(5.5)	0
Derivative asset after the effects of netting	38.1	29.7	14.9
LIABILITIES
Effects of netting and cash margin receivables/payables	(2.3)	(5.5)	0
Derivative liability after the effects of netting	75.6	91.2	12.2
Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	61.2	166.6	38.3
LIABILITIES
Derivative liability before effects of netting	15.9	6	4.9
Quoted Prices in Active Markets (Level 1) | Spire Missouri
ASSETS
Derivative asset before effects of netting	27.2	127.8	23.8
Quoted Prices in Active Markets (Level 1) | U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Derivative asset before effects of netting	24.8	23.8	23.4
Quoted Prices in Active Markets (Level 1) | NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting	2.4	104
LIABILITIES
Derivative liability before effects of netting	8.6	0.3	4.9
Quoted Prices in Active Markets (Level 1) | Gasoline And Heating Oil Contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting			0.4
Quoted Prices in Active Markets (Level 1) | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	2.4
Quoted Prices in Active Markets (Level 1) | Other | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	24.6	26.2	14.2
Quoted Prices in Active Markets (Level 1) | Other | Interest Rate Swap
ASSETS
Derivative asset before effects of netting	9.4	12.6	0
LIABILITIES
Derivative liability before effects of netting	7.3	5.7	0
Quoted Prices in Active Markets (Level 1) | Gas Utility | Operating Segments | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	24.8	23.8	23.4
Quoted Prices in Active Markets (Level 1) | Gas Utility | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting		104
LIABILITIES
Derivative liability before effects of netting	8.6	0.3	4.9
Quoted Prices in Active Markets (Level 1) | Gas Utility | Operating Segments | Gasoline And Heating Oil Contracts
ASSETS
Derivative asset before effects of netting			0.4
Quoted Prices in Active Markets (Level 1) | Gas Marketing | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0	0	0.3
LIABILITIES
Derivative liability before effects of netting	0	0	0
Quoted Prices in Active Markets (Level 1) | Gas Marketing | Operating Segments | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	107.4	149.9	43.4
LIABILITIES
Derivative liability before effects of netting	118.1	158.7	65.4
Significant Observable Inputs (Level 2) | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | Gasoline And Heating Oil Contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting			0
Significant Observable Inputs (Level 2) | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0
Significant Observable Inputs (Level 2) | Other | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | Other | Interest Rate Swap
ASSETS
Derivative asset before effects of netting	0	0	7
LIABILITIES
Derivative liability before effects of netting	0	0	44
Significant Observable Inputs (Level 2) | Gas Utility | Operating Segments | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | Gas Utility | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting		0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Observable Inputs (Level 2) | Gas Utility | Operating Segments | Gasoline And Heating Oil Contracts
ASSETS
Derivative asset before effects of netting			0
Significant Observable Inputs (Level 2) | Gas Marketing | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	67	114.7	21.5
LIABILITIES
Derivative liability before effects of netting	40.2	62	9.2
Significant Observable Inputs (Level 2) | Gas Marketing | Operating Segments | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	40.4	35.2	14.9
LIABILITIES
Derivative liability before effects of netting	77.9	96.7	12.2
Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Gasoline And Heating Oil Contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting			0
Significant Unobservable Inputs (Level 3) | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0
Significant Unobservable Inputs (Level 3) | Other | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Other | Interest Rate Swap
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Gas Utility | Operating Segments | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Gas Utility | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting		0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Gas Utility | Operating Segments | Gasoline And Heating Oil Contracts
ASSETS
Derivative asset before effects of netting			0
Significant Unobservable Inputs (Level 3) | Gas Marketing | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Significant Unobservable Inputs (Level 3) | Gas Marketing | Operating Segments | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	$ 0	$ 0	$ 0

Pension Plans and Other Postr_3

Pension Plans and Other Postretirement Benefits - Schedule of Net Periodic Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	$ 5.4	$ 5.6
Interest cost on projected benefit obligation	5.1	5.2
Expected return on plan assets	(8.2)	(8)
Amortization of prior service cost (credit)	(1.1)	(0.8)
Amortization of actuarial (gain) loss	3.7	4
Subtotal	4.9	6
Regulatory adjustment	10.6	9.6
Net pension cost	15.5	15.6
Other Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.9	1.8
Interest cost on projected benefit obligation	1.5	1.4
Expected return on plan assets	(4.2)	(4)
Amortization of prior service cost (credit)	0.3	0.3
Amortization of actuarial (gain) loss	(0.6)	(0.4)
Subtotal	(1.1)	(0.9)
Regulatory adjustment	3.2	3.4
Net pension cost	2.1	2.5
Spire Missouri | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	3.9	3.9
Interest cost on projected benefit obligation	3.5	3.5
Expected return on plan assets	(6)	(5.6)
Amortization of prior service cost (credit)	(0.5)	(0.2)
Amortization of actuarial (gain) loss	2.8	2.9
Subtotal	3.7	4.5
Regulatory adjustment	8.5	7.6
Net pension cost	12.2	12.1
Spire Missouri | Other Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.6	1.6
Interest cost on projected benefit obligation	1.1	1.1
Expected return on plan assets	(2.8)	(2.7)
Amortization of prior service cost (credit)	0.2	0.2
Amortization of actuarial (gain) loss	(0.5)	(0.4)
Subtotal	(0.4)	(0.2)
Regulatory adjustment	3.6	3.8
Net pension cost	3.2	3.6
Spire Alabama | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.4	1.5
Interest cost on projected benefit obligation	1.1	1.2
Expected return on plan assets	(1.4)	(1.6)
Amortization of prior service cost (credit)	(0.6)	(0.6)
Amortization of actuarial (gain) loss	0.9	1.1
Subtotal	1.4	1.6
Regulatory adjustment	1.9	1.8
Net pension cost	3.3	3.4
Spire Alabama | Other Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	0.3	0.2
Interest cost on projected benefit obligation	0.4	0.3
Expected return on plan assets	(1.3)	(1.2)
Amortization of prior service cost (credit)	0.1	0.1
Subtotal	(0.5)	(0.6)
Regulatory adjustment	(0.5)	(0.4)
Net pension cost	$ (1)	$ (1)

Pension Plans and Other Postr_4

Pension Plans and Other Postretirement Benefits - Additional Information (Details)	3 Months Ended
	Dec. 31, 2021USD ($)
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Medical insurance available until age is reached after early retirement	65 years
Other Postretirement Benefits Plan
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 2,600,000
Other Postretirement Benefits Plan | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to pension plans for qualified trust	23,900,000
Other Postretirement Benefits Plan | Spire Alabama
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to pension plans for qualified trust	11,800,000
Other Postretirement Benefits Plan | Qualified Plan | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	13,700,000
Other Postretirement Benefits Plan | Nonqualified Plan | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	0
Other Postretirement Benefits Plan | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	0
Anticipated contributions to pension plans for qualified trust	0
Other Postretirement Benefits Plan | Spire Alabama
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	0
Anticipated contributions to pension plans for qualified trust	$ 0

Information by Operating Segm_3

Information by Operating Segment - Additional Information (Details) - 3 months ended Dec. 31, 2021	ReportingUnit	operating-segment
Segment Reporting [Abstract]
Number of reportable segments	2	2

Information by Operating Segm_4

Information by Operating Segment - Schedule of Operating Segment Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Operating Segment Information [Abstract]
Revenues from external customers	$ 555.4	$ 512.6
Total operating revenues	555.4	512.6
Operating Expenses:
Natural gas	249.2	181.2
Operation and maintenance	116.4	111.6
Depreciation and amortization	56.9	50.8
Taxes, other than income taxes	37.6	36.1
Total Operating Expenses	460.1	379.7
Operating Income	95.3	132.9
Net Economic Earnings (Loss)	62.6	76.9
Total Assets	9,650.5	8,515.6	$ 9,356.4
Eliminations
Operating Segment Information [Abstract]
Total operating revenues	(12.6)	(27.1)
Operating Expenses:
Natural gas	(9)	(23.8)
Operation and maintenance	(3.6)	(3.3)
Total Operating Expenses	(12.6)	(27.1)
Total Assets	(1,073.6)	(1,083.8)	(1,076.8)
Other
Operating Segment Information [Abstract]
Revenues from external customers	4	4.7
Intersegment revenues	12.6	12
Total operating revenues	16.6	16.7
Operating Expenses:
Operation and maintenance	10	8.6
Depreciation and amortization	2	1.9
Taxes, other than income taxes	0.6	0.4
Total Operating Expenses	12.6	10.9
Operating Income	4	5.8
Net Economic Earnings (Loss)	(5.1)	(2.8)
Total Assets	2,417.6	2,462.3	2,351.7
Gas Utility
Operating Segment Information [Abstract]
Revenues from external customers	503.5	497.2
Intersegment revenues		1
Gas Utility | Operating Segments
Operating Segment Information [Abstract]
Total operating revenues	503.5	498.2
Operating Expenses:
Natural gas	210.2	204.3
Operation and maintenance	107.3	103
Depreciation and amortization	54.6	48.6
Taxes, other than income taxes	37	35.5
Total Operating Expenses	409.1	391.4
Operating Income	94.4	106.8
Net Economic Earnings (Loss)	67.2	76.4
Total Assets	7,882.1	6,932.3	7,615.4
Gas Marketing
Operating Segment Information [Abstract]
Revenues from external customers	47.9	10.7
Intersegment revenues		14.1
Gas Marketing | Operating Segments
Operating Segment Information [Abstract]
Total operating revenues	47.9	24.8
Operating Expenses:
Natural gas	48	0.7
Operation and maintenance	2.7	3.3
Depreciation and amortization	0.3	0.3
Taxes, other than income taxes		0.2
Total Operating Expenses	51	4.5
Operating Income	(3.1)	20.3
Net Economic Earnings (Loss)	0.5	3.3
Total Assets	$ 424.4	$ 204.8	$ 466.1

Information by Operating Segm_5

Information by Operating Segment - Reconciliation of Consolidated Net Economic Earnings to Consolidated Net Income (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting [Abstract]
Net Income	$ 55.7	$ 88.9
Fair value and timing adjustments	3.7	(16)
Income tax adjustments	3.2	4
Net Economic Earnings	$ 62.6	$ 76.9

Commitments and Contingencies -

Commitments and Contingencies - Additional Information - Commitments (Details) $ in Millions	3 Months Ended
	Dec. 31, 2021USD ($)
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 1,840.4
Spire Missouri
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	1,422.4
Spire Alabama
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 310.3

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information - Contingencies (Details)	Dec. 31, 2021site
Spire Missouri East
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP) sites in Missouri	3
Number of sites enrolled in Brownfields/Voluntary clean up program	2
Spire Missouri West | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)	6
Spire Alabama
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)	9
Number of former manufactured gas distribution	5
Spire Alabama | Current Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)	4
Number of former manufactured gas distribution	1