Spire Alabama 10-Q 1 May 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2019	Apr. 29, 2019
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 Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		50,745,880
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	SR
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		24,577
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	SR
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
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 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 Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	SR
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Operating Revenues:
Gas Utility	$ 776.7	$ 790.6	$ 1,350.5	$ 1,332.5
Gas Marketing and other	26.8	22.8	55	42.7
Total Operating Revenues	803.5	813.4	1,405.5	1,375.2
Gas Utility
Natural and propane gas	337.4	383.7	589.1	624.5
Other operation and maintenance expenses	109.5	135.3	212	234.3
Depreciation and amortization	44.4	41.1	88.1	81.4
Taxes, other than income taxes	57.4	58	96.6	94.7
Total Gas Utility Operating Expenses	548.7	618.1	985.8	1,034.9
Gas Marketing and other	45.3	45.2	105.1	86.2
Total Operating Expenses	594	663.3	1,090.9	1,121.1
Operating Income	209.5	150.1	314.6	254.1
Other Income (Expense), Net	6.1	(7.6)	8.9	(4.3)
Interest Charges:
Interest on long-term debt	21.5	21	41.9	41.7
Other interest charges	6.1	4.4	11.6	8.1
Total Interest Charges	27.6	25.4	53.5	49.8
Income Before Income Taxes	188	117.1	270	200
Income Tax Expense (Benefit)	33.4	18.9	48.1	(14.2)
Net Income (Loss)	$ 154.6	$ 98.2	$ 221.9	$ 214.2
Weighted Average Number of Shares Outstanding:
Basic	50.6	48.2	50.6	48.2
Diluted	50.8	48.4	50.8	48.4
Basic Earnings Per Share	$ 3.05	$ 2.03	$ 4.37	$ 4.43
Diluted Earnings Per Share	$ 3.04	$ 2.03	$ 4.36	$ 4.42
Spire Alabama
Operating Revenues:
Gas Utility	$ 180.4	$ 218.3	$ 313.9	$ 339.1
Total Operating Revenues	180.4	218.3	313.9	339.1
Gas Utility
Natural and propane gas	41.1	78.5	100.6	127.5
Other operation and maintenance expenses	33.4	35.2	67.8	68
Depreciation and amortization	13.7	13.1	27.3	25.9
Taxes, other than income taxes	12.6	14.4	21.5	22.6
Total Operating Expenses	100.8	141.2	217.2	244
Operating Income	79.6	77.1	96.7	95.1
Other Income (Expense), Net	1.5	1.6	3.3	3
Interest Charges:
Interest on long-term debt	4.4	3.5	8	6.4
Other interest charges	1	0.9	2.5	2
Total Interest Charges	5.4	4.4	10.5	8.4
Income Before Income Taxes	75.7	74.3	89.5	89.7
Income Tax Expense (Benefit)	19	18.7	22.5	83.7
Net Income (Loss)	$ 56.7	$ 55.6	$ 67	$ 6

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Net Income	$ 154.6	$ 98.2	$ 221.9	$ 214.2
Cash flow hedging derivative instruments:
Net hedging (loss) gain arising during the period	(7.7)	1.8	(18.1)	1.9
Reclassification adjustment for gains included in net income	(0.4)	(0.4)	(0.7)	(0.8)
Net unrealized (loss) gain on cash flow hedging derivative instruments	(8.1)	1.4	(18.8)	1.1
Net gain on defined benefit pension and other postretirement plans	0.1		0.1	0.1
Net unrealized gain (loss) on available for sale securities	0.1		0.1	(0.1)
Other Comprehensive (Loss) Income, Before Tax	(7.9)	1.4	(18.6)	1.1
Income Tax (Benefit) Expense Related to Items of Other Comprehensive (Loss) Income	(1.9)	0.3	(4.4)	0.2
Other Comprehensive (Loss) Income, Net of Tax	(6)	1.1	(14.2)	0.9
Comprehensive Income	148.6	99.3	207.7	215.1
Operating Revenues:
Gas Utility	776.7	790.6	1,350.5	1,332.5
Total Operating Revenues	803.5	813.4	1,405.5	1,375.2
Gas Utility
Natural and propane gas	337.4	383.7	589.1	624.5
Other operation and maintenance expenses	109.5	135.3	212	234.3
Depreciation and amortization	44.4	41.1	88.1	81.4
Taxes, other than income taxes	57.4	58	96.6	94.7
Total Operating Expenses	594	663.3	1,090.9	1,121.1
Operating Income	209.5	150.1	314.6	254.1
Other Income (Expense), Net	6.1	(7.6)	8.9	(4.3)
Interest Charges:
Interest on long-term debt	21.5	21	41.9	41.7
Other interest charges	6.1	4.4	11.6	8.1
Total Interest Charges	27.6	25.4	53.5	49.8
Income Before Income Taxes	188	117.1	270	200
Income Tax Expense (Benefit)	33.4	18.9	48.1	(14.2)
Net Income (Loss)	154.6	98.2	221.9	214.2
Spire Missouri
Net Income	80	38.4	131.2	127.8
Cash flow hedging derivative instruments:
Other Comprehensive (Loss) Income, Net of Tax		(0.1)		(0.1)
Comprehensive Income	80	38.3	131.2	127.7
Operating Revenues:
Gas Utility	556.6	533.2	969.8	925.5
Total Operating Revenues	556.6	533.2	969.8	925.5
Gas Utility
Natural and propane gas	313.8	311.2	537.2	517.4
Other operation and maintenance expenses	70.7	94	133.8	154.1
Depreciation and amortization	27.8	25.2	55	50
Taxes, other than income taxes	41.9	41.2	70	67.4
Total Operating Expenses	454.2	471.6	796	788.9
Operating Income	102.4	61.6	173.8	136.6
Other Income (Expense), Net	2.5	(9.9)	1.8	(8.9)
Interest Charges:
Interest on long-term debt	10	9.8	19.4	19.7
Other interest charges	3.2	2.1	5.9	3.8
Total Interest Charges	13.2	11.9	25.3	23.5
Income Before Income Taxes	91.7	39.8	150.3	104.2
Income Tax Expense (Benefit)	11.7	1.4	19.1	(23.6)
Net Income (Loss)	$ 80	$ 38.4	$ 131.2	$ 127.8

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
ASSETS
Utility Plant	$ 5,856.8	$ 5,653.3	$ 5,403.4
Less: Accumulated depreciation and amortization	1,738.5	1,682.8	1,645
Net Utility Plant	4,118.3	3,970.5	3,758.4
Non-utility Property (net of accumulated depreciation and amortization of $11.9, $10.4 and $9.1 at March 31, 2019, September 30, 2018, and March 31, 2018, respectively)	329.1	174.5	116.9
Goodwill	1,171.6	1,171.6	1,171.6
Other Investments	68.4	68.7	66.4
Total Other Property and Investments	1,569.1	1,414.8	1,354.9
Current Assets:
Cash and cash equivalents	11.1	4.4	17.8
Accounts receivable:
Utility	318.6	151.9	302.4
Other	196.5	167.3	111.3
Allowance for doubtful accounts	(28.1)	(22.4)	(25.7)
Delayed customer billings	43.8	6.9	45.6
Inventories:
Natural gas	91.3	175.2	94.3
Propane gas	10.7	12	12
Materials and supplies	24.3	23.1	22.2
Natural gas receivable	0.3	1.8	3
Derivative instrument assets	24.5	13.3	7.3
Regulatory assets	75.3	72.8	97.7
Prepayments	21	31	18.3
Other	4.3	22.3	12.1
Total Current Assets	793.6	659.6	718.3
Deferred Charges and Other Assets:
Regulatory assets	659.9	669.8	673.6
Other	132.7	128.9	81.6
Total Deferred Charges and Other Assets	792.6	798.7	755.2
Total Assets	7,273.6	6,843.6	6,586.8
Capitalization:
Common stock (par value $1.00 per share; 70.0 million shares authorized; 50.7 million, 50.7 million and 48.4 million shares issued and outstanding at March 31, 2019, September 30, 2018, and March 31, 2018, respectively)	50.7	50.7	48.4
Paid-in capital and common stock	1,485.6	1,482.7	1,327.3
Retained earnings	877.5	715.6	773.7
Accumulated other comprehensive (loss) income	(7.8)	6.4	4.1
Total Shareholders' Equity	2,406	2,255.4	2,153.5
Redeemable noncontrolling interest	0	7.9	6.5
Long-term debt (less current portion)	2,041.9	1,900.1	2,073.9
Total Capitalization	4,447.9	4,163.4	4,233.9
Current Liabilities:
Current portion of long-term debt	215	175.5	105.5
Notes payable	512	553.6	391.7
Accounts payable	324.8	290.1	194.8
Advance customer billings	6.5	22.7	8.1
Wages and compensation accrued	32.2	39.7	30
Dividends payable	31.1	30	28.3
Customer deposits	36.7	35.5	36.1
Interest accrued	18.9	15.2	15.8
Taxes accrued	50.9	65.4	49.1
Regulatory liabilities	35.3	35.7	22.2
Other	73.3	58.3	46.4
Total Current Liabilities	1,336.7	1,321.7	928
Deferred Credits and Other Liabilities:
Deferred income taxes	490.2	435.8	465.6
Pension and postretirement benefit costs	178.3	180.2	233.4
Asset retirement obligations	325.5	321.1	302.8
Regulatory liabilities	431.3	354.6	353.1
Other	63.7	66.8	70
Total Deferred Credits and Other Liabilities	1,489	1,358.5	1,424.9
Commitments and Contingencies (Note 11)
Total Capitalization and Liabilities	7,273.6	6,843.6	6,586.8
Spire Missouri
ASSETS
Utility Plant	3,460.1	3,331	3,163.8
Less: Accumulated depreciation and amortization	736.7	705.8	687.2
Net Utility Plant	2,723.4	2,625.2	2,476.6
Goodwill	210.2	210.2	210.2
Other Investments	52.8	55	59
Total Other Property and Investments	263	265.2	269.2
Current Assets:
Cash and cash equivalents	6.9	2	10.2
Accounts receivable:
Utility	231.8	103.9	222.4
Associated companies	2.4	2.7	1.3
Other	18.5	16.6	26
Allowance for doubtful accounts	(21.9)	(16)	(20.7)
Delayed customer billings	43.8	6.9	45.6
Inventories:
Natural gas	53.1	127.9	60
Propane gas	10.7	12	12
Materials and supplies	14.4	13.2	13.1
Regulatory assets	30	30.7	51.7
Prepayments	11.1	19.1	10.7
Total Current Assets	400.8	319	432.3
Deferred Charges and Other Assets:
Regulatory assets	433.6	441.1	446.6
Other	53	50.8	9
Total Deferred Charges and Other Assets	486.6	491.9	455.6
Total Assets	3,873.8	3,701.3	3,633.7
Capitalization:
Paid-in capital and common stock	762.8	760.4	758.4
Retained earnings	612.8	501.1	517.3
Accumulated other comprehensive (loss) income	(1.6)	(1.6)	(1.8)
Total Shareholders' Equity	1,374	1,259.9	1,273.9
Long-term debt (less current portion)	924.7	824.4	874
Total Capitalization	2,298.7	2,084.3	2,147.9
Current Liabilities:
Current portion of long-term debt	50	50	100
Notes payable – associated companies	232.9	345.3	175.8
Accounts payable	72.6	81.7	69.2
Accounts payable – associated companies	8.1	5.8	3.6
Advance customer billings	0	9.5	0
Wages and compensation accrued	24.5	31.3	23.4
Dividends payable	0	9	13.5
Customer deposits	13	13.1	13.2
Interest accrued	8.6	7.8	8.2
Taxes accrued	27.2	32	25.2
Regulatory liabilities	24.2	16.7	2.7
Other	22.4	20.1	19.4
Total Current Liabilities	483.5	622.3	454.2
Deferred Credits and Other Liabilities:
Deferred income taxes	390.5	361	388.6
Pension and postretirement benefit costs	132.7	136.9	161.9
Asset retirement obligations	177.8	174.1	161.9
Regulatory liabilities	345.1	274.9	272.5
Other	45.5	47.8	46.7
Total Deferred Credits and Other Liabilities	1,091.6	994.7	1,031.6
Commitments and Contingencies (Note 11)
Total Capitalization and Liabilities	3,873.8	3,701.3	3,633.7
Spire Alabama
ASSETS
Utility Plant	2,032.5	1,964.3	1,885.4
Less: Accumulated depreciation and amortization	852.8	830.2	803.9
Net Utility Plant	1,179.7	1,134.1	1,081.5
Current Assets:
Cash and cash equivalents	0.1	0	0
Accounts receivable:
Utility	69.8	39.6	64.1
Associated companies	0.1	0.5	0.1
Other	8.4	8.5	6.4
Allowance for doubtful accounts	(3.8)	(3.9)	(2.7)
Inventories:
Natural gas	30.1	33.9	26.2
Materials and supplies	7.8	7.8	7.8
Regulatory assets	30.4	26.2	32.1
Prepayments	3.9	6	3.6
Other	0.2	2.4	2
Total Current Assets	147	121	139.6
Deferred Charges and Other Assets:
Regulatory assets	198.9	201.5	198.9
Deferred income taxes	79.3	101.8	100.3
Other	58.9	57.8	57.9
Total Deferred Charges and Other Assets	337.1	361.1	357.1
Total Assets	1,663.8	1,616.2	1,578.2
Capitalization:
Paid-in capital and common stock	370.9	390.9	390.9
Retained earnings	467.8	417.8	437.5
Total Shareholders' Equity	838.7	808.7	828.4
Long-term debt (less current portion)	372.1	322.6	322.5
Total Capitalization	1,210.8	1,131.3	1,150.9
Current Liabilities:
Current portion of long-term debt	40	0	0
Notes payable – associated companies	73.7	142.5	82.3
Accounts payable	54.6	48.4	42.9
Accounts payable – associated companies	3.1	2.1	1.5
Advance customer billings	5.3	13.1	7.9
Wages and compensation accrued	5.3	6.7	5.3
Customer deposits	20.5	18.6	19
Interest accrued	5.4	3.9	4.1
Taxes accrued	21.2	28.3	21.9
Regulatory liabilities	6.1	7.6	10.8
Other	4.6	3.2	2.4
Total Current Liabilities	239.8	274.4	198.1
Deferred Credits and Other Liabilities:
Pension and postretirement benefit costs	37.4	35	55.3
Asset retirement obligations	138.6	135.7	131.1
Regulatory liabilities	30.5	31.3	35
Other	6.7	8.5	7.8
Total Deferred Credits and Other Liabilities	213.2	210.5	229.2
Commitments and Contingencies (Note 11)
Total Capitalization and Liabilities	$ 1,663.8	$ 1,616.2	$ 1,578.2

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2018
ASSETS
Non-utility property, accumulated depreciation and amortization	$ 11.9		$ 10.4	$ 9.1
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)	50,700,000		50,700,000	48,400,000
Common stock, outstanding (in shares)	50,700,000		50,700,000	48,400,000
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

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Spire Missouri	Spire Alabama	Common Stock Outstanding	Common Stock OutstandingSpire Missouri	Common Stock OutstandingSpire Alabama	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, 2017	$ 1,991.3	$ 1,171	$ 867.4	$ 48.3	$ 0.1	$ 0	$ 1,325.6	$ 756.1	$ 420.9	$ 614.2	$ 416.5	$ 446.5	$ 3.2		$ (1.7)
BALANCE (in shares) at Sep. 30, 2017				48,263,243	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	116	89.4	(49.6)							116	89.4	(49.6)
Dividend reinvestment plan	0.3						0.3
Dividend reinvestment plan (in shares)				4,618
Stock-based compensation costs	1.9	1.1					1.9	1.1
Stock issued under stock-based compensation plans				$ 0.1			(0.1)
Stock issued under stock-based compensation plans (in shares)				105,434
Employees’ tax withholding for stock-based compensation	(2.9)			$ (0.1)			(2.8)
Employee's tax withholding for stock-based compensation (in shares)				(33,581)
Dividends declared	(27.2)	(13.5)	(7.5)							(27.2)	(13.5)	(7.5)
Other comprehensive loss, net of tax	(0.2)												(0.2)
BALANCE at Dec. 31, 2017	2,079.2	1,248	810.3	$ 48.3	$ 0.1		1,324.9	757.2	420.9	703	492.4	389.4	3		(1.7)
BALANCE (in shares) at Dec. 31, 2017				48,339,714	24,577	1,972,052
BALANCE at Sep. 30, 2017	1,991.3	1,171	867.4	$ 48.3	$ 0.1	$ 0	1,325.6	756.1	420.9	614.2	416.5	446.5	3.2		(1.7)
BALANCE (in shares) at Sep. 30, 2017				48,263,243	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	214.2	127.8	6
Other comprehensive loss, net of tax	0.9	(0.1)
BALANCE at Mar. 31, 2018	2,153.5	1,273.9	828.4	$ 48.4	$ 0.1		1,327.3	758.3	390.9	773.7	517.3	437.5	4.1		(1.8)
BALANCE (in shares) at Mar. 31, 2018				48,354,779	24,577	1,972,052
BALANCE at Dec. 31, 2017	2,079.2	1,248	810.3	$ 48.3	$ 0.1		1,324.9	757.2	420.9	703	492.4	389.4	3		(1.7)
BALANCE (in shares) at Dec. 31, 2017				48,339,714	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	98.2	38.4	55.6							98.2	38.4	55.6
Dividend reinvestment plan	0.5						0.5
Dividend reinvestment plan (in shares)				6,385
Stock-based compensation costs	1.9	1.1					1.9	1.1
Stock issued under stock-based compensation plans (in shares)				8,680
Employees’ tax withholding for stock-based compensation	0.1			$ 0.1
Dividends declared	(27.5)	(13.5)	(7.5)							(27.5)	(13.5)	(7.5)
Other comprehensive loss, net of tax	1.1	(0.1)											1.1		(0.1)
BALANCE at Mar. 31, 2018	2,153.5	1,273.9	828.4	$ 48.4	$ 0.1		1,327.3	758.3	390.9	773.7	517.3	437.5	4.1		(1.8)
BALANCE (in shares) at Mar. 31, 2018				48,354,779	24,577	1,972,052
Stockholders' Equity Rollforward
Return of capital to Spire			(30)						(30)
BALANCE at Sep. 30, 2018	2,255.4	1,259.9	808.7	$ 50.7	$ 0.1		1,482.7	760.3	390.9	715.6	501.1	417.8	6.4		(1.6)
BALANCE (in shares) at Sep. 30, 2018				50,671,903	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	67.3	51.2	10.3							67.3	51.2	10.3
Dividend reinvestment plan	0.4						0.4
Dividend reinvestment plan (in shares)				5,063
Stock-based compensation costs	2	1.2					2	1.2
Stock issued under stock-based compensation plans				$ 0.1			(0.1)
Stock issued under stock-based compensation plans (in shares)				74,835
Employees’ tax withholding for stock-based compensation	(2.3)			$ (0.1)			(2.2)
Employee's tax withholding for stock-based compensation (in shares)				(27,633)
Dividends declared	(30)	(9.8)	(8.5)							(30)	(9.8)	(8.5)
Other comprehensive loss, net of tax	(8.2)												(8.2)
BALANCE at Dec. 31, 2018	2,284.6	1,302.5	810.5	$ 50.7	$ 0.1		1,482.8	761.5	390.9	752.9	542.5	419.6	(1.8)		(1.6)
BALANCE (in shares) at Dec. 31, 2018				50,724,168	24,577	1,972,052
BALANCE at Sep. 30, 2018	2,255.4	1,259.9	808.7	$ 50.7	$ 0.1		1,482.7	760.3	390.9	715.6	501.1	417.8	6.4		(1.6)
BALANCE (in shares) at Sep. 30, 2018				50,671,903	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	221.9	131.2	67
Other comprehensive loss, net of tax	(14.2)
BALANCE at Mar. 31, 2019	2,406	1,374	838.7	$ 50.7	$ 0.1		1,485.6	762.7	370.9	877.5	612.8	467.8	(7.8)		(1.6)
BALANCE (in shares) at Mar. 31, 2019				50,742,637	24,577	1,972,052
BALANCE at Dec. 31, 2018	2,284.6	1,302.5	810.5	$ 50.7	$ 0.1		1,482.8	761.5	390.9	752.9	542.5	419.6	(1.8)		(1.6)
BALANCE (in shares) at Dec. 31, 2018				50,724,168	24,577	1,972,052
Stockholders' Equity Rollforward
Net income (loss)	154.6	80	56.7							154.6	80	56.7
Dividend reinvestment plan	0.4						0.4
Dividend reinvestment plan (in shares)				6,204
Stock-based compensation costs	2.4	1.2					2.4	1.2
Stock issued under stock-based compensation plans (in shares)				12,633
Employee's tax withholding for stock-based compensation (in shares)				(368)
Dividends declared	(30)	(9.7)	(8.5)							(30)	(9.7)	(8.5)
Other comprehensive loss, net of tax	(6)												(6)
BALANCE at Mar. 31, 2019	$ 2,406	$ 1,374	838.7	$ 50.7	$ 0.1		$ 1,485.6	$ 762.7	370.9	$ 877.5	$ 612.8	$ 467.8	$ (7.8)		$ (1.6)
BALANCE (in shares) at Mar. 31, 2019				50,742,637	24,577	1,972,052
Stockholders' Equity Rollforward
Return of capital to Spire			$ (20)						$ (20)
[1]	Accumulated other comprehensive income (loss)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Statement Of Stockholders Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.5925	$ 0.5925	$ 0.5625	$ 0.5625

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities:
Net Income	$ 221.9	$ 214.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	89.1	81.9
Deferred income taxes and investment tax credits	45.5	(15.2)
Changes in assets and liabilities:
Accounts receivable	(194.3)	(122.8)
Inventories	83.9	97.3
Regulatory assets and liabilities	105.9	149.5
Accounts payable	33.6	(50)
Delayed/advance customer billings, net	(53.2)	(66)
Taxes accrued	(12.9)	(11.9)
Other assets and liabilities	(20.6)	(8.9)
Other	(1.4)	41.5
Net cash provided by operating activities	297.5	309.6
Investing Activities:
Capital expenditures	(376.8)	(215.8)
Business acquisitions	(7.9)	(17.1)
Other	(1.9)	(0.4)
Net cash used in investing activities	(386.6)	(233.3)
Financing Activities:
Issuance of long-term debt	190	75
Repayment of long-term debt	(9.1)	0
Repayment of short-term debt, net	(41.6)	(85.6)
Issuance of common stock	1	0.8
Dividends paid	(58.8)	(53)
Other	(2.7)	(3.1)
Net cash provided by (used in) financing activities	78.8	(65.9)
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	(10.3)	10.4
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	21.4	7.4
Cash and Cash Equivalents at End of Period	11.1	17.8
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(49)	(47.2)
Income taxes	(2)	(0.6)
Cash and Cash Equivalents at Beginning of Period	4.4
Cash and Cash Equivalents at End of Period	11.1	17.8
Spire Missouri
Operating Activities:
Net Income	131.2	127.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	55	50
Deferred income taxes and investment tax credits	19.1	(23.6)
Changes in assets and liabilities:
Accounts receivable	(123.5)	(123.2)
Inventories	74.9	76.4
Regulatory assets and liabilities	107.3	111.7
Accounts payable	11.1	(10.8)
Delayed/advance customer billings, net	(46.4)	(55.5)
Taxes accrued	(4.8)	(8.9)
Other assets and liabilities	(14.4)	(6.7)
Other	2.6	40.9
Net cash provided by operating activities	212.1	178.1
Investing Activities:
Capital expenditures	(167.1)	(129.6)
Other	0.8	(0.1)
Net cash used in investing activities	(166.3)	(129.7)
Financing Activities:
Issuance of long-term debt	100	0
(Repayments to) borrowings from Spire - net	(112.4)	(27.2)
Dividends paid	(28.5)	(13.5)
Net cash provided by (used in) financing activities	(40.9)	(40.7)
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(23.8)	(22.8)
Income taxes	0	0
Net Increase (Decrease) in Cash and Cash Equivalents	4.9	7.7
Cash and Cash Equivalents at Beginning of Period	2	2.5
Cash and Cash Equivalents at End of Period	6.9	10.2
Spire Alabama
Operating Activities:
Net Income	67	6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	27.3	25.9
Deferred income taxes and investment tax credits	22.5	83.7
Changes in assets and liabilities:
Accounts receivable	(33.5)	(38.6)
Inventories	3.7	6.4
Regulatory assets and liabilities	0.6	34.6
Accounts payable	4	0.3
Delayed/advance customer billings, net	(7.8)	(10.6)
Taxes accrued	(7.1)	(1.5)
Other assets and liabilities	8.9	4.3
Other	(2.4)	(0.5)
Net cash provided by operating activities	83.2	110
Investing Activities:
Capital expenditures	(65.7)	(51.8)
Other	(1.1)	(0.4)
Net cash used in investing activities	(66.8)	(52.2)
Financing Activities:
Issuance of long-term debt	90	75
(Repayments to) borrowings from Spire - net	(68.8)	(87.6)
Return of capital to Spire	(20)	(30)
Dividends paid	(17)	(15)
Other	(0.5)	(0.3)
Net cash provided by (used in) financing activities	(16.3)	(57.9)
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(8.7)	(7)
Income taxes	0	0
Net Increase (Decrease) in Cash and Cash Equivalents	0.1	(0.1)
Cash and Cash Equivalents at Beginning of Period	0	0.1
Cash and Cash Equivalents at End of Period	$ 0.1	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
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” or the “Missouri Utilities”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri and Spire Alabama are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth Inc. (“Spire EnergySouth”) are collectively referred to as the “Utilities.” The subsidiaries of Spire EnergySouth are Spire Gulf Inc. and Spire Mississippi Inc. 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 (consisting of only normal recurring 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’s, Spire Missouri’s and Spire Alabama’s combined Annual Report on Form 10-K for the fiscal year ended September 30, 2018. 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: the Missouri Utilities, serving St. Louis and eastern Missouri (“Spire Missouri East”) and Kansas City and western Missouri (“Spire Missouri West”); Spire Alabama, serving central and northern Alabama; and the subsidiaries of Spire EnergySouth, serving southern Alabama and south-central Mississippi. The Gas Marketing segment includes Spire’s primary gas-related business, Spire Marketing Inc. (“Spire Marketing”), which provides non-regulated natural gas services. The activities of other subsidiaries are reported as Other and are described in Note 10 , 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. 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 Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“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 using a gross presentation. 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. Under GAAP, revenues and expenses associated with trading activities are presented on a net basis in Gas Marketing operating revenues (or expenses, if negative) in the Condensed Consolidated Statements of Income. This net presentation has no effect on operating income or net income. REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with FASB 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 TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated statements of Spire. Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest, as reflected in their separate financial statements, and they participated in normal intercompany shared services transactions Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Purchases of natural gas from Spire Marketing $ 29.2 $ 19.3 $ 69.0 $ 41.6 Sales of natural gas to Spire Marketing — 0.2 1.4 0.3 Transportation services received from Spire NGL Inc. 0.2 0.2 0.5 0.5 ACCRUED CAPITAL EXPENDITURES – Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid. March 31, September 30, March 31, 2019 2018 2018 Spire $ 63.6 $ 62.1 $ 29.1 Spire Missouri 19.0 36.7 17.9 Spire Alabama 12.1 8.9 7.0 NEW ACCOUNTING PRONOUNCEMENTS – Spire, Spire Missouri and Spire Alabama adopted the guidance in Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , and related amendments (collectively, “ASC 606”), in the first quarter of fiscal year 2019 using the modified retrospective method applied to all contracts at October 1, 2018. The core principle of ASC 606 is that revenue should be recognized to depict the transfer of control of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Under the new standard, an entity must identify the performance obligations in a contract, determine the transaction price and allocate the price to specific performance obligations to recognize revenue when the obligation is completed. In addition, ASC 606 requires disclosure of the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The adoption of ASC 606 did not result in significant changes to how Spire, Spire Missouri and Spire Alabama recognize revenue, and therefore, no cumulative effect adjustment to the opening balance of retained earnings was required, and there was no significant impact to financial results after adoption. The adoption did result in changes to the disclosures about revenue, which are included in Note 2 , Revenue. Some revenue arrangements, such as alternative revenue programs and certain derivative contracts, are excluded from the scope of ASC 606 and, therefore, are presented separately in disclosures. Also effective October 1, 2018, Spire, Spire Missouri and Spire Alabama adopted ASU No. Compensation – Retirement Benefits : Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost The amended guidance that the of net periodic pension and postretirement benefit costs presented within line item in the income statement as other compensation costs (except for the amount being capitalized), while other components presented outside the subtotal of operating income and . The amended guidance is applied retrospectively for income statement presentation and prospectively for capitalization. The Company, Spire practical expedient permitting the use of the amounts disclosed in its pension and other postretirement benefit plan note for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements. Accordingly, for the three months ended March 31, 2018, the Company, Spire Missouri and Spire Alabama reclassified net benefit (income) costs of $8.3, $9.5 and $(1.1), respectively, from “operation and maintenance” to “other income, net” or “other income (expense), net.” The corresponding amounts for the six months ended March 31, 2018 were $7.2, $9.7 and $(2.1), respectively. The corresponding annual amounts to be reclassified for the years ended September 30, 2018, 2017 and 2016 are $14.4, $19.2 and $9.6 for the Company, respectively, $17.2, $17.2 and $11.2 for Spire Missouri, respectively, and $(2.0), $2.2 and $(1.6) for Spire Alabama, respectively. For Spire Missouri, Spire Alabama, and the Company’s other rate-regulated entities, all components of net benefit cost have historically been recovered from customers as a component of utility plant and will continue to be recovered in the same manner over the depreciable lives of the related plant assets; therefore, for those entities, the components that are no longer eligible to be capitalized as a component of plant under GAAP will be reported as regulatory assets Effective January 1, 2019, the Company, Spire Missouri and Spire Alabama adopted ASU No. Intangibles – Goodwill and Other – Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In February 2016, the FASB issued ASU No. 2016-02, Leases In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities

Revenue

Revenue	6 Months Ended
	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Revenue	The following tables show revenue disaggregated by source and customer type. Three Months Ended March 31, 2019 Six Months Ended March 31, 2019 Spire Gas Utility: Residential $ 551.3 $ 944.9 Commercial & industrial 185.9 316.2 Transportation 31.3 60.8 Off-system & other incentive 11.5 26.4 Other customer revenue 10.9 23.6 Total revenue from contracts with customers 790.9 1,371.9 Changes in accrued revenue under alternative revenue programs (14.1 ) (19.9 ) Total Gas Utility operating revenues 776.8 1,352.0 Gas Marketing: Revenue from contracts with retail customers 25.5 51.3 Revenue from wholesale derivative contracts — — Total Gas Marketing operating revenues 25.5 51.3 Other 4.3 9.7 Total before eliminations 806.6 1,413.0 Intersegment eliminations (see Note 10, Information by Operating Segment) (3.1 ) (7.5 ) Total Operating Revenues $ 803.5 $ 1,405.5 Three Months Ended March 31, 2019 Six Months Ended March 31, 2019 Spire Missouri Residential $ 410.9 $ 713.0 Commercial & industrial 129.2 218.3 Transportation 9.9 18.9 Off-system & other incentive 11.5 26.4 Other customer revenue 4.2 6.8 Total revenue from contracts with customers 565.7 983.4 Changes in accrued revenue under alternative revenue programs (9.1 ) (13.6 ) Total Operating Revenues $ 556.6 $ 969.8 Spire Alabama Residential $ 116.9 $ 192.3 Commercial & industrial 44.1 75.5 Transportation 18.8 37.0 Other customer revenue 5.3 14.9 Total revenue from contracts with customers 185.1 319.7 Changes in accrued revenue under alternative revenue programs (4.7 ) (5.8 ) Total Operating Revenues $ 180.4 $ 313.9 The Utilities sell natural gas to residential and other customers. The sale of natural gas is governed by the various state utility commissions, which set rates, charges, and terms and conditions of service, collectively included in a “tariff.” The performance obligation, which relates to the promise to provide natural gas, is satisfied over time as the customer simultaneously receives and consumes the natural gas, and revenue is recognized accordingly. The Utilities’ transportation revenue relates to the promise to transport the specified quantities of natural gas at tariff rates. This performance obligation is satisfied over time as the gas is transported, and revenue is recognized as invoiced monthly. The Utilities have alternative revenue programs (“ARPs”), which represent an agreement between the utility and its regulator, currently consisting of decoupling mechanisms (also known as weather normalization adjustments) and incentive programs (primarily Alabama’s Cost Control Measure). When the criteria to recognize additional (or reduced) revenue from ARPs have been met, the Utilities establish a regulatory asset (or liability). When amounts previously recognized for ARPs are billed, the Utilities reduce the regulatory asset (or liability) and increase (or decrease) accounts receivable. Billed amounts, which are part of the overall tariff paid by customers, are included in revenue from contracts with customers, while the change in the related regulatory asset or liability is presented as revenue from ARPs. Depending on whether the beginning accrued ARP balance was a regulatory asset or liability and depending on the size and direction of the current period accrual, the amount presented as revenue from ARPs could be negative. The Utilities read meters and bill customers on monthly cycles. The Missouri Utilities, Spire Gulf and Spire Mississippi record their gas utility revenues from gas sales and transportation services on an accrual basis that includes estimated amounts for gas delivered but not yet billed. The accruals for unbilled revenues are reversed in the subsequent accounting period when meters are actually read and customers are billed. Spire Alabama records natural gas distribution revenues in accordance with the tariff established by the APSC. Unbilled revenue is accrued in an amount equal to the related gas cost, as profit margin is not considered earned until billed. Spire’s other subsidiaries, including Spire Marketing, record revenues when earned, as the product is delivered or as services are performed. Gas Marketing’s contracts are derivatives. The wholesale contracts (with producers, municipalities, and utility companies) are subject to derivative accounting. The retail contracts (with large commercial and industrial customers) are designated as “normal purchase, normal sale” arrangements and are therefore accounted for as revenue from contracts with customers. The performance obligation is satisfied over time by the transfer of control of natural gas to the customer, and revenue is recognized as invoiced monthly. Payments are generally required within 30 days of billing, and contracts generally do not have a significant financing component. Spire’s revenues are not subject to significant returns, refunds, or warranty obligations. Spire, Spire Missouri, and Spire Alabama have elected to apply a “right to invoice” practical expedient, recognizing revenue for volumes delivered for which they have a right to invoice, as long as that amount corresponds with the value to the customer. Disclosures about remaining performance obligations are not required because either contracts have an original expected duration of one year or less, or revenue is recognized under the right to invoice practical expedient, or both. Sales taxes imposed on applicable Spire Alabama and Spire Missouri sales are billed to customers. These amounts are not recorded in the statements of income but are recorded as tax collections payable and included in the “Other” line of the Current Liabilities section of the balance sheets. 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 revenue and expense amounts are recorded gross in the “Operating Revenues” and “Taxes, other than income taxes” lines, respectively, in the statements of income. The following table presents gross receipts taxes recorded as revenues: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire $ 43.5 $ 43.6 $ 69.4 $ 66.7 Spire Missouri 32.1 30.6 50.6 46.8 Spire Alabama 9.6 11.6 15.9 17.2

Earnings Per Share

Earnings Per Share	6 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Basic Earnings Per Share: Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Less: Income allocated to participating securities 0.3 0.2 0.5 0.5 Income Available to Common Shareholders $ 154.3 $ 98.0 $ 221.4 $ 213.7 Weighted Average Shares Outstanding (in millions) 50.6 48.2 50.6 48.2 Basic Earnings Per Share $ 3.05 $ 2.03 $ 4.37 $ 4.43 Diluted Earnings Per Share: Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Less: Income allocated to participating securities 0.3 0.2 0.5 0.5 Income Available to Common Shareholders $ 154.3 $ 98.0 $ 221.4 $ 213.7 Weighted Average Shares Outstanding (in millions) 50.6 48.2 50.6 48.2 Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)* 0.2 0.2 0.2 0.2 Weighted Average Diluted Shares (in millions) 50.8 48.4 50.8 48.4 Diluted Earnings Per Share $ 3.04 $ 2.03 $ 4.36 $ 4.42 * Calculation excludes certain outstanding 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 0.3 0.4 0.3 0.4

Regulatory Matters

Regulatory Matters	6 Months Ended
	Mar. 31, 2019
Regulated Operations [Abstract]
Regulatory Matters	As explained in Note 1, Regulated Operations March 31, September 30, March 31, Spire 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 30.2 $ 30.2 $ 43.0 Unamortized purchased gas adjustments 19.3 8.2 32.6 Other 25.8 34.4 22.1 Total Current Regulatory Assets 75.3 72.8 97.7 Noncurrent: Pension and postretirement benefit costs 345.8 364.9 358.2 Cost of removal 134.6 133.4 125.0 Future income taxes due from customers 102.2 96.3 113.0 Energy efficiency 32.0 32.8 31.3 Other 45.3 42.4 46.1 Total Noncurrent Regulatory Assets 659.9 669.8 673.6 Total Regulatory Assets $ 735.2 $ 742.6 $ 771.3 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 5.8 $ 2.2 $ 2.2 Unamortized purchased gas adjustments 3.4 2.9 1.5 Other 26.1 30.6 18.5 Total Current Regulatory Liabilities 35.3 35.7 22.2 Noncurrent: Deferred taxes due to customers 155.7 178.3 170.7 Pension and postretirement benefit costs 115.3 27.8 30.8 Accrued cost of removal 53.7 63.6 71.0 Unamortized purchased gas adjustments 75.7 4.7 50.3 Other 30.9 80.2 30.3 Total Noncurrent Regulatory Liabilities 431.3 354.6 353.1 Total Regulatory Liabilities $ 466.6 $ 390.3 $ 375.3 March 31, September 30, March 31, Spire Missouri 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 21.9 $ 21.9 $ 34.9 Unamortized purchased gas adjustments 0.6 1.0 13.5 Other 7.5 7.8 3.3 Total Current Regulatory Assets 30.0 30.7 51.7 Noncurrent: Future income taxes due from customers 99.0 94.4 111.4 Pension and postretirement benefit costs 277.9 292.5 279.0 Energy efficiency 32.0 32.8 31.3 Other 24.7 21.4 24.9 Total Noncurrent Regulatory Assets 433.6 441.1 446.6 Total Regulatory Assets $ 463.6 $ 471.8 $ 498.3 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 3.6 $ — $ — Unamortized purchased gas adjustments 2.7 1.9 — Other 17.9 14.8 2.7 Total Current Regulatory Liabilities 24.2 16.7 2.7 Noncurrent: Deferred taxes due to customers 138.3 161.1 152.6 Pension and postretirement benefit costs 79.4 — — Accrued cost of removal 26.8 39.8 48.7 Unamortized purchased gas adjustments 75.7 4.7 50.3 Other 24.9 69.3 20.9 Total Noncurrent Regulatory Liabilities 345.1 274.9 272.5 Total Regulatory Liabilities $ 369.3 $ 291.6 $ 275.2 March 31, September 30, March 31, Spire Alabama 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 7.3 $ 7.3 $ 7.1 Unamortized purchased gas adjustments 18.0 6.4 19.0 Other 5.1 12.5 6.0 Total Current Regulatory Assets 30.4 26.2 32.1 Noncurrent: Pension and postretirement benefit costs 61.1 64.8 71.2 Cost of removal 134.6 133.4 125.0 Other 3.2 3.3 2.7 Total Noncurrent Regulatory Assets 198.9 201.5 198.9 Total Regulatory Assets $ 229.3 $ 227.7 $ 231.0 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 2.2 $ 2.2 $ 2.2 Other 3.9 5.4 8.6 Total Current Regulatory Liabilities 6.1 7.6 10.8 Noncurrent: Pension and postretirement benefit costs 26.5 27.8 30.8 Other 4.0 3.5 4.2 Total Noncurrent Regulatory Liabilities 30.5 31.3 35.0 Total Regulatory Liabilities $ 36.6 $ 38.9 $ 45.8 A portion of the Company’s and Spire Missouri’s regulatory assets are not earning a return, as shown in the table below: March 31, September 30, March 31, 2019 2018 2018 Spire Pension and postretirement benefit costs $ 144.7 $ 148.4 $ 185.8 Future income taxes due from customers 102.2 96.3 113.0 Other 14.8 15.1 11.0 Total Regulatory Assets Not Earning a Return $ 261.7 $ 259.8 $ 309.8 Spire Missouri Pension and postretirement benefit costs $ 144.7 $ 148.4 $ 185.8 Future income taxes due from customers 99.0 94.4 111.4 Other 14.8 15.1 11.0 Total Regulatory Assets Not Earning a Return $ 258.5 $ 257.9 $ 308.2 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 (“IRS”) guidelines and average remaining service life of active participants, respectively. 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. On March 7, 2018, the MoPSC issued its order in two general rate cases, approving new tariffs that became effective on April 19, 2018. On April 25, 2018, Spire Missouri filed an appeal of the MoPSC’s order related to the disallowance of certain pension costs incurred prior to 1997 ($28.8), real estate sold in 2014 ($1.8), and rate case expenses ($0.9) to Missouri’s Southern District Court of Appeals. On March 15, 2019, the appeal was denied by the Southern District, and Spire Missouri has requested review by the Missouri Supreme Court. In September 2016 and February 2017, Spire Missouri filed Infrastructure System Replacement Surcharge (“ISRS”) cases for both Spire Missouri East and Spire Missouri West (the “2016/2017 ISRS Cases”). The Missouri Office of the Public Counsel (“OPC”) appealed the MoPSC’s decisions approving these cases to Missouri’s Western District Court of Appeals, arguing that they contained ISRS-ineligible costs. In November 2017, the appellate court reversed the MoPSC’s decision in the 2016/2017 ISRS Cases and remanded the case back to the MoPSC. In June 2018, Spire Missouri filed to establish new ISRS rates in both its East and West divisions (the “2018 ISRS Cases”). In September 2018, the MoPSC issued a report and order finding that Spire Missouri’s ISRS petitions in the 2016/2017 ISRS Cases contained ISRS costs related to the replacement of plastic pipe components that should be removed from the requested revenue requirement; however, the MoPSC ordered that no adjustment to Spire Missouri’s revenues was necessary as the ISRS revenues approved in these cases had been rebased as part of its last general rate cases. Also in September 2018, the MoPSC issued a report and order in the 2018 ISRS Cases stating additional evidence was required to support all investments included in the Spire Missouri’s applications in order to support the recovery of costs related to the replacement of plastic pipe components and approved rates in the 2018 ISRS Cases providing annual revenues of $2.6 for Spire Missouri East and $5.4 for Spire Missouri West. Spire is appealing the removal of costs related to plastic in all cases in the Western District Court. On January 14, 2019, Spire Missouri refiled requests with additional information for approximately $3.2 of the ISRS revenues that were removed by the MoPSC in the 2018 ISRS Cases and filed new ISRS applications for both its East and West service territories. After updating the pro-forma months of December 2018 and January 2019, Spire Missouri is requesting approval of ISRS revenues of $7.4 for Spire Missouri East and $7.4 for Spire Missouri West related to investments made from July 1, 2018, through January 31, 2019. Evidentiary hearings were held in the 2019 cases in April 2019, and Spire Missouri expects an order from the MoPSC prior to the effective date. Per Missouri statute, new rates must become effective within 120 days of the application, or by May 14, 2019. As part of the annual update for Rate Stabilization and Equalization (“RSE”), on November 30, 2018, Spire Alabama filed an increase for rate year 2019 of $8.7, which became effective December 1, 2018. There was no RSE reduction for the January 31, 2019 quarterly point of test. At March 31, 2019, an estimated RSE reduction for the April 30, 2019 quarterly point of test of $3.3 was recorded to bring the expected rate of return on average common equity at the end of the year to within the allowed rate of return. On January 25, 2019, the Federal Energy Regulatory Commission (“FERC”) approved the Company’s application to combine its two adjacent natural gas storage facilities in Wyoming into one FERC certificate with a market-based tariff. On February 13, 2019, Spire Storage filed a prior notice request pursuant to the FERC’s regulations and Spire Storage’s blanket certificate authority proposing to construct and operate 10.1 miles of dual 20-inch-diameter pipeline, one new pipeline interconnection with measurement equipment, and related facilities in Uinta County, Wyoming. If authorized by the FERC, the pipeline, interconnection and measurement facilities, will allow Spire Storage to enhance the link between its two storage facilities, provide new, bi-directional access to Kern River Gas Transmission Company’s mainline and afford enhanced access with other interstate pipelines. On April 26, 2019, FERC staff filed a protest stating that Spire Storage did not provide documentation of the project’s compliance with the National Historic Preservation Act. Under the FERC’s regulations, a protested prior notice filing will be treated like a traditional application under Section 7 of the Natural Gas Act unless the protest is withdrawn within 30 days from the date upon which protests are due. Under the terms of the January 2017 Precedent Agreement between Spire STL Pipeline and Spire Missouri, if Spire STL Pipeline files with FERC to increase its initial recourse rate at any time before the pipeline’s in-service date, and if FERC approves such request in whole or in part, then Spire Missouri’s negotiated rate will automatically increase by the same percentage increase to the initial recourse rate, up to a maximum increase of two cents per dekatherm per day.

Financing Arrangements and Long

Financing Arrangements and Long-term Debt	6 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Financing Arrangements and Long-term Debt	Spire, Spire Missouri and Spire Alabama have a syndicated revolving credit facility pursuant to a loan agreement with 11 banks, expiring October 31, 2023. The loan agreement has an aggregate credit commitment of $975.0, including sublimits of $300.0 for Spire, $475.0 for Spire Missouri, and $200.0 for Spire Alabama. These sublimits may be reallocated from time to time among the three borrowers within the $975.0 aggregate commitment, with commitments fees applied for each borrower relative to its credit rating. Spire may use its line to provide for the funding needs of various subsidiaries. The agreement also contains financial covenants limiting each borrower’s consolidated total debt, including short-term debt, to no more than 70% of its total capitalization. As defined in the line of credit, on March 31, 2019, total debt was 54% of total capitalization for the consolidated Company, 47% for Spire Missouri, and 37% for Spire Alabama. There were no borrowings against this credit facility as of March 31, 2019, September 30, 2018, or March 31, 2018. Spire has 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. Information about Spire’s consolidated short-term borrowings and about Spire Missouri’s and Spire Alabama’s borrowings from Spire is presented in the following table. As of March 31, 2019, $344.6 of Spire’s short-term borrowings were used to support lending to the Utilities. Spire Commercial Paper Borrowings Spire Missouri Borrowings from Spire Spire Alabama Borrowings from Spire Six Months Ended March 31, 2019 Weighted average borrowings outstanding $598.3 $313.5 $117.3 Weighted average interest rate 2.8% 2.8% 2.8% Range of borrowings outstanding $482.5 – $689.3 $205.1 – $404.9 $43.8 – $169.2 As of March 31, 2019 Borrowings outstanding $512.0 $232.9 $73.7 Weighted average interest rate 2.8% 2.8% 2.8% As of September 30, 2018 Borrowings outstanding $553.6 $345.3 $142.5 Weighted average interest rate 2.4% 2.3% 2.3% As of March 31, 2018 Borrowings outstanding $391.7 $175.8 $82.3 Weighted average interest rate 2.2% 2.2% 2.2% The long-term debt agreements of Spire, Spire Missouri and Spire Alabama contain customary covenants and default provisions. As of March 31, 2019, there were no events of default under these covenants. Interest expense shown on Spire’s consolidated statements of income and Spire Missouri’s statements of comprehensive income is net of the capitalized interest amounts shown in the following table. Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire $ 1.4 $ 0.6 $ 2.6 $ 1.0 Spire Missouri 0.4 0.2 0.9 0.4 In October 2018, the Company settled a $10.0 non-interest-bearing note. In December 2018, Spire Missouri entered into a new loan agreement providing for a term loan of $100.0, which was fully funded on December 3, 2018, and which matures on December 1, 2021, subject to optional prepayment by Spire Missouri. Borrowings under the loan agreement bear interest at a rate determined by reference to the London Interbank Offered Rate (LIBOR), plus a margin based on Spire Missouri’s senior debt rating as determined by Standard & Poor’s Rating Services or Moody’s Investors Services, Inc. On January 15, 2019, Spire Alabama entered into the Second Supplement to Master Note Purchase Agreement with certain institutional investors. Pursuant to the terms of that supplement, Spire Alabama issued and sold to those institutional investors in a private placement $90.0 of 4.64% Series 2019A Senior Notes due January 15, 2049. The notes bear interest from the date of issuance, payable semi-annually on the 15th day of July and January of each year, commencing on July 15, 2019. The notes are senior unsecured obligations of Spire Alabama, rank equal in right to payment with all its other senior unsecured indebtedness, and have make-whole and par call options. Spire Alabama used the proceeds to repay short-term debt and for general corporate purposes.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	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 March 31, 2019, September 30, 2018, or March 31, 2018. The carrying amounts of cash and cash equivalents 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 Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Spire As of March 31, 2019 Cash and cash equivalents $ 11.1 $ 11.1 $ 11.1 $ — Notes payable 512.0 512.0 — 512.0 Long-term debt, including current portion 2,256.9 2,319.9 — 2,319.9 As of September 30, 2018 Cash and cash equivalents $ 4.4 $ 4.4 $ 4.4 $ — Notes payable 553.6 553.6 — 553.6 Long-term debt, including current portion 2,075.6 2,074.0 — 2,074.0 As of March 31, 2018 Cash and cash equivalents $ 17.8 $ 17.8 $ 17.8 $ — Notes payable 391.7 391.7 — 391.7 Long-term debt, including current portion 2,179.4 2,241.3 — 2,241.3 Spire Missouri As of March 31, 2019 Cash and cash equivalents $ 6.9 $ 6.9 $ 6.9 $ — Notes payable – 232.9 232.9 — 232.9 Long-term debt, including current portion 974.7 1,036.9 — 1,036.9 As of September 30, 2018 Cash and cash equivalents $ 2.0 $ 2.0 $ 2.0 $ — Notes payable – 345.3 345.3 — 345.3 Long-term debt, including current portion 874.4 906.6 — 906.6 As of March 31, 2018 Cash and cash equivalents $ 10.2 $ 10.2 $ 10.2 $ — Notes payable – 175.8 175.8 — 175.8 Long-term debt, including current portion 974.0 1,033.6 — 1,033.6 Spire Alabama As of March 31, 2019 Cash and cash equivalents $ 0.1 $ 0.1 $ 0.1 $ — Notes payable – 73.7 73.7 — 73.7 Long-term debt, including current portion 412.1 423.8 — 423.8 As of September 30, 2018 Notes payable – $ 142.5 $ 142.5 $ — $ 142.5 Long-term debt 322.6 321.7 — 321.7 As of March 31, 2018 Notes payable – $ 82.3 $ 82.3 $ — $ 82.3 Long-term debt 322.5 332.7 — 332.7

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
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. The mutual funds included in Level 2 are valued based on the closing net asset value per unit. 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. The Level 3 balances as of March 31, 2019, September 30, 2018, and March 31, 2018, consisted of gas commodity contracts. 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 March 31, 2019 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 19.7 $ — $ — $ — $ 19.7 NYMEX/ICE natural gas contracts 2.5 — — (2.5 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 7.1 — (4.3 ) 3.0 Natural gas commodity contracts — 30.4 — (3.4 ) 27.0 Other: U.S. stock/bond mutual funds 11.9 — — — 11.9 Total $ 34.3 $ 37.5 $ — $ (10.2 ) $ 61.6 LIABILITIES Gas Marketing: NYMEX/ICE natural gas contracts $ 0.4 $ 4.1 $ - $ (4.5 ) $ - Natural gas commodity contracts — 18.9 0.2 (3.5 ) 15.6 Other: Interest rate swaps — 15.2 — — 15.2 Total $ 0.4 $ 38.2 $ 0.2 $ (8.0 ) $ 30.8 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, 2018 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 20.3 $ — $ — $ — $ 20.3 NYMEX/ICE natural gas contracts 2.7 — — (2.7 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 4.0 — (4.2 ) — Natural gas commodity contracts — 17.5 — (1.5 ) 16.0 Other: U.S. stock/bond mutual funds 8.9 — — — 8.9 Interest rate swaps — 3.0 — — 3.0 Total $ 32.1 $ 24.5 $ — $ (8.4 ) $ 48.2 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 1.9 $ — $ — $ (1.9 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts 0.9 10.5 — (11.4 ) — Natural gas commodity contracts — 7.5 0.2 (1.5 ) 6.2 Total $ 2.8 $ 18.0 $ 0.2 $ (14.8 ) $ 6.2 As of March 31, 2018 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 19.1 $ 4.1 $ — $ — $ 23.2 NYMEX/ICE natural gas contracts 0.1 — — (0.1 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 3.3 — (3.5 ) — Natural gas commodity contracts — 7.4 0.1 (2.1 ) 5.4 Other: Interest rate swaps — 1.0 — — 1.0 Total $ 19.4 $ 15.8 $ 0.1 $ (5.7 ) $ 29.6 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 0.2 $ — $ — $ (0.2 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts 0.6 9.8 — (10.4 ) — Natural gas commodity contracts — 14.3 — (2.1 ) 12.2 Total $ 0.8 $ 24.1 $ — $ (12.7 ) $ 12.2 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 March 31, 2019 ASSETS U.S. stock/bond mutual funds $ 19.7 $ — $ — $ — $ 19.7 NYMEX/ICE natural gas contracts 2.5 — — (2.5 ) — Total $ 22.2 $ — $ — $ (2.5 ) $ 19.7 As of September 30, 2018 ASSETS U.S. stock/bond mutual funds $ 20.3 $ — $ — $ — $ 20.3 NYMEX/ICE natural gas contracts 2.7 — — (2.7 ) — Total $ 23.0 $ — $ — $ (2.7 ) $ 20.3 LIABILITIES NYMEX/ICE natural gas contracts $ 1.9 $ — $ — $ (1.9 ) $ — As of March 31, 2018 ASSETS U.S. stock/bond mutual funds $ 19.1 $ 4.1 $ — $ — $ 23.2 NYMEX/ICE natural gas contracts 0.1 — — (0.1 ) — Total $ 19.2 $ 4.1 $ — $ (0.1 ) $ 23.2 LIABILITIES NYMEX/ICE natural gas contracts $ 0.2 $ — $ — $ (0.2 ) $ — Spire Alabama Spire Alabama occasionally utilizes a gasoline derivative program to stabilize the cost of fuel used in operations. As of March 31, 2019, September 30, 2018, and March 31, 2018, Spire Alabama had no outstanding derivative contracts.

Concentration of Credit Risk

Concentration of Credit Risk	6 Months Ended
	Mar. 31, 2019
Risks And Uncertainties [Abstract]
Concentration of Credit Risk	Other than in Spire Marketing, Spire has no significant concentrations of credit risk. A significant portion of Spire Marketing’s transactions are with (or are associated with) energy producers, utility companies, and pipelines. The concentration of transactions with these counterparties has the potential to affect the Company’s overall exposure to credit risk, either positively or negatively, in that each of these three groups may be affected similarly by changes in economic, industry, or other conditions. To manage this risk, as well as credit risk from significant counterparties in these and other industries, Spire Marketing has established procedures to determine the creditworthiness of its counterparties. These procedures include obtaining credit ratings and credit reports, analyzing counterparty financial statements to assess financial condition, and considering the industry environment in which the counterparty operates. This information is monitored on an ongoing basis. In some instances, Spire Marketing may require credit assurances such as prepayments, letters of credit, or parental guarantees. In addition, Spire Marketing may enter into netting arrangements to mitigate credit risk with counterparties in the energy industry with whom it conducts both sales and purchases of natural gas. Sales are typically made on an unsecured credit basis with payment due the month following delivery. Accounts receivable amounts are closely monitored and provisions for uncollectible amounts are accrued when losses are probable. Spire Marketing records accounts receivable, accounts payable, and prepayments for physical sales and purchases of natural gas on a gross basis. The amount included in its accounts receivable attributable to energy producers and their marketing affiliates totaled $18.1 at March 31, 2019 ($7.3 reflecting netting arrangements). Spire Marketing’s accounts receivable attributable to utility companies and their marketing affiliates totaled $94.8 at March 31, 2019 ($84.0 reflecting netting arrangements). Spire Marketing also has concentrations of credit risk with pipeline companies associated with its natural gas receivable and with certain individually significant counterparties. At March 31, 2019, the amounts included in accounts receivable from its five largest counterparties (in terms of net accounts receivable exposure) totaled $31.5 ($27.3 reflecting netting arrangements). Four of these five counterparties are investment-grade rated companies. The fifth is not rated but is a subsidiary of an investment-grade rated company.

Pension Plans and Other Postret

Pension Plans and Other Postretirement Benefits	6 Months Ended
	Mar. 31, 2019
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Pension Plans and Other Postretirement Benefits	Pension Plans Spire and the Utilities maintain pension plans for their employees. The Missouri Utilities have non-contributory, defined benefit, trusteed forms of pension plans covering the majority of their employees. Plan assets consist primarily of corporate and United States (“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 included the following components: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire Service cost – benefits earned during the period $ 4.9 $ 5.2 $ 9.7 $ 10.4 Interest cost on projected benefit obligation* 7.0 6.9 14.1 13.8 Expected return on plan assets* (8.9 ) (9.5 ) (18.0 ) (19.2 ) Amortization of prior service credit* (0.3 ) (0.2 ) (0.6 ) (0.5 ) Amortization of actuarial loss* 2.3 2.9 4.6 6.0 Loss on lump-sum settlements* — 9.4 — 9.4 Subtotal 5.0 14.7 9.8 19.9 Regulatory adjustment 9.8 24.0 19.7 28.3 Net pension cost $ 14.8 $ 38.7 $ 29.5 $ 48.2 Spire Missouri Service cost – benefits earned during the period $ 3.1 $ 3.2 $ 6.2 $ 6.5 Interest cost on projected benefit obligation* 4.9 4.9 9.9 9.8 Expected return on plan assets* (6.3 ) (7.0 ) (12.7 ) (14.2 ) Amortization of prior service cost* 0.2 0.2 0.4 0.4 Amortization of actuarial loss* 2.2 2.5 4.3 5.1 Loss on lump-sum settlements* — 9.4 — 9.4 Subtotal 4.1 13.2 8.1 17.0 Regulatory adjustment 7.9 21.9 15.9 24.3 Net pension cost $ 12.0 $ 35.1 $ 24.0 $ 41.3 Spire Alabama Service cost – benefits earned during the period $ 1.6 $ 1.7 $ 3.1 $ 3.3 Interest cost on projected benefit obligation* 1.5 1.4 3.0 2.8 Expected return on plan assets* (1.8 ) (1.7 ) (3.6 ) (3.4 ) Amortization of prior service credit* (0.5 ) (0.4 ) (0.9 ) (0.9 ) Amortization of actuarial loss* 0.2 0.4 0.4 0.9 Subtotal 1.0 1.4 2.0 2.7 Regulatory adjustment 1.7 1.9 3.4 3.6 Net pension cost $ 2.7 $ 3.3 $ 5.4 $ 6.3 * Denotes pension expense line items that are recorded below the operating income line in the income statements, in the line items “Other Income, Net” or “Other Income (Expense), Net.” Pursuant to the provisions of the Missouri Utilities’ 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 gains or losses. For the second quarter and first six months of fiscal 2019, no pension plans met the criteria for settlement recognition. In the quarter ended March 31, 2018, the two Spire Missouri plans met the criteria for settlement recognition, resulting in the remeasurement of the obligation of the plans using updated census data and assumptions for discount and mortality. For these plans the total lump-sum payments recognized as settlements for plan remeasurement was $39.5 and the lump-sum settlements resulted in losses of $9.4. As part of the remeasurement, the discount rate on the one Missouri plan was updated to 4.0% from 3.75%, while the other Missouri plan had its discount rate updated to 4.0% from 3.70%. 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 2019 contributions to Spire Missouri’s pension plans through March 31, 2019 were $8.5 to the qualified trusts and none to non-qualified plans. There were no fiscal 2019 contributions to the Spire Alabama pension plans through March 31, 2019. Contributions to the qualified trusts of the Missouri Utilities’ pension plans for the remainder of fiscal 2019 are anticipated to be $18.2. No material contributions to Spire Alabama’s pension plans are expected to be required for the remainder of fiscal 2019. 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, the Spire Missouri West 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. Net periodic postretirement benefit costs consisted of the following components: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire Service cost – benefits earned during the period $ 1.8 $ 2.4 $ 3.7 $ 4.7 Interest cost on accumulated postretirement benefit obligation* 2.1 2.2 4.4 4.4 Expected return on plan assets* (3.9 ) (3.5 ) (8.0 ) (7.0 ) Amortization of prior service credit* (0.1 ) (0.1 ) (0.1 ) (0.1 ) Amortization of actuarial (gain) loss* (0.2 ) 0.2 (0.3 ) 0.4 Subtotal (0.3 ) 1.2 (0.3 ) 2.4 Regulatory adjustment 2.6 — 5.0 0.1 Net postretirement benefit cost $ 2.3 $ 1.2 $ 4.7 $ 2.5 Spire Missouri Service cost – benefits earned during the period $ 1.7 $ 2.3 $ 3.4 $ 4.5 Interest cost on accumulated postretirement benefit obligation* 1.7 1.8 3.4 3.6 Expected return on plan assets* (2.7 ) (2.5 ) (5.5 ) (4.9 ) Amortization of prior service cost* — — 0.1 0.1 Amortization of actuarial (gain) loss* (0.2 ) 0.2 (0.3 ) 0.4 Subtotal 0.5 1.8 1.1 3.7 Regulatory adjustment 3.0 0.5 5.9 1.0 Net postretirement benefit cost $ 3.5 $ 2.3 $ 7.0 $ 4.7 Spire Alabama Service cost – benefits earned during the period $ 0.1 $ 0.1 $ 0.2 $ 0.1 Interest cost on accumulated postretirement benefit obligation* 0.4 0.3 0.9 0.7 Expected return on plan assets* (1.2 ) (1.0 ) (2.4 ) (2.0 ) Amortization of prior service credit* (0.1 ) (0.1 ) (0.2 ) (0.2 ) Subtotal (0.8 ) (0.7 ) (1.5 ) (1.4 ) Regulatory adjustment (0.4 ) (0.5 ) (0.9 ) (0.9 ) Net postretirement benefit income $ (1.2 ) $ (1.2 ) $ (2.4 ) $ (2.3 ) * Denotes other postretirement expense line items that are recorded below the operating income line in the income statements, in the line items “Other Income, Net” or “Other Income (Expense), Net.” 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	6 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
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 LLC, a subsidiary of Spire constructing and planning the operation of a 65-mile FERC-regulated pipeline to deliver natural gas into eastern Missouri; • Spire Storage, providing physical natural gas storage services; and • Spire’s subsidiaries engaged in the operation of a propane pipeline, compression of natural gas, and risk management, among other activities. Accounting policies are described in Note 1 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 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 March 31, 2019 Operating Revenues: Revenues from external customers $ 776.7 $ 25.4 $ 1.4 $ — $ 803.5 Intersegment revenues 0.1 0.1 2.9 (3.1 ) — Total Operating Revenues 776.8 25.5 4.3 (3.1 ) 803.5 Operating Expenses: Gas Utility Natural and propane gas 366.7 — — (29.3 ) 337.4 Operation and maintenance 112.0 — — (2.5 ) 109.5 Depreciation and amortization 44.4 — — — 44.4 Taxes, other than income taxes 57.4 — — — 57.4 Total Gas Utility Operating Expenses 580.5 — — (31.8 ) 548.7 Gas Marketing and Other — 8.7 7.9 28.7 45.3 Total Operating Expenses 580.5 8.7 7.9 (3.1 ) 594.0 Operating Income (Loss) $ 196.3 $ 16.8 $ (3.6 ) $ — $ 209.5 Net Economic Earnings (Loss) $ 146.7 $ 6.2 $ (5.0 ) $ — $ 147.9 Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended March 31, 2018 Operating Revenues: Revenues from external customers $ 790.6 $ 21.3 $ 1.5 $ — $ 813.4 Intersegment revenues 0.2 — 2.9 (3.1 ) — Total Operating Revenues 790.8 21.3 4.4 (3.1 ) 813.4 Operating Expenses: Gas Utility Natural and propane gas 403.2 — — (19.5 ) 383.7 Operation and maintenance 137.5 — — (2.2 ) 135.3 Depreciation and amortization 41.1 — — — 41.1 Taxes, other than income taxes 58.0 — — — 58.0 Total Gas Utility Operating Expenses 639.8 — — (21.7 ) 618.1 Gas Marketing and Other — 20.2 6.4 18.6 45.2 Total Operating Expenses 639.8 20.2 6.4 (3.1 ) 663.3 Operating Income (Loss) $ 151.0 $ 1.1 $ (2.0 ) $ — $ 150.1 Net Economic Earnings (Loss) $ 131.7 $ 10.2 $ (4.7 ) $ — $ 137.2 Gas Utility Gas Marketing Other Eliminations Consolidated Six Months Ended March 31, 2019 Operating Revenues: Revenues from external customers $ 1,350.5 $ 51.2 $ 3.8 $ — $ 1,405.5 Intersegment revenues 1.5 0.1 5.9 (7.5 ) — Total Operating Revenues 1,352.0 51.3 9.7 (7.5 ) 1,405.5 Operating Expenses: Gas Utility Natural and propane gas 658.5 — — (69.4 ) 589.1 Operation and maintenance 216.9 — — (4.9 ) 212.0 Depreciation and amortization 88.1 — — — 88.1 Taxes, other than income taxes 96.6 — — — 96.6 Total Gas Utility Operating Expenses 1,060.1 — — (74.3 ) 985.8 Gas Marketing and Other — 22.0 16.3 66.8 105.1 Total Operating Expenses 1,060.1 22.0 16.3 (7.5 ) 1,090.9 Operating Income (Loss) $ 291.9 $ 29.3 $ (6.6 ) $ — $ 314.6 Net Economic Earnings (Loss) $ 213.1 $ 14.5 $ (13.8 ) $ — $ 213.8 Gas Utility Gas Marketing Other Eliminations Consolidated Six Months Ended March 31, 2018 Operating Revenues: Revenues from external customers $ 1,332.5 $ 40.9 $ 1.8 $ — $ 1,375.2 Intersegment revenues 0.3 — 5.4 (5.7 ) — Total Operating Revenues 1,332.8 40.9 7.2 (5.7 ) 1,375.2 Operating Expenses: Gas Utility Natural and propane gas 666.6 — — (42.1 ) 624.5 Operation and maintenance 238.4 — — (4.1 ) 234.3 Depreciation and amortization 81.4 — — — 81.4 Taxes, other than income taxes 94.7 — — — 94.7 Total Gas Utility Operating Expenses 1,081.1 — — (46.2 ) 1,034.9 Gas Marketing and Other — 34.8 10.9 40.5 86.2 Total Operating Expenses 1,081.1 34.8 10.9 (5.7 ) 1,121.1 Operating Income (Loss) $ 251.7 $ 6.1 $ (3.7 ) $ — $ 254.1 Net Economic Earnings (Loss) $ 191.2 $ 13.8 $ (9.9 ) $ — $ 195.1 March 31, September 30, March 31, 2019 2018 2018 Total Assets: Gas Utility $ 5,850.1 $ 5,606.7 $ 5,484.3 Gas Marketing 366.7 295.3 208.6 Other 2,396.8 2,508.0 2,211.9 Eliminations (1,340.0 ) (1,566.4 ) (1,318.0 ) Total Assets $ 7,273.6 $ 6,843.6 $ 6,586.8 The following table reconciles the Company’s net economic earnings to net income. Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Adjustments, pre-tax: Missouri regulatory adjustments — 30.6 — 30.6 Unrealized (gain) loss on energy-related derivatives (9.1 ) 11.8 (11.3 ) 12.6 Realized gain on economic hedges prior to the sale of the physical commodity — (0.2 ) — (0.3 ) Acquisition, divestiture and restructuring activities — 2.0 0.4 3.7 Income tax effect of adjustments 2.4 (11.1 ) 2.8 (11.7 ) Effect of the Tax Cuts and Jobs Act — 5.9 — (54.0 ) Net Economic Earnings $ 147.9 $ 137.2 $ 213.8 $ 195.1

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments The Company and the Utilities have entered into contracts with various counterparties, expiring on dates through 2032, for the storage, transportation, and supply of natural gas. Minimum payments required under the contracts in place at March 31, 2019, are estimated at $1,826.5, $648.2, and $385.8 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. 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. 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 (“MDNR”) Brownfields/Voluntary Cleanup Program (“BVCP”). The third site is the result of a relatively new claim assertion by the U.S. Environmental Protection Agency (“EPA”) and such claim is currently being investigated. In conjunction with redevelopment of one of the sites, 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 letter from the MDNR. 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 amount paid by Spire Missouri did not materially impact the financial condition, results of operations, or cash flows of the Company. Spire Missouri has not owned the second site for many years. In a letter dated June 29, 2011, the Attorney General for the State of Missouri informed Spire Missouri that the MDNR had completed an investigation of the site. 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 that are willing to contribute to such efforts in a meaningful and equitable fashion. Accordingly, Spire Missouri entered into a cost sharing agreement for remedial investigation with other PRPs. To date, MDNR has not approved the agreement, so remedial investigation has not yet occurred. 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 in the northern portion of the City on which Spire Missouri operated a MGP. Spire Missouri has not owned or operated the site for over 70 years. Spire Missouri and the site owner have met with the EPA and reviewed its assertions. Both Spire Missouri and the site owner have 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, Spire Missouri requested more information from the EPA, some of which would also be utilized to identify other former owners and operators of the site that could be added as PRPs. To date, Spire Missouri has not 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 the 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, in an effort 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 seven 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 North, Kansas City Coal Gas Station A South, and Independence MGP #2. Source removal has been conducted at all of the owned sites since 2003 with the exception of Joplin. On September 15, 2016, a request was made with the MDNR for a restrictive covenant use limitation with respect to Joplin. Remediation efforts at the seven sites are at various stages of completion, ranging from groundwater monitoring and sampling following source removal activities to the aforementioned request in respect to Joplin. As part of its participation in the BVCP, Spire Missouri communicates regularly with the MDNR with respect to its remediation efforts and monitoring activities at these sites. On May 11, 2015, MDNR approved the next phase of investigation at the Kansas City Station A North and Railroad areas. To date, costs incurred for all Missouri Utilities’ MGP sites for investigation, remediation and monitoring these sites 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 may incur could be materially higher or lower depending upon several factors, including whether remediation actions 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 2013, Spire Missouri retained an outside consultant to conduct probabilistic cost modeling of 19 former MGP sites owned or operated by Spire Missouri. The purpose of this analysis was to develop an estimated range of probabilistic future liability for each site. That analysis, completed in August 2014, provided a range of demonstrated possible future expenditures to investigate, monitor and remediate all 19 MGP sites. Spire Missouri has recorded its best estimate of the probable expenditures that relate to these matters. The amount is not material. Spire Missouri 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 Alabama On December 17, 2013, an incident occurred at a Housing Authority apartment complex in Birmingham, Alabama that resulted in one fatality, personal injuries and property damage. Spire Alabama cooperated with the National Transportation Safety Board (“NTSB”) which investigated the incident. The NTSB report of findings was issued on March 30, 2016 and no safety recommendations, fines, or penalties were contained therein. Spire Alabama has been named as a defendant in several lawsuits arising from the incident, some of which remain pending. Spire Alabama does not expect potential liabilities that may arise from these lawsuits to have a material impact on its future financial condition or results of operations. 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. Spire Alabama does not foresee a probable or reasonably estimable loss associated with these sites. 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. 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. Since April 2012, a total of 14 lawsuits encompassing more than 1,600 plaintiffs have been filed against Spire Gulf in Mobile County Circuit Court alleging that in the first half of 2008, Spire Gulf spilled tert-butyl mercaptan, an odorant added to natural gas for safety reasons, in Eight Mile, Alabama. All of the lawsuits have been substantially settled, with the exception of 13 individuals who rejected their settlement offers and whose claims remain pending. Those remaining claims allege nuisance, fraud and negligence causes of actions and seek unspecified compensatory and punitive damages. A claim has been made against the insurance carriers requesting reimbursement for costs accrued in respect to this spill, and a related receivable has been recorded. The Company does not expect potential liabilities that may arise from these lawsuits to have a material impact on its future financial condition or results of operations.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	The Tax Cuts and Jobs Act (“TCJA”) was signed into law on December 22, 2017, with an effective date of January 1, 2018, for substantially all of the provisions. The specific provisions related to regulated public utilities in the TCJA generally allow for the continued deductibility of interest expense, the elimination of full expensing for tax purposes of certain property acquired after September 27, 2017, and the continuation of certain rate normalization requirements for accelerated depreciation benefits. The Department of the Treasury (“Treasury”) has issued proposed regulations associated with the deductibility of interest expense, but further clarification of certain provisions is expected. Treasury has also issued proposed regulations on bonus depreciation which allow full expensing for certain property acquired in tax years beginning prior to January 1, 2018. As indicated in Note 1 Regulated Operations

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Mar. 31, 2019
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” or the “Missouri Utilities”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri and Spire Alabama are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth Inc. (“Spire EnergySouth”) are collectively referred to as the “Utilities.” The subsidiaries of Spire EnergySouth are Spire Gulf Inc. and Spire Mississippi Inc. 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 (consisting of only normal recurring 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’s, Spire Missouri’s and Spire Alabama’s combined Annual Report on Form 10-K for the fiscal year ended September 30, 2018. 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.
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 Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“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 using a gross presentation. 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. Under GAAP, revenues and expenses associated with trading activities are presented on a net basis in Gas Marketing operating revenues (or expenses, if negative) in the Condensed Consolidated Statements of Income. This net presentation has no effect on operating income or net income.
Regulated Operations	REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with FASB 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
Transactions with Affiliates	TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated statements of Spire. Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest, as reflected in their separate financial statements, and they participated in normal intercompany shared services transactions
Accrued Capital Expenditures	Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid.
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS – Spire, Spire Missouri and Spire Alabama adopted the guidance in Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , and related amendments (collectively, “ASC 606”), in the first quarter of fiscal year 2019 using the modified retrospective method applied to all contracts at October 1, 2018. The core principle of ASC 606 is that revenue should be recognized to depict the transfer of control of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Under the new standard, an entity must identify the performance obligations in a contract, determine the transaction price and allocate the price to specific performance obligations to recognize revenue when the obligation is completed. In addition, ASC 606 requires disclosure of the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The adoption of ASC 606 did not result in significant changes to how Spire, Spire Missouri and Spire Alabama recognize revenue, and therefore, no cumulative effect adjustment to the opening balance of retained earnings was required, and there was no significant impact to financial results after adoption. The adoption did result in changes to the disclosures about revenue, which are included in Note 2 , Revenue. Some revenue arrangements, such as alternative revenue programs and certain derivative contracts, are excluded from the scope of ASC 606 and, therefore, are presented separately in disclosures. Also effective October 1, 2018, Spire, Spire Missouri and Spire Alabama adopted ASU No. Compensation – Retirement Benefits : Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost The amended guidance that the of net periodic pension and postretirement benefit costs presented within line item in the income statement as other compensation costs (except for the amount being capitalized), while other components presented outside the subtotal of operating income and . The amended guidance is applied retrospectively for income statement presentation and prospectively for capitalization. The Company, Spire practical expedient permitting the use of the amounts disclosed in its pension and other postretirement benefit plan note for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements. Accordingly, for the three months ended March 31, 2018, the Company, Spire Missouri and Spire Alabama reclassified net benefit (income) costs of $8.3, $9.5 and $(1.1), respectively, from “operation and maintenance” to “other income, net” or “other income (expense), net.” The corresponding amounts for the six months ended March 31, 2018 were $7.2, $9.7 and $(2.1), respectively. The corresponding annual amounts to be reclassified for the years ended September 30, 2018, 2017 and 2016 are $14.4, $19.2 and $9.6 for the Company, respectively, $17.2, $17.2 and $11.2 for Spire Missouri, respectively, and $(2.0), $2.2 and $(1.6) for Spire Alabama, respectively. For Spire Missouri, Spire Alabama, and the Company’s other rate-regulated entities, all components of net benefit cost have historically been recovered from customers as a component of utility plant and will continue to be recovered in the same manner over the depreciable lives of the related plant assets; therefore, for those entities, the components that are no longer eligible to be capitalized as a component of plant under GAAP will be reported as regulatory assets Effective January 1, 2019, the Company, Spire Missouri and Spire Alabama adopted ASU No. Intangibles – Goodwill and Other – Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In February 2016, the FASB issued ASU No. 2016-02, Leases In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Schedule of Inter-Company Transactions	In addition, Spire Missouri’s other transactions with affiliates included Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Purchases of natural gas from Spire Marketing $ 29.2 $ 19.3 $ 69.0 $ 41.6 Sales of natural gas to Spire Marketing — 0.2 1.4 0.3 Transportation services received from Spire NGL Inc. 0.2 0.2 0.5 0.5
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. March 31, September 30, March 31, 2019 2018 2018 Spire $ 63.6 $ 62.1 $ 29.1 Spire Missouri 19.0 36.7 17.9 Spire Alabama 12.1 8.9 7.0

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Mar. 31, 2019
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 March 31, 2019 Six Months Ended March 31, 2019 Spire Gas Utility: Residential $ 551.3 $ 944.9 Commercial & industrial 185.9 316.2 Transportation 31.3 60.8 Off-system & other incentive 11.5 26.4 Other customer revenue 10.9 23.6 Total revenue from contracts with customers 790.9 1,371.9 Changes in accrued revenue under alternative revenue programs (14.1 ) (19.9 ) Total Gas Utility operating revenues 776.8 1,352.0 Gas Marketing: Revenue from contracts with retail customers 25.5 51.3 Revenue from wholesale derivative contracts — — Total Gas Marketing operating revenues 25.5 51.3 Other 4.3 9.7 Total before eliminations 806.6 1,413.0 Intersegment eliminations (see Note 10, Information by Operating Segment) (3.1 ) (7.5 ) Total Operating Revenues $ 803.5 $ 1,405.5 Three Months Ended March 31, 2019 Six Months Ended March 31, 2019 Spire Missouri Residential $ 410.9 $ 713.0 Commercial & industrial 129.2 218.3 Transportation 9.9 18.9 Off-system & other incentive 11.5 26.4 Other customer revenue 4.2 6.8 Total revenue from contracts with customers 565.7 983.4 Changes in accrued revenue under alternative revenue programs (9.1 ) (13.6 ) Total Operating Revenues $ 556.6 $ 969.8 Spire Alabama Residential $ 116.9 $ 192.3 Commercial & industrial 44.1 75.5 Transportation 18.8 37.0 Other customer revenue 5.3 14.9 Total revenue from contracts with customers 185.1 319.7 Changes in accrued revenue under alternative revenue programs (4.7 ) (5.8 ) Total Operating Revenues $ 180.4 $ 313.9
Schedule of Gross Receipts Taxes	The following table presents gross receipts taxes recorded as revenues: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire $ 43.5 $ 43.6 $ 69.4 $ 66.7 Spire Missouri 32.1 30.6 50.6 46.8 Spire Alabama 9.6 11.6 15.9 17.2

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Basic Earnings Per Share: Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Less: Income allocated to participating securities 0.3 0.2 0.5 0.5 Income Available to Common Shareholders $ 154.3 $ 98.0 $ 221.4 $ 213.7 Weighted Average Shares Outstanding (in millions) 50.6 48.2 50.6 48.2 Basic Earnings Per Share $ 3.05 $ 2.03 $ 4.37 $ 4.43 Diluted Earnings Per Share: Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Less: Income allocated to participating securities 0.3 0.2 0.5 0.5 Income Available to Common Shareholders $ 154.3 $ 98.0 $ 221.4 $ 213.7 Weighted Average Shares Outstanding (in millions) 50.6 48.2 50.6 48.2 Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)* 0.2 0.2 0.2 0.2 Weighted Average Diluted Shares (in millions) 50.8 48.4 50.8 48.4 Diluted Earnings Per Share $ 3.04 $ 2.03 $ 4.36 $ 4.42 * Calculation excludes certain outstanding 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 0.3 0.4 0.3 0.4

Regulatory Matters (Tables)

Regulatory Matters (Tables)	6 Months Ended
	Mar. 31, 2019
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 March 31, 2019, September 30, 2018, and March 31, 2018. March 31, September 30, March 31, Spire 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 30.2 $ 30.2 $ 43.0 Unamortized purchased gas adjustments 19.3 8.2 32.6 Other 25.8 34.4 22.1 Total Current Regulatory Assets 75.3 72.8 97.7 Noncurrent: Pension and postretirement benefit costs 345.8 364.9 358.2 Cost of removal 134.6 133.4 125.0 Future income taxes due from customers 102.2 96.3 113.0 Energy efficiency 32.0 32.8 31.3 Other 45.3 42.4 46.1 Total Noncurrent Regulatory Assets 659.9 669.8 673.6 Total Regulatory Assets $ 735.2 $ 742.6 $ 771.3 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 5.8 $ 2.2 $ 2.2 Unamortized purchased gas adjustments 3.4 2.9 1.5 Other 26.1 30.6 18.5 Total Current Regulatory Liabilities 35.3 35.7 22.2 Noncurrent: Deferred taxes due to customers 155.7 178.3 170.7 Pension and postretirement benefit costs 115.3 27.8 30.8 Accrued cost of removal 53.7 63.6 71.0 Unamortized purchased gas adjustments 75.7 4.7 50.3 Other 30.9 80.2 30.3 Total Noncurrent Regulatory Liabilities 431.3 354.6 353.1 Total Regulatory Liabilities $ 466.6 $ 390.3 $ 375.3 March 31, September 30, March 31, Spire Missouri 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 21.9 $ 21.9 $ 34.9 Unamortized purchased gas adjustments 0.6 1.0 13.5 Other 7.5 7.8 3.3 Total Current Regulatory Assets 30.0 30.7 51.7 Noncurrent: Future income taxes due from customers 99.0 94.4 111.4 Pension and postretirement benefit costs 277.9 292.5 279.0 Energy efficiency 32.0 32.8 31.3 Other 24.7 21.4 24.9 Total Noncurrent Regulatory Assets 433.6 441.1 446.6 Total Regulatory Assets $ 463.6 $ 471.8 $ 498.3 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 3.6 $ — $ — Unamortized purchased gas adjustments 2.7 1.9 — Other 17.9 14.8 2.7 Total Current Regulatory Liabilities 24.2 16.7 2.7 Noncurrent: Deferred taxes due to customers 138.3 161.1 152.6 Pension and postretirement benefit costs 79.4 — — Accrued cost of removal 26.8 39.8 48.7 Unamortized purchased gas adjustments 75.7 4.7 50.3 Other 24.9 69.3 20.9 Total Noncurrent Regulatory Liabilities 345.1 274.9 272.5 Total Regulatory Liabilities $ 369.3 $ 291.6 $ 275.2 March 31, September 30, March 31, Spire Alabama 2019 2018 2018 Regulatory Assets: Current: Pension and postretirement benefit costs $ 7.3 $ 7.3 $ 7.1 Unamortized purchased gas adjustments 18.0 6.4 19.0 Other 5.1 12.5 6.0 Total Current Regulatory Assets 30.4 26.2 32.1 Noncurrent: Pension and postretirement benefit costs 61.1 64.8 71.2 Cost of removal 134.6 133.4 125.0 Other 3.2 3.3 2.7 Total Noncurrent Regulatory Assets 198.9 201.5 198.9 Total Regulatory Assets $ 229.3 $ 227.7 $ 231.0 Regulatory Liabilities: Current: Pension and postretirement benefit costs $ 2.2 $ 2.2 $ 2.2 Other 3.9 5.4 8.6 Total Current Regulatory Liabilities 6.1 7.6 10.8 Noncurrent: Pension and postretirement benefit costs 26.5 27.8 30.8 Other 4.0 3.5 4.2 Total Noncurrent Regulatory Liabilities 30.5 31.3 35.0 Total Regulatory Liabilities $ 36.6 $ 38.9 $ 45.8
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: March 31, September 30, March 31, 2019 2018 2018 Spire Pension and postretirement benefit costs $ 144.7 $ 148.4 $ 185.8 Future income taxes due from customers 102.2 96.3 113.0 Other 14.8 15.1 11.0 Total Regulatory Assets Not Earning a Return $ 261.7 $ 259.8 $ 309.8 Spire Missouri Pension and postretirement benefit costs $ 144.7 $ 148.4 $ 185.8 Future income taxes due from customers 99.0 94.4 111.4 Other 14.8 15.1 11.0 Total Regulatory Assets Not Earning a Return $ 258.5 $ 257.9 $ 308.2

Financing Arrangements and Lo_2

Financing Arrangements and Long-term Debt (Tables)	6 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Spire Missouri and Alabama Short-term Borrowings	Information about Spire’s consolidated short-term borrowings and about Spire Missouri’s and Spire Alabama’s borrowings from Spire is presented in the following table. As of March 31, 2019, $344.6 of Spire’s short-term borrowings were used to support lending to the Utilities. Spire Commercial Paper Borrowings Spire Missouri Borrowings from Spire Spire Alabama Borrowings from Spire Six Months Ended March 31, 2019 Weighted average borrowings outstanding $598.3 $313.5 $117.3 Weighted average interest rate 2.8% 2.8% 2.8% Range of borrowings outstanding $482.5 – $689.3 $205.1 – $404.9 $43.8 – $169.2 As of March 31, 2019 Borrowings outstanding $512.0 $232.9 $73.7 Weighted average interest rate 2.8% 2.8% 2.8% As of September 30, 2018 Borrowings outstanding $553.6 $345.3 $142.5 Weighted average interest rate 2.4% 2.3% 2.3% As of March 31, 2018 Borrowings outstanding $391.7 $175.8 $82.3 Weighted average interest rate 2.2% 2.2% 2.2%
Summary Capitalized Interest	Interest expense shown on Spire’s consolidated statements of income and Spire Missouri’s statements of comprehensive income is net of the capitalized interest amounts shown in the following table. Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire $ 1.4 $ 0.6 $ 2.6 $ 1.0 Spire Missouri 0.4 0.2 0.9 0.4

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on Recurring Basis	Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Spire As of March 31, 2019 Cash and cash equivalents $ 11.1 $ 11.1 $ 11.1 $ — Notes payable 512.0 512.0 — 512.0 Long-term debt, including current portion 2,256.9 2,319.9 — 2,319.9 As of September 30, 2018 Cash and cash equivalents $ 4.4 $ 4.4 $ 4.4 $ — Notes payable 553.6 553.6 — 553.6 Long-term debt, including current portion 2,075.6 2,074.0 — 2,074.0 As of March 31, 2018 Cash and cash equivalents $ 17.8 $ 17.8 $ 17.8 $ — Notes payable 391.7 391.7 — 391.7 Long-term debt, including current portion 2,179.4 2,241.3 — 2,241.3 Spire Missouri As of March 31, 2019 Cash and cash equivalents $ 6.9 $ 6.9 $ 6.9 $ — Notes payable – 232.9 232.9 — 232.9 Long-term debt, including current portion 974.7 1,036.9 — 1,036.9 As of September 30, 2018 Cash and cash equivalents $ 2.0 $ 2.0 $ 2.0 $ — Notes payable – 345.3 345.3 — 345.3 Long-term debt, including current portion 874.4 906.6 — 906.6 As of March 31, 2018 Cash and cash equivalents $ 10.2 $ 10.2 $ 10.2 $ — Notes payable – 175.8 175.8 — 175.8 Long-term debt, including current portion 974.0 1,033.6 — 1,033.6 Spire Alabama As of March 31, 2019 Cash and cash equivalents $ 0.1 $ 0.1 $ 0.1 $ — Notes payable – 73.7 73.7 — 73.7 Long-term debt, including current portion 412.1 423.8 — 423.8 As of September 30, 2018 Notes payable – $ 142.5 $ 142.5 $ — $ 142.5 Long-term debt 322.6 321.7 — 321.7 As of March 31, 2018 Notes payable – $ 82.3 $ 82.3 $ — $ 82.3 Long-term debt 322.5 332.7 — 332.7

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Mar. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis	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. The mutual funds included in Level 2 are valued based on the closing net asset value per unit. 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. The Level 3 balances as of March 31, 2019, September 30, 2018, and March 31, 2018, consisted of gas commodity contracts. 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 March 31, 2019 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 19.7 $ — $ — $ — $ 19.7 NYMEX/ICE natural gas contracts 2.5 — — (2.5 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 7.1 — (4.3 ) 3.0 Natural gas commodity contracts — 30.4 — (3.4 ) 27.0 Other: U.S. stock/bond mutual funds 11.9 — — — 11.9 Total $ 34.3 $ 37.5 $ — $ (10.2 ) $ 61.6 LIABILITIES Gas Marketing: NYMEX/ICE natural gas contracts $ 0.4 $ 4.1 $ - $ (4.5 ) $ - Natural gas commodity contracts — 18.9 0.2 (3.5 ) 15.6 Other: Interest rate swaps — 15.2 — — 15.2 Total $ 0.4 $ 38.2 $ 0.2 $ (8.0 ) $ 30.8 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, 2018 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 20.3 $ — $ — $ — $ 20.3 NYMEX/ICE natural gas contracts 2.7 — — (2.7 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 4.0 — (4.2 ) — Natural gas commodity contracts — 17.5 — (1.5 ) 16.0 Other: U.S. stock/bond mutual funds 8.9 — — — 8.9 Interest rate swaps — 3.0 — — 3.0 Total $ 32.1 $ 24.5 $ — $ (8.4 ) $ 48.2 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 1.9 $ — $ — $ (1.9 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts 0.9 10.5 — (11.4 ) — Natural gas commodity contracts — 7.5 0.2 (1.5 ) 6.2 Total $ 2.8 $ 18.0 $ 0.2 $ (14.8 ) $ 6.2 As of March 31, 2018 ASSETS Gas Utility: U.S. stock/bond mutual funds $ 19.1 $ 4.1 $ — $ — $ 23.2 NYMEX/ICE natural gas contracts 0.1 — — (0.1 ) — Gas Marketing: NYMEX/ICE natural gas contracts 0.2 3.3 — (3.5 ) — Natural gas commodity contracts — 7.4 0.1 (2.1 ) 5.4 Other: Interest rate swaps — 1.0 — — 1.0 Total $ 19.4 $ 15.8 $ 0.1 $ (5.7 ) $ 29.6 LIABILITIES Gas Utility: NYMEX/ICE natural gas contracts $ 0.2 $ — $ — $ (0.2 ) $ — Gas Marketing: NYMEX/ICE natural gas contracts 0.6 9.8 — (10.4 ) — Natural gas commodity contracts — 14.3 — (2.1 ) 12.2 Total $ 0.8 $ 24.1 $ — $ (12.7 ) $ 12.2
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	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 March 31, 2019 ASSETS U.S. stock/bond mutual funds $ 19.7 $ — $ — $ — $ 19.7 NYMEX/ICE natural gas contracts 2.5 — — (2.5 ) — Total $ 22.2 $ — $ — $ (2.5 ) $ 19.7 As of September 30, 2018 ASSETS U.S. stock/bond mutual funds $ 20.3 $ — $ — $ — $ 20.3 NYMEX/ICE natural gas contracts 2.7 — — (2.7 ) — Total $ 23.0 $ — $ — $ (2.7 ) $ 20.3 LIABILITIES NYMEX/ICE natural gas contracts $ 1.9 $ — $ — $ (1.9 ) $ — As of March 31, 2018 ASSETS U.S. stock/bond mutual funds $ 19.1 $ 4.1 $ — $ — $ 23.2 NYMEX/ICE natural gas contracts 0.1 — — (0.1 ) — Total $ 19.2 $ 4.1 $ — $ (0.1 ) $ 23.2 LIABILITIES NYMEX/ICE natural gas contracts $ 0.2 $ — $ — $ (0.2 ) $ —

Pension Plans and Other Postr_2

Pension Plans and Other Postretirement Benefits (Tables)	6 Months Ended
	Mar. 31, 2019
Pension Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	The net periodic pension cost included the following components: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire Service cost – benefits earned during the period $ 4.9 $ 5.2 $ 9.7 $ 10.4 Interest cost on projected benefit obligation* 7.0 6.9 14.1 13.8 Expected return on plan assets* (8.9 ) (9.5 ) (18.0 ) (19.2 ) Amortization of prior service credit* (0.3 ) (0.2 ) (0.6 ) (0.5 ) Amortization of actuarial loss* 2.3 2.9 4.6 6.0 Loss on lump-sum settlements* — 9.4 — 9.4 Subtotal 5.0 14.7 9.8 19.9 Regulatory adjustment 9.8 24.0 19.7 28.3 Net pension cost $ 14.8 $ 38.7 $ 29.5 $ 48.2 Spire Missouri Service cost – benefits earned during the period $ 3.1 $ 3.2 $ 6.2 $ 6.5 Interest cost on projected benefit obligation* 4.9 4.9 9.9 9.8 Expected return on plan assets* (6.3 ) (7.0 ) (12.7 ) (14.2 ) Amortization of prior service cost* 0.2 0.2 0.4 0.4 Amortization of actuarial loss* 2.2 2.5 4.3 5.1 Loss on lump-sum settlements* — 9.4 — 9.4 Subtotal 4.1 13.2 8.1 17.0 Regulatory adjustment 7.9 21.9 15.9 24.3 Net pension cost $ 12.0 $ 35.1 $ 24.0 $ 41.3 Spire Alabama Service cost – benefits earned during the period $ 1.6 $ 1.7 $ 3.1 $ 3.3 Interest cost on projected benefit obligation* 1.5 1.4 3.0 2.8 Expected return on plan assets* (1.8 ) (1.7 ) (3.6 ) (3.4 ) Amortization of prior service credit* (0.5 ) (0.4 ) (0.9 ) (0.9 ) Amortization of actuarial loss* 0.2 0.4 0.4 0.9 Subtotal 1.0 1.4 2.0 2.7 Regulatory adjustment 1.7 1.9 3.4 3.6 Net pension cost $ 2.7 $ 3.3 $ 5.4 $ 6.3 * Denotes pension expense line items that are recorded below the operating income line in the income statements, in the line items “Other Income, Net” or “Other Income (Expense), Net.”
Postretirement Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	Net periodic postretirement benefit costs consisted of the following components: Three Months Ended March 31, Six Months Ended March 31, 2019 2018 2019 2018 Spire Service cost – benefits earned during the period $ 1.8 $ 2.4 $ 3.7 $ 4.7 Interest cost on accumulated postretirement benefit obligation* 2.1 2.2 4.4 4.4 Expected return on plan assets* (3.9 ) (3.5 ) (8.0 ) (7.0 ) Amortization of prior service credit* (0.1 ) (0.1 ) (0.1 ) (0.1 ) Amortization of actuarial (gain) loss* (0.2 ) 0.2 (0.3 ) 0.4 Subtotal (0.3 ) 1.2 (0.3 ) 2.4 Regulatory adjustment 2.6 — 5.0 0.1 Net postretirement benefit cost $ 2.3 $ 1.2 $ 4.7 $ 2.5 Spire Missouri Service cost – benefits earned during the period $ 1.7 $ 2.3 $ 3.4 $ 4.5 Interest cost on accumulated postretirement benefit obligation* 1.7 1.8 3.4 3.6 Expected return on plan assets* (2.7 ) (2.5 ) (5.5 ) (4.9 ) Amortization of prior service cost* — — 0.1 0.1 Amortization of actuarial (gain) loss* (0.2 ) 0.2 (0.3 ) 0.4 Subtotal 0.5 1.8 1.1 3.7 Regulatory adjustment 3.0 0.5 5.9 1.0 Net postretirement benefit cost $ 3.5 $ 2.3 $ 7.0 $ 4.7 Spire Alabama Service cost – benefits earned during the period $ 0.1 $ 0.1 $ 0.2 $ 0.1 Interest cost on accumulated postretirement benefit obligation* 0.4 0.3 0.9 0.7 Expected return on plan assets* (1.2 ) (1.0 ) (2.4 ) (2.0 ) Amortization of prior service credit* (0.1 ) (0.1 ) (0.2 ) (0.2 ) Subtotal (0.8 ) (0.7 ) (1.5 ) (1.4 ) Regulatory adjustment (0.4 ) (0.5 ) (0.9 ) (0.9 ) Net postretirement benefit income $ (1.2 ) $ (1.2 ) $ (2.4 ) $ (2.3 ) * Denotes other postretirement expense line items that are recorded below the operating income line in the income statements, in the line items “Other Income, Net” or “Other Income (Expense), Net.”

Information by Operating Segm_2

Information by Operating Segment (Tables)	6 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of operating segment information	Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended March 31, 2019 Operating Revenues: Revenues from external customers $ 776.7 $ 25.4 $ 1.4 $ — $ 803.5 Intersegment revenues 0.1 0.1 2.9 (3.1 ) — Total Operating Revenues 776.8 25.5 4.3 (3.1 ) 803.5 Operating Expenses: Gas Utility Natural and propane gas 366.7 — — (29.3 ) 337.4 Operation and maintenance 112.0 — — (2.5 ) 109.5 Depreciation and amortization 44.4 — — — 44.4 Taxes, other than income taxes 57.4 — — — 57.4 Total Gas Utility Operating Expenses 580.5 — — (31.8 ) 548.7 Gas Marketing and Other — 8.7 7.9 28.7 45.3 Total Operating Expenses 580.5 8.7 7.9 (3.1 ) 594.0 Operating Income (Loss) $ 196.3 $ 16.8 $ (3.6 ) $ — $ 209.5 Net Economic Earnings (Loss) $ 146.7 $ 6.2 $ (5.0 ) $ — $ 147.9 Gas Utility Gas Marketing Other Eliminations Consolidated Three Months Ended March 31, 2018 Operating Revenues: Revenues from external customers $ 790.6 $ 21.3 $ 1.5 $ — $ 813.4 Intersegment revenues 0.2 — 2.9 (3.1 ) — Total Operating Revenues 790.8 21.3 4.4 (3.1 ) 813.4 Operating Expenses: Gas Utility Natural and propane gas 403.2 — — (19.5 ) 383.7 Operation and maintenance 137.5 — — (2.2 ) 135.3 Depreciation and amortization 41.1 — — — 41.1 Taxes, other than income taxes 58.0 — — — 58.0 Total Gas Utility Operating Expenses 639.8 — — (21.7 ) 618.1 Gas Marketing and Other — 20.2 6.4 18.6 45.2 Total Operating Expenses 639.8 20.2 6.4 (3.1 ) 663.3 Operating Income (Loss) $ 151.0 $ 1.1 $ (2.0 ) $ — $ 150.1 Net Economic Earnings (Loss) $ 131.7 $ 10.2 $ (4.7 ) $ — $ 137.2 Gas Utility Gas Marketing Other Eliminations Consolidated Six Months Ended March 31, 2019 Operating Revenues: Revenues from external customers $ 1,350.5 $ 51.2 $ 3.8 $ — $ 1,405.5 Intersegment revenues 1.5 0.1 5.9 (7.5 ) — Total Operating Revenues 1,352.0 51.3 9.7 (7.5 ) 1,405.5 Operating Expenses: Gas Utility Natural and propane gas 658.5 — — (69.4 ) 589.1 Operation and maintenance 216.9 — — (4.9 ) 212.0 Depreciation and amortization 88.1 — — — 88.1 Taxes, other than income taxes 96.6 — — — 96.6 Total Gas Utility Operating Expenses 1,060.1 — — (74.3 ) 985.8 Gas Marketing and Other — 22.0 16.3 66.8 105.1 Total Operating Expenses 1,060.1 22.0 16.3 (7.5 ) 1,090.9 Operating Income (Loss) $ 291.9 $ 29.3 $ (6.6 ) $ — $ 314.6 Net Economic Earnings (Loss) $ 213.1 $ 14.5 $ (13.8 ) $ — $ 213.8 Gas Utility Gas Marketing Other Eliminations Consolidated Six Months Ended March 31, 2018 Operating Revenues: Revenues from external customers $ 1,332.5 $ 40.9 $ 1.8 $ — $ 1,375.2 Intersegment revenues 0.3 — 5.4 (5.7 ) — Total Operating Revenues 1,332.8 40.9 7.2 (5.7 ) 1,375.2 Operating Expenses: Gas Utility Natural and propane gas 666.6 — — (42.1 ) 624.5 Operation and maintenance 238.4 — — (4.1 ) 234.3 Depreciation and amortization 81.4 — — — 81.4 Taxes, other than income taxes 94.7 — — — 94.7 Total Gas Utility Operating Expenses 1,081.1 — — (46.2 ) 1,034.9 Gas Marketing and Other — 34.8 10.9 40.5 86.2 Total Operating Expenses 1,081.1 34.8 10.9 (5.7 ) 1,121.1 Operating Income (Loss) $ 251.7 $ 6.1 $ (3.7 ) $ — $ 254.1 Net Economic Earnings (Loss) $ 191.2 $ 13.8 $ (9.9 ) $ — $ 195.1 March 31, September 30, March 31, 2019 2018 2018 Total Assets: Gas Utility $ 5,850.1 $ 5,606.7 $ 5,484.3 Gas Marketing 366.7 295.3 208.6 Other 2,396.8 2,508.0 2,211.9 Eliminations (1,340.0 ) (1,566.4 ) (1,318.0 ) Total Assets $ 7,273.6 $ 6,843.6 $ 6,586.8
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 March 31, Six Months Ended March 31, 2019 2018 2019 2018 Net Income $ 154.6 $ 98.2 $ 221.9 $ 214.2 Adjustments, pre-tax: Missouri regulatory adjustments — 30.6 — 30.6 Unrealized (gain) loss on energy-related derivatives (9.1 ) 11.8 (11.3 ) 12.6 Realized gain on economic hedges prior to the sale of the physical commodity — (0.2 ) — (0.3 ) Acquisition, divestiture and restructuring activities — 2.0 0.4 3.7 Income tax effect of adjustments 2.4 (11.1 ) 2.8 (11.7 ) Effect of the Tax Cuts and Jobs Act — 5.9 — (54.0 ) Net Economic Earnings $ 147.9 $ 137.2 $ 213.8 $ 195.1

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	3 Months Ended	6 Months Ended			12 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2019reporting_unit	Mar. 31, 2019operating-segment	Mar. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Number of operating segments		2	2
ASU 2017-07
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Reclassification of net periodic benefit costs (income) to other income, net	$ 8.3			$ 7.2	$ 14.4	$ 19.2	$ 9.6
Spire Missouri | ASU 2017-07
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Reclassification of net periodic benefit costs (income) to other income, net	9.5			9.7	17.2	17.2	11.2
Spire Alabama | ASU 2017-07
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Reclassification of net periodic benefit costs (income) to other income, net	$ (1.1)			$ (2.1)	$ (2)	$ 2.2	$ (1.6)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Inter-company Transactions (Details) - Affiliated Entity - Spire Missouri - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Spire Marketing | Regulated Operation
Related Party Transaction [Line Items]
Purchases of natural gas from Spire Marketing	$ 29.2	$ 19.3	$ 69	$ 41.6
Sales of natural gas to Spire Marketing		0.2	1.4	0.3
Spire NGL Inc. | Unregulated Operation
Related Party Transaction [Line Items]
Transportation services received from Spire NGL Inc.	$ 0.2	$ 0.2	$ 0.5	$ 0.5

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Accrued Capital Expenditures (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	$ 63.6	$ 29.1	$ 62.1
Spire Missouri
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	19	17.9	36.7
Spire Alabama
Schedule Of Accrued Capital Expenditures Excluded From Statement Of Cash Flow [Line Items]
Accruals for capital expenditures	$ 12.1	$ 7	$ 8.9

Revenue - Schedule of Revenue D

Revenue - Schedule of Revenue Disaggregated by Source and Customer Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 776.7	$ 790.6	$ 1,350.5	$ 1,332.5
Total operating revenues	26.8	22.8	55	42.7
Total operating revenues	803.5	813.4	1,405.5	1,375.2
Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues	(3.1)	(3.1)	(7.5)	(5.7)
Gas Utility
Disaggregation Of Revenue [Line Items]
Total operating revenues	776.7	790.6	1,350.5	1,332.5
Gas Utility | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	776.8	790.8	1,352	1,332.8
Gas Utility | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues	0.1	0.2	1.5	0.3
Gas Marketing
Disaggregation Of Revenue [Line Items]
Total operating revenues	25.4	21.3	51.2	40.9
Gas Marketing | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	25.5	21.3	51.3	$ 40.9
Gas Marketing | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues	0.1	$ 0	0.1
Spire
Disaggregation Of Revenue [Line Items]
Total operating revenues	803.5		1,405.5
Spire | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	806.6		1,413
Spire | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total operating revenues	(3.1)		(7.5)
Spire | Gas Utility | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	790.9		1,371.9
Changes in accrued revenue under alternative revenue programs	(14.1)		(19.9)
Total operating revenues	776.8		1,352
Spire | Gas Utility | Operating Segments | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues	551.3		944.9
Spire | Gas Utility | Operating Segments | Commercial & Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues	185.9		316.2
Spire | Gas Utility | Operating Segments | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues	31.3		60.8
Spire | Gas Utility | Operating Segments | Off-system & Other Incentive
Disaggregation Of Revenue [Line Items]
Total operating revenues	11.5		26.4
Spire | Gas Utility | Operating Segments | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues	10.9		23.6
Spire | Gas Marketing | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	25.5		51.3
Spire | Gas Marketing | Operating Segments | Revenue From Contracts With Retail Customers
Disaggregation Of Revenue [Line Items]
Total operating revenues	25.5		51.3
Spire | Other | Operating Segments
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 4.3		$ 9.7

Revenue - Schedule of Operating

Revenue - Schedule of Operating Revenue Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Total Operating Revenues	$ 803.5	$ 813.4	$ 1,405.5	$ 1,375.2
Spire Missouri
Disaggregation Of Revenue [Line Items]
Total operating revenues	565.7		983.4
Changes in accrued revenue under alternative revenue programs	(9.1)		(13.6)
Total Operating Revenues	556.6	533.2	969.8	925.5
Spire Missouri | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues	410.9		713
Spire Missouri | Commercial & Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues	129.2		218.3
Spire Missouri | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues	9.9		18.9
Spire Missouri | Off-system & Other Incentive
Disaggregation Of Revenue [Line Items]
Total operating revenues	11.5		26.4
Spire Missouri | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues	4.2		6.8
Spire Alabama
Disaggregation Of Revenue [Line Items]
Total operating revenues	185.1		319.7
Changes in accrued revenue under alternative revenue programs	(4.7)		(5.8)
Total Operating Revenues	180.4	$ 218.3	313.9	$ 339.1
Spire Alabama | Residential
Disaggregation Of Revenue [Line Items]
Total operating revenues	116.9		192.3
Spire Alabama | Commercial & Industrial
Disaggregation Of Revenue [Line Items]
Total operating revenues	44.1		75.5
Spire Alabama | Transportation
Disaggregation Of Revenue [Line Items]
Total operating revenues	18.8		37
Spire Alabama | Other Customer Revenue
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 5.3		$ 14.9

Revenue - Additional Informatio

Revenue - Additional Information (Details)	6 Months Ended
	Mar. 31, 2019
Revenue Recognition [Line Items]
Remaining performance obligation, practical expedient	true
Maximum
Revenue Recognition [Line Items]
Revenue remaining performance obligation original excepted duration	1 year

Revenue - Schedule of Gross Rec

Revenue - Schedule of Gross Receipts Taxes Recorded Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	$ 43.5	$ 43.6	$ 69.4	$ 66.7
Spire Missouri
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	32.1	30.6	50.6	46.8
Spire Alabama
Scheduleof Gross Receipts Taxes [Line Items]
Gross receipts taxes recorded in regulated gas distribution operating revenues	$ 9.6	$ 11.6	$ 15.9	$ 17.2

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Mar. 31, 2018
Basic Earnings Per Share:
Net Income	$ 154.6	$ 67.3	$ 98.2	$ 116	$ 221.9	$ 214.2
Less: Income allocated to participating securities	0.3		0.2		0.5	0.5
Income Available to Common Shareholders	$ 154.3		$ 98		$ 221.4	$ 213.7
Weighted Average Shares Outstanding (in millions)	50.6		48.2		50.6	48.2
Basic Earnings Per Share	$ 3.05		$ 2.03		$ 4.37	$ 4.43
Diluted Earnings Per Share:
Net Income	$ 154.6	$ 67.3	$ 98.2	$ 116	$ 221.9	$ 214.2
Less: Income allocated to participating securities	0.3		0.2		0.5	0.5
Income Available to Common Shareholders	$ 154.3		$ 98		$ 221.4	$ 213.7
Weighted Average Shares Outstanding (in millions)	50.6		48.2		50.6	48.2
Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)	0.2		0.2		0.2	0.2
Weighted Average Diluted Shares (in millions)	50.8		48.4		50.8	48.4
Diluted Earnings Per Share	$ 3.04		$ 2.03		$ 4.36	$ 4.42

Earnings Per Share - Schedule_2

Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Parenthetical) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Restricted Stock and Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding shares excluded from calculation of diluted EPS (in shares)	0.3	0.4	0.3	0.4

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Regulatory Assets and Liabilities, Reflected in Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	$ 75.3	$ 72.8	$ 97.7
Regulatory assets, non current	659.9	669.8	673.6
Total Regulatory Assets	735.2	742.6	771.3
Regulatory liabilities, current	35.3	35.7	22.2
Regulatory liabilities, non current	431.3	354.6	353.1
Total Regulatory Liabilities	466.6	390.3	375.3
Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	30	30.7	51.7
Regulatory assets, non current	433.6	441.1	446.6
Total Regulatory Assets	463.6	471.8	498.3
Regulatory liabilities, current	24.2	16.7	2.7
Regulatory liabilities, non current	345.1	274.9	272.5
Total Regulatory Liabilities	369.3	291.6	275.2
Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	30.4	26.2	32.1
Regulatory assets, non current	198.9	201.5	198.9
Total Regulatory Assets	229.3	227.7	231
Regulatory liabilities, current	6.1	7.6	10.8
Regulatory liabilities, non current	30.5	31.3	35
Total Regulatory Liabilities	36.6	38.9	45.8
Pension and Postretirement Benefit Costs
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	30.2	30.2	43
Regulatory assets, non current	345.8	364.9	358.2
Pension and Postretirement Benefit Costs | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	21.9	21.9	34.9
Regulatory assets, non current	277.9	292.5	279
Pension and Postretirement Benefit Costs | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	7.3	7.3	7.1
Regulatory assets, non current	61.1	64.8	71.2
Unamortized Purchased Gas Adjustments
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	19.3	8.2	32.6
Unamortized Purchased Gas Adjustments | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	0.6	1	13.5
Unamortized Purchased Gas Adjustments | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	18	6.4	19
Other
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	25.8	34.4	22.1
Regulatory assets, non current	45.3	42.4	46.1
Other | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	7.5	7.8	3.3
Regulatory assets, non current	24.7	21.4	24.9
Other | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, current	5.1	12.5	6
Regulatory assets, non current	3.2	3.3	2.7
Future Income Taxes Due from Customers
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	102.2	96.3	113
Future Income Taxes Due from Customers | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	99	94.4	111.4
Accrued Cost of Removal
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	134.6	133.4	125
Accrued Cost of Removal | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	134.6	133.4	125
Energy Efficiency
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	32	32.8	31.3
Energy Efficiency | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory assets, non current	32	32.8	31.3
Pension and Postretirement Benefit Costs
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	5.8	2.2	2.2
Regulatory liabilities, non current	115.3	27.8	30.8
Pension and Postretirement Benefit Costs | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	3.6	0	0
Regulatory liabilities, non current	79.4	0	0
Pension and Postretirement Benefit Costs | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	2.2	2.2	2.2
Regulatory liabilities, non current	26.5	27.8	30.8
Unamortized Purchased Gas Adjustments
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	3.4	2.9	1.5
Regulatory liabilities, non current	75.7	4.7	50.3
Unamortized Purchased Gas Adjustments | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	2.7	1.9	0
Regulatory liabilities, non current	75.7	4.7	50.3
Other
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	26.1	30.6	18.5
Regulatory liabilities, non current	30.9	80.2	30.3
Other | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	17.9	14.8	2.7
Regulatory liabilities, non current	24.9	69.3	20.9
Other | Spire Alabama
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, current	3.9	5.4	8.6
Regulatory liabilities, non current	4	3.5	4.2
Deferred Taxes Due to Customers
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	155.7	178.3	170.7
Deferred Taxes Due to Customers | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	138.3	161.1	152.6
Accrued Cost of Removal
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	53.7	63.6	71
Accrued Cost of Removal | Spire Missouri
Regulatory Asset And Liabilities [Line Items]
Regulatory liabilities, non current	$ 26.8	$ 39.8	$ 48.7

Regulatory Matters - Schedule_2

Regulatory Matters - Schedule of Regulatory Assets Not Earning a Return (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 261.7	$ 259.8	$ 309.8
Pension and Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	144.7	148.4	185.8
Future Income Taxes Due from Customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	102.2	96.3	113
Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	14.8	15.1	11
Spire Missouri
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	258.5	257.9	308.2
Spire Missouri | Pension and Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	144.7	148.4	185.8
Spire Missouri | Future Income Taxes Due from Customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	99	94.4	111.4
Spire Missouri | Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 14.8	$ 15.1	$ 11

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) $ in Millions	Jan. 14, 2019USD ($)	Nov. 30, 2018USD ($)	Sep. 28, 2018USD ($)	Apr. 25, 2018USD ($)	Mar. 31, 2019USD ($)mi$ / MMBTU	Jan. 31, 2019USD ($)
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
Length of dual 20-inch diameter pipeline | mi					10.1
Spire Missouri
Public Utilities, General Disclosures [Line Items]
Increase in negotiated rate per day | $ / MMBTU					0.02
Spire Alabama
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount					$ (3.3)
Public utilities, requested rate increase (decrease), amount		$ 8.7
Infrastructure System Replacement Surcharge | Spire Missouri East
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount			$ 2.6
Applications requests for the approval of revenue related to commission amount						$ 7.4
Infrastructure System Replacement Surcharge | Spire Missouri West
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount			$ 5.4
Applications requests for the approval of revenue related to commission amount						$ 7.4
Infrastructure System Replacement Surcharge | Spire Missouri
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amount	$ 3.2
Infrastructure System Replacement Surcharge | MoPSC
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), costs from buildings sold in 2014 excluded from rate base				$ 1.8
Rate case expenses				0.9
Pension Cost | Infrastructure System Replacement Surcharge | MoPSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets recovery				$ 28.8

Financing Arrangements and Lo_3

Financing Arrangements and Long-term Debt - Additional Information (Details)	1 Months Ended		6 Months Ended
	Dec. 31, 2018USD ($)	Oct. 31, 2018USD ($)	Mar. 31, 2019USD ($)	Jan. 15, 2019USD ($)	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 14, 2016bank
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity			$ 975,000,000
Credit facility borrowings			0		$ 0	$ 0
Non-interest-bearing Note
Line of Credit Facility [Line Items]
Settlement of debt		$ 10,000,000
Term Loan
Line of Credit Facility [Line Items]
Long-term Debt	$ 100,000,000
Debt instrument, maturity date	Dec. 1, 2021
Liabilities | Lender Concentration Risk
Line of Credit Facility [Line Items]
Line of credit facility, number of banks in agreement | bank							11
Spire
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity			300,000,000
Short-term borrowings used to support lending to Utilities			344,600,000
Spire Missouri
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity			475,000,000
Spire Alabama
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity			$ 200,000,000
Spire Alabama | Senior Notes | Private Placement | Series 2019 A senior notes due 2049
Line of Credit Facility [Line Items]
Long-term debt				$ 90,000,000
Stated interest rate				4.64%
Line of Credit
Line of Credit Facility [Line Items]
Minimum required ratio of earnings before interest, taxes, depreciation, and amortization (EBITDA) times interest expense as required by the line of credit covenant			70.00%
Debt to total capitalization ratio			0.54
Line of Credit | Spire Missouri
Line of Credit Facility [Line Items]
Debt to total capitalization ratio			0.47
Line of Credit | Spire Alabama
Line of Credit Facility [Line Items]
Debt to total capitalization ratio			0.37
Commercial Paper Notes
Line of Credit Facility [Line Items]
Long-term debt			$ 975,000,000
Debt term			365 days

Financing Arrangements and Lo_4

Financing Arrangements and Long-term Debt - Schedule of Spire Missouri and Alabama Short-term Borrowings (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
Spire Missouri | Borrowings
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 313.5
Weighted average interest rate	2.80%
Minimum borrowing outstanding	$ 205.1
Maximum borrowing outstanding	404.9
Borrowings outstanding	$ 232.9	$ 345.3	$ 175.8
Weighted average interest rate	2.80%	2.30%	2.20%
Spire Alabama | Borrowings
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 117.3
Weighted average interest rate	2.80%
Minimum borrowing outstanding	$ 43.8
Maximum borrowing outstanding	169.2
Borrowings outstanding	$ 73.7	$ 142.5	$ 82.3
Weighted average interest rate	2.80%	2.30%	2.20%
Spire | Commercial Paper Notes
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 598.3
Weighted average interest rate	2.80%
Minimum borrowing outstanding	$ 482.5
Maximum borrowing outstanding	689.3
Borrowings outstanding	$ 512	$ 553.6	$ 391.7
Weighted average interest rate	2.80%	2.40%	2.20%

Financing Arrangements and Lo_5

Financing Arrangements and Long-term Debt - Summary of Net of Capitalized Interest (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Spire
Line of Credit Facility [Line Items]
Interest expense, net	$ 1.4	$ 0.6	$ 2.6	$ 1
Spire Missouri
Line of Credit Facility [Line Items]
Interest expense, net	$ 0.4	$ 0.2	$ 0.9	$ 0.4

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	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
Quoted Prices in Active Markets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 11.1	$ 4.4	$ 17.8
Quoted Prices in Active Markets (Level 1) | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	6.9	2	10.2
Quoted Prices in Active Markets (Level 1) | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0.1
Significant Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	512	553.6	391.7
Long-term debt, including current portion	2,319.9	2,074	2,241.3
Significant Observable Inputs (Level 2) | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion	1,036.9	906.6	1,033.6
Significant Observable Inputs (Level 2) | Spire Missouri | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	232.9	345.3	175.8
Significant Observable Inputs (Level 2) | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion	423.8	321.7	332.7
Significant Observable Inputs (Level 2) | Spire Alabama | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	73.7	142.5	82.3
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	11.1	4.4	17.8
Notes payable	512	553.6	391.7
Long-term debt, including current portion	2,256.9	2,075.6	2,179.4
Carrying Amount | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	6.9	2	10.2
Long-term debt, including current portion	974.7	874.4	974
Carrying Amount | Spire Missouri | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	232.9	345.3	175.8
Carrying Amount | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0.1
Long-term debt, including current portion	412.1	322.6	322.5
Carrying Amount | Spire Alabama | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	73.7	142.5	82.3
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	11.1	4.4	17.8
Notes payable	512	553.6	391.7
Long-term debt, including current portion	2,319.9	2,074	2,241.3
Fair Value | Spire Missouri
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	6.9	2	10.2
Long-term debt, including current portion	1,036.9	906.6	1,033.6
Fair Value | Spire Missouri | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	232.9	345.3	175.8
Fair Value | Spire Alabama
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0.1
Long-term debt, including current portion	423.8	321.7	332.7
Fair Value | Spire Alabama | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	$ 73.7	$ 142.5	$ 82.3

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	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
ASSETS
Effects of netting and cash margin receivables/payables	$ (10.2)	$ (8.4)	$ (5.7)
Derivative asset after the effects of netting	61.6	48.2	29.6
LIABILITIES
Effects of netting and cash margin receivables/payables	(8)	(14.8)	(12.7)
Derivative liability after the effects of netting	30.8	6.2	12.2
Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables	(2.5)	(2.7)	(0.1)
Derivative asset after the effects of netting	19.7	20.3	23.2
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	19.7	20.3	23.2
NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Effects of netting and cash margin receivables/payables	(2.5)	(2.7)	(0.1)
Derivative asset after the effects of netting	0	0	0
LIABILITIES
Effects of netting and cash margin receivables/payables		(1.9)	(0.2)
Derivative liability after the effects of netting		0	0
Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	34.3	32.1	19.4
LIABILITIES
Derivative liability before effects of netting	0.4	2.8	0.8
Quoted Prices in Active Markets (Level 1) | Spire Missouri
ASSETS
Derivative asset before effects of netting	22.2	23	19.2
Quoted Prices in Active Markets (Level 1) | U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Derivative asset before effects of netting	19.7	20.3	19.1
Quoted Prices in Active Markets (Level 1) | NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting	2.5	2.7	0.1
LIABILITIES
Derivative liability before effects of netting		1.9	0.2
Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	37.5	24.5	15.8
LIABILITIES
Derivative liability before effects of netting	38.2	18	24.1
Significant Observable Inputs (Level 2) | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	4.1
Significant Observable Inputs (Level 2) | U.S. stock/bond mutual funds | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	4.1
Significant Observable Inputs (Level 2) | NYMEX/ICE natural gas contracts | Spire Missouri
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting		0	0
Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0	0	0.1
LIABILITIES
Derivative liability before effects of netting	0.2	0.2	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	0
LIABILITIES
Derivative liability before effects of netting		0	0
Corporate, Non-Segment | U.S. stock/bond mutual funds
ASSETS
Effects of netting and cash margin receivables/payables	0	0
Derivative asset after the effects of netting	11.9	8.9
Corporate, Non-Segment | Interest rate swaps
ASSETS
Effects of netting and cash margin receivables/payables		0	0
Derivative asset after the effects of netting		3	1
LIABILITIES
Effects of netting and cash margin receivables/payables	0
Derivative liability after the effects of netting	15.2
Corporate, Non-Segment | Quoted Prices in Active Markets (Level 1) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	11.9	8.9
Corporate, Non-Segment | Quoted Prices in Active Markets (Level 1) | Interest rate swaps
ASSETS
Derivative asset before effects of netting		0	0
LIABILITIES
Derivative liability before effects of netting	0
Corporate, Non-Segment | Significant Observable Inputs (Level 2) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0
Corporate, Non-Segment | Significant Observable Inputs (Level 2) | Interest rate swaps
ASSETS
Derivative asset before effects of netting		3	1
LIABILITIES
Derivative liability before effects of netting	15.2
Corporate, Non-Segment | Significant Unobservable Inputs (Level 3) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0
Corporate, Non-Segment | Significant Unobservable Inputs (Level 3) | Interest rate swaps
ASSETS
Derivative asset before effects of netting		0	0
LIABILITIES
Derivative liability before effects of netting	0
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	19.7	20.3	23.2
Gas Utility | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(2.5)	(2.7)	(0.1)
Derivative asset after the effects of netting	0	0	0
LIABILITIES
Effects of netting and cash margin receivables/payables		(1.9)	(0.2)
Derivative liability after the effects of netting		0	0
Gas Utility | Operating Segments | Quoted Prices in Active Markets (Level 1) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	19.7	20.3	19.1
Gas Utility | Operating Segments | Quoted Prices in Active Markets (Level 1) | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	2.5	2.7	0.1
LIABILITIES
Derivative liability before effects of netting		1.9	0.2
Gas Utility | Operating Segments | Significant Observable Inputs (Level 2) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	4.1
Gas Utility | Operating Segments | Significant Observable Inputs (Level 2) | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting		0	0
Gas Utility | Operating Segments | Significant Unobservable Inputs (Level 3) | U.S. stock/bond mutual funds
ASSETS
Derivative asset before effects of netting	0	0	0
Gas Utility | Operating Segments | Significant Unobservable Inputs (Level 3) | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting		0	0
Gas Marketing | Operating Segments | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(4.3)	(4.2)	(3.5)
Derivative asset after the effects of netting	3	0	0
LIABILITIES
Effects of netting and cash margin receivables/payables	(4.5)	(11.4)	(10.4)
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	(3.4)	(1.5)	(2.1)
Derivative asset after the effects of netting	27	16	5.4
LIABILITIES
Effects of netting and cash margin receivables/payables	(3.5)	(1.5)	(2.1)
Derivative liability after the effects of netting	15.6	6.2	12.2
Gas Marketing | Operating Segments | Quoted Prices in Active Markets (Level 1) | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	0.2	0.2	0.2
LIABILITIES
Derivative liability before effects of netting	0.4	0.9	0.6
Gas Marketing | Operating Segments | Quoted Prices in Active Markets (Level 1) | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	0	0	0
LIABILITIES
Derivative liability before effects of netting	0	0	0
Gas Marketing | Operating Segments | Significant Observable Inputs (Level 2) | NYMEX/ICE natural gas contracts
ASSETS
Derivative asset before effects of netting	7.1	4	3.3
LIABILITIES
Derivative liability before effects of netting	4.1	10.5	9.8
Gas Marketing | Operating Segments | Significant Observable Inputs (Level 2) | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	30.4	17.5	7.4
LIABILITIES
Derivative liability before effects of netting	18.9	7.5	14.3
Gas Marketing | Operating Segments | Significant Unobservable Inputs (Level 3) | 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
Gas Marketing | Operating Segments | Significant Unobservable Inputs (Level 3) | Natural gas commodity contracts
ASSETS
Derivative asset before effects of netting	0	0	0.1
LIABILITIES
Derivative liability before effects of netting	$ 0.2	$ 0.2	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018
Spire Alabama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding derivative contracts	$ 0	$ 0	$ 0

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Details) $ in Millions	6 Months Ended
	Mar. 31, 2019USD ($)subsegmentcounterparty
Concentration Risk [Line Items]
Number of groups with potential to affect overall exposure | subsegment	3
Number of large counterparties for which credit risk is disclosed | counterparty	5
Number of counterparties with investment-grade rating | counterparty	4
Energy Producers And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	$ 18.1
Net receivable amount	7.3
Utility Companies And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	94.8
Net receivable amount	84
Five Largest Counterparties
Concentration Risk [Line Items]
Accounts receivable	31.5
Net receivable amount	$ 27.3

Pension Plans and Other Postr_3

Pension Plans and Other Postretirement Benefits - Schedule of Net Periodic Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	$ 4.9	$ 5.2	$ 9.7	$ 10.4
Interest cost on projected benefit obligation	7	6.9	14.1	13.8
Expected return on plan assets	(8.9)	(9.5)	(18)	(19.2)
Amortization of prior service cost (credit)	(0.3)	(0.2)	(0.6)	(0.5)
Amortization of actuarial (gain) loss	2.3	2.9	4.6	6
Loss on lump-sum settlements*		9.4		9.4
Subtotal	5	14.7	9.8	19.9
Regulatory adjustment	9.8	24	19.7	28.3
Net pension cost	14.8	38.7	29.5	48.2
Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.8	2.4	3.7	4.7
Interest cost on projected benefit obligation	2.1	2.2	4.4	4.4
Expected return on plan assets	(3.9)	(3.5)	(8)	(7)
Amortization of prior service cost (credit)	(0.1)	(0.1)	(0.1)	(0.1)
Amortization of actuarial (gain) loss	(0.2)	0.2	(0.3)	0.4
Subtotal	(0.3)	1.2	(0.3)	2.4
Regulatory adjustment	2.6		5	0.1
Net pension cost	2.3	1.2	4.7	2.5
Spire Missouri | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	3.1	3.2	6.2	6.5
Interest cost on projected benefit obligation	4.9	4.9	9.9	9.8
Expected return on plan assets	(6.3)	(7)	(12.7)	(14.2)
Amortization of prior service cost (credit)	0.2	0.2	0.4	0.4
Amortization of actuarial (gain) loss	2.2	2.5	4.3	5.1
Loss on lump-sum settlements*		9.4		9.4
Subtotal	4.1	13.2	8.1	17
Regulatory adjustment	7.9	21.9	15.9	24.3
Net pension cost	12	35.1	24	41.3
Spire Missouri | Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.7	2.3	3.4	4.5
Interest cost on projected benefit obligation	1.7	1.8	3.4	3.6
Expected return on plan assets	(2.7)	(2.5)	(5.5)	(4.9)
Amortization of prior service cost (credit)			0.1	0.1
Subtotal	0.5	1.8	1.1	3.7
Regulatory adjustment	3	0.5	5.9	1
Net pension cost	3.5	2.3	7	4.7
Spire Alabama | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	1.6	1.7	3.1	3.3
Interest cost on projected benefit obligation	1.5	1.4	3	2.8
Expected return on plan assets	(1.8)	(1.7)	(3.6)	(3.4)
Amortization of prior service cost (credit)	(0.5)	(0.4)	(0.9)	(0.9)
Amortization of actuarial (gain) loss	0.2	0.4	0.4	0.9
Subtotal	1	1.4	2	2.7
Regulatory adjustment	1.7	1.9	3.4	3.6
Net pension cost	2.7	3.3	5.4	6.3
Spire Alabama | Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost – benefits earned during the period	0.1	0.1	0.2	0.1
Interest cost on projected benefit obligation	0.4	0.3	0.9	0.7
Expected return on plan assets	(1.2)	(1)	(2.4)	(2)
Amortization of prior service cost (credit)	(0.1)	(0.1)	(0.2)	(0.2)
Subtotal	(0.8)	(0.7)	(1.5)	(1.4)
Regulatory adjustment	(0.4)	(0.5)	(0.9)	(0.9)
Net pension cost	$ (1.2)	$ (1.2)	$ (2.4)	$ (2.3)

Pension Plans and Other Postr_4

Pension Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2017
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
Pension Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement benefits paid	$ 39,500,000
Settlement loss	$ 9,400,000
Pension Plans | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rates	3.75%		4.00%
Employer contributions		$ 8,500,000
Anticipated contributions to pension plans for qualified trust		18,200,000
Other Pension Plan | Spire Missouri
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rates	3.70%		4.00%
Postretirement Plans | 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
Postretirement Plans | 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) - 6 months ended Mar. 31, 2019	reporting_unit	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		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Operating Segment Information [Abstract]
Total Operating Revenues	$ 803.5	$ 813.4	$ 1,405.5	$ 1,375.2
Gas Utility
Natural and propane gas	337.4	383.7	589.1	624.5
Other operation and maintenance expenses	109.5	135.3	212	234.3
Depreciation and amortization	44.4	41.1	88.1	81.4
Taxes, other than income taxes	57.4	58	96.6	94.7
Total Gas Utility Operating Expenses	548.7	618.1	985.8	1,034.9
Gas Marketing and other	45.3	45.2	105.1	86.2
Total Operating Expenses	594	663.3	1,090.9	1,121.1
Operating Income	209.5	150.1	314.6	254.1
Net Economic Earnings (Loss)	147.9	137.2	213.8	195.1
Total Assets	7,273.6	6,586.8	7,273.6	6,586.8	$ 6,843.6
Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues	(3.1)	(3.1)	(7.5)	(5.7)
Gas Utility
Natural and propane gas	(29.3)	(19.5)	(69.4)	(42.1)
Other operation and maintenance expenses	(2.5)	(2.2)	(4.9)	(4.1)
Depreciation and amortization	0	0
Taxes, other than income taxes	0	0
Total Gas Utility Operating Expenses	(31.8)	(21.7)	(74.3)	(46.2)
Gas Marketing and other	28.7	18.6	66.8	40.5
Total Operating Expenses	(3.1)	(3.1)	(7.5)	(5.7)
Operating Income	0	0
Net Economic Earnings (Loss)	0	0
Total Assets	(1,340)	(1,318)	(1,340)	(1,318)	(1,566.4)
Gas Utility
Operating Segment Information [Abstract]
Total Operating Revenues	776.7	790.6	1,350.5	1,332.5
Gas Utility | Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues	0.1	0.2	1.5	0.3
Gas Utility | Operating Segments
Operating Segment Information [Abstract]
Total Operating Revenues	776.8	790.8	1,352	1,332.8
Gas Utility
Natural and propane gas	366.7	403.2	658.5	666.6
Other operation and maintenance expenses	112	137.5	216.9	238.4
Depreciation and amortization	44.4	41.1	88.1	81.4
Taxes, other than income taxes	57.4	58	96.6	94.7
Total Gas Utility Operating Expenses	580.5	639.8	1,060.1	1,081.1
Gas Marketing and other	0	0
Total Operating Expenses	580.5	639.8	1,060.1	1,081.1
Operating Income	196.3	151	291.9	251.7
Net Economic Earnings (Loss)	146.7	131.7	213.1	191.2
Total Assets	5,850.1	5,484.3	5,850.1	5,484.3	5,606.7
Gas Marketing
Operating Segment Information [Abstract]
Total Operating Revenues	25.4	21.3	51.2	40.9
Gas Marketing | Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues	0.1	0	0.1
Gas Marketing | Operating Segments
Operating Segment Information [Abstract]
Total Operating Revenues	25.5	21.3	51.3	40.9
Gas Utility
Natural and propane gas	0	0
Other operation and maintenance expenses	0	0
Depreciation and amortization	0	0
Taxes, other than income taxes	0	0
Total Gas Utility Operating Expenses	0	0
Gas Marketing and other	8.7	20.2	22	34.8
Total Operating Expenses	8.7	20.2	22	34.8
Operating Income	16.8	1.1	29.3	6.1
Net Economic Earnings (Loss)	6.2	10.2	14.5	13.8
Total Assets	366.7	208.6	366.7	208.6	295.3
Corporate, Non-Segment
Operating Segment Information [Abstract]
Total Operating Revenues	1.4	1.5	3.8	1.8
Corporate, Non-Segment | Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues	2.9	2.9	5.9	5.4
Corporate, Non-Segment | Operating Segments
Operating Segment Information [Abstract]
Total Operating Revenues	4.3	4.4	9.7	7.2
Gas Utility
Natural and propane gas	0	0
Other operation and maintenance expenses	0	0
Depreciation and amortization	0	0
Taxes, other than income taxes	0	0
Total Gas Utility Operating Expenses	0	0
Gas Marketing and other	7.9	6.4	16.3	10.9
Total Operating Expenses	7.9	6.4	16.3	10.9
Operating Income	(3.6)	(2)	(6.6)	(3.7)
Net Economic Earnings (Loss)	(5)	(4.7)	(13.8)	(9.9)
Total Assets	$ 2,396.8	$ 2,211.9	$ 2,396.8	$ 2,211.9	$ 2,508

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				6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting [Abstract]
Net Income (Loss)	$ 154.6	$ 67.3	$ 98.2	$ 116	$ 221.9	$ 214.2
Missouri regulatory adjustments	0		30.6		0	30.6
Unrealized (gain) loss on energy-related derivatives	(9.1)		11.8		(11.3)	12.6
Realized gain on economic hedges prior to the sale of the physical commodity	0		(0.2)		0	(0.3)
Acquisition, divestiture and restructuring activities	0		2		0.4	3.7
Income tax effect of adjustments	2.4		(11.1)		2.8	(11.7)
Effect of the Tax Cuts and Jobs Act	0		5.9		0	(54)
Net Economic Earnings	$ 147.9		$ 137.2		$ 213.8	$ 195.1

Commitments and Contingencies -

Commitments and Contingencies - Additional Information - Commitments (Details) $ in Millions	6 Months Ended
	Mar. 31, 2019USD ($)
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 1,826.5
Spire Missouri
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	648.2
Spire Alabama
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 385.8

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information - Contingencies (Details)	Dec. 17, 2013fatality	Mar. 31, 2019sitelawsuitplaintiff	Sep. 30, 2013site
Site Contingency [Line Items]
Number of lawsuits | lawsuit		14
Number of plaintiffs | plaintiff		1,600
Pending Litigation
Site Contingency [Line Items]
Number of lawsuits pending | plaintiff		13
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 East | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)			19
Spire Missouri West | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		7
Spire Alabama
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		9
Number of former manufactured gas distribution		5
Number of incident fatalities | fatality	1
Spire Alabama | Current Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		4
Number of former manufactured gas distribution		1

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2019
Spire Missouri
Income Taxes [Line Items]
Excess accumulated deferred taxes returned	$ 2.1	$ 4.2