Spire Missouri 10-K 15 Nov 16 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2016	Nov. 11, 2016	Mar. 31, 2016
Entity Information [Line Items]
Entity Registrant Name	SPIRE INC
Entity Central Index Key	1,126,956
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2,843,343,450
Entity Common Stock, Shares Outstanding		45,656,218
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Laclede Gas
Entity Information [Line Items]
Entity Registrant Name	LACLEDE GAS CO
Entity Central Index Key	57,183
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			0
Entity Common Stock, Shares Outstanding		24,577
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Alagasco
Entity Information [Line Items]
Entity Registrant Name	ALABAMA GAS CORP
Entity Central Index Key	3,146
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,972,052
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2016

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Operating Revenues:
Gas Utility		$ 1,457.2	$ 1,891.8	$ 1,462.6
Gas Marketing and other		80.1	84.6	164.6
Total Operating Revenues		1,537.3	1,976.4	1,627.2
Gas Utility
Natural and propane gas		492.2	882.4	731.7
Other operation and maintenance expenses		377.5	390.6	287.8
Depreciation and amortization		136.9	129.9	82.4
Taxes, other than income taxes		125.2	142.1	112
Total Gas Utility Operating Expenses		1,131.8	1,545	1,213.9
Gas Marketing and other		123.2	158.9	246.9
Total Operating Expenses		1,255	1,703.9	1,460.8
Operating Income		282.3	272.5	166.4
Other Income and (Income Deductions) – Net		8.6	1.2	(3.3)
Interest Charges:
Interest on long-term debt		67.6	66.6	39.3
Other interest charges		9.6	8	6.9
Total Interest Charges		77.2	74.6	46.2
Income Before Income Taxes		213.7	199.1	116.9
Income Tax Expense		69.5	62.2	32.3
Net Income		$ 144.2	$ 136.9	$ 84.6
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)		44.1	43.2	35.8
Diluted (in shares)		44.3	43.3	35.9
Basic Earnings Per Share of Common Stock (in dollars per share)		$ 3.26	$ 3.16	$ 2.36
Diluted Earnings Per Share of Common Stock (in dollars per share)		$ 3.24	$ 3.16	$ 2.35
Laclede Gas
Operating Revenues:
Gas Utility		$ 1,087.5	$ 1,416.6	$ 1,448.1
Other		0	0	0.1
Total Operating Revenues		1,087.5	1,416.6	1,448.2
Gas Utility
Natural and propane gas		471.3	786.1	816.9
Other operation and maintenance expenses		244.4	253.6	276.4
Depreciation and amortization		88.6	82.6	78.5
Taxes, other than income taxes		96.3	108.9	110.1
Total Gas Utility Operating Expenses		900.6	1,231.2	1,281.9
Gas Marketing and other		0	0	(0.1)
Total Operating Expenses		900.6	1,231.2	1,281.8
Operating Income		186.9	185.4	166.4
Other Income and (Income Deductions) – Net		1.8	(0.5)	(3.4)
Interest Charges:
Interest on long-term debt		32.9	33.1	34.4
Other interest charges		4.5	3.3	3
Total Interest Charges		37.4	36.4	37.4
Income Before Income Taxes		151.3	148.5	125.6
Income Tax Expense		45.4	43.2	35.5
Net Income		105.9	105.3	$ 90.1
Alagasco
Operating Revenues:
Gas Utility	$ 417.2	368.5	479.2
Total Operating Revenues	417.2	368.5	479.2
Gas Utility
Natural and propane gas	184.5	67.3	171.5
Other operation and maintenance expenses	107.5	133.5	138
Depreciation and amortization	34.4	47.8	47.3
Taxes, other than income taxes	28.6	28.4	33.2
Total Operating Expenses	355	277	390
Operating Income	62.2	91.5	89.2
Other Income and (Income Deductions) – Net	2.2	7.9	2
Interest Charges:
Interest on long-term debt	10.1	11.4	11.6
Other interest charges	1.4	2.4	2.3
Total Interest Charges	11.5	13.8	13.9
Income Before Income Taxes	52.9	85.6	77.3
Income Tax Expense	19.9	32.4	29.3
Net Income	$ 33	$ 53.2	$ 48

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Net income	$ 144.2	$ 136.9	$ 84.6
Cash flow hedging derivative instruments:
Net hedging loss arising during the period	(4)	(5.5)	(4.5)
Reclassification adjustment for loss included in net income	1.1	4.4	2.5
Net unrealized loss on cash flow hedging derivative instruments	(2.9)	(1.1)	(2)
Defined benefit pension and other postretirement benefit plans:
Net actuarial gain arising during the period	0	0.1	0
Amortization of actuarial (gain) loss included in net periodic pension and postretirement benefit cost	(0.3)	0.4	0.5
Net defined benefit pension and other postretirement benefit plans	(0.3)	0.5	0.5
Other Comprehensive Loss, Before Tax	(3.2)	(0.6)	(1.5)
Income Tax Benefit Related to Items of Other Comprehensive Loss	(1)	(0.3)	(0.6)
Other Comprehensive Loss, Net of Tax	(2.2)	(0.3)	(0.9)
Comprehensive Income	142	136.6	83.7
Laclede Gas
Net income	105.9	105.3	90.1
Cash flow hedging derivative instruments:
Net hedging loss arising during the period	0	(1.2)	0.1
Reclassification adjustment for loss included in net income	0.5	0.9	(0.2)
Net unrealized loss on cash flow hedging derivative instruments	0.5	(0.3)	(0.1)
Defined benefit pension and other postretirement benefit plans:
Net actuarial gain arising during the period	0	0.1	0
Amortization of actuarial (gain) loss included in net periodic pension and postretirement benefit cost	(0.3)	0.4	0.4
Net defined benefit pension and other postretirement benefit plans	(0.3)	0.5	0.4
Loss on available for sale securities	(0.1)	0	0
Other Comprehensive Loss, Before Tax	0.1	0.2	0.3
Income Tax Benefit Related to Items of Other Comprehensive Loss	0.2	0	0.1
Other Comprehensive Loss, Net of Tax	(0.1)	0.2	0.2
Comprehensive Income	$ 105.8	$ 105.5	$ 90.3

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
ASSETS
Utility Plant	$ 4,793.6	$ 4,234.5
Less: Accumulated depreciation and amortization	1,506.4	1,307
Net Utility Plant	3,287.2	2,927.5
Non-utility property (net of accumulated depreciation and amortization, $8.1 and $7.5 at September 30, 2016 and 2015, respectively)	13.7	13.7
Goodwill	1,164.9	946
Other investments	62.1	59.9
Other Property and Investments	1,240.7	1,019.6
Current Assets:
Cash and cash equivalents	5.2	13.8
Accounts receivable:
Utility	127.8	138.1
Other	113.4	86.7
Allowance for doubtful accounts	(20.5)	(14.2)
Delayed customer billings	1.6	2.6
Inventories:
Natural gas	174	188.6
Propane gas	12	12
Materials and supplies	16.3	14.8
Natural gas receivable	9.7	17.3
Derivative instrument assets	11.4	4.6
Unamortized purchased gas adjustments	49.7	12.9
Other regulatory assets	44.2	27.6
Deferred income tax	0	5.8
Prepayments and other	24.8	25.3
Total Current Assets	569.6	530.1
Deferred Charges:
Regulatory assets	838	737.6
Other	141.9	75.4
Total Deferred Charges	979.9	813
Total Assets	6,077.4	5,290.2
Capitalization:
Common stock equity	1,768.2	1,573.6
Long-term debt	1,833.7	1,771.5
Total Capitalization	3,601.9	3,345.1
Current Liabilities:
Current portion of long-term debt	250	80
Notes payable	398.7	338
Accounts payable	210.9	146.5
Advance customer billings	70.2	44.3
Wages and compensation accrued	39.8	32.7
Dividends payable	23.5	21.1
Customer deposits	34.9	32.1
Interest accrued	14.8	14.3
Unamortized purchased gas adjustments	1.7	28.2
Taxes accrued	55.2	51.7
Other regulatory liabilities	28.9	32.4
Other	32.7	32.5
Total Current Liabilities	1,161.3	853.8
Deferred Credits and Other Liabilities:
Deferred income taxes	607.3
Deferred income taxes		482.1
Pension and postretirement benefit costs	303.7	253.4
Asset retirement obligations	206.4	159.2
Regulatory liabilities	130.7	119.3
Other	66.1	77.3
Total Deferred Credits and Other Liabilities	1,314.2	1,091.3
Commitments and Contingencies
Total Capitalization and Liabilities	6,077.4	5,290.2
Laclede Gas
ASSETS
Utility Plant	2,718.5	2,579.1
Less: Accumulated depreciation and amortization	604.5	590
Net Utility Plant	2,114	1,989.1
Goodwill	210.2	210.2
Other investments	57.3	55.3
Other Property and Investments	267.5	265.5
Current Assets:
Cash and cash equivalents	2.1	1.7
Accounts receivable:
Utility	87.9	103.4
Other	11.4	25.2
Allowance for doubtful accounts	(16.1)	(10)
Delayed customer billings	1.6	2.6
Receivables from associated companies	2.2	2.5
Inventories:
Natural gas	127.3	138.2
Propane gas	12	12
Materials and supplies	9.2	9.3
Derivative instrument assets	4.9	0
Unamortized purchased gas adjustments	43.1	12.9
Other regulatory assets	23.9	16.2
Deferred income tax	0	0.4
Prepayments and other	14.5	12.5
Total Current Assets	324	326.5
Deferred Charges:
Regulatory assets	589.8	573.6
Other	5.3	12.8
Total Deferred Charges	595.1	586.4
Total Assets	3,300.6	3,167.5
Capitalization:
Common stock equity	1,068.5	1,037.8
Long-term debt	808.3	808.1
Total Capitalization	1,876.8	1,845.9
Current Liabilities:
Notes payable	243.7	233
Accounts payable	67.6	61.5
Accounts payable to associated companies	5.4	5.5
Advance customer billings	49.1	25.2
Wages and compensation accrued	29.9	26.8
Dividends payable	14	19.9
Customer deposits	13.5	13
Interest accrued	7.7	7.6
Taxes accrued	29.1	25.4
Other regulatory liabilities	1.3	0.6
Other	9.9	18.5
Total Current Liabilities	471.2	437
Deferred Credits and Other Liabilities:
Deferred income taxes	556.9
Deferred income taxes		485.2
Pension and postretirement benefit costs	211.8	207.8
Asset retirement obligations	75.2	72.4
Regulatory liabilities	67.3	70.6
Other	41.4	48.6
Total Deferred Credits and Other Liabilities	952.6	884.6
Commitments and Contingencies
Total Capitalization and Liabilities	3,300.6	3,167.5
Alagasco
ASSETS
Utility Plant	1,729.6	1,655.4
Less: Accumulated depreciation and amortization	756.6	717
Net Utility Plant	973	938.4
Current Assets:
Cash and cash equivalents	0	7.2
Accounts receivable:
Utility	34	34.7
Other	7.2	5.2
Allowance for doubtful accounts	(3.3)	(4.2)
Inventories:
Natural gas	34.6	40.4
Materials and supplies	5.9	5.4
Unamortized purchased gas adjustments	5.6	0
Other regulatory assets	14.9	11.4
Deferred income tax	0	6.2
Prepayments and other	5.1	4.6
Total Current Assets	104	110.9
Deferred Charges:
Regulatory assets	230.7	163.6
Deferred income tax	221.4
Deferred income tax		248.4
Other	63.2	57.7
Total Deferred Charges	515.3	469.7
Total Assets	1,592.3	1,519
Capitalization:
Common stock equity	867.3	874.6
Long-term debt	250	170
Total Capitalization	1,117.3	1,044.6
Current Liabilities:
Current portion of long-term debt	0	80
Notes payable	82	31
Accounts payable	34.3	21.8
Accounts payable to associated companies	0.4	0.2
Advance customer billings	21.1	19.1
Wages and compensation accrued	7.8	5.8
Customer deposits	18.2	19.1
Interest accrued	3.3	3.5
Unamortized purchased gas adjustments	0	28.2
Taxes accrued	21.6	26
Other regulatory liabilities	22.7	31.8
Other	6.3	5.4
Total Current Liabilities	217.7	271.9
Deferred Credits and Other Liabilities:
Pension and postretirement benefit costs	74.3	45.6
Asset retirement obligations	120.1	86.6
Regulatory liabilities	41.7	48.7
Other	21.2	21.6
Total Deferred Credits and Other Liabilities	257.3	202.5
Total Capitalization and Liabilities	$ 1,592.3	$ 1,519

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Assets
Non-utility property, accumulated depreciation and amortization	$ 8.1	$ 7.5

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITALIZATION - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Common Stock Equity:
Common stock, par value $1 per share	$ 45.6	$ 43.3
Paid-in capital	1,175.9	1,038.1
Retained earnings	550.9	494.2
Accumulated other comprehensive loss	(4.2)	(2)
Total Common Stock Equity	1,768.2	1,573.6
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	1,835.8	1,773.8
Unamortized discounts on long-term debt	(2.1)	(2.3)
Total Long-Term Debt	1,833.7	1,771.5
Total Capitalization	3,601.9	3,345.1
Spire | Floating Rate Senior Notes, due August 15, 2017
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	0	250
Spire | 2.55% Senior Notes, due August 15, 2019
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	125	125
Spire | 2.52% Senior Notes, due September 1, 2021
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	35	0
Spire | 2.0% Series A Remarketable Subordinated Notes, due April 1, 2022
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	143.8	143.8
Spire | 3.31% Notes Payable, due December 15, 2022
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	25	25
Spire | 3.13% Senior Notes, due September 1, 2026
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	130	0
Spire | 4.70% Senior Notes, due August 15, 2044
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	250	250
Laclede Gas
Common Stock Equity:
Common stock, par value $1 per share	0.1	0.1
Paid-in capital	751.9	748.2
Retained earnings	318.3	291.2
Accumulated other comprehensive loss	(1.8)	(1.7)
Total Common Stock Equity	1,068.5	1,037.8
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	810	810
Unamortized discounts on long-term debt	(1.7)	(1.9)
Total Long-Term Debt	808.3	808.1
Total Capitalization	1,876.8	1,845.9
Laclede Gas | 2.0% Series, due August 15, 2018
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	100	100
Laclede Gas | 5.5% Series, due May 1, 2019
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	50	50
Laclede Gas | 3.0% Series, due March 15, 2023
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	55	55
Laclede Gas | 3.4% Series, due August 15, 2023
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	250	250
Laclede Gas | 3.4% Series, due March 15, 2028
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	45	45
Laclede Gas | 7.0% Series, due June 1, 2029
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	25	25
Laclede Gas | 7.9% Series, due September 15, 2030
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	30	30
Laclede Gas | 6.0% Series, due May 1, 2034
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	100	100
Laclede Gas | 6.15% Series, due June 1, 2036
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	55	55
Laclede Gas | 4.625% Series, due August 15, 2043
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	100	100
Alagasco
Common Stock Equity:
Common stock, par value $1 per share, and paid-in capital	451.9	480.9
Retained earnings	415.4	393.7
Total Common Stock Equity	867.3	874.6
Long-Term Debt - Laclede Gas:
Total Long-Term Debt	250	170
Total Capitalization	1,117.3	1,044.6
Alagasco | 5.2% Notes, due January 15, 2020
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	40	40
Alagasco | 3.86% Notes, due December 23, 2021
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	50	50
Alagasco | 3.21% Notes, due September 15, 2025
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	35	35
Alagasco | 5.9% Notes, due January 15, 2037
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	45	45
Alagasco | 4.31% Notes, due December 1, 2045
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	80	0
Other | 3.10%, due December 30, 2018
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	5	0
Other | 4.14%, due September 30, 2021
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	20	0
Other | 5.00%, due September 30, 2031
Long-Term Debt - Laclede Gas:
Debt instrument, principal outstanding	$ 42	$ 0

CONSOLIDATED STATEMENTS OF CAP7

CONSOLIDATED STATEMENTS OF CAPITALIZATION (Parenthetical) - $ / shares	Sep. 30, 2016	Sep. 30, 2015
Long - Term Debt - Laclede Gas:
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	70,000,000	70,000,000
Common stock, outstanding (in shares)	45,650,642	43,335,012
Spire | 2.55% Senior Notes, due August 15, 2019
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	2.55%	2.55%
Spire | 2.52% Senior Notes, due September 1, 2021
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	2.52%	2.52%
Spire | 3.31% Notes Payable, due December 15, 2022
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.31%	3.31%
Spire | 2.0% Series A Remarketable Subordinated Notes, due April 1, 2022
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	2.00%	2.00%
Spire | 3.13% Senior Notes, due September 1, 2026
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.13%	3.13%
Spire | 4.70% Senior Notes, due August 15, 2044
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	4.70%	4.70%
Laclede Gas
Long - Term Debt - Laclede Gas:
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	50,000,000	50,000,000
Common stock, outstanding (in shares)	24,577	24,577
Laclede Gas | 2.0% Series, due August 15, 2018
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	2.00%	2.00%
Laclede Gas | 5.5% Series, due May 1, 2019
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	5.50%	5.50%
Laclede Gas | 3.0% Series, due March 15, 2023
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.00%	3.00%
Laclede Gas | 3.4% Series, due August 15, 2023
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.40%	3.40%
Laclede Gas | 3.4% Series, due March 15, 2028
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.40%	3.40%
Laclede Gas | 7.0% Series, due June 1, 2029
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	7.00%	7.00%
Laclede Gas | 7.9% Series, due September 15, 2030
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	7.90%	7.90%
Laclede Gas | 6.0% Series, due May 1, 2034
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	6.00%	6.00%
Laclede Gas | 6.15% Series, due June 1, 2036
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	6.15%	6.15%
Laclede Gas | 4.625% Series, due August 15, 2043
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	4.625%	4.625%
Alagasco
Long - Term Debt - Laclede Gas:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	3,000,000	3,000,000
Common stock, outstanding (in shares)	1,972,052	1,972,052
Alagasco | 5.2% Notes, due January 15, 2020
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	5.20%	5.20%
Alagasco | 3.86% Notes, due December 23, 2021
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.86%	3.86%
Alagasco | 3.21% Notes, due September 15, 2025
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.21%	3.21%
Alagasco | 5.9% Notes, due January 15, 2037
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	5.90%	5.90%
Alagasco | 4.31% Notes, due December 1, 2045
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	4.31%	4.31%
Other | 3.10%, due December 30, 2018
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	3.10%	3.10%
Other | 4.14%, due September 30, 2021
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	4.14%	4.14%
Other | 5.00%, due September 30, 2031
Long - Term Debt - Laclede Gas:
Debt instrument, interest rate, stated percentage	5.00%	5.00%

CONSOLIDATED STATEMENTS OF COMM

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock Outstanding	Paid-in Capital	Retained Earnings	AOCI	Laclede Gas	Laclede GasCommon Stock Outstanding	Laclede GasPaid-in Capital	Laclede GasRetained Earnings	Laclede GasAOCI	Alagasco	AlagascoCommon Stock Outstanding	AlagascoPaid-in Capital	AlagascoRetained Earnings
BALANCE (in shares) at Sep. 30, 2013		32,696,836					24,549
BALANCE at Sep. 30, 2013	$ 1,046.3	$ 32.7	$ 594.3	$ 420.1	$ (0.8)	$ 973.9	$ 0.1	$ 738.1	$ 237.8	$ (2.1)
Stockholders' Equity Rollforward
Net income	84.6			84.6		90.1			90.1
Common stock offering (in shares)		10,350,000					28
Common stock offering	456.8	$ 10.4	446.4			1.1		1.1
Equity units offering	(19.7)		(19.7)
Dividend reinvestment plan (in shares)		33,667
Dividend reinvestment plan	1.5	$ 0	1.5
Stock-based compensation costs	5.8		5.8			4.2		4.2
Equity Incentive Plan (in shares)		97,902
Equity Incentive Plan	1.7	$ 0.1	1.6
Employees’ taxes paid associated with restricted shares withheld upon vesting	(1.1)		(1.1)
Tax benefit - stock compensation	0.6		0.6			0.6		0.6
Dividends declared on common stock	(67.2)			(67.2)		(62.3)			(62.3)
Other comprehensive loss, net of tax	(0.9)				(0.9)	0.2				0.2
BALANCE (in shares) at Sep. 30, 2014		43,178,405					24,577					1,972,052
BALANCE at Sep. 30, 2014	1,508.4	$ 43.2	1,029.4	437.5	(1.7)	1,007.8	$ 0.1	744	265.6	(1.9)	$ 849.6	$ 0	$ 503.9	$ 345.7
BALANCE (in shares) at Dec. 31, 2013												1,972,052
BALANCE at Dec. 31, 2013											384.6	$ 0	34.5	350.1
Stockholders' Equity Rollforward
Net income											33			33
Purchase accounting adjustments											469.4		469.4
Dividends declared on common stock											(37.4)			(37.4)
BALANCE (in shares) at Sep. 30, 2014		43,178,405					24,577					1,972,052
BALANCE at Sep. 30, 2014	1,508.4	$ 43.2	1,029.4	437.5	(1.7)	1,007.8	$ 0.1	744	265.6	(1.9)	849.6	$ 0	503.9	345.7
Stockholders' Equity Rollforward
Net income	136.9			136.9		105.3			105.3		48			48
Purchase accounting adjustments											4		4
Dividend reinvestment plan (in shares)		31,166
Dividend reinvestment plan	1.6		1.6
Stock-based compensation costs	3		3			3.7		3.7
Equity Incentive Plan (in shares)		125,441
Equity Incentive Plan	5.1	$ 0.1	5
Employees’ taxes paid associated with restricted shares withheld upon vesting	(1.6)		(1.6)
Tax benefit - stock compensation	0.7		0.7			0.5		0.5
Dividends declared on common stock	(80.2)			(80.2)		(79.7)			(79.7)
Return of capital to Spire											(27)		(27)
Other comprehensive loss, net of tax	(0.3)				(0.3)	0.2				0.2
BALANCE (in shares) at Sep. 30, 2015		43,335,012					24,577					1,972,052
BALANCE at Sep. 30, 2015	1,573.6	$ 43.3	1,038.1	494.2	(2)	1,037.8	$ 0.1	748.2	291.2	(1.7)	874.6	$ 0	480.9	393.7
Stockholders' Equity Rollforward
Net income	144.2			144.2		105.9			105.9		53.2			53.2
Common stock offering (in shares)		2,185,000
Common stock offering	133.2	$ 2.2	131
Dividend reinvestment plan (in shares)		22,878
Dividend reinvestment plan	1.4		1.4
Stock-based compensation costs	2.2		2.2			3.7		3.7
Equity Incentive Plan (in shares)		107,752
Equity Incentive Plan	5.1	$ 0.1	5
Employees’ taxes paid associated with restricted shares withheld upon vesting	(1.8)		(1.8)
Dividends declared on common stock	(87.5)			(87.5)		(78.8)			(78.8)		(31.5)			(31.5)
Return of capital to Spire											(29)		(29)
Other comprehensive loss, net of tax	(2.2)				(2.2)	(0.1)				(0.1)
BALANCE (in shares) at Sep. 30, 2016		45,650,642					24,577					1,972,052
BALANCE at Sep. 30, 2016	$ 1,768.2	$ 45.6	$ 1,175.9	$ 550.9	$ (4.2)	$ 1,068.5	$ 0.1	$ 751.9	$ 318.3	$ (1.8)	$ 867.3	$ 0	$ 451.9	$ 415.4

CONSOLIDATED STATEMENTS OF COM9

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Statement of Stockholders' Equity [Abstract]
Dividends declared, common stock (in dollars per share)	$ 1.96	$ 1.84	$ 1.76

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Operating Activities:
Net income		$ 144.2	$ 136.9	$ 84.6
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion		137.5	130.8	83.3
Deferred income taxes and investment tax credits		68.8	65.5	31.4
Changes in assets and liabilities:
Accounts receivable – net		(12.3)	(4.8)	(5.3)
Unamortized purchased gas adjustments		(64.3)	46.9	(36.4)
Deferred purchased gas costs		11.5	(19.8)	13.9
Accounts payable		30	(30)	8.6
Delayed / advance customer billings – net		26.9	20.3	(19.1)
Taxes accrued		(0.4)	(17)	(0.8)
Inventories		16.5	54.8	(15.5)
Other assets and liabilities		(35)	(67.6)	(27.5)
Other		4.9	6.4	5.4
Net cash provided by operating activities		328.3	322.4	122.6
Investing Activities:
Capital expenditures		(293.3)	(289.8)	(171)
Acquisition of EnergySouth (net of $2.0 cash acquired)		(317.7)	0	0
Acquisition of Alagasco (net of $12.1 cash acquired in 2014)		0	(8.2)	(1,305.2)
Acquisition of MGE		0	0	23.9
Proceeds from sale of right to acquire New England Gas Company		0	0	11
Other		(1.7)	(0.7)	3.7
Net cash used in investing activities		(612.7)	(298.7)	(1,437.6)
Financing Activities:
Issuance of long-term debt		245	35	768.8
Repayment of long-term debt		(80)	(34.8)	(80)
Issuance of short-term debt - net		60.7	50.8	198.1
Issuance of common stock		137.1	3.1	460
Dividends paid		(85.2)	(79)	(61.9)
Other		(1.8)	(1.1)	(6.9)
Net cash provided by (used in) financing activities		275.8	(26)	1,278.1
Net Decrease in Cash and Cash Equivalents		(8.6)	(2.3)	(36.9)
Cash and Cash Equivalents at Beginning of Year		13.8	16.1	53
Cash and Cash Equivalents at End of Year	$ 16.1	5.2	13.8	16.1
Supplemental disclosure of cash (paid) refunded for:
Interest		(72.5)	(65.3)	(40.6)
Income taxes		2.9	1.3	(3.4)
Laclede Gas
Operating Activities:
Net income		105.9	105.3	90.1
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion		88.6	82.6	78.5
Deferred income taxes and investment tax credits		45.3	45.4	35.6
Changes in assets and liabilities:
Accounts receivable – net		35.7	9.9	(21.5)
Unamortized purchased gas adjustments		(30.2)	41.1	(36.4)
Deferred purchased gas costs		11.5	(19.8)	13.9
Accounts payable		0.9	(11.4)	6.8
Delayed / advance customer billings – net		24.9	17.9	(19.1)
Taxes accrued		4.9	(14.6)	10
Inventories		11	51.2	(26.4)
Other assets and liabilities		(29.6)	(32.8)	(3.3)
Other		2.3	2.8	2.8
Net cash provided by operating activities		271.2	277.6	131
Investing Activities:
Capital expenditures		(197.8)	(198.6)	(163)
Acquisition of MGE		0	0	23.9
Other		1.1	2.9	4.1
Net cash used in investing activities		(196.7)	(195.7)	(135)
Financing Activities:
Repayment of long-term debt		0	0	(80)
Issuance of short-term debt - net		10.7	(5.7)	164.6
Borrowings from Spire		0	18.4	276.1
Repayment of borrowings from Spire		0	(18.4)	(322.7)
Issuance of common stock		0	0	1.2
Dividends paid		(84.8)	(78.7)	(57.2)
Other		0	0.5	1.8
Net cash provided by (used in) financing activities		(74.1)	(83.9)	(16.2)
Net Decrease in Cash and Cash Equivalents		0.4	(2)	(20.2)
Cash and Cash Equivalents at Beginning of Year		1.7	3.7	23.9
Cash and Cash Equivalents at End of Year	3.7	2.1	1.7	3.7
Supplemental disclosure of cash (paid) refunded for:
Interest		(35.7)	(31)	(36.4)
Income taxes		2.1	0.7	(0.2)
Alagasco
Operating Activities:
Net income	33	53.2	48
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion	34.4	47.8	47.3
Deferred income taxes and investment tax credits	4	33.2	29.2
Changes in assets and liabilities:
Accounts receivable – net	26.4	(11.1)	(9.1)
Unamortized purchased gas adjustments	24.8	(33.8)	5.8
Accounts payable	(11.5)	9.1	(10.4)
Delayed / advance customer billings – net	(0.3)	2	2.4
Taxes accrued	1.9	(5.2)	(4)
Inventories	(11.8)	5.3	7.2
Other assets and liabilities	17.1	(3.2)	(18)
Other	(3)	0.9	2
Net cash provided by operating activities	115	98.2	100.4
Investing Activities:
Capital expenditures	(46.2)	(93.4)	(85.8)	(46.2)
Proceeds from the sale of assets	0.8	0	0
Other	0	(2.5)	(1)
Net cash used in investing activities	(45.4)	(95.9)	(86.8)
Financing Activities:
Issuance of long-term debt	0	80	35
Repayment of long-term debt	0	(80)	(34.8)
Issuance of short-term debt - net	(34)	51	15
Return of capital to Spire	0	(29)	(27)
Dividends paid	(37.4)	(31.5)	0
Other	4.4	0	(0.2)
Net cash provided by (used in) financing activities	(67)	(9.5)	(12)
Net Decrease in Cash and Cash Equivalents	2.6	(7.2)	1.6
Cash and Cash Equivalents at Beginning of Year	3	7.2	5.6
Cash and Cash Equivalents at End of Year	5.6	0	7.2	$ 5.6
Supplemental disclosure of cash (paid) refunded for:
Interest	(9.6)	(12.4)	(12.3)
Income taxes	$ (20.4)	$ 0.8	$ 0

CONSOLIDATED STATEMENTS OF CA11

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2014
Statement of Cash Flows [Abstract]
Cash acquired from acquisition	$ 2	$ 12.1

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES BASIS OF PRESENTATION – These notes are an integral part of the accompanying audited financial statements of Spire Inc. (Spire or the Company), as well as Laclede Gas Company (Laclede Gas or the Missouri Utilities) and Alabama Gas Corporation (Alagasco). Laclede Gas, which includes the operations of Missouri Gas Energy (MGE), and Alagasco are wholly owned subsidiaries of the Company. Laclede Gas, Alagasco and the subsidiaries of EnergySouth, Inc. (EnergySouth) are collectively referred to as the Utilities. The subsidiaries of EnergySouth are Mobile Gas Service Corporation (Mobile Gas) and Willmut Gas and Oil Company (Willmut Gas). The accompanying audited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The consolidated financial position, results of operations, and cash flows of Spire are primarily derived from the financial position, results of operations, and cash flows of the Utilities. In compliance with GAAP, transactions between Laclede Gas and Alagasco and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements. The Company’s September 12, 2016 acquisition of EnergySouth and the August 31, 2014 acquisition of Alagasco are included in the results of operations since their acquisition dates and impact the comparability of the financial statement periods presented for the Company. For a further discussion of the acquisitions, see Note 2 , Acquisitions. The Utilities are regulated natural gas distribution utilities. Due to the seasonal nature of the Utilities, the earnings of Spire, Laclede Gas and Alagasco are typically concentrated during the heating season of November through April each fiscal year. Effective September 2, 2014, Alagasco amended its bylaws to change Alagasco’s fiscal year from beginning January 1 and ending on December 31, to beginning October 1 and ending September 30. As a result, the financial statements covering the nine-month period from January 1, 2014 through September 30, 2014 (the “transition period”) were included in Alagasco’s transition report on Form 10-K/T for such period and are presented in the financial statements and notes herein. NATURE OF OPERATIONS – Spire Inc. (NYSE: SR), headquartered in St. Louis, Missouri, is a public utility holding company. The Company 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 generation. The Gas Utility segment is comprised of the operations of the Missouri Utilities, serving St. Louis and eastern Missouri, Kansas City and western Missouri (through MGE), Alagasco serving central and northern Alabama, and the subsidiaries of EnergySouth, serving southern Alabama and south-central Mississippi. Spire’s primary non-utility business, Laclede Energy Resources, Inc. (LER), included in the Gas Marketing segment, provides non-regulated natural gas services. The activities of other subsidiaries are described in Note 14 , Information by Operating Segment, and are reported as Other. Laclede Gas and Alagasco each have a single reportable segment. USE OF ESTIMATES – The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. SYSTEM OF ACCOUNTS – The accounts of the Utilities are maintained in accordance with the Uniform System of Accounts prescribed by the applicable state public service commissions, which systems substantially conform to that prescribed by the Federal Energy Regulatory Commission (FERC). UTILITY PLANT, DEPRECIATION AND AMORTIZATION – Utility plant is stated at original cost. The cost of additions to utility plant includes contracted work, direct labor and materials, allocable overheads, and an allowance for funds used during construction. The costs of units of property retired, replaced, or renewed are removed from utility plant and are charged to accumulated depreciation. Maintenance and repairs of property and replacement and renewal of items determined to be less than units of property are charged to maintenance expenses. For Laclede Gas, utility plant is depreciated on a straight-line basis at rates based on estimated service lives of the various classes of property. In fiscal years 2016 , 2015 and 2014 , annual depreciation and amortization expense averaged 3.0% of the original cost of depreciable and amortizable property. Laclede Gas’ capital expenditures were $197.8 , $198.6 and $163.0 for fiscal years 2016 , 2015 , and 2014 , respectively. Additionally, Laclede Gas had recorded accruals for capital expenditures totaling $14.8 at September 30, 2016 , $9.6 at September 30, 2015 , and $3.0 at September 30, 2014 . For Alagasco, depreciation is provided using the composite method of depreciation on a straight-line basis over the estimated useful lives of utility property at rates approved by the Alabama Public Service Commission (APSC). On June 28, 2010, the APSC approved a reduction in depreciation rates, effective June 1, 2010, for Alagasco with the revised prospective composite depreciation rate approximating 3.1% . As required by the APSC, Alagasco performed another depreciation study in 2015. The composite depreciation rate from this study was also approximately 3.1% . Alagasco anticipates refunding approximately $9.3 of refundable negative salvage costs through lower tariff rates over the next twelve months. Related to the lower depreciation rates, an estimated $18.7 of refundable negative salvage costs will be refunded to eligible customers on a declining basis through lower tariff rates over a three year period through 2019. Alagasco’s capital expenditures were $93.4 , $85.8 and $46.2 for fiscal years 2016 , 2015 , and 2014 , respectively. Additionally, Alagasco recorded accruals for capital expenditures totaling $6.8 at September 30, 2016 , $3.1 at September 30, 2015 and $5.0 at September 30, 2014 . Accrued capital expenditures are excluded from the capital expenditures included in the statements of cash flows of the Company, Laclede Gas and Alagasco. ASSET RETIREMENT OBLIGATIONS – Spire, Laclede Gas, and Alagasco record legal obligations associated with the retirement of long-lived assets in the period in which the obligations are incurred, if sufficient information exists to reasonably estimate the fair value of the obligations. Obligations are recorded as both a cost of the related long-lived asset and as a corresponding liability. Subsequently, the asset retirement costs are depreciated over the life of the asset and the asset retirement obligations are accreted to the expected settlement amounts. The Company, Laclede Gas and Alagasco record asset retirement obligations associated with certain safety requirements to purge and seal gas distribution mains upon retirement, the plugging and abandonment of storage wells and other storage facilities, specific service line obligations, and certain removal and disposal obligations related to components of Laclede Gas’, Alagasco’s and Mobile Gas’ distribution systems and general plant. Asset retirement obligations recorded by Spire’s other subsidiaries are not material. As authorized by the Missouri Public Service Commission (MoPSC) and APSC, Laclede Gas, Alagasco and Mobile Gas accrue future asset removal costs associated with their property, plant and equipment even if a legal obligation does not exist. Such accruals are provided for through depreciation expense and are recorded with corresponding credits to regulatory liabilities or assets. When those utilities retire depreciable utility plant and equipment, they charge the associated original costs to accumulated depreciation and amortization, and any related removal costs incurred are charged to regulatory liabilities or assets. The difference between removal costs recognized in depreciation rates and the accretion expense and depreciation expense recognized for financial reporting purposes is a timing difference between recovery of these costs in rates and their recognition for financial reporting purposes. Accordingly, these differences are deferred as regulatory liabilities or assets. In the rate setting process, the regulatory liability or asset is excluded from the rate base upon which those utilities have the opportunity to earn their allowed rates of return. The costs associated with asset retirement obligations of Laclede Gas, Alagasco and Mobile Gas are either currently being recovered in rates or are probable of recovery in future rates. The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets. Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Asset retirement obligations, beginning of year $ 159.2 $ 99.2 $ 72.4 $ 71.2 $ 86.6 $ 27.7 Liabilities incurred during the period 4.1 2.3 1.2 0.6 2.9 1.7 Liabilities settled during the period (9.5 ) (2.0 ) (1.9 ) (1.9 ) (6.8 ) (0.1 ) Accretion 13.2 4.5 3.5 3.4 9.7 1.1 Revisions in estimated cash flows 27.5 55.2 — (0.9 ) 27.7 56.2 Addition of EnergySouth asset retirement obligations 11.9 — — — — — Asset retirement obligations, end of year $ 206.4 $ 159.2 $ 75.2 $ 72.4 $ 120.1 $ 86.6 REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, “Regulated Operations.” This Topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. See additional discussion on regulated operations in Note 15 , Regulatory Matters. As discussed below for Laclede Gas and Alagasco, 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 rider are both labeled Unamortized Purchased Gas Adjustments herein. Laclede Gas As authorized by the MoPSC, the PGA clause allows Laclede Gas to flow through to customers, subject to prudence review by the MoPSC, the cost of purchased gas supplies. To better match customer billings with market natural gas prices, Laclede Gas is allowed to file to modify, on a periodic basis, the level of gas costs in its PGA. Certain provisions of the PGA clause are included below: • Laclede Gas has a risk management policy that allows for the purchase of natural gas derivative instruments with the goal of managing price risk associated with purchasing natural gas on behalf of its customers. The MoPSC clarified that costs, cost reductions, and carrying costs associated with the Utility’s use of natural gas derivative instruments are gas costs recoverable through the PGA mechanism. • The tariffs allow Laclede Gas flexibility to make up to three discretionary PGA changes during each year, in addition to its mandatory November PGA change, so long as such changes are separated by at least two months . • Laclede Gas is authorized to apply carrying costs to all over- or under-recoveries of gas costs, including costs and cost reductions associated with the use of derivative instruments, including cash payments for margin deposits. Laclede Gas’ eastern Missouri service territory is also authorized to recover gas inventory carrying costs through its PGA rates to recover costs it incurs to finance its investment in gas supplies that are purchased during the storage injection season for sale during the heating season. • The MoPSC approved a plan applicable to Laclede Gas’ gas supply commodity costs under which it retains a portion of cost savings associated with the acquisition of natural gas below an established benchmark level. This gas supply cost management program allows Laclede Gas to retain 10% of cost savings, up to a maximum of $3.0 annually. Laclede Gas did not record any income under the plan during the three fiscal years reported. Income recorded under the plan, if any, is included in Gas Utility Operating Revenues on the Consolidated Statements of Income and under Operating Revenues on Laclede Gas’ Statements of Income. Pursuant to the provisions of the PGA clause, the difference between actual costs incurred and costs recovered through the application of the PGA clause are reflected as a deferred charge or credit at the end of the fiscal year. These costs include costs and cost reductions associated with the use of derivative instruments and gas inventory carrying costs, amounts due to or from customers related to operation of the gas supply cost management program, refunds received from the Company’s suppliers in connection with gas supply, transportation, and storage services, and carrying costs on such over- or under-recoveries. At that time, the balance is classified as a current asset or current liability and recovered from, or credited to, customers over an annual period commencing in November. The balance in the current account is amortized as amounts are reflected in customer billings. The PGA clause also provides for the treatment of income from off-system sales and capacity release revenues. Pre-tax income from off-system sales and capacity release revenues is shared with customers, with an estimated amount assumed in PGA rates. The difference between the actual amount allocated to customers for each fiscal year and the estimated amount assumed in PGA rates is recovered from, or credited to, customers over an annual period commencing in the subsequent November. The customer share of such income is determined in accordance with the following tables, shown for each service territory for which the PGA clauses were approved by the MoPSC. Customer Share Company Share Eastern Missouri First $2.0* 100% —% Next $2.0 80% 20% Next $2.0 75% 25% Amounts exceeding $6.0 70% 30% * Customer share reverts to 85% and company share reverts to 15% in 2017. Western Missouri First $1.2 85% 15% Next $1.2 80% 20% Next $1.2 75% 25% Amounts exceeding $3.6 70% 30% Alagasco Alagasco’s rate schedules for natural gas distribution charges contain a GSA rider, established in 1993, which permits the pass-through to customers of changes in the cost of gas supply. Alagasco’s tariff provides a temperature adjustment mechanism, also included in the GSA rider, which is designed to moderate the impact of departures from normal temperatures on Alagasco’s earnings. The temperature adjustment applies primarily to residential, small commercial and small industrial customers. Other non-temperature weather-related conditions that may affect customer usage are not included in the temperature adjustment. NATURAL GAS AND PROPANE GAS – For Laclede Gas’ eastern Missouri utility, inventory of natural gas in storage is priced on a last in, first out (LIFO) basis and inventory of propane gas in storage is priced on a first in, first out (FIFO) basis. For the rest of the Gas Utility segment, inventory of natural gas in storage is priced on the weighted average cost basis. The replacement cost of Laclede Gas’ natural gas for current use in eastern Missouri at September 30, 2016 and September 30, 2015 was less than the LIFO cost by $11.4 and $20.4 , respectively. The carrying value of Laclede Gas’ inventory is not adjusted to the lower of cost or market prices because, pursuant to the Missouri Utilities’ PGA clauses, actual gas costs are recovered in customer rates. Natural gas and propane gas storage inventory in Spire’s other operating segments is recorded at the lower of average cost or market. BUSINESS COMBINATIONS – The EnergySouth and Alagasco acquisitions are accounted for by Spire using business combination accounting. Under this method, the purchase price paid by the acquirer is allocated to the assets acquired and liabilities assumed as of the acquisition date based on their fair value. For additional information on the acquisition of EnergySouth and Alagasco, refer to Note 2 , Acquisitions. GOODWILL – Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the amount of acquisition-date identifiable assets acquired net of assumed liabilities. Spire and Laclede Gas evaluate goodwill for impairment as of July 1st of each year, or more frequently if events and circumstances indicate that goodwill might be impaired. At July 1, 2016, 2015 and 2014, Spire and Laclede Gas each applied a quantitative goodwill evaluation model to their reporting units and concluded goodwill was not impaired because the fair value exceeded the carrying amount. The changes in the carrying amount of goodwill by reportable segment were as follows: Gas Utility Gas Marketing Other Total Balance as of September 30, 2013 $ 247.1 $ — $ — $ 247.1 Adjustments to finalize the 2013 acquisition of MGE (36.9 ) — — (36.9 ) Acquisition of Alagasco — — 727.6 727.6 Balance as of September 30, 2014 210.2 — 727.6 937.8 Adjustments to finalize the acquisition of Alagasco — — 8.2 8.2 Balance as of September 30, 2015 210.2 — 735.8 946.0 Acquisition of EnergySouth — — 218.9 218.9 Balance as of September 30, 2016 $ 210.2 $ — $ 954.7 $ 1,164.9 IMPAIRMENT OF LONG-LIVED ASSETS – Long-lived assets classified as held and used are evaluated for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Whether impairment has occurred is determined by comparing the estimated undiscounted cash flows attributable to the assets with the carrying value of the assets. If the carrying value exceeds the undiscounted cash flows, the Company recognizes an impairment charge equal to the amount of the carrying value that exceeds the estimated fair value of the assets. In the period in which the Company determines an asset meets held-for-sale criteria, an impairment charge is recorded to the extent the book value exceeds its fair value less cost to sell. REVENUE RECOGNITION – The Utilities read meters and bill customers on monthly cycles. The Missouri Utilities 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. The amounts of accrued unbilled revenues for Laclede Gas at September 30, 2016 and 2015 were $26.1 and $27.6 , respectively. Alagasco records natural gas distribution revenues in accordance with the tariff established by the APSC. The amount of accrued unbilled revenues, which are not recorded as revenues until billed, for Alagasco at September 30, 2016 and 2015 were $5.9 and $6.4 , respectively. All related costs and margins are also deferred. The subsidiaries of EnergySouth record natural gas revenues in accordance with tariffs established by the APSC and MSPSC. Unbilled revenues are accrued and related costs and margins are also deferred. Spire’s other subsidiaries, including LER, record revenues when earned, either when the product is delivered or when services are performed. In the course of its business, LER enters into commitments associated with the purchase or sale of natural gas. Certain of its derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of 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. For additional information on derivative instruments, refer to Note 10 , Derivative Instruments and Hedging Activities. Certain of LER’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 Consolidated Statements of Income. This net presentation has no effect on operating income or net income. INCOME TAXES – Spire and its subsidiaries account for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amount of existing assets and liabilities and the respective tax basis and for tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effects on deferred tax assets and liabilities of a change in enacted tax rates is recognized in income or loss for a non-regulated company, and in a regulatory asset or regulatory liability for a regulated company. A valuation allowance is established when it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with authoritative guidance. The authoritative guidance addresses the determination of whether tax benefits claimed, or expected to be claimed, on a tax return should be recorded in the financial statements. Spire may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by the taxing authority, based on the technical merits of the position. Tax-related interest and penalties, if any, are classified as a liability on the balance sheets. CASH AND CASH EQUIVALENTS – All highly liquid debt instruments purchased with original maturities of three months or less are considered to be cash equivalents. Such instruments are carried at cost, which approximates market value. Outstanding checks on the Company’s and Utilities’ bank accounts in excess of funds on deposit create book overdrafts (which are funded at the time checks are presented for payment) and are classified as Other in the Current Liabilities section of the balance sheets. Changes in book overdrafts are reflected as Operating Activities in the statements of cash flows. NATURAL GAS RECEIVABLE – LER enters into natural gas transactions with natural gas pipeline companies known as park and loan arrangements. Under the terms of the arrangements, LER purchases natural gas from a third party and delivers that natural gas to the pipeline company for the right to receive the same quantity of natural gas from the pipeline company at the same location in a future period. These arrangements are accounted for as non-monetary transactions under GAAP and are recorded at the carrying amount. As such, natural gas receivables are reflected on the Consolidated Balance Sheets at cost, which includes related pipeline fees associated with the transactions. In the period that the natural gas is returned to LER, concurrent with the sale of the natural gas to a third party, the related natural gas receivable is expensed in the Consolidated Statements of Income. In conjunction with these transactions, LER usually enters into New York Mercantile Exchange (NYMEX) and Intercontinental Exchange (ICE) natural gas futures, options, and swap contracts or fixed price sales agreements to protect against market changes in future sales prices. EARNINGS PER COMMON SHARE – GAAP requires dual presentation of basic and diluted earnings per share (EPS). EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareholders. Certain of the Company’s stock-based compensation awards pay non-forfeitable dividends to the participants during the vesting period and, as such, are deemed participating securities. Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding that are increased for additional shares that would be outstanding if potentially dilutive non-participating securities were converted to common shares, pursuant to the treasury stock method. Shares attributable to equity units, non-participating stock options and time-vested restricted stock/units are excluded from the calculation of diluted earnings per share if the effect would be antidilutive. Shares attributable to non-participating performance-contingent restricted stock awards are only included in the calculation of diluted earnings per share to the extent the underlying performance and/or market conditions are satisfied (a) prior to the end of the reporting period or (b) would be satisfied if the end of the reporting period were the end of the related contingency period and the result would be dilutive. The Company’s EPS computations are presented in Note 4 , Earnings Per Common Share. GROSS RECEIPTS AND SALES TAXES – Gross receipts taxes associated with the Company’s natural gas utility services are imposed on the Company, Laclede Gas, and Alagasco 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: 2016 2015 2014 Spire $ 75.5 $ 97.3 $ 77.5 Laclede Gas 57.4 74.5 76.3 Alagasco 17.9 22.6 20.6 Sales taxes imposed on applicable Alagasco and Laclede Gas 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. TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire. Other than borrowings from Spire reflected in Alagasco’s Balance Sheets and Statements of Cash Flows and normal intercompany shared services transactions, there were no transactions between Alagasco and affiliates. Laclede Gas had the following transactions with affiliates: 2016 2015 2014 Purchases of natural gas from LER $ 46.3 $ 74.1 $ 89.1 Sales of natural gas to LER 1.9 4.0 5.1 Services received from Laclede Insurance Risk Services, Inc. 1.8 1.0 0.6 ACCOUNTS RECEIVABLE AND ALLOWANCE FOR DOUBTFUL ACCOUNTS – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Estimates of the collectability of trade accounts receivable are based on historical trends, age of receivables, economic conditions, credit risk of specific customers, and other factors. Accounts receivable are written off against the allowance for doubtful accounts when they are deemed to be uncollectible. Spire’s provision for uncollectible accounts includes the amortization of previously deferred uncollectible expenses for Laclede Gas and Alagasco, as approved by the MoPSC and the APSC. FINANCE RECEIVABLES – Alagasco finances third party contractor sales of merchandise including gas furnaces and appliances. At September 30, 2016 and September 30, 2015 , the Company’s finance receivable totaled approximately $11.8 and $11.2 , respectively. Financing is available only to qualified customers who meet creditworthiness thresholds for customer payment history and external agency credit reports. Alagasco relies upon ongoing payments as the primary indicator of credit quality during the term of each contract. The allowance for credit losses is recognized using an estimate of write-off percentages based on historical experience applied to an aging of the finance receivable balance. Delinquent accounts are evaluated on a case-by-case basis and, absent evidence of debt repayment after 90 days, are due in full and assigned to a third party collection agency. The remaining finance receivable is written off approximately 12 months after being assigned to the third party collection agency. Alagasco had finance receivables past due 90 days or more of $0.4 at September 30, 2016 and September 30, 2015 . Alagasco recorded an allowance for credit losses at September 30, 2016 and September 30, 2015 of $0.4 . GROUP MEDICAL AND WORKERS’ COMPENSATION RESERVES – The Company self-insures its group medical and workers’ compensation costs and carries stop-loss coverage in relation to medical claims and workers’ compensation claims. Reserves for amounts incurred but not reported are established based on historical cost levels and lags between occurrences and reporting. FAIR VALUE MEASUREMENTS – Certain assets and liabilities are recognized or disclosed at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The levels of the hierarchy are described below: • Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2 – Pricing inputs other than quoted prices included within Level 1, which are either directly or indirectly observable for the asset or liability as of the reporting date. These inputs are derived principally from, or corroborated by, observable market data. • Level 3 – Pricing that is based upon inputs that are generally unobservable that are based on the best information available and reflect management’s assumptions about how market participants would price the asset or liability. Assessment of the significance of a particular input to the fair value measurements may require judgment and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. Additional information about fair value measurements is provided in Note 8 , Fair Value of Financial Instruments, Note 9 , Fair Value Measurements, and Note 13 , Pension Plans and Other Postretirement Benefits. STOCK-BASED COMPENSATION – The Company measures stock-based compensation awards at fair value at the date of grant and recognizes the compensation cost of the awards over the requisite service period. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if the actual forfeitures differ from those estimates. Refer to Note 3 , Stock-Based Compensation, for further discussion of the accounting for the Company’s stock-based compensation plans. REVISIONS TO PRIOR FINANCIAL STATEMENTS - Certain amounts in the prior period have been adjusted to conform with the current period presentation for Spire and Laclede Gas. The adjustment was related to the presentation of categories of deferred tax assets in Note 12 , Income Taxes. NEW ACCOUNTING PRONOUNCEMENTS – In May 2014, the FASB issued

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Spire’s recent acquisitions are described below. The following table summarizes the consideration paid and the amounts of the assets acquired and liabilities assumed at the acquisition dates. Measurement period adjustments were immaterial. Alagasco EnergySouth Recognized amounts of identifiable assets acquired and liabilities assumed: Utility plant $ 892.7 $ 199.5 Cash 12.1 2.0 Other current assets 99.4 17.5 Deferred tax assets 282.0 — Other assets 143.4 79.8 Long-term debt (249.8 ) (67.0 ) Current portion of long-term debt (15.0 ) — Other current liabilities (173.4 ) (42.7 ) Deferred tax liabilities — (35.5 ) Other liabilities (130.4 ) (52.8 ) Total identifiable net assets 861.0 100.8 Goodwill 735.8 218.9 Deferred tax elimination (Spire) (271.3 ) — Consideration (cash) $ 1,325.5 $ 319.7 Acquisition of Alagasco Spire completed the acquisition of 100% of the common stock of Alagasco from Energen effective on August 31, 2014. Total cash consideration paid at closing, net of cash acquired and debt assumed was $1,305.2 . Subsequently, the Company and Energen agreed to a final reconciliation of net assets, and $8.2 was paid by the Company to Energen on January 6, 2015, effectively increasing the total net consideration to $1,313.4 . The goodwill of $735.8 arising from this acquisition, $717.6 of which is expected to be deductible for tax purposes, is attributable to Alagasco’s assembled workforce and the expected cost efficiencies and strategic benefits of the transaction. The acquisition was supportive of the strategic focus on growing the Company’s regulated footprint and created geographic and regulatory diversity. The Company determined that the Alagasco acquisition met the scope exceptions for pushdown accounting; therefore, the goodwill was recorded on the Spire parent company balance sheet rather than the Alagasco subsidiary balance sheet and included in disclosures of segment assets under Other rather than the Gas Utility segment. The Company and Energen made an election under Section 338(h)(10) of the Internal Revenue Code of 1986, as amended, to treat the Alagasco acquisition as a deemed purchase and sale of assets for tax purposes. As a result of the election, goodwill was generated for tax purposes at Alagasco. For book purposes, as noted above, goodwill was recorded on the Spire parent entity and not pushed down to Alagasco. Consequently, a deferred tax asset (DTA) was recorded at Alagasco related to the excess of tax deductible goodwill over book goodwill for the stand-alone entity. That initial goodwill DTA is eliminated (along with the investment in subsidiary and Alagasco’s equity) in the Spire consolidated balance sheet because, at that consolidated level, there is no excess of tax deductible goodwill over book goodwill. As the tax goodwill is amortized and deducted for tax purposes, the DTA at Alagasco is reduced, and for Spire, a deferred tax liability (DTL) is created. For both Alagasco and consolidated Spire, the changes to the goodwill DTA/DTL are reported as a component of deferred tax expense in the income statement. Because the deferred tax expense impact will be offset by an opposite current tax expense impact, there will be no significant impact on the effective tax rate of the Company. Acquisition of EnergySouth Effective September 12, 2016, Spire completed the acquisition of 100% of the common stock of EnergySouth, the parent company of Mobile Gas and Willmut Gas, serving natural gas utility customers in Alabama and Mississippi. This acquisition is supportive of the strategic focus on growing Spire’s gas utility business and creating geographic and regulatory diversity. Total cash consideration paid at closing, net of cash acquired and debt assumed was $317.7 . The goodwill of $218.9 arising from this acquisition, which is not deductible for tax purposes, is attributable to the assembled workforce and the expected cost efficiencies and strategic benefits of the transaction. The Company did not elect pushdown accounting, so the goodwill was recorded on the Spire parent company balance sheet rather than the EnergySouth subsidiary balance sheet and is included in disclosures of segment assets under Other. Because the acquisition occurred near the end of the fiscal year and certain assessments are still in progress, the assignment of goodwill to reporting units has not yet been completed. Similarly, the recorded values of some of the assets acquired and liabilities assumed, such as those related to income taxes and contingencies, are provisional pending completion of analyses of those items. Actual and Pro Forma Results The results of operations of each of the acquisitions are included in the Spire statements of income from the date of acquisition, as shown in the following table. Alagasco EnergySouth 2016 2015 2014 2016 Total Operating Revenues $ 368.5 $ 479.2 $ 19.7 $ 3.3 Net Income (Loss) 53.2 48.0 (2.9 ) (0.2 ) Earnings (Loss) Per Share $ 1.20 $ 1.11 $ (0.08 ) $ — The following unaudited pro forma financial information presents Spire’s combined results of operations as though the EnergySouth acquisition had occurred as of the beginning of fiscal year 2015 and the Alagasco acquisition had occurred as of the beginning of fiscal year 2013. The unaudited pro forma financial information is not necessarily indicative of either future results of operations or results that would have been achieved if the acquisitions had occurred as of those earlier dates. It does not reflect the costs of any integration activities. It includes estimates and assumptions which management believes are reasonable. 2016 2015 2014 Total Operating Revenues $ 1,632.4 $ 2,081.6 $ 2,187.1 Net Income 153.9 143.6 133.5 Basic Earnings Per Share $ 3.48 $ 3.32 $ 3.11 Diluted Earnings Per Share 3.46 3.31 3.10

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Spire’s 2015 incentive plan, The Laclede Group 2015 Equity Incentive Plan (the 2015 Plan), was approved at the annual meeting of shareholders of Spire on January 29, 2015. The purpose of the 2015 Plan is to encourage directors, officers, and employees of the Company and its subsidiaries to contribute to the Company’s success and align their interests with that of shareholders. To accomplish this purpose, the Compensation Committee (Committee) of the Board of Directors may grant awards under the 2015 Plan that may be earned by achieving performance objectives and/or other criteria as determined by the Committee. Under the terms of the 2015 Plan, officers and employees of the Company and its subsidiaries, as determined by the Committee, are eligible to be selected for awards. The 2015 Plan provides for restricted stock, restricted stock units, qualified and non-qualified stock options, stock appreciation rights, and performance shares payable in stock, cash, or a combination of both. The 2015 Plan generally provides a minimum vesting period of at least three years for each type of award, with pro rata vesting permitted during the minimum three -year vesting period. The maximum number of shares reserved for issuance under the 2015 Plan is 1,000,000 . The 2015 Plan replaced The Laclede Group 2006 Equity Incentive Plan (the 2006 Plan), which in turn replaced The Laclede Group, Inc. 2002 Equity Incentive Plan (the 2002 Plan). Shares reserved under the 2006 Plan and the 2002 Plan, other than those needed for currently outstanding awards, were canceled upon shareholder approval of the 2015 Plan. The Company issues new shares to satisfy employee restricted stock awards and stock option exercises. Restricted Stock Awards During fiscal year 2016 , the Company granted 199,140 performance-contingent restricted share units to executive officers and key employees at a weighted average grant date fair value of $45.95 per share. This number represents the maximum shares that can be earned pursuant to the terms of the awards. The share units have a performance period ending September 30, 2018. While the participants have no interim voting rights on these share units, dividends accrue during the performance period and are paid to the participants upon vesting, but are subject to forfeiture if the underlying share units do not vest. The number of share units that will ultimately vest is dependent upon the attainment of certain levels of earnings and other strategic goals, as well as the Company’s level of total shareholder return (TSR) during the performance period relative to a comparator group of companies. This TSR provision is considered a market condition under GAAP and is discussed further below. The weighted average grant date fair value of performance-contingent restricted shares and share units granted during fiscal years 2015 and 2014 was $36.69 and $37.21 per share, respectively. Fiscal year 2016 activity of restricted stock and restricted stock units subject to performance and/or market conditions is presented below: Shares/ Units Weighted Average Grant Date Fair Value Per Share Nonvested at September 30, 2015 397,270 $ 36.28 Granted (maximum shares that can be earned) 199,140 $ 45.95 Vested (62,593 ) $ 35.29 Forfeited (23,234 ) $ 30.96 Nonvested at September 30, 2016 510,583 $ 40.37 During fiscal year 2016 , the Company granted 35,210 shares of time-vested restricted stock to executive officers and key employees at a weighted average grant date fair value of $59.40 per share. These shares were awarded between December 2015 and September 2016 and vest between December 2018 and September 2019 based on terms of the agreements. In the interim, participants receive full voting rights and dividends, which are not subject to forfeiture. The weighted average grant date fair value of time-vested restricted stock and restricted stock units awarded to employees during fiscal year 2015 and 2014 was $50.90 and $45.66 per share, respectively. During fiscal year 2016 , the Company granted 13,520 shares of time-vested restricted stock to non-employee directors at a weighted average grant date fair value of $63.93 per share. The weighted average grant date fair value of restricted stock awarded to non-employee directors during fiscal years 2015 and 2014 was $54.66 and $46.02 per share, respectively. Time-vested restricted stock and stock unit activity for fiscal year 2016 is presented below: Shares/ Units Weighted Average Grant Date Fair Value Per Share Nonvested at September 30, 2015 129,304 $ 44.89 Granted 48,730 $ 60.65 Vested (44,645 ) $ 47.30 Forfeited (610 ) $ 53.12 Nonvested at September 30, 2016 132,779 $ 49.83 During fiscal year 2016, 107,238 shares of restricted stock and stock units (performance-contingent and time-vested), awarded on October 1, 2012, December 3, 2012, February 1, 2013, June 3, 2013, and August 1, 2013 vested. The Company withheld 30,712 of the vested shares at a weighted average price of $57.29 per share pursuant to elections by employees to satisfy tax withholding obligations. During fiscal year 2015, 128,135 shares of restricted stock and stock units (performance-contingent and time-vested), awarded on December 1, 2011, May 1, 2012, December 2, 2013 and January 1, 2014 vested. The Company withheld 31,688 of the vested shares at a weighted average price of $50.65 per share pursuant to elections by employees to satisfy tax withholding obligations. During fiscal year 2014, 88,533 shares of restricted stock and stock units (performance-contingent and time-vested), awarded on December 1, 2010, September 1, 2011, October 1, 2012, January 30, 2014 and February 21, 2014 vested. The Company withheld 23,776 of these vested shares at a weighted average price of $45.96 per share pursuant to elections by employees to satisfy tax withholding obligations. The total fair value of restricted stock (performance-contingent and time-vested) vested during fiscal years 2016 , 2015 , and 2014 was $6.3 , $6.4 , and $4.1 , respectively, and the related tax benefit was $2.4 , $2.4 and $1.6 , respectively. None of the tax benefits have been realized. Stock Option Awards No stock options were granted during fiscal years 2016 , 2015 , and 2014 . Stock option activity for fiscal year 2016 is presented below: Stock Options Weighted Average Exercise Price Per Share Outstanding at September 30, 2015 28,500 $ 33.65 Exercised (27,750 ) $ 33.66 Forfeited (750 ) $ 33.45 Outstanding at September 30, 2016 — $ — During fiscal year 2016 , cash received from the exercise of stock options was $0.7 and the related intrinsic value was $0.7 . During fiscal year 2015 , cash received from the exercise of stock options was $1.5 and the related intrinsic value was $0.9 . During fiscal year 2014 , cash received from the exercise of stock options was $1.7 and the related intrinsic value was $0.9 . Related tax benefits were not material in any of those years. The closing price of the Company’s common stock was $63.74 per share at September 30, 2016 . Equity Compensation Costs Compensation cost for performance-contingent restricted stock and stock unit awards is based upon the probable outcome of the performance conditions. For shares or units that do not vest or that are not expected to vest due to the outcome of the performance conditions (excluding market conditions), no compensation cost is recognized and any previously recognized compensation cost is reversed. The fair value of awards of performance-contingent and time-vested restricted stock and restricted stock units, not subject to the TSR provision, are estimated using the closing price of the Company’s stock on the date of the grant. For those awards that do not pay dividends during the vesting period, the estimate of fair value is reduced by the present value of the dividends expected to be paid on the Company’s common stock during the performance period, discounted using an appropriate US Treasury yield. For shares subject to the TSR provision, the estimated impact of this market condition is reflected in the grant date fair value per share of the awards. Accordingly, compensation cost is not reversed to reflect any actual reductions in the awards that may result from the TSR provision. However, if the Company’s TSR during the performance period ranks below the level specified in the award agreements, relative to a comparator group of companies, and the Committee elects not to reduce the award (or reduce by a lesser amount), this election would be accounted for as a modification of the original award and additional compensation cost would be recognized at that time. The grant date fair value of the awards subject to the TSR provision awarded during fiscal years 2016 , 2015 , and 2014 was valued by a Monte Carlo simulation model that assessed the probabilities of various TSR outcomes. The significant assumptions used in the Monte Carlo simulations are as follows: 2016 2015 2014 Risk free interest rate 1.14% 0.83% 0.53% Expected dividend yield of stock — — — Expected volatility of stock 15.0% 14.0% 18.0% Vesting period 2.8 years 2.8 years 2.8 years The risk free interest rate was based on the yield on US Treasury securities matching the vesting period. A zero percent dividend yield was used, which is mathematically equivalent to the assumption that dividends are reinvested as they are paid. The expected volatility is based on the historical volatility of the Company’s stock. Volatility assumptions were also made for each of the companies included in the comparator group. The vesting period is equal to the performance period set forth in the terms of the award. The amounts of compensation cost recognized for share-based compensation arrangements are presented below: 2016 2015 2014 Total equity compensation cost $ 6.7 $ 6.7 $ 5.8 Compensation cost capitalized (2.2 ) (1.8 ) (1.8 ) Compensation cost recognized in net income $ 4.5 $ 4.9 $ 4.0 Income tax benefit recognized in net income (1.7 ) (1.9 ) (1.5 ) Compensation cost recognized in net income, net of income tax $ 2.8 $ 3.0 $ 2.5 As of September 30, 2016 , there was $9.2 of total unrecognized compensation cost related to non-vested share-based compensation arrangements. That cost is expected to be recognized over a weighted average period of 1.8 years .

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	12 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE 2016 2015 2014 Basic EPS: Net Income $ 144.2 $ 136.9 $ 84.6 Less: Income allocated to participating securities 0.5 0.5 0.3 Net Income Available to Common Shareholders $ 143.7 $ 136.4 $ 84.3 Weighted Average Shares Outstanding (millions) 44.1 43.2 35.8 Earnings Per Share of Common Stock $ 3.26 $ 3.16 $ 2.36 Diluted EPS: Net Income $ 144.2 $ 136.9 $ 84.6 Less: Income allocated to participating securities 0.5 0.5 0.3 Net Income Available to Common Shareholders $ 143.7 $ 136.4 $ 84.3 Weighted Average Shares Outstanding (millions) 44.1 43.2 35.8 Dilutive Effect of Stock Options, Restricted Stock, and Restricted Stock Units (millions) 0.2 0.1 0.1 Weighted Average Diluted Shares (millions) 44.3 43.3 35.9 Earnings Per Share of Common Stock $ 3.24 $ 3.16 $ 2.35 Outstanding Shares (in millions) Excluded from the Calculation of Diluted EPS Attributable to: Restricted stock and stock units subject to performance and/or market conditions 0.3 0.3 0.3 Spire’s 2014 2.0% Series Equity Units issued in June 2014 are potentially dilutive securities, but were excluded from the calculation of diluted EPS for the years ended September 30, 2016 , 2015 and 2014. The potential shares were not included in the outstanding shares excluded from the calculation of Diluted EPS in the table above. See Note 5 for more information.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Sep. 30, 2016
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Equity Units In June 2014, Spire issued 2.875 million equity units, initially consisting of Corporate Units, for an aggregate stated amount of approximately $143.8 . Each Corporate Unit has a stated amount of fifty dollars and consists of (i) a stock purchase contract obligating the holder to purchase shares of Spire’s common stock, par value $1.00 per share, and (ii) a 1/20, or 5% , undivided beneficial ownership interest in one thousand dollars principal amount of Spire’s 2014 Series A 2.00% Remarketable Junior Subordinated Notes due 2022 (RSNs). The stock purchase contracts obligate the holders to purchase shares of common stock at a future settlement date prior to the relevant RSN maturity date. The purchase price to be paid under the stock purchase contracts is fifty dollars per Corporate Unit and the number of shares to be purchased will be determined as follows: If the applicable market value per share of Spire common stock is: Number of shares to be purchased per purchase contract is: Equal to or greater than $57.8125 0.8649 Less than $57.8125, but greater than $46.25 $50 ÷ applicable market value Less than or equal to $46.25 1.0811 The RSNs are pledged as collateral to secure the purchase of Spire’s common stock under the related stock purchase contracts. The Company makes quarterly interest payments on the RSNs and quarterly contract adjustment payments on the stock purchase contracts, at the rates described below. The Company may defer payments on the stock purchase contracts and the RSNs for one or more consecutive periods but generally not beyond the purchase contract settlement date. If payments are deferred, interest on the RSNs and contract adjustment payments will compound on each respective payment date in which the payment was deferred. Also, during the deferral period, the Company may not make any cash distributions related to its capital stock, including dividends, redemptions, repurchases, liquidation payments or guarantee payments. Additionally, the Company may not make any payments on or redeem or repurchase any debt securities that are equal in right of payment with, or subordinated to, the RSNs during the deferral period. The Company has recorded the present value of the stock purchase contract payments as a liability offset by a charge to additional paid-in capital in equity. Interest payments on the RSNs are recorded as interest expense and stock purchase contract payments are charged against the liability. Accretion of the stock purchase contract liability is recorded as imputed interest expense. In calculating diluted EPS, the Company applies the treasury stock method to the Corporate Units. These securities did not have an effect on diluted EPS for the years ended September 30, 2016 and 2015. Under the terms of the stock purchase contracts, assuming no anti-dilution or other adjustments, Spire will issue between approximately 2.5 million and 3.1 million shares of its common stock in April 2017. A total of approximately 4.2 million shares of common stock have been reserved for issuance in connection with the stock purchase contracts. The stock purchase contracts obligate the holders to purchase shares of common stock at a future settlement date (April 1, 2017, or if such day is not a business day, the following business day) prior to the relevant RSN maturity date. Selected information about the Company’s equity units is presented below: Issuance Date Units Issued (Millions) Total Net Proceeds Total Long-term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Contract Liability 6/11/2014 2.875 $139.4 $143.8 2.00% 4.75% $19.7 Other Stock Information Spire On June 20, 2014, Spire filed a registration statement on Form S-3 for the issuance and sale of up to 168,698 shares of its common stock under its Dividend Reinvestment and Stock Purchase Program. There were 106,535 and 101,439 shares at September 30, 2016 and November 11, 2016 , respectively, remaining available for issuance under this Form S-3. On May 17, 2016, Spire completed a public offering of 2,185,000 shares of its common stock, generating $133.2 of proceeds net of issuance costs. On September 23, 2016, Spire and Laclede Gas filed with the SEC a joint shelf registration statement on Form S-3 for issuance of various types of debt and equity securities, which registration statement will expire September 22, 2019. The amount, timing, and type of additional financing to be issued under this shelf registration statement will depend on cash requirements and market conditions. At September 30, 2016 and 2015 , Spire had authorized 5,000,000 shares of preferred stock, but none were issued and outstanding. Laclede Gas Laclede Gas periodically sells shares of its stock to Spire at prices per share equal to book value on the last day of the quarter preceding each sale. There was no sale of shares to Spire during fiscal years 2016 or 2015. Laclede Gas sold 28 shares to Spire for $1.1 during fiscal year 2014. Exemption from registration for all of the sales was claimed under section 4(a)(2) of the Securities Act of 1933, as amended. Substantially all of Laclede Gas plant is subject to the liens of its first mortgage bonds. The mortgage contains several restrictions on Laclede Gas’ ability to pay cash dividends on its common stock or to make loans to its parent company. These mortgage restrictions are applicable regardless of whether the stock is publicly held or held solely by Laclede Gas’ parent company. Under the most restrictive of these provisions, no cash dividend may be declared or paid if, after the dividend, the aggregate net amount spent for all dividends after September 30, 1953 would exceed a maximum amount determined by a formula set out in the mortgage. Under that formula, the maximum amount is the sum of $8.0 plus earnings applicable to common stock (adjusted for stock repurchases and issuances) for the period from September 30, 1953 to the last day of the quarter before the declaration or payment date for the dividends. As of September 30, 2016 and 2015 , the amount under the mortgage’s formula that was available to pay dividends was $916.8 and $891.7 , respectively. Thus, all of Laclede Gas’ retained earnings were free from such dividend restrictions as of those dates. On September 23, 2016, Spire and Laclede Gas filed with the SEC a joint shelf registration statement on Form S-3 for issuance of various types of debt and equity securities, which registration statement will expire September 22, 2019. The amount, timing, and type of additional financing to be issued under this shelf registration statement will depend on cash requirements and market conditions, as well as future MoPSC authorizations. Laclede Gas has authority from the MoPSC to issue debt securities and preferred stock, including on a private placement basis, as well as to issue common stock, receive paid-in capital, and enter into capital lease agreements, all for a total of up to $300.0 . Laclede Gas has issued no securities under this authorization. At September 30, 2016 and 2015 , Laclede Gas had authorized 1,480,000 shares of preferred stock, but none were issued and outstanding. Alagasco At September 30, 2016 and 2015 , Alagasco has authorized 120,000 shares of preferred stock, but none were issued and outstanding. Other Comprehensive Income The components of accumulated other comprehensive income (loss), net of income taxes, recognized in the balance sheets at September 30 were as follows: Net Unrealized Gains (Losses) on Cash Flow Hedges Defined Benefit Pension and Other Postretirement Benefit Plans Net Unrealized Losses on Available for Sale Securities Total Spire Balance at September 30, 2014 $ 0.2 $ (1.9 ) $ — $ (1.7 ) Other comprehensive (loss) income (0.6 ) 0.4 (0.1 ) (0.3 ) Balance at September 30, 2015 (0.4 ) (1.5 ) (0.1 ) (2.0 ) Other comprehensive (loss) income (1.9 ) (0.3 ) — (2.2 ) Balance at September 30, 2016 $ (2.3 ) $ (1.8 ) $ (0.1 ) $ (4.2 ) Laclede Gas Balance at September 30, 2014 $ — $ (1.9 ) $ — $ (1.9 ) Other comprehensive (loss) income (0.2 ) 0.4 — 0.2 Balance at September 30, 2015 (0.2 ) (1.5 ) — (1.7 ) Other comprehensive income (loss) 0.3 (0.3 ) (0.1 ) (0.1 ) Balance at September 30, 2016 $ 0.1 $ (1.8 ) $ (0.1 ) $ (1.8 ) Income tax expense (benefit) recorded for items of other comprehensive income (loss) reported in the statements of comprehensive income is calculated by applying statutory federal, state, and local income tax rates applicable to ordinary income. The tax rates applied to individual items of other comprehensive income are similar within each reporting period. For the periods presented, Alagasco had no accumulated other comprehensive income (loss) balances.

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT Composition of long-term debt for Spire, Laclede Gas and Alagasco are shown in each registrant’s statements of capitalization as part of the financial statements. Maturities of long-term debt for Spire, Laclede Gas and Alagasco for the five fiscal years subsequent to September 30, 2016 are as follows: Spire Laclede Gas Alagasco 2017 $ 250.0 $ — $ — 2018 100.0 100.0 — 2019 180.0 50.0 — 2020 40.0 — 40.0 2021 55.0 — — Spire’s, Laclede Gas’ and Alagasco’s short-term credit facilities and long-term debt agreements contain customary covenants and default provisions. As of September 30, 2016 , there were no events of default under these covenants. The Company’s, Laclede Gas’, and Alagasco’s access to capital markets, including the commercial paper market, and their respective financing costs, may depend on the credit rating of the entity that is accessing the capital markets. The credit ratings of the Company, Laclede Gas and Alagasco remain at investment grade, but are subject to review and change by the rating agencies. It is management’s view that the Company, Laclede Gas and Alagasco have adequate access to capital markets and will have sufficient capital resources, both internal and external, to meet anticipated capital requirements, which primarily include capital expenditures, interest payments on long-term debt, scheduled maturities of long-term debt, short-term seasonal needs, and dividends. Spire Spire entered into a master note purchase agreement on June 20, 2016, with certain institutional purchasers pursuant to which Spire issued a total of $165.0 unsecured notes in the private placement market. These notes were issued on September 9, 2016 to fund a portion of the purchase price for the EnergySouth acquisition and consisted of $35 million in aggregate principal amount of its unsecured Series 2016 Senior Notes, Tranche A, due September 1, 2021 (Tranche A Notes) and $130 million in aggregate principal amount of its unsecured Series 2016 Senior Notes, Tranche B, due September 1, 2026 (Tranche B Notes). Tranche A Notes and Tranche B Notes bear interest at a rate per annum of 2.52% and 3.13% , respectively. At September 30, 2016 , including the current portion but excluding unamortized discounts and net hedging gains, Spire had long-term debt totaling $2,085.8 , of which $810.0 was issued by Laclede Gas, $250.0 was issued by Alagasco, and $67.0 was issued by other subsidiaries. With the exception of $250.0 floating rate senior notes issued by Spire, all long-term debt bears fixed rates and is subject to changes in fair value as market interest rates change. However, increases and decreases in fair value would impact earnings and cash flows only if the Company were to reacquire any of these issues in the open market prior to maturity. Under GAAP applicable to the Utilities’ regulated operations, losses or gains on early redemption of long-term debt typically would be deferred as regulatory assets or liabilities and amortized over a future period. Of the Company’s $1,942.0 senior long-term debt (including the current portion) , $25.0 have no call options, $937.0 have make-whole call options, $250.0 is callable currently, and $730.0 are callable at par between one to six months prior to maturity. The remainder of the Company’s long-term debt is $143.8 of 2% Remarketable Junior Subordinated Notes due in 2022. None of the debt has put options. Spire has a shelf registration statement on Form S-3 on file with the SEC for the issuance and sale of up to 168,698 shares of common stock under its Dividend Reinvestment and Direct Stock Purchase Plan. There were 106,535 and 101,439 at September 30, 2016 and November 11, 2016, respectively, remaining available for issuance under this Form S-3. Spire also has a shelf registration statement on Form S-3 on file with the SEC for the issuance of equity and debt securities. The Company’s capitalization at September 30, 2016 consisted of 49.1% of Spire common stock equity and 50.9% long-term debt, compared to 47.0% of Spire common stock equity and 53.0% of long-term debt at September 30, 2015 . The decline in the proportion of long-term debt is due primarily to the reclassification of $250.0 of Spire’s long-term debt to “current.” Laclede Gas At September 30, 2016 , Laclede Gas had fixed-rate long-term debt, including the current portion, totaling $810.0 . While these long-term debt issues are fixed-rate, they are subject to changes in fair value as market interest rates change. Of Laclede Gas’ $810.0 in long-term debt, $25.0 have no call options, $435.0 have make-whole call options and $350.0 are callable at par three to six months prior to maturity. None of the debt has any put options. Laclede Gas has authority from the MoPSC to issue debt securities and preferred stock, including on a private placement basis, as well as to issue common stock, receive paid-in-capital, and enter into capital lease agreements, all for a total of up to $300.0 for financings placed any time before September 30, 2018. On March 31, 2016, Laclede Gas filed an appeal with Missouri’s Western District Court of Appeals challenging the level of authority. On July 20, 2016, Laclede Gas filed its initial brief in the appeal. Oral arguments are scheduled for November 17, 2016. During the year ended September 30, 2016 , Laclede Gas issued no securities under this authorization, so that as of November 11, 2016, $300.0 remains available to be issued. On September 23, 2016, Laclede Gas filed a shelf registration on Form S-3 with the SEC for issuance of first mortgage bonds, unsecured debt, and preferred stock, which expires on September 22, 2019. The amount, timing, and type of additional financing to be issued under this shelf registration will depend on cash requirements and market conditions, as well as future MoPSC authorizations. This authorization is more fully described in Note 5 , Stockholders’ Equity. Laclede Gas’ capitalization at September 30, 2016 consisted of 56.9% of Laclede Gas common stock equity and 43.1% long-term debt compared to 56.2% of Laclede Gas common stock equity and 43.8% of long-term debt at September 30, 2015 . Substantially all of Laclede Gas’ plant is subject to the liens of its first mortgage bonds. The mortgage contains several restrictions on Laclede Gas’ ability to pay cash dividends on its common stock, which are described more fully in Note 5 , Stockholders’ Equity. Alagasco Because Alagasco has no standing authority to issue long-term debt, it must petition the APSC for each planned issuance. On November 3, 2014, Alagasco received authorization and approval from the APSC to borrow $35.0 for the purpose of redeeming, without penalty, $34.8 in existing long-term, callable debt financed at 5.7% . Pursuant to a call notice issued on December 15, 2014, Alagasco redeemed $34.8 of debt effective January 15, 2015. On February 3, 2015, Alagasco received authorization and approval from the APSC to borrow $80.0 for the purpose of refinancing the scheduled maturity on December 1, 2015 of $80.0 of existing debt. Pursuant to these authorizations, Alagasco committed to issue $115.0 unsecured notes in the private placement market: $35.0 at a rate of 3.21% for 10 years issued on September 15, 2015, and $80.0 at a rate of 4.31% for 30 years issued on December 1, 2015. The Notes are senior unsecured obligations of Alagasco and rank equal in right to payment with all other senior unsecured indebtedness. Alagasco used the proceeds from the sale of the Notes to refinance existing indebtedness and for general corporate purposes. At September 30, 2016 , Alagasco had fixed-rate long-term debt totaling $250.0 . While these long-term debt issues are fixed-rate, they are subject to changes in fair value as market interest rates change. All of Alagasco’s $250.0 long-term debt has make-whole call options. Alagasco’s capitalization at September 30, 2016 consisted of 77.6% of Alagasco common stock equity and 22.4% long-term debt compared to 83.7% of Alagasco common stock equity and 16.3% of long-term debt at September 30, 2015 .

NOTES PAYABLE AND CREDIT AGREEM

NOTES PAYABLE AND CREDIT AGREEMENTS	12 Months Ended
	Sep. 30, 2016
Short-term Debt [Abstract]
NOTES PAYABLE AND CREDIT AGREEMENTS	NOTES PAYABLE AND CREDIT AGREEMENTS Short-term cash requirements outside of the Utilities have generally been funded by Spire or met with internally generated funds. At September 30, 2016 , Spire had a $150.0 syndicated line of credit from nine banks maturing on September 3, 2019, with the largest portion provided by a single bank being 15.6% . The line of credit has a covenant limiting the total debt of the consolidated Spire to no more than 70% of the Company’s total capitalization. As defined in the line of credit, this ratio was 58.5% on September 30, 2016 . Spire’s line may be used to provide for the funding needs of various subsidiaries. The maturity date of the loan agreement is September 3, 2019. The Utilities’ short-term borrowing requirements typically peak during the colder months while the Company’s needs are less seasonal. These short-term cash requirements can be met through the sale of commercial paper supported by lines of credit with banks or through direct use of the lines of credit. At September 30, 2016 , Laclede Gas had a syndicated line of credit of $450.0 in place from ten banks. The largest portion provided by a single bank is 15.6% . Laclede Gas’ line of credit includes a covenant limiting total debt, including short-term debt, to no more than 70% of total capitalization. As defined in the line of credit, on September 30, 2016 total debt was 49.7% of total capitalization. Laclede Gas’ commercial paper program is backed by the line of credit. The maturity date of the line of credit is September 3, 2019. On September 2, 2014, Alagasco entered into a new $150.0 syndicated line of credit with twelve banks and extinguished the line that was in place prior to its acquisition by Spire. The largest portion provided by a single bank is 10% . The line of credit, which matures on September 2, 2019, has a covenant limiting total debt to no more than 70% of Alagasco’s total capitalization. As defined in the line of credit, this ratio stood at 27.8% on September 30, 2016 . Spire Information about Spire’s short-term borrowings (excluding intercompany borrowings) during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Laclede Gas Commercial Paper Borrowings Spire Bank Line Borrowings* Alagasco Bank Line Borrowings Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $201.0 $42.7 $30.2 $273.9 Weighted average interest rate 0.7% 1.6% 1.4% 0.9% Range of borrowings outstanding $43.0 - $307.2 $0.0 - $82.0 $0.0 - $82.0 $73.1 - $427.2 As of September 30, 2016 Borrowings outstanding at end of period $243.7 $73.0 $82.0 $398.7 Weighted average interest rate 0.8% 1.8% 1.5% 1.1% Year Ended September 30, 2015 Weighted average borrowings outstanding $212.7 $65.6 $22.3 $300.6 Weighted average interest rate 0.4% 1.4% 1.1% 0.7% Range of borrowings outstanding $ 102.1 - $341.0 $32.5 - $80.0 $0.0 - $69.5 $180.1 - $488.5 As of September 30, 2015 Borrowings outstanding at end of period $233.0 $74.0 $31.0 $338.0 Weighted average interest rate 0.5% 1.5% 1.2% 0.8% * Spire Inc., excluding its wholly owned subsidiaries. Based on average short-term borrowings for the twelve months ended September 30, 2016 , an increase in the average interest rate of 100 basis points would decrease Spire’s pre-tax earnings and cash flows by approximately $2.7 on an annual basis, portions of which may be offset through the application of PGA or GSA carrying costs. Laclede Gas Information about Laclede Gas’ short-term borrowings during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Commercial Paper Borrowings Borrowings from Spire Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $201.0 $14.7 $215.7 Weighted average interest rate 0.7% 0.8% 0.7% Range of borrowings outstanding $43.0 - $307.2 $0.0 - $114.2 $127.8 - $ 307.2 As of September 30, 2016 Borrowings outstanding at end of period $243.7 $— $243.7 Weighted average interest rate 0.8% —% 0.8% Year Ended September 30, 2015 Weighted average borrowings outstanding $212.7 $0.3 $213.0 Weighted average interest rate 0.4% 0.5% 0.4% Range of borrowings outstanding $102.1 - $341.0 $0.0 - $10.4 $104.2 - $ 341.0 As of September 30, 2015 Borrowings outstanding at end of period $233.0 $— $233.0 Weighted average interest rate 0.5% —% 0.5% Based on average short-term borrowings for the twelve months ended September 30, 2016 , an increase in the average interest rate of 100 basis points would decrease Laclede Gas’ pre-tax earnings and cash flows by approximately $2.2 on an annual basis, portions of which may be offset through the application of PGA carrying costs. Alagasco Information about Alagasco’s short-term borrowings during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Bank Line Borrowings Borrowings from Spire Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $30.2 $12.4 $42.6 Weighted average interest rate 1.4% 1.4% 1.4% Range of borrowings outstanding $0.0 - $82 $0.0 - $61.9 $19.0 - $82.0 As of September 30, 2016 Borrowings outstanding at end of period $82.0 $— $82.0 Weighted average interest rate 1.5% —% 1.5% Year Ended September 30, 2015 Weighted average borrowings outstanding $22.3 $— $22.3 Weighted average interest rate 1.1% —% 1.1% Range of borrowings outstanding $0.0 - $69.5 0 $0.0- $69.5 As of September 30, 2015 Borrowings outstanding at end of period $31.0 $— $31.0 Weighted average interest rate 1.2% —% 1.2% Based on average short-term borrowings for the twelve months ended September 30, 2016 , an increase in the average interest rate of 100 basis points would decrease Alagasco’s pre-tax earnings and cash flows by approximately $0.4 on an annual basis, portions of which may be offset through the application of GSA carrying costs.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS Spire The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for the Company are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ 5.2 $ 5.2 $ 5.2 $ — $ — Short-term debt 398.7 398.7 — 398.7 — Long-term debt, including current portion 2,083.7 2,257.1 — 2,257.1 — As of September 30, 2015 Cash and cash equivalents $ 13.8 $ 13.8 $ 13.8 $ — $ — Short-term debt 338.0 338.0 — 338.0 — Long-term debt, including current portion 1,851.5 1,944.2 — 1,944.2 — Laclede Gas The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Laclede Gas are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ 2.1 $ 2.1 $ 2.1 $ — $ — Short-term debt 243.7 243.7 — 243.7 — Long-term debt 808.3 900.4 — 900.4 — As of September 30, 2015 Cash and cash equivalents $ 1.7 $ 1.7 $ 1.7 $ — $ — Short-term debt 233.0 233.0 — 233.0 — Long-term debt 808.1 880.2 — 880.2 — Alagasco The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Alagasco are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ — $ — $ — $ — $ — Short-term debt 82.0 82.0 — 82.0 — Long-term debt 250.0 275.5 — 275.5 — As of September 30, 2015 Cash and cash equivalents $ 7.2 $ 7.2 $ 7.2 $ — $ — Short-term debt 31.0 31.0 — 31.0 — Long-term debt, including current portion 250.0 263.2 — 263.2 — The carrying amounts for 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 9 , Fair Value Measurements, for information on financial instruments measured at fair value on a recurring basis.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Spire 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 NYMEX. Derivative instruments classified as Level 2 include physical commodity derivatives that are valued using Over-the-Counter Bulletin Board (OTCBB), broker, or dealer quotation services whose prices are derived principally from, or are corroborated by, observable market inputs. Also included in Level 2 are certain derivative instruments that have values that are similar to, and correlate with, quoted prices for exchange-traded instruments in active markets. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. There were no material Level 3 balances as of September 30, 2016 or 2015 . 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 the “Other investments” line of the 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 exist between the Company or Laclede Gas and the counterparty to the derivative contract. For additional information on derivative instruments, see Note 10 , Derivative Instruments and Hedging Activities. 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, 2016 ASSETS Gas Utility US stock/bond mutual funds $ 16.8 $ 4.1 $ — $ — $ 20.9 NYMEX/ICE natural gas contracts 5.3 — — (0.4 ) 4.9 Gasoline and heating oil contracts 0.4 — — (0.3 ) 0.1 Subtotal 22.5 4.1 — (0.7 ) 25.9 Gas Marketing NYMEX/ICE natural gas contracts 0.4 3.4 — (3.4 ) 0.4 Natural gas commodity contracts — 8.7 0.2 (0.9 ) 8.0 Total $ 22.9 $ 16.2 $ 0.2 $ (5.0 ) $ 34.3 LIABILITIES Gas Utility NYMEX/ICE natural gas contracts $ 1.6 $ — $ — $ (1.6 ) $ — OTCBB natural gas contracts — 0.2 — — 0.2 Subtotal 1.6 0.2 — (1.6 ) 0.2 Gas Marketing NYMEX/ICE natural gas contracts 3.5 1.6 — (5.1 ) — Natural gas commodity contracts — 2.6 — (0.9 ) 1.7 Other Interest rate swaps — 3.0 — — 3.0 Total $ 5.1 $ 7.4 $ — $ (7.6 ) $ 4.9 As of September 30, 2015 ASSETS Gas Utility US stock/bond mutual funds $ 15.5 $ 4.0 $ — $ — $ 19.5 NYMEX/ICE natural gas contracts 1.3 — — (1.3 ) — Subtotal 16.8 4.0 — (1.3 ) 19.5 Gas Marketing NYMEX natural gas contracts 6.3 4.3 — (6.6 ) 4.0 Natural gas commodity contracts — 1.5 0.2 (0.5 ) 1.2 Total $ 23.1 $ 9.8 $ 0.2 $ (8.4 ) $ 24.7 LIABILITIES Gas Utility NYMEX/ICE natural gas contracts $ 16.4 $ — $ — $ (16.4 ) $ — OTCBB natural gas contracts — 5.9 — — 5.9 NYMEX gasoline and heating oil contracts 0.3 — — (0.3 ) — Subtotal 16.7 5.9 — (16.7 ) 5.9 Gas Marketing NYMEX/ICE natural gas contracts 1.2 3.9 — (5.1 ) — Natural gas commodity contracts — 2.2 — (0.5 ) 1.7 Total $ 17.9 $ 12.0 $ — $ (22.3 ) $ 7.6 Laclede Gas 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, 2016 ASSETS US stock/bond mutual funds $ 16.8 $ 4.1 $ — $ — $ 20.9 NYMEX/ICE natural gas contracts 5.3 — — (0.4 ) 4.9 Gasoline and heating oil contracts 0.3 — — (0.3 ) — Total $ 22.4 $ 4.1 $ — $ (0.7 ) $ 25.8 LIABILITIES NYMEX/ICE natural gas contracts $ 1.6 $ — $ — $ (1.6 ) $ — OTCBB natural gas contracts — 0.2 — — 0.2 Total $ 1.6 $ 0.2 $ — $ (1.6 ) $ 0.2 As of September 30, 2015 ASSETS US stock/bond mutual funds $ 15.5 $ 4.0 $ — $ — $ 19.5 NYMEX/ICE natural gas contracts 1.3 — — (1.3 ) — Total $ 16.8 $ 4.0 $ — $ (1.3 ) $ 19.5 LIABILITIES NYMEX/ICE natural gas contracts $ 16.4 $ — $ — $ (16.4 ) $ — OTCBB natural gas contracts — 5.9 — — 5.9 NYMEX gasoline and heating oil contracts 0.3 — — (0.3 ) — Total $ 16.7 $ 5.9 $ — $ (16.7 ) $ 5.9 Alagasco During the fiscal second quarter of 2016 Alagasco commenced a gasoline derivative program to stabilize the cost of fuel used in operations. As of September 30, 2016, the fair value of related gasoline contracts was not significant.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	12 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Spire Laclede Gas has a risk management policy to utilize various derivatives, including futures contracts, exchange-traded options, swaps and over-the-counter instruments for the explicit purpose of managing price risk associated with purchasing and delivering natural gas on a regular basis to customers in accordance with its tariffs. The objective of this policy is to limit Laclede Gas’ exposure to natural gas price volatility and to manage, hedge and mitigate substantial price risk. Further discussion of this policy can be found in the Laclede Gas section. From time to time Laclede Gas and Alagasco purchase NYMEX futures and options contracts to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment used in the course of their business. Further information on these derivatives can be found in the Laclede Gas and Alagasco sections, respectively. In the course of its business, Spire’s gas marketing subsidiary, LER, which includes its wholly owned subsidiary LER Storage Services, Inc., enters into commitments associated with the purchase or sale of natural gas. Certain of LER’s derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of ASC Topic 815 and are accounted for as executory contracts on an accrual basis. Any of LER’s derivative natural gas contracts that are not designated as normal purchases or normal sales are accounted for at fair value. At September 30, 2016 , the fair values of 122.7 million MMBtu of non-exchange traded natural gas commodity contracts were reflected in the Consolidated Balance Sheet. Of these contracts, 110.8 million MMBtu will settle during fiscal year 2017 , and 11.4 million MMBtu, 0.2 million MMBtu, and 0.3 million MMBtu will settle during 2018 , 2019 , and 2020 , respectively. These contracts have not been designated as hedges; therefore, changes in the fair value of these contracts are reported in earnings each period. Furthermore, LER manages the price risk associated with its fixed-priced commitments by either closely matching the offsetting physical purchase or sale of natural gas at fixed prices or through the use of NYMEX or ICE futures, swap, and option contracts to lock in margins. At September 30, 2016 , LER’s unmatched fixed-price positions were not material to Spire’s financial position or results of operations. LER’s NYMEX and ICE natural gas futures, swap, and option contracts used to lock in margins may be designated as cash flow hedges of forecasted transactions for financial reporting purposes. On April 14, 2014, as amended on July 8, 2014, Spire entered into certain interest rate swap agreements, with a notional amount $375.0 , to effectively lock in interest rates on a portion of the long-term debt it anticipated issuing to finance its acquisition of Alagasco. These derivative instruments were designated as cash flow hedges of forecasted transactions. These forward starting swaps involved the payment of a fixed interest rate and the receipt of a floating interest rate (the London Interbank Offered Rate, also known as LIBOR) over the terms specified in the contracts. On August 6, 2014, the interest rate swap agreements were terminated and the settlement resulted in a $19.0 loss by Spire, which assigned the loss as a regulatory asset since the interest rate swaps were entered into to hedge the interest payments on the $625.0 of long-term debt issued on August 19, 2014 by Spire. During the second quarter of fiscal year 2015, Alagasco entered into certain interest rate swap transactions to protect itself against adverse movement in interest rates in anticipation of its issuance of $115.0 of long-term debt. Alagasco received prior approval from the APSC to enter into these hedges. The notional amount of interest rate swaps outstanding was $80.5 with stated maturities ranging from 2025 to 2045 and fixed interest rates ranging between 2.18% and 2.85% . In April 2015, Alagasco entered into an additional hedge with a notional amount of $24.0 and terms within the same range. These derivative instruments were designated as cash flow hedges of forecasted transactions. These forward starting swaps involved the payment of a fixed interest rate and the receipt of LIBOR over the terms specified in the contracts. On May 21, 2015, the interest rate swap agreements were terminated and the settlement resulted in a $2.7 gain which was recorded as a regulatory liability. Of the total issuance of long-term debt, $35.0 was issued on September 15, 2015 and the remaining $80.0 was issued on December 1, 2015. During the second quarter of fiscal 2016, Spire entered into five -year interest rate swap transactions with a fixed interest rate of 1.776% and a notional amount of $105.0 to protect itself against adverse movement in interest rates in anticipation of the issuance of long-term debt in 2017. During the third quarter of 2016, the Company entered into seven -year swap transactions with an average fixed interest rate of 1.501% and a notional amount of $120.0 to hedge against additional debt expected to be issued in 2017 or early 2018. As a result, a $1.0 mark-to-market gain and $3.0 mark-to-market losses were recognized for the three and twelve months ended September 30, 2016, respectively. On May 5, 2016, Spire entered into certain interest rate swap agreements, with a notional amount of $85.0 , to effectively lock in interest rates on a portion of the long-term debt it anticipated issuing to finance its acquisition of EnergySouth. These derivative instruments were designated as cash flow hedges of forecasted transactions. On June 3, 2016, the interest rate swap agreements were terminated and the settlement resulted in a $0.4 payment recorded in accumulated other comprehensive loss to be amortized over the life of the related debt issuances. The Company’s and Laclede Gas’ exchange-traded/cleared derivative instruments consist primarily of NYMEX, OTCBB, and ICE positions. The NYMEX and OTCBB is the primary national commodities exchange on which natural gas derivatives are traded. Open NYMEX/ICE and OTCBB natural gas futures and swap positions at September 30, 2016 were as follows: Gas Utility Gas Marketing MMBtu (millions) Avg. Price Per MMBtu MMBtu (millions) Avg. Price Per MMBtu NYMEX/ICE Open short futures positions Fiscal 2017 — $ — 12.20 $ 2.86 Fiscal 2018 — — 1.27 2.95 NYMEX/ICE Open long futures/swap positions Fiscal 2017 18.43 2.95 4.62 3.12 Fiscal 2018 0.33 2.83 0.45 3.02 Fiscal 2019 — — 0.04 2.89 ICE Open long basis swap positions Fiscal 2017 — — 16.62 0.34 Fiscal 2018 — — 2.01 0.43 Fiscal 2019 — — 0.08 0.40 ICE Open short basis swap positions Fiscal 2017 — — 11.88 0.19 Fiscal 2018 — — 0.93 0.27 Fiscal 2019 — — 2.27 0.13 OTC Open long futures/swap positions Fiscal 2017 0.32 3.64 — — At September 30, 2016 , Laclede Gas also had 19.8 million MMBtu of other price mitigation in place through the use of NYMEX and OTCBB natural gas option-based strategies while LER had none. Derivative instruments designated as cash flow hedges of forecasted transactions are recognized on the balance sheets of the Company at fair value and the change in the fair value of the effective portion of these hedge instruments is recorded, net of tax, in other comprehensive income or loss (OCI). Accumulated other comprehensive income or loss (AOCI) is a component of Total Common Stock Equity. Amounts are reclassified from AOCI into earnings when the hedged items affect net income, using the same revenue or expense category that the hedged item impacts. Based on market prices at September 30, 2016 , it is expected that an immaterial amount of unrealized gains will be reclassified into the Consolidated Statements of Income of the Company during the next twelve months. Cash flows from hedging transactions are classified in the same category as the cash flows from the items that are being hedged in the Consolidated Statements of Cash Flows. Effect of Derivative Instruments on the Consolidated Statements of Income and Consolidated Statements of Comprehensive Income Location of Gain (Loss) Recorded in Income 2016 2015 2014 Derivatives in Cash Flow Hedging Relationships Effective portion of gain (loss) recognized in OCI on derivatives: Gas Marketing natural gas contracts $ (0.6 ) $ (4.3 ) $ (4.6 ) Gas Utility gasoline and heating oil contracts — (1.2 ) 0.1 Interest Rate Swaps (3.4 ) — — Total $ (4.0 ) $ (5.5 ) $ (4.5 ) Effective portion of gain (loss) reclassified from AOCI to income: Natural gas contracts Gas Marketing Operating Revenues $ 4.3 $ 1.7 $ 4.2 Gas Marketing Operating Expenses (4.9 ) (5.2 ) (1.5 ) Subtotal (0.6 ) (3.5 ) 2.7 Gasoline and heating oil contracts Gas Utility Other Operating Expenses (0.5 ) (0.9 ) (0.2 ) Total $ (1.1 ) $ (4.4 ) $ 2.5 Ineffective portion of gain (loss) on derivatives recognized in income: Natural gas contracts Gas Marketing Operating Revenues $ 0.1 $ — $ (0.1 ) Gas Marketing Operating Expenses 0.1 (0.5 ) 0.1 Subtotal 0.2 (0.5 ) — Gasoline and heating oil contracts Gas Utility Other Operating Expenses 0.1 0.1 (0.2 ) Total $ 0.3 $ (0.4 ) $ (0.2 ) Derivatives Not Designated as Hedging Instruments* Gain (loss) recognized in income on derivatives: Natural gas commodity contracts Gas Marketing Operating Revenues $ 12.3 $ (1.3 ) $ (8.7 ) NYMEX / ICE natural gas contracts Gas Marketing Operating Revenues (1.7 ) (9.6 ) 3.0 Gasoline and heating oil contracts Other Income and (Income Deductions) - Net — (0.2 ) — Total $ 10.6 $ (11.1 ) $ (5.7 ) * Gains and losses on Laclede Gas’ natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Missouri Utilities’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the statements of income. Such amounts are recognized in the statements of income as a component of Regulated Gas Distribution Natural and Propane Gas operating expenses when they are recovered through the PGA clause and reflected in customer billings. Fair Value of Derivative Instruments in the Consolidated Balance Sheet Asset Derivatives* Liability Derivatives* September 30, 2016 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gas Utility: Gasoline and heating oil contracts Derivative Instrument Assets $ 0.3 Derivative Instrument Assets $ — Gas Marketing: Natural gas contracts Derivative Instrument Assets 2.5 Derivative Instrument Assets 0.8 Deferred Charges – Other 0.4 Deferred Charges – Other 0.1 Other: Interest swaps Derivative Instrument Assets — Derivative Instrument Assets 3.0 Subtotal 3.2 3.9 Derivatives not designated as hedging instruments Gas Utility: Natural gas contracts Accounts Receivable – Other 5.4 Accounts Receivable – Other 1.6 Derivative Instrument Assets — Derivative Instrument Assets 0.2 Gas Marketing: NYMEX / ICE natural gas contracts Derivative Instrument Assets 0.8 Derivative Instrument Assets 4.1 Deferred Charges – Other — Deferred Charges – Other 0.1 Natural gas commodity Derivative Instrument Assets 6.5 Derivative Instrument Assets 0.2 Other Deferred Charges 2.1 Other Deferred Charges 0.3 Current Liabilities – Other 0.2 Current Liabilities – Other 2.0 Deferred Credits – Other 0.2 Deferred Credits – Other 0.1 Subtotal 15.2 8.6 Total derivatives $ 18.4 $ 12.5 September 30, 2015 Derivatives designated as hedging instruments Gas Utility: Gasoline and heating oil contracts Accounts Receivable – Other $ — Accounts Receivable – Other $ 0.3 Gas Marketing: Natural gas contracts Derivative Instrument Assets 4.1 Derivative Instrument Assets 3.2 Deferred Charges – Other 1.1 Deferred Charges – Other 0.5 Subtotal 5.2 4.0 Derivatives not designated as hedging instruments Gas Utility: Natural gas contracts Accounts Receivable – Other 1.2 Accounts Receivable – Other 16.4 Derivative Instrument Assets — Derivative Instrument Assets 5.7 Deferred Charges – Other — Deferred Charges – Other 0.2 Gas Marketing: NYMEX / ICE natural gas contracts Derivative Instrument Assets 4.7 Derivative Instrument Assets 0.6 Deferred Charges – Other 0.7 Deferred Charges – Other 0.7 Natural gas commodity Derivative Instrument Assets 1.4 Derivative Instrument Assets 0.1 Current Liabilities – Other 0.2 Current Liabilities – Other 1.4 Deferred Credits – Other 0.1 Deferred Credits – Other 0.7 Subtotal 8.3 25.8 Total derivatives $ 13.5 $ 29.8 * The fair values of Asset Derivatives and Liability Derivatives exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9 , Fair Value Measurements, for information on the valuation of derivative instruments. Following is a reconciliation of the amounts in the tables above to the amounts presented in the Consolidated Balance Sheets: 2016 2015 Fair value of asset derivatives presented above $ 18.4 $ 13.5 Fair value of cash margin receivables offset with derivatives 2.5 13.9 Netting of assets and liabilities with the same counterparty (7.6 ) (22.2 ) Total $ 13.3 $ 5.2 Derivative Instrument Assets, per Consolidated Balance Sheets: Derivative instrument assets $ 11.4 $ 4.6 Deferred Charges – Other 1.9 0.6 Total $ 13.3 $ 5.2 Fair value of liability derivatives presented above $ 12.5 $ 29.8 Netting of assets and liabilities with the same counterparty (7.6 ) (22.2 ) Total $ 4.9 $ 7.6 Derivative Instrument Liabilities, per Consolidated Balance Sheets: Current Liabilities – Other $ 4.8 $ 6.8 Deferred Credits – Other 0.1 0.8 Total $ 4.9 $ 7.6 Additionally, at September 30, 2016 and 2015 , the Company had $2.9 and $5.9 , respectively, in cash margin receivables not offset with derivatives, which are presented in Accounts Receivable – Other. Laclede Gas Laclede Gas has a risk management policy to utilize various derivatives, including futures contracts, exchange-traded options, swaps and over-the-counter instruments for the explicit purpose of managing price risk associated with purchasing and delivering natural gas on a regular basis to customers in accordance with its tariffs. The objective of this policy is to limit Laclede Gas’ exposure to natural gas price volatility and to manage, hedge and mitigate substantial price risk. This policy strictly prohibits speculation and permits Laclede Gas to hedge current physical natural gas purchase commitments or forecasted or anticipated future peak (maximum) physical need for natural gas delivered. Costs and cost reductions, including carrying costs, associated with Laclede Gas’ use of natural gas derivative instruments are allowed to be passed on to Laclede Gas customers through the operation of its PGA clause, through which the MoPSC allows Laclede Gas to recover gas supply costs, subject to prudence review by the MoPSC. Accordingly, Laclede Gas does not expect any adverse earnings impact as a result of the use of these derivative instruments. Laclede Gas does not designate these instruments as hedging instruments for financial reporting purposes because gains or losses associated with the use of these derivative instruments are deferred and recorded as regulatory assets or regulatory liabilities pursuant to ASC Topic 980, “Regulated Operations,” and, as a result, have no direct impact on the statements of income. The timing of the operation of the PGA clause may cause interim variations in short-term cash flows, because Laclede Gas is subject to cash margin requirements associated with changes in the values of these instruments. Nevertheless, carrying costs associated with such requirements are recovered through the PGA clause. From time to time, Laclede Gas purchases NYMEX futures and options contracts to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment used in the course of its business. At September 30, 2016 , Laclede Gas held 1.8 million gallons of gasoline futures contracts at an average price of $1.37 per gallon. Most of these contracts, the longest of which extends to December 2016, are designated as cash flow hedges of forecasted transactions pursuant to ASC Topic 815, “Derivatives and Hedging.” The gains or losses on these derivative instruments are not subject to Laclede Gas’ PGA clause. Derivative instruments designated as cash flow hedges of forecasted transactions are recognized on the balance sheets at fair value and the change in the fair value of the effective portion of these hedge instruments is recorded, net of tax, in OCI. AOCI is a component of Total Common Stock Equity. Amounts are reclassified from AOCI into earnings when the hedged items affect net income, using the same revenue or expense category that the hedged item impacts. Based on market prices at September 30, 2016 , it is expected that an immaterial amount of pre-tax gains will be reclassified into the statements of income during fiscal year 2016. Cash flows from hedging transactions are classified in the same category as the cash flows from the items that are being hedged in the statements of cash flows. Laclede Gas’ derivative instruments consist primarily of NYMEX and OTCBB positions. The NYMEX is the primary national commodities exchange on which natural gas derivatives are traded. Open NYMEX and OTCBB natural gas futures positions at September 30, 2016 were as follows: MMBtu (millions) Avg. Price Per MMBtu NYMEX/ICE Open long futures/swap positions Fiscal 2017 18.43 $ 2.95 Fiscal 2018 0.33 2.83 OTC Open long futures/swap positions Fiscal 2017 0.32 $ 3.64 At September 30, 2016 , Laclede Gas also had 19.8 million MMBtu of other price mitigation in place through the use of NYMEX and OTCBB natural gas option-based strategies. Effect of Derivative Instruments on the Statements of Income and Statements of Comprehensive Income Location of Gain (Loss) Recorded in Income 2016 2015 2014 Derivatives in Cash Flow Hedging Relationships Effective portion of gain (loss) recognized in OCI on derivatives: Gasoline and heating oil contracts $ — $ (1.2 ) $ 0.1 Effective portion of gain (loss) reclassified from AOCI to income: Gasoline and heating oil contracts Gas Utility Other Operating Expenses $ (0.5 ) $ (0.9 ) $ (0.2 ) Ineffective portion of gain (loss) on derivatives recognized in income: Gasoline and heating oil contracts Gas Utility Other Operating Expenses $ 0.1 $ 0.1 $ (0.2 ) Derivatives Not Designated as Hedging Instruments* Gain (loss) recognized in income on derivatives: Gasoline and heating oil contracts Other Income and (Income Deductions) - Net $ — $ (0.2 ) $ — * Gains and losses on Laclede Gas’ natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Laclede Gas’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the Statements of Income. Such amounts are recognized in the Statements of Income as a component of Regulated Gas Distribution Natural and Propane Gas operating expenses when they are recovered through the PGA clause and reflected in customer billings. Fair Value of Derivative Instruments in the Balance Sheet at September 30, 2016 Asset Derivatives* Liability Derivatives* Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gasoline and heating oil contracts Derivative Instrument Assets $ 0.3 Derivative Instrument Assets $ — Subtotal 0.3 — Derivatives not designated as hedging instruments Natural gas contracts Accounts Receivable – Other 5.4 Accounts Receivable – Other 1.6 OTCBB natural gas contracts Derivative Instrument Assets — Derivative Instrument Assets 0.2 Subtotal 5.4 1.8 Total derivatives $ 5.7 $ 1.8 Fair Value of Derivative Instruments in the Balance Sheet at September 30, 2015 Asset Derivatives Liability Derivatives* Balance Sheet Location Fair Value * Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gasoline and heating oil contracts Accounts Receivable – Other $ — Accounts Receivable – Other $ 0.3 Subtotal — 0.3 Derivatives not designated as hedging instruments Natural gas contracts Accounts Receivable – Other 1.2 Accounts Receivable – Other 16.4 Derivative Instrument Assets — Derivative Instrument Assets 5.7 Deferred Charges - Other — Deferred Charges - Other 0.2 Subtotal 1.2 22.3 Total derivatives $ 1.2 $ 22.6 * The fair values of Asset Derivatives and Liability Derivatives exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the Balance Sheets. As such, the gross balances presented in the table above are not indicative of Laclede Gas’ net economic exposure. Refer to Note 9 , Fair Value Measurements, for information on the valuation of derivative instruments. Following is a reconciliation of the amounts in the tables above to the amounts presented in Laclede Gas’ Balance Sheets: 2016 2015 Fair value of asset derivatives presented above $ 5.7 $ 1.2 Fair value of cash margin receivables offset with derivatives 0.8 15.5 Netting of assets and liabilities with the same counterparty (1.6 ) (16.7 ) Total $ 4.9 $ — Derivative Instrument Assets, per Balance Sheets: Derivative instrument assets $ 4.9 $ — Total $ 4.9 $ — Fair value of liability derivatives presented above $ 1.8 $ 22.6 Netting of assets and liabilities with the same counterparty (1.6 ) (16.7 ) Total $ 0.2 $ 5.9 Derivative Instrument Liabilities, per Balance Sheets: Current Liabilities – Other $ 0.2 $ 5.7 Deferred Credits – Other — 0.2 Total $ 0.2 $ 5.9 Additionally, at September 30, 2016 and 2015, Laclede Gas had $0.5 and $5.9 , respectively, in cash margin receivables not offset with derivatives, which are presented in Accounts Receivable – Other. Alagasco In prior years, Alagasco entered into cash flow derivative commodity instruments to hedge its exposure to price fluctuations on its gas supply. Alagasco recognizes all derivatives at fair value as either assets or liabilities on the balance sheet. Any realized gains or losses are passed through to customers using the mechanisms of the GSA rider in accordance with Alagasco’s APSC approved tariff. During the second quarter of fiscal year 2015, Alagasco entered into certain interest rate swap transactions to protect itself against adverse movement in interest rates in anticipation of its issuance of $115.0 of long-term debt. Alagasco received prior approval from the APSC to enter into these hedges. The notional amount of interest rate swaps outstanding was $80.5 with stated maturities ranging from 2025 to 2045 and fixed interest rates ranging between 2.18% and 2.85% . In April 2015, Alagasco entered into an additional hedge with a notional amount of $24.0 and terms within the same range. These derivative instruments were designated as cash flow hedges of forecasted transactions. These forward starting swaps involved the payment of a fixed interest rate and the receipt of LIBOR over the terms specified in the contracts. On May 21, 2015, the interest rate swap agreements were terminated and the settlement resulted in a $2.7 gain which was recorded as a regulatory liability. Of the total issuance of long-term debt, $35.0 was issued on September 15, 2015 and the remaining $80.0 was issued on December 1, 2015. During the fiscal second quarter of 2016, Alagasco commenced a gasoline derivative program to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment used in the course of its business. At September 30, 2016 , Alagasco held 0.6 million gallons of gasoline futures contracts at an average price of $1.53 per gallon. Most of these contracts, the longest of which extends to December 2017, are designated as cash flow hedges of forecasted transactions pursuant to ASC Topic 815, “Derivatives and Hedging.” The gains or losses on these derivative instruments are not subject to Alagasco’s GSA clause. As of September 30, 2016, the fair value of related gasoline contracts was not significant.

CONCENTRATIONS OF CREDIT RISK

CONCENTRATIONS OF CREDIT RISK	12 Months Ended
	Sep. 30, 2016
Risks and Uncertainties [Abstract]
CONCENTRATIONS OF CREDIT RISK	CONCENTRATIONS OF CREDIT RISK Other than in LER (the Gas Marketing segment), Spire has no significant concentration of credit risk. A significant portion of LER’s transactions are with (or are associated with) energy producers, utility companies, and pipelines. These concentrations of transactions with these counterparties have 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, LER 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, LER may require credit assurances such as prepayments, letters of credit, or parental guarantees. In addition, LER may enter into netting arrangements to mitigate credit risk with counterparties in the energy industry from which LER both sells and purchases 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. LER records accounts receivable, accounts payable, and prepayments for physical sales and purchases of natural gas on a gross basis. The amount included in accounts receivable attributable to energy producers and their marketing affiliates amounted to $15.8 at September 30, 2016 ( $12.4 reflecting netting arrangements). LER’s accounts receivable attributable to utility companies and their marketing affiliates comprised $52.8 of total accounts receivable at September 30, 2016 ( $50.5 reflecting netting arrangements). LER also has concentrations of credit risk with certain individually significant counterparties and with pipeline companies associated with its natural gas receivable amount. At September 30, 2016 , the amounts included in accounts receivable from LER’s five largest counterparties (in terms of net accounts receivable exposure) totaled $31.2 ( $27.2 reflecting netting arrangements). These five counterparties are either investment-grade rated or owned by investment-grade rated companies.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Spire The Company’s provision for income taxes charged during the fiscal years ended September 30, 2016 , 2015 , and 2014 are as follows: 2016 2015 2014 Federal Current $ 0.1 $ (3.3 ) $ 0.3 Deferred 62.0 58.8 30.6 Investment tax credits (0.2 ) (0.2 ) (0.2 ) State and local Current 0.6 — 0.6 Deferred 7.0 6.9 1.0 Total income tax expense $ 69.5 $ 62.2 $ 32.3 The Company’s effective income tax rate varied from the federal statutory income tax rate for each year due to the following: 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 3.0 1.8 Certain expenses capitalized on books and deducted on tax return (3.4 ) (3.7 ) (4.9 ) Taxes related to prior years (0.2 ) (0.6 ) (0.7 ) Other items – net * (1.7 ) (2.5 ) (3.6 ) Effective income tax rate 32.5 % 31.2 % 27.6 % * Other consists primarily of property adjustments. The Company’s significant items comprising the net deferred tax liability recorded in the Consolidated Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 21.3 $ 14.8 Pension and other postretirement benefits 68.3 62.5 Operating losses 102.3 47.3 Other — 1.5 Deferred tax assets 191.9 126.1 Less: valuation allowance 0.9 — Total deferred tax assets 191.0 126.1 Deferred tax liabilities: Relating to property 623.1 472.1 Regulatory pension and other postretirement benefits 106.8 110.6 Deferred gas costs 20.0 8.1 Other 48.4 11.6 Total deferred tax liabilities 798.3 602.4 Net deferred tax liability 607.3 476.3 Net deferred tax asset – current — 5.8 Net deferred tax liability – noncurrent $ 607.3 $ 482.1 In assessing whether deferred tax assets are realizable, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers all significant available positive and negative evidence, including the existence of losses in recent years, the timing of deferred tax liability reversals, projected future taxable income, taxable income in carryback years, and tax planning strategies to assess the need for a valuation allowance. Based upon this evidence, management believes it is more likely than not the Company will realize the benefits of these deferred tax assets. The Company has federal and state loss carryforwards of approximately $297.0 at September 30, 2016 . The Company also has contribution carryforwards of approximately $12.2 at September 30, 2016 . The loss carryforwards begin to expire in the fiscal year ending 2030 for certain state purposes and 2035 for federal and other states purposes. The contribution carryforwards begin to expire in fiscal year 2017. The Company has established a valuation allowance of $0.9 during the fiscal year as a portion of the charitable contribution carryforward will not be realized prior to its expiration. The Company also has various tax credit carryforwards of approximately $3.5 that begin to expire in 2017. The Company recognizes the tax benefit from a tax position only if it is at least more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The Company records potential interest and penalties related to its uncertain tax positions as interest expense and other income deductions, respectively. Unrecognized tax benefits, accrued interest payable, and accrued penalties payable are reported as a reduction of a deferred tax asset for an operating loss carryforward. The following table presents a reconciliation of the beginning and ending balances of the Company’s unrecognized tax benefits: 2016 2015 2014 Unrecognized tax benefits, beginning of year $ 7.1 $ 4.6 $ 2.4 Increases related to tax positions taken in current year 3.4 2.9 2.6 Reductions due to lapse of applicable statute of limitations (0.5 ) (0.4 ) (0.4 ) Unrecognized tax benefits, end of year $ 10.0 $ 7.1 $ 4.6 The amount of unrecognized tax benefits which, if recognized, would affect the Company’s effective tax rate were $3.3 and $3.1 as of September 30, 2016 and 2015 , respectively. It is reasonably possible that events will occur in the next 12 months that could increase or decrease the amount of the Company’s unrecognized tax benefits. The Company does not expect that any such change will be significant to the Consolidated Balance Sheets. As of September 30, 2016 and 2015 , interest accrued associated with the Company’s uncertain tax positions was de minimis, and no penalties were accrued as of September 30, 2016 . The Company is subject to US federal income tax as well as income tax in various state and local jurisdictions. The Company is no longer subject to examination for fiscal years prior to 2013. Regarding the Company’s recent EnergySouth acquisition, tax returns for the calendar years 2013 through 2015 remain open and subject to examination by the Internal Revenue Service and state taxing jurisdictions. These returns cover periods during which EnergySouth was owned by Sempra Global. The impact of any adjustments made to these returns by the relevant taxing authorities would be addressed by the indemnification provisions of the stock purchase agreement with Sempra Global. Laclede Gas Laclede Gas’ provision for income taxes charged during the fiscal years ended September 30, 2016 , 2015 , and 2014 are as follows: 2016 2015 2014 Federal Current $ — $ (2.1 ) $ (0.1 ) Deferred 37.5 40.9 34.3 Investment tax credits (0.2 ) (0.2 ) (0.2 ) State and local Current 0.1 (0.1 ) — Deferred 8.0 4.7 1.5 Total income tax expense $ 45.4 $ 43.2 $ 35.5 Laclede Gas’ effective income tax rate varied from the federal statutory income tax rate for each year due to the following: 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 2.8 1.8 Certain expenses capitalized on books and deducted on tax return (4.8 ) (4.9 ) (4.5 ) Taxes related to prior years (0.2 ) (0.8 ) (0.7 ) Other items – net * (2.8 ) (3.0 ) (3.3 ) Effective income tax rate 30.0 % 29.1 % 28.3 % * Other consists primarily of property adjustments. Laclede Gas’ significant items comprising the net deferred tax liability reported in the Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 14.9 $ 15.4 Pension and other postretirement benefits 56.9 62.5 Operating losses 29.9 3.7 Other — 1.5 Deferred tax assets 101.7 83.1 Less: valuation allowance 0.9 — Total deferred tax assets 100.8 83.1 Deferred tax liabilities: Relating to utility property 497.0 425.0 Regulatory pension and other postretirement benefits 106.8 120.2 Deferred gas costs 20.0 8.2 Other 33.9 14.5 Total deferred tax liabilities 657.7 567.9 Net deferred tax liability 556.9 484.8 Net deferred tax asset – current — 0.4 Net deferred tax liability – noncurrent $ 556.9 $ 485.2 Spire files a consolidated federal return and various state income tax returns and allocates income taxes to Laclede Gas and its other subsidiaries as if each entity were a separate taxpayer. In assessing whether deferred tax assets are realizable, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers all significant available positive and negative evidence, including the existence of losses in recent years, the timing of deferred tax liability reversals, projected future taxable income, taxable income in carryback years, and tax planning strategies to assess the need for a valuation allowance. Based upon this evidence, management believes it is more likely than not that Laclede Gas will realize the benefits of these deferred tax assets. Laclede Gas has state and federal loss carryforwards of approximately $105.0 , at September 30, 2016 , based on a separate company basis. For federal tax purposes, these loss carryforwards may be utilized against income from another member of the consolidated group. Laclede Gas also has contribution carryforwards of approximately $12.0 at September 30, 2016 . The loss carryforwards begin to expire in the fiscal year ending 2035 for federal and state purposes. The contribution carryforwards begin to expire in fiscal year ending 2017. Laclede Gas has established a valuation allowance of $0.9 during the fiscal year as a portion of the charitable contribution carryforward will not be realized prior to its expiration. Laclede Gas also has approximately $2.0 of various tax credit carryforwards with expiration dates which begin to expire in 2017. Laclede Gas recognizes the tax benefit from a tax position only if it is at least more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. Laclede Gas records potential interest and penalties related to its uncertain tax positions as interest expense and other income deductions, respectively. Unrecognized tax benefits, accrued interest payable, and accrued penalties payable are reported as a reduction of a deferred tax asset for an operating loss carryforward. The following table presents a reconciliation of the beginning and ending balances of Laclede Gas unrecognized tax benefits: 2016 2015 2014 Unrecognized tax benefits, beginning of year $ 6.9 $ 4.2 $ 2.0 Increases related to tax positions taken in current year 3.3 2.9 2.5 Reductions due to lapse of applicable statute of limitations (0.5 ) (0.2 ) (0.3 ) Unrecognized tax benefits, end of year $ 9.7 $ 6.9 $ 4.2 The amount of unrecognized tax benefits, which, if recognized, would affect Laclede Gas’ effective tax rate were $3.1 and $2.9 as of September 30, 2016 and 2015 , respectively. It is reasonably possible that events will occur in the next 12 months that could increase or decrease the amount of Laclede Gas’ unrecognized tax benefits. Laclede Gas does not expect that any such change will be significant to Laclede Gas’ Balance Sheets. As of September 30, 2016 and 2015 , interest accrued associated with Laclede Gas’ uncertain tax positions was de minimis, and no penalties were accrued. Laclede Gas is subject to US federal income tax as well as income tax in various state and local jurisdictions, and is no longer subject to examination for fiscal years prior to 2013. Alagasco Alagasco’s provision for income taxes charged during the fiscal years ended September 30, 2016 and 2015 , and the nine months ended September 30, 2014 , are as follows: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Federal Current $ (0.8 ) $ — $ 14.1 Deferred 29.4 25.9 3.5 State and local Current — 0.1 1.8 Deferred 3.8 3.3 0.5 Total income tax expense $ 32.4 $ 29.3 $ 19.9 Alagasco’s effective income tax rate varied from the federal statutory income tax rate for each year due to the following: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 2.8 2.8 Other items – net 0.1 0.1 (0.2 ) Effective income tax rate 37.9 % 37.9 % 37.6 % Alagasco’s significant items comprising the net deferred tax asset reported in the Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 6.3 $ 7.0 Pension and other postretirement benefits 11.4 9.6 Goodwill 233.4 251.5 Operating losses 60.2 32.4 Other — 1.4 Total deferred tax assets 311.3 301.9 Deferred tax liabilities: Relating to utility property 87.6 45.1 Other 2.3 2.2 Total deferred tax liabilities 89.9 47.3 Net deferred tax asset 221.4 254.6 Net deferred tax asset – current — 6.2 Net deferred tax asset – noncurrent $ 221.4 $ 248.4 Spire files a consolidated federal return and various state income tax returns and allocates income taxes to Alagasco and its other subsidiaries as if each entity were a separate taxpayer. In assessing whether deferred tax assets are realizable, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers all significant available positive and negative evidence, including the existence of losses in recent years, the timing of deferred tax liability reversals, projected future taxable income, taxable income in carryback years, and tax planning strategies to assess the need for a valuation allowance. Based upon this evidence, management believes it is more likely than not that Alagasco will realize the benefits of these deferred tax assets. On a separate company basis, Alagasco has state and federal loss carryforwards of approximately $159.0 , at September 30, 2016 generated since the acquisition. The loss carryforwards begin to expire in the fiscal year ending 2030 for state purposes and 2035 for federal purposes. For federal tax purposes, these loss carryforwards may be utilized against income from another member of the consolidated group. Alagasco recognizes the tax benefit from a tax position only if it is at least more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. Alagasco records potential interest and penalties related to its uncertain tax positions as interest expense and other income deductions, respectively. Alagasco has reported no unrecognized tax benefits since the acquisition by Spire in August 2014. The following table presents a reconciliation of the beginning and ending balances of Alagasco’s unrecognized tax benefits: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Unrecognized tax benefits, beginning of period $ — $ — $ 0.3 Reduction for transfer of balance to Energen — — (0.3 ) Unrecognized tax benefits, end of period $ — $ — $ — Alagasco is subject to US federal income tax as well as income tax in various state and local jurisdictions. Alagasco’s tax returns for the periods after 2012 remain open and subject to examination by the Internal Revenue Service and state taxing jurisdictions. The returns covering 2013 and 2014 include periods during which Alagasco was owned by Energen. The impact of any adjustments made to those returns by the relevant taxing authorities would be addressed by the indemnification provisions of the stock purchase agreement with Energen.

PENSION PLANS AND OTHER POSTRET

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	12 Months Ended
	Sep. 30, 2016
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS The Spire information in this note reflects all plans of the Company, including information for plans of EnergySouth since September 12, 2016 and Alagasco since August 31, 2014 . The net pension and postretirement obligations were re-measured at those acquisition dates as well as at the fiscal year end. Pension Plans The pension plans of Spire consist of plans for employees at the Missouri Utilities, plans covering the employees of Alagasco, and plans covering employees for EnergySouth. 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 US government obligations and a growth segment consisting of exposure to equity markets, commodities, real estate and inflation-indexed securities, achieved through derivative instruments and investments in diversified mutual funds. Alagasco has non-contributory, defined benefit, trusteed forms of pension plans covering the majority of its employees. Qualified plan assets are comprised of United States equities consisting of mutual and commingled funds with varying strategies, global equities consisting of mutual funds, alternative investments of limited partnerships and commingled and mutual funds, and fixed income investments. The net periodic pension costs include the following components: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Service cost – benefits earned during the period $ 15.3 $ 17.3 $ 10.2 $ 10.0 $ 11.5 $ 9.7 $ 5.3 $ 5.8 $ 5.1 Interest cost on projected benefit obligation 28.0 29.5 24.5 21.7 23.3 24.0 6.3 6.2 4.1 Expected return on plan assets (34.9 ) (37.4 ) (27.2 ) (26.7 ) (29.2 ) (26.5 ) (8.2 ) (8.2 ) (5.2 ) Amortization of other comprehensive income — — 0.4 — — — — — — Amortization of prior service cost 0.4 0.5 0.5 0.4 0.5 0.5 — — 0.1 Amortization of actuarial loss 8.0 7.5 7.1 7.9 7.5 7.1 0.1 — 2.2 Loss on lump-sum settlements 3.3 19.6 1.5 — 18.0 1.5 3.3 1.6 10.1 Special termination benefits 1.6 — — 1.6 — — — — — Subtotal 21.7 37.0 17.0 14.9 31.6 16.3 6.8 5.4 16.4 Regulatory adjustment 17.8 (2.1 ) 10.4 11.7 (5.2 ) 10.4 6.1 3.1 0.4 Net pension cost $ 39.5 $ 34.9 $ 27.4 $ 26.6 $ 26.4 $ 26.7 $ 12.9 $ 8.5 $ 16.8 * Nine months ended September 30 Other changes in plan assets and pension benefit obligations recognized in other comprehensive income or loss (OCI) include the following: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Current year actuarial loss $ 46.8 $ 48.3 $ 15.7 $ 21.6 $ 26.0 $ 14.2 $ 25.2 $ 22.3 $ 1.5 Amortization of actuarial loss (8.0 ) (7.5 ) (7.1 ) (7.9 ) (7.5 ) (7.1 ) (0.1 ) — — Acceleration of loss recognized due to settlement (3.3 ) (19.6 ) (1.5 ) — (18.0 ) (1.5 ) (3.3 ) (1.6 ) — Amortization of current year service cost 5.0 — — 5.0 — — — — — Amortization of prior service cost (0.4 ) (0.5 ) (0.5 ) (0.4 ) (0.5 ) (0.5 ) — — — Subtotal 40.1 20.7 6.6 18.3 — 5.1 21.8 20.7 1.5 Regulatory adjustment (39.8 ) (21.2 ) (6.1 ) (18.0 ) (0.5 ) (4.7 ) (21.8 ) (20.7 ) (1.5 ) Total recognized in OCI $ 0.3 $ (0.5 ) $ 0.5 $ 0.3 $ (0.5 ) $ 0.4 $ — $ — $ — * Nine months ended September 30 Spire pension obligations are driven by separate plan and regulatory provisions governing Laclede Gas, Alagasco and EnergySouth pension plans. Pursuant to the provisions of the Missouri Utilities’ and Alagasco’s pension plans, pension obligations may be satisfied by lump-sum cash payments. Lump-sum payments are recognized as settlements (which can result in gains or losses) only if the total of such payments exceeds 100% of 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. Two Alagasco plans and one Laclede plan met the criteria for settlement recognition in the fiscal year ended September 30, 2016 , requiring re-measurement of the obligation under those plans using updated census data and assumptions for discount rate and mortality. Lump-sum payments recognized as settlements during fiscal year 2016 , 2015 , and 2014 were $16.6 (attributable to Alagasco), $71.1 , and $22.1 , respectively. Pursuant to a MoPSC Order, the return on plan assets is based on the market-related value of plan assets implemented prospectively over a four -year period. Gains or losses not yet includible in pension cost are amortized only to the extent that such gain or loss exceeds 10% of the greater of the projected benefit obligation or the market-related value of plan assets. Such excess is amortized over the average remaining service life of active participants. The recovery in rates for Laclede Gas’ eastern Missouri qualified pension plan is based on an annual allowance of $15.5 effective January 1, 2011. The recovery in rates for MGE’s qualified pension plan is based on an annual allowance of $10 effective February 20, 2010. The difference between these amounts and pension expense as calculated pursuant to the above and that otherwise would be included in the statements of income and statements of comprehensive income is deferred as a regulatory asset or regulatory liability. The following table shows the reconciliation of the beginning and ending balances of the pension benefit obligation at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Benefit obligation, beginning of year $ 652.3 $ 692.4 $ 497.6 $ 543.6 $ 154.7 $ 148.8 Service cost 15.3 17.3 10.0 11.5 5.3 5.8 Interest cost 28.0 29.5 21.7 23.3 6.3 6.2 Actuarial loss (gain) 85.8 (12.8 ) 59.2 (20.7 ) 26.6 7.9 Plan amendments 5.1 — 5.1 — — — EnergySouth acquisition 60.4 — — — — — Settlement loss 1.1 16.5 — 14.5 1.1 2.0 Special termination benefits 1.6 — 1.6 — — — Settlement benefits paid (16.6 ) (71.1 ) — (58.2 ) (16.6 ) (12.9 ) Regular benefits paid (38.3 ) (19.5 ) (35.2 ) (16.4 ) (3.1 ) (3.1 ) Benefit obligation, end of year $ 794.7 $ 652.3 $ 560.0 $ 497.6 $ 174.3 $ 154.7 Accumulated benefit obligation, end of year 724.5 $ 591.4 517.7 $ 456.9 149.8 $ 134.5 The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Fair value of plan assets, beginning of year $ 448.9 $ 506.6 $ 339.9 $ 387.4 $ 109.0 $ 119.2 Actual return on plan assets 75.1 (7.2 ) 64.4 (3.0 ) 10.7 (4.2 ) Employer contributions 26.6 40.1 26.6 30.1 — 10.0 EnergySouth acquisition 44.8 — — — — — Settlement benefits paid (16.6 ) (71.1 ) — (58.2 ) (16.6 ) (12.9 ) Regular benefits paid (38.3 ) (19.5 ) (35.2 ) (16.4 ) (3.1 ) (3.1 ) Fair value of plan assets, end of year $ 540.5 $ 448.9 $ 395.7 $ 339.9 $ 100.0 $ 109.0 Funded status of plans, end of year $ (254.2 ) $ (203.4 ) $ (164.3 ) $ (157.7 ) $ (74.3 ) $ (45.7 ) The following table sets forth the amounts recognized in the balance sheets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Current liabilities $ (0.6 ) $ (0.5 ) $ (0.6 ) $ (0.5 ) $ — $ — Noncurrent liabilities (253.6 ) (202.9 ) (163.7 ) (157.2 ) (74.3 ) (45.7 ) Total $ (254.2 ) $ (203.4 ) $ (164.3 ) $ (157.7 ) $ (74.3 ) $ (45.7 ) Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic pension cost consist of: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 179.4 $ 143.9 $ 135.5 $ 121.9 $ 43.9 $ 22.0 Prior service costs 8.2 3.5 8.2 3.5 — — Subtotal 187.6 147.4 143.7 125.4 43.9 22.0 Adjustments for amounts included in regulatory assets (184.8 ) (144.9 ) (140.9 ) (122.9 ) (43.9 ) (22.0 ) Total $ 2.8 $ 2.5 $ 2.8 $ 2.5 $ — $ — At September 30, 2016 , the following pre-tax amounts are expected to be amortized from accumulated other comprehensive loss into net periodic pension cost during fiscal year 2017 : Spire Laclede Gas Alagasco Amortization of net actuarial loss $ 13.5 $ 11.6 $ 1.9 Amortization of prior service cost 1.0 1.0 — Subtotal 14.5 12.6 1.9 Regulatory adjustment (14.2 ) (12.3 ) (1.9 ) Total $ 0.3 $ 0.3 $ — The assumptions used to calculate net periodic pension costs for Laclede Gas are as follows: 2016 2015 2014 Weighted average discount rate - Laclede Gas division plans 4.40% 4.30% 4.70% Weighted average discount rate - MGE division plans 4.50% 4.45% 5.00% Weighted average rate of future compensation increase * 3.00% 3.00% 3.00% Expected long-term rate of return on plan assets * 7.75% 7.75% 7.75% * Assumptions for weighted average rate of future compensation increase and expected long-term rate of return on plan assets are the same for both Laclede Gas and MGE plans. The assumptions used to calculate net periodic pension costs for Alagasco are as follows: 2016 2015 2014* Weighted average discount rate 4.25% /4.30% 4.15% /4.25% 4.00% / 4.05% Weighted average rate of future compensation increase 3.00% 2.92% 2.92% Expected long-term rate of return on plan assets 7.50% 7.00% / 7.25% 7.00% / 7.25% * Nine-month transition period ended September 30 The weighted average discount rate is based on long-term, high quality bond indices at the measurement date. The expected long-term rate of return on plan assets is based on historical and projected rates of return for current and planned asset classes in the investment portfolio. Assumed projected rates of return for each asset class were selected after analyzing historical experience and future expectations of the returns. The overall expected rate of return for the portfolio was developed based on the target allocation for each class. The assumptions used to calculate the benefit obligations are as follows: 2016 2015 Weighted average discount rate - Laclede Gas division 3.50% 4.40% Weighted average discount rate - MGE division 3.50% 4.50% Weighted average discount rate - Alagasco 3.45%/3.50% 4.25%/4.30% Weighted average rate of future compensation increase - Laclede Gas, Alagasco and MGE 3.00% 3.00% Following are the projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for plans that have a projected benefit obligation and an accumulated benefit obligation in excess of plan assets: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Projected benefit obligation $ 794.8 $ 652.3 $ 560.0 $ 497.6 $ 174.3 $ 154.7 Accumulated benefit obligation 724.5 591.4 517.7 456.9 149.8 134.5 Fair value of plan assets 540.5 448.9 395.7 339.9 100.0 109.0 Following are the targeted and actual plan assets by category as of September 30 of each year for Laclede Gas and Alagasco: Laclede Gas 2016 Target 2016 Actual 2015 Target 2015 Actual Equity markets 56.2 % 56.9 % 52.0 % 48.4 % Debt securities 43.8 % 43.1 % 48.0 % 50.1 % Other* — % — % — % 1.5 % Total 100.0 % 100.0 % 100.0 % 100.0 % * Other investments in 2016 and 2015 consisted of cash equivalents. Alagasco 2016 Target 2016 Actual 2015 Target 2015 Actual Equity markets 60.0 % 59.2 % 60.0 % 52.9 % Debt securities 29.0 % 28.8 % 29.0 % 27.9 % Other* 11.0 % 12.0 % 11.0 % 19.2 % Total 100.0 % 100.0 % 100.0 % 100.0 % * Other investments in 2016 included cash, real estate, commodities, natural resources and TIPS. In 2015, this included cash and cash equivalents, hedge funds, real estate, and all asset funds, which can invest in equities or fixed income. Laclede Gas’ investment policies are designed to maximize, to the extent possible, the funded status of the plan over time, and minimize volatility of funding and costs. The policy seeks to maximize investment returns consistent with these objectives and Laclede Gas’ tolerance for risk. The duration of plan liabilities and the impact of potential changes in asset values on the funded status are fundamental considerations in the selection of plan assets. Outside investment management specialists are utilized in each asset class. Such specialists are provided with guidelines, where appropriate, designed to ensure that the investment portfolio is managed in accordance with the policy. The policy seeks to avoid significant concentrations of risk by investing in a diversified portfolio of assets. Investments in corporate, US government and agencies, and, to a lesser extent, international debt securities seek to provide duration matching with plan liabilities, and typically have investment grade ratings and reflect allocations across various entities and industries. There are also exposures to additional asset types in the target portfolio: commodities, real estate and inflation-indexed securities. During 2015, the target portfolio was rebalanced to include a higher weighting for the growth (equity) component and a lower weighting to the liability-driven (debt) component. The investment policy permits the use of derivative instruments, which may be used to achieve the desired market exposure of an index, adjust portfolio duration, or rebalance the total portfolio to the target asset allocation. The Growth Strategy utilizes a combination of derivative instruments and debt securities to achieve diversified exposure to equity and other markets while generating returns from the fixed-income investments and providing further duration matching with the liabilities. Performance and compliance with the guidelines is regularly monitored. The policy calls for increased allocations to debt securities as the funded status improves. Alagasco employs a total return investment approach whereby a mix of equities and fixed income investments are used to maximize the long-term return of plan assets with a prudent level of risk. Risk tolerance is established through consideration of plan liabilities, plan funded status, corporate financial condition and market conditions. Alagasco has developed an investment strategy that focuses on asset allocation, diversification and quality guidelines. The investment goals are to obtain an adequate level of return to meet future obligations of the plan by providing above average risk-adjusted returns with a risk exposure in the mid-range of comparable funds. Investment managers are retained by Alagasco to manage separate pools of assets. Funds are allocated to such managers in order to achieve an appropriate, diversified, and balanced asset mix. Comparative market and peer group benchmarks are utilized to ensure that investment managers are performing satisfactorily. Alagasco seeks to maintain an appropriate level of diversification to minimize the risk of large losses in a single asset class. Accordingly, plan assets for the pension plans do not have a concentration of assets in a single entity, industry, country, commodity or class of investment fund. Following are expected pension benefit payments for the succeeding five fiscal years, and in aggregate for the five years thereafter, for Spire, Laclede Gas, and Alagasco: 2017 2018 2019 2020 2021 2022- 2026 Spire $ 61.3 $ 56.2 $ 57.1 $ 56.6 $ 56.8 $ 286.3 Laclede Gas 48.2 43.3 43.5 42.2 40.4 196.6 Alagasco 10.9 10.6 11.2 11.9 13.7 74.5 The funding policy of Laclede Gas and Alagasco 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. Laclede Gas contributions to the pension plans in fiscal year 2017 are anticipated to be $29.0 into the qualified trusts, and $0.6 into the non-qualified plans. Alagasco has no required contributions to the qualified pension plans during 2017. Additionally, it is not anticipated that the funded status of the qualified pension plans will fall below statutory thresholds requiring accelerated funding or constraints on benefit levels or plan administration. During fiscal 2017, Alagasco may make additional discretionary contributions to the qualified pension plans depending on the amount and timing of employee retirements and market conditions. Postretirement Benefits The Utilities provide certain life insurance benefits at retirement. Laclede Gas plans provide for medical insurance after early retirement until age 65 . For retirements prior to January 1, 2015, the MGE plans provided medical insurance after retirement until death. For retirements after January 1, 2015, the MGE plans provide medical insurance after early retirement until age 65 . Under the Alagasco plans, medical insurance is currently available 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 consist of the following components: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Service cost – benefits earned during the period $ 10.9 $ 12.8 $ 11.3 $ 10.6 $ 12.3 $ 11.2 $ 0.3 $ 0.5 $ 0.4 Interest cost on accumulated postretirement benefit obligation 10.2 11.2 8.9 8.1 8.6 8.7 2.1 2.6 1.9 Expected return on plan assets (13.5 ) (13.2 ) (7.3 ) (8.5 ) (8.1 ) (6.8 ) (5.0 ) (5.1 ) (3.6 ) Amortization of prior other comprehensive loss — — (0.2 ) — — — — — — Amortization of prior service cost 0.3 0.8 — 0.3 0.8 — — — — Amortization of actuarial loss (gain) 3.6 5.1 6.0 3.8 5.1 6.0 (0.2 ) — (1.0 ) Special termination benefits 2.6 — — 2.6 — — — — — Subtotal 14.1 16.7 18.7 16.9 18.7 19.1 (2.8 ) (2.0 ) (2.3 ) Regulatory adjustment (6.6 ) (11.0 ) (9.6 ) (4.8 ) (9.2 ) (9.6 ) (1.8 ) (1.8 ) (0.2 ) Net postretirement benefit cost $ 7.5 $ 5.7 $ 9.1 $ 12.1 $ 9.5 $ 9.5 $ (4.6 ) $ (3.8 ) $ (2.5 ) * Nine months ended September 30 Other changes in plan assets and postretirement benefit obligations recognized in OCI include the following: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Current year actuarial loss (gain) $ 0.8 $ (8.5 ) $ (3.1 ) $ 1.4 $ (2.4 ) $ (4.2 ) $ (0.6 ) $ (6.1 ) $ 1.1 Amortization of actuarial (loss) gain (3.6 ) (5.1 ) (6.0 ) (3.8 ) (5.1 ) (6.0 ) 0.2 — — Amortization of prior service (cost) credit (0.3 ) (0.8 ) 2.5 (0.3 ) (0.8 ) 2.5 — — — Current year prior service credit (1.8 ) (4.9 ) — — (4.9 ) — (1.8 ) — — Subtotal (4.9 ) (19.3 ) (6.6 ) (2.7 ) (13.2 ) (7.7 ) (2.2 ) (6.1 ) 1.1 Regulatory adjustment 4.9 19.3 6.6 2.7 13.2 7.7 2.2 6.1 (1.1 ) Total recognized in OCI $ — $ — $ — $ — $ — $ — $ — $ — $ — * Nine months ended September 30 Pursuant to a MoPSC Order, the return on plan assets is based on the market-related value of plan assets implemented prospectively over a four -year period. Gains and losses not yet includible in postretirement benefit cost are amortized only to the extent that such gain or loss exceeds 10% of the greater of the accumulated postretirement benefit obligation or the market-related value of plan assets. Such excess is amortized over the average remaining service life of active participants. The recovery in rates for Laclede Gas’ postretirement benefit plans is based on an annual allowance of $9.5 effective January 1, 2011. The difference between these amounts and postretirement benefit cost based on the above and that otherwise would be included in the statements of income and statements of comprehensive income is deferred as a regulatory asset or regulatory liability. The following table sets forth the reconciliation of the beginning and ending balances of the postretirement benefit obligation at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Benefit obligation, beginning of year $ 239.2 $ 258.5 $ 191.9 $ 197.9 $ 47.3 $ 60.6 Service cost 10.9 12.8 10.6 12.3 0.3 0.5 Interest cost 10.2 11.2 8.1 8.6 2.1 2.6 Actuarial loss (gain) 7.1 (23.7 ) 6.7 (10.9 ) 0.4 (12.8 ) Plan amendments (1.8 ) (4.9 ) — (4.9 ) (1.8 ) — EnergySouth acquisition 5.9 — — — — — Special termination benefits 2.6 — 2.6 — — — Retiree drug subsidy program 0.2 0.4 — — 0.2 0.4 Gross benefits paid (15.1 ) (15.1 ) (12.0 ) (11.1 ) (3.1 ) (4.0 ) Benefit obligation, end of year $ 259.2 $ 239.2 $ 207.9 $ 191.9 $ 45.4 $ 47.3 The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Fair value of plan assets at beginning of year $ 223.3 $ 222.5 $ 143.6 $ 137.2 $ 79.7 $ 85.3 Actual return on plan assets 19.9 (2.0 ) 13.8 (0.4 ) 6.2 (1.6 ) Employer contributions 14.3 17.9 14.3 17.9 — — EnergySouth acquisition 4.0 — — — — — Gross benefits paid (15.1 ) (15.1 ) (12.0 ) (11.1 ) (3.1 ) (4.0 ) Fair value of plan assets, end of year $ 246.4 $ 223.3 $ 159.7 $ 143.6 $ 82.8 $ 79.7 Funded status of plans, end of year $ (12.8 ) $ (15.9 ) $ (48.2 ) $ (48.3 ) $ 37.4 $ 32.4 The following table sets forth the amounts recognized in the balance sheets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Current assets $ 0.3 $ — $ 0.3 $ — $ — $ — Noncurrent assets 37.4 35.5 — 3.1 37.4 32.4 Current liabilities (0.4 ) (0.3 ) (0.4 ) (0.3 ) — — Noncurrent liabilities (50.1 ) (51.1 ) (48.1 ) (51.1 ) — — Total $ (12.8 ) $ (15.9 ) $ (48.2 ) $ (48.3 ) $ 37.4 $ 32.4 Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic postretirement benefit cost consist of: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 38.0 $ 40.8 $ 43.4 $ 45.8 $ (5.4 ) $ (5.0 ) Prior service credit (5.2 ) (3.1 ) (3.4 ) (3.1 ) (1.8 ) — Subtotal 32.8 37.7 40.0 42.7 (7.2 ) (5.0 ) Adjustments for amounts included in regulatory assets (32.8 ) (37.7 ) (40.0 ) (42.7 ) 7.2 5.0 Total $ — $ — $ — $ — $ — $ — At September 30, 2016 , the following pre-tax amounts are expected to be amortized from accumulated other comprehensive loss into net periodic postretirement benefit cost during fiscal year 2017: Spire Laclede Gas Alagasco Amortization of net actuarial loss (gain) $ 2.4 $ 2.5 $ (0.1 ) Amortization of prior service cost 0.1 0.3 (0.2 ) Subtotal 2.5 2.8 (0.3 ) Regulatory adjustment (2.5 ) (2.8 ) 0.3 Total $ — $ — $ — The assumptions used to calculate net periodic postretirement benefit costs for Laclede Gas are as follows: 2016 2015 2014 Weighted average discount rate Laclede Gas division plans 4.00 % 4.15 % 4.60 % Weighted average discount rate MGE division plans 4.30 % 4.40 % 4.95 % Weighted average rate of future compensation increase - Laclede Gas plans 3.00 % 3.00 % 3.00 % Expected long-term rate of return on plan assets - Laclede Gas division plans 6.00% / 7.75% 6.25% / 7.75% 6.25% / 7.75% Expected long-term rate of return on plan assets - MGE division plans 4.75 % 5.00 % 3.75% / 5.75% The assumptions used to calculate net periodic postretirement benefit costs for Alagasco are as follows: 2016 2015 2014 Weighted average discount rate 4.50 % 4.40 % 4.25 % Weighted average rate of future compensation increase n/a n/a 2.92 % Expected long-term rate of return on plan assets 4.50% / 7.25% 4.75% / 7.50% 4.75% / 7.25% The weighted average discount rate is based on long-term, high quality bond indices at the measurement date. The expected long-term rate of return on plan assets is based on historical and projected rates of return for current and planned asset classes in the investment portfolio. Assumed projected rates of return for each asset class were selected after analyzing historical experience and future expectations of the returns. The overall expected rate of return for the portfolio was developed based on the target allocation for each class. The assumptions used to calculate the accumulated postretirement benefit obligations for Laclede Gas are as follows: 2016 2015 Weighted average discount rate - Laclede Gas division plans 3.15 % 4.00 % Weighted average discount rate - MGE division plans 3.45 % 4.30 % Weighted average rate of future compensation increase 3.00 % 3.00 % The assumptions used to calculate the accumulated postretirement benefit obligations for Alagasco are as follows: 2016 2015 Weighted average discount rate 3.60 % 4.50 % Weighted average rate of future compensation increase n/a n/a The assumed medical cost trend rates at September 30 are as follows: 2016 2015 Medical cost trend assumed for next year - Laclede Gas 7.50 % 7.00 % Medical cost trend assumed for next year - Alagasco 7.50 % 7.00 % Rate to which the medical cost trend rate is assumed to decline (the ultimate medical cost trend rate) 5.00 % 5.00 % Year the rate reaches the ultimate trend 2023 2020 The following table presents the effects of an assumed 1% change in the assumed medical cost trend rate: Spire Laclede Gas Alagasco 1% Increase 1% Decrease 1% Increase 1% Decrease 1% Increase 1% Decrease Net periodic postretirement benefit cost $ 1.5 $ (1.4 ) $ 1.5 $ (1.4 ) $ — $ — Accumulated postretirement benefit obligation 11.0 (10.2 ) 9.0 (8.4 ) 1.3 (1.2 ) Following are the targeted and actual plan assets by category as of September 30 of each year for Laclede Gas and Alagasco: Laclede Gas Target 2016 Actual 2015 Actual Equity securities 60.0 % 59.1 % 59.6 % Debt securities 40.0 % 39.4 % 39.7 % Other (cash and cash equivalents) — % 1.5 % 0.7 % Total 100.0 % 100.0 % 100.0 % Alagasco Target 2016 Actual 2015 Actual Equity securities 60.0 % 60.5 % 59.7 % Debt securities 40.0 % 39.5 % 40.3 % Total 100.0 % 100.0 % 100.0 % Missouri state law provides for the recovery in rates of costs accrued pursuant to GAAP provided that such costs are funded through an independent, external funding mechanism. Laclede Gas established Voluntary Employees’ Beneficiary Association and Rabbi Trusts as its external funding mechanisms. Laclede Gas’ investment policy seeks to maximize investment returns consistent with Laclede Gas’ tolerance for risk. Outside investment management specialists are utilized in each asset class. Such specialists are provided with guidelines, where appropriate, designed to ensure that the investment portfolio is managed in accordance with policy. Performance and compliance with the guidelines is regularly monitored. Laclede Gas’ current investment policy targets an asset allocation of 60% to equity securities and 40% to debt securities, excluding cash held in short-term debt securities for the purpose of making benefit payments. Laclede Gas currently invests in a mutual fund which is rebalanced on an ongoing basis to the target allocation. The mutual fund is diversified across US stock and bond markets. Alagasco established Voluntary Employees’ Beneficiary Association accounts as its external funding mechanisms for post-retirement benefit costs. Alagasco’s investment policy seeks to maximize investment returns consistent with its tolerance for risk. Outside investment management specialists are utilized in each asset class. Such specialists are provided with guidelines, where appropriate, designed to ensure that the investment portfolio is managed in accordance with policy. Performance and compliance with the guidelines is regularly monitored. Alagasco’s current investment policy targets an asset allocation of 60% to equity securities and 40% to debt securities. Alagasco currently invests in several mutual funds which are rebalanced periodically to the target allocation. The mutual funds are diversified across US and international stock markets and the US bond market. Following are expected postretirement benefit payments for the succeeding five fiscal years, and in aggregate for the five years thereafter for Spire, Laclede Gas, and Alagasco: 2017 2018 2019 2020 2021 2022- 2026 Spire $ 15.4 $ 16.7 $ 17.9 $ 19.1 $ 20.1 $ 108.6 Laclede Gas 12.3 13.7 14.8 15.8 16.8 92.5 Alagasco 2.9 2.8 2.8 2.9 2.9 14.1 Laclede Gas’ funding policy is to contribute amounts to the trusts equal to the periodic benefit cost calculated pursuant to GAAP as recovered in rates. Contributions to the postretirement plans in fiscal year 2017 are anticipated to be $10.3 to the qualified trusts and $0.4 paid directly to participants from Laclede Gas funds. Alagasco’s funding policy is to contribute amounts to the trusts equal to the periodic benefit cost calculated pursuant to GAAP as recovered in rates. In fiscal 2017 , it is not anticipated that contributions will be made to the postretirement plans. Other Plans Laclede Gas and Alagasco sponsor 401(k) plans that cover substantially all employees. The plans allow employees to contribute a portion of their base pay in accordance with specific guidelines. Laclede Gas provides a match of such contributions within specific limits. The cost of the defined contribution plans of Laclede Gas amounted to $8.2 , $8.0 , and $6.7 for fiscal years 2016 , 2015 , and 2014 , respectively. Alagasco also provides a match of employee contributions within specific limits. The cost of the defined contribution plans of Alagasco amounted to $2.3 , $3.0 , and $4.7 for fiscal years 2016 and 2015 , and the nine months ended September 30, 2014, respectively. Fair Value Measurements of Pension and Other Postretirement Plan Assets Spire The table below categorizes the fair value measurements of the Spire pension plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 51.2 $ — $ — $ 51.2 Stock/bond mutual fund 99.3 26.7 0.1 126.1 Debt Securities US bond mutual funds 23.0 126.0 — 149.0 US government 42.1 3.0 — 45.1 US corporate 137.4 — — 137.4 US municipal 6.3 — — 6.3 International 25.3 — — 25.3 Derivatives and margin (payable) (1.0 ) 1.1 — 0.1 Total $ 383.6 $ 156.8 $ 0.1 $ 540.5 As of September 30, 2015 Cash and cash equivalents $ 43.4 $ 0.2 $ — $ 43.6 Stock/bond mutual fund 46.4 74.6 9.6 130.6 Debt Securities US bond mutual funds — 9.3 — 9.3 US government 58.7 — — 58.7 US corporate 123.7 42.9 — 166.6 US municipal — 5.9 — 5.9 International — 31.3 — 31.3 Derivative instruments — 2.9 — 2.9 Total $ 272.2 $ 167.1 $ 9.6 $ 448.9 The table below categorizes the fair value measurements of Spire’s postretirement plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 4.8 $ — $ — $ 4.8 US stock/bond mutual fund 157.9 68.5 — 226.4 International fund 0.9 14.3 — 15.2 Total $ 163.6 $ 82.8 $ — $ 246.4 As of September 30, 2015 Cash and cash equivalents $ 1.6 $ — $ — $ 1.6 US stock/bond mutual fund 115.5 92.8 — 208.3 International fund — 13.4 — 13.4 Total $ 117.1 $ 106.2 $ — $ 223.3 Cash and cash equivalents include money market mutual funds valued based on quoted market prices. Fair values of derivative instruments are calculated by investment managers who use valuation models that incorporate observable market inputs. Debt securities are valued based on broker/dealer quotations or by using observable market inputs. The stock and bond mutual funds are valued at the quoted market price of the identical securities. Laclede Gas The table below categorizes the fair value measurements of Laclede Gas’ pension plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 46.5 $ — $ — $ 46.5 Stock/bond mutual fund — 14.8 0.1 14.9 Debt Securities US bond mutual funds — 120.2 — 120.2 US government 42.1 3.0 — 45.1 US corporate 137.4 — — 137.4 US municipal 6.3 — — 6.3 International 25.2 — — 25.2 Derivatives and margin (payable) (1.0 ) 1.1 — 0.1 Total $ 256.5 $ 139.1 $ 0.1 $ 395.7 As of September 30, 2015 Cash and cash equivalents $ 31.8 $ — $ — $ 31.8 Stock/bond mutual funds — 67.6 0.1 67.7 Debt Securities US government 37.7 — — 37.7 US corporate 123.7 42.9 — 166.6 US municipal — 5.9 — 5.9 International — 27.3 — 27.3 Derivative instruments — 2.9 — 2.9 Total $ 193.2 $ 146.6 $ 0.1 $ 339.9 The table below categorizes the fair value measurements of Laclede Gas’ postretirement plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 4.6 $ — $ — $ 4.6 US stock/bond mutual funds 155.1 — — 155.1 Total $ 159.7 $ — $ — $ 159.7 As of September 30, 2015 Cash and cash equivalents $ 1.6 $ — $ — $ 1.6 US stock/bond mutual funds 115.5 26.5 — 142.0 Total $ 117.1 $ 26.5 $ — $ 143.6 Cash and cash equivalents include money market mutual funds valued based on quoted market prices. Fair values of derivative instruments are calculated by investment managers who use valuation models that incorporate observable market inputs. Debt securities are valued based on broker/dealer quotations or by using observable market inputs. The stock and bond mutual funds are valued at the quoted market price of the identical securities. Alagasco The table below categorizes the fair value measurements of Alagasco’s pension plan assets: Quoted Prices in Activ

INFORMATION BY OPERATING SEGMEN

INFORMATION BY OPERATING SEGMENT	12 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
INFORMATION BY OPERATING SEGMENT	INFORMATION BY OPERATING SEGMENT Spire The Company has two reportable segments: Gas Utility and Gas Marketing. The Gas Utility segment is the aggregation of the regulated operations of the Utilities. The Gas Marketing segment includes the results of LER, a subsidiary engaged in the non-regulated marketing of natural gas and related activities, and LER Storage Services, Inc., which utilizes natural gas storage contracts for providing natural gas sales. Other includes: • unallocated corporate items, including certain debt and associated interest costs, • Laclede Pipeline Company, a subsidiary of Spire which operates a propane pipeline under Federal Energy Regulatory Commission (FERC) jurisdiction, • Spire STL Pipeline, a subsidiary of Spire planning construction of a 70-mile FERC-regulated pipeline to deliver natural gas into eastern Missouri, and • Spire’s subsidiaries that are engaged in compression of natural gas and risk management, among other activities. All subsidiaries are wholly owned. Accounting policies are described in Note 1 , Summary of Significant Accounting Policies. Intersegment transactions include sales of natural gas from LER to Laclede Gas, sales of natural gas from Laclede Gas to LER, risk management services provided by Laclede Insurance Risk Services, Inc. to Laclede Gas, propane transportation services provided by Laclede Pipeline Company to Laclede Gas, and propane storage services provided by Laclede Gas to Laclede Pipeline Company. 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 net unrealized gains and losses and other timing differences associated with energy-related transactions. Net economic earnings also exclude the after-tax impacts related to acquisition, divestiture, and restructuring activities. Gas Utility Gas Marketing Other Eliminations Consolidated 2016 Revenues from external customers $ 1,457.2 $ 78.5 $ 1.6 $ — $ 1,537.3 Intersegment revenues 2.2 — 3.2 (5.4 ) — Total Operating Revenues 1,459.4 78.5 4.8 (5.4 ) 1,537.3 Operating Expenses Gas Utility Natural and propane gas 539.7 — — (47.5 ) 492.2 Other operation and maintenance 379.3 — — (1.8 ) 377.5 Depreciation and amortization 136.9 — — — 136.9 Taxes, other than income taxes 125.2 — — — 125.2 Total Gas Utility Operating Expenses 1,181.1 — — (49.3 ) 1,131.8 Gas Marketing and Other — 66.7 (a) 12.6 (b) 43.9 123.2 Total Operating Expenses 1,181.1 66.7 12.6 (5.4 ) 1,255.0 Operating Income (Loss) 278.3 11.8 (7.8 ) — 282.3 Net Economic Earnings (Loss) 160.3 6.4 (17.6 ) — 149.1 Capital Expenditures 291.7 — 1.6 — 293.3 Gas Utility Gas Marketing Other Eliminations Consolidated 2015 Revenues from external customers $ 1,891.8 $ 82.9 $ 1.7 $ — $ 1,976.4 Intersegment revenues 4.0 70.5 2.0 (76.5 ) — Total Operating Revenues 1,895.8 153.4 3.7 (76.5 ) 1,976.4 Operating Expenses Gas Utility Natural and propane gas 957.6 — — (75.2 ) 882.4 Other operation and maintenance 391.6 — — (1.0 ) 390.6 Depreciation and amortization 129.9 — — — 129.9 Taxes, other than income taxes 142.1 — — — 142.1 Total Gas Utility Operating Expenses 1,621.2 — — (76.2 ) 1,545.0 Gas Marketing and Other — 146.6 (a) 12.6 (b) (0.3 ) 158.9 Total Operating Expenses 1,621.2 146.6 12.6 (76.5 ) 1,703.9 Operating Income (Loss) 274.6 6.8 (8.9 ) — 272.5 Net Economic Earnings (Loss) 150.4 4.2 (16.3 ) — 138.3 Capital Expenditures 284.4 — 5.4 — 289.8 Gas Utility Gas Marketing Other Eliminations Consolidated 2014 Revenues from external customers $ 1,462.6 $ 162.6 $ 2.0 $ — $ 1,627.2 Intersegment revenues 5.2 84.0 1.8 (91.0 ) — Total Operating Revenues 1,467.8 246.6 3.8 (91.0 ) 1,627.2 Operating Expenses Gas Utility Natural and propane gas 821.8 — — (90.1 ) 731.7 Other operation and maintenance 288.7 — — (0.9 ) 287.8 Depreciation and amortization 82.4 — — — 82.4 Taxes, other than income taxes 112.0 — — — 112.0 Total Gas Utility Operating Expenses 1,304.9 — — (91.0 ) 1,213.9 Gas Marketing and Other — 226.4 (a) 20.5 (b) — 246.9 Total Operating Expenses 1,304.9 226.4 20.5 (91.0 ) 1,460.8 Operating Income (Loss) 162.9 20.2 (16.7 ) — 166.4 Net Economic Earnings (Loss) 92.8 10.2 (2.9 ) — 100.1 Capital Expenditures 168.6 — 2.4 — 171.0 (a) Depreciation and amortization for Gas Marketing are included in Gas Marketing Expenses on the Consolidated Statements of Income ( $0.1 for 2016 , $0.3 for 2015 , and $0.4 for 2014 ). (b) Depreciation, amortization, and accretion for Other are included in the Other Operating Expenses on the Consolidated Statements of Income ( $0.5 for 2016 , $0.6 for 2015 , and $0.5 for 2014 ). Total Assets at End of Year 2016 2015 2014 Gas Utility $ 5,191.9 $ 4,686.2 $ 4,520.0 Gas Marketing 205.0 160.6 156.7 Other 1,842.4 1,560.2 1,575.7 Eliminations (1,161.9 ) (1,116.8 ) (1,178.4 ) Total Assets $ 6,077.4 $ 5,290.2 $ 5,074.0 Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings 2016 2015 2014 Net Income (GAAP) $ 144.2 $ 136.9 $ 84.6 Unrealized gain on energy-related derivatives (0.1 ) (2.8 ) (1.6 ) Lower of cost or market inventory adjustments 0.2 0.4 (1.1 ) Realized (gain) loss on economic hedges prior to the sale of the physical commodity (1.6 ) 2.4 (0.4 ) Acquisition, divestiture and restructuring activities 9.2 9.8 29.5 Gain on sale of property — (7.6 ) — Income tax effect of adjustments (2.8 ) (0.8 ) (10.9 ) Net Economic Earnings $ 149.1 $ 138.3 $ 100.1

REGULATORY MATTERS

REGULATORY MATTERS	12 Months Ended
	Sep. 30, 2016
Regulated Operations [Abstract]
REGULATORY MATTERS	REGULATORY MATTERS The Utilities account for regulated operations in accordance with 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. Also, 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). The following regulatory assets and regulatory liabilities were reflected in the Balance Sheets as of September 30, 2016 and 2015 . Unamortized Purchased Gas Adjustments are also included below, which are reported separately in the current assets and liabilities sections of each balance sheet. Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Regulatory Assets: Current: Pension and postretirement benefit costs $ 27.0 $ 22.0 $ 20.2 $ 15.5 $ 6.8 $ 6.5 Unamortized purchased gas adjustments 49.7 12.9 43.1 12.9 5.6 — Other 17.2 5.6 3.7 0.7 8.1 4.9 Total Current Regulatory Assets 93.9 40.5 67.0 29.1 20.5 11.4 Noncurrent: Future income taxes due from customers 151.3 134.5 151.3 134.5 — — Pension and postretirement benefit costs 487.9 448.7 375.7 368.0 98.9 80.7 Cost of removal 130.6 78.9 — — 130.6 78.9 Purchased gas costs 12.6 24.1 12.6 24.1 — — Energy efficiency 25.5 22.3 25.5 22.3 — — Other 30.1 29.1 24.7 24.7 1.2 4.0 Total Noncurrent Regulatory Assets 838.0 737.6 589.8 573.6 230.7 163.6 Total Regulatory Assets $ 931.9 $ 778.1 $ 656.8 $ 602.7 $ 251.2 $ 175.0 Regulatory Liabilities: Current: RSE adjustment $ 7.5 $ 12.2 $ — $ — $ 5.0 $ 12.2 Unbilled service margin 5.9 6.4 — — 5.9 6.4 Refundable negative salvage 9.3 10.8 — — 9.3 10.8 Unamortized purchased gas adjustments 1.7 28.2 — — — 28.2 Other 6.2 3.0 1.3 0.6 2.5 2.4 Total Current Regulatory Liabilities 30.6 60.6 1.3 0.6 22.7 60.0 Noncurrent: Postretirement liabilities 28.9 28.9 — — 28.9 28.9 Refundable negative salvage 9.4 16.2 — — 9.4 16.2 Accrued cost of removal 74.8 58.7 55.1 58.7 — — Other 17.6 15.5 12.2 11.9 3.4 3.6 Total Noncurrent Regulatory Liabilities 130.7 119.3 67.3 70.6 41.7 48.7 Total Regulatory Liabilities $ 161.3 $ 179.9 $ 68.6 $ 71.2 $ 64.4 $ 108.7 Regulatory assets are expected to be recovered in rates charged to customers. A portion of the Company’s regulatory assets are not earning a return and are shown in the schedule below: Spire Laclede Gas 2016 2015 2016 2015 Future income taxes due from customers $ 151.3 $ 134.5 $ 151.3 $ 134.5 Pension and postretirement benefit costs 240.6 223.7 240.6 223.7 Compensated absences — — — — Other 12.9 14.2 12.9 14.2 Total Regulatory Assets Not Earning a Return $ 404.8 $ 372.4 $ 404.8 $ 372.4 All of Alagasco’s regulatory assets currently earn a return. These regulatory assets are expected to be recovered from customers in future rates. Excluding deferred income taxes and purchased gas adjustment items, as of September 30, 2016 and 2015 , approximately $404.8 and $372.4 , respectively, of regulatory assets were not earning a rate of return. The Company expects these items to be recovered over a period not to exceed 15 years consistent with precedent set by the MoPSC. The portion of the regulatory asset related to pensions and other postemployment benefits that relates to unfunded differences between the projected benefit obligation and plan assets also does not earn a rate of return. Laclede Gas On November 12, 2015, the MoPSC approved an incremental Infrastructure System Replacement Surcharge (ISRS) amount of $4.4 for Laclede Gas’ eastern Missouri service territory and $1.9 for MGE, effective December 1, 2015, bringing total annualized ISRS revenue to $19.6 for Laclede Gas’ eastern Missouri service territory and $6.7 for MGE’s service territory. On January 15, 2016, the Missouri Office of the Public Counsel (OPC) filed an appeal to Missouri’s Western District Court of Appeals of the MoPSC’s decision permitting Laclede Gas to update its ISRS applications during the pendency of the case. On September 27, 2016, the Western District affirmed the report and order of the MoPSC. On May 19, 2016, the MoPSC approved an incremental ISRS amount of $5.4 for Laclede Gas’ eastern Missouri service territory and $3.6 for MGE, effective May 31, 2016, bringing total annualized ISRS revenue to $25.0 for Laclede Gas’ eastern Missouri service territory and $10.3 for MGE’s service territory. On June 30, 2016, the OPC again filed an appeal to Missouri’s Western District Court of Appeals of the MoPSC’s decision permitting Laclede Gas to update its ISRS applications during the pendency of the case. Laclede Gas believes the MoPSC’s decision was lawful and reasonable, and believes the updating process will again be upheld by the Western District and intends to vigorously oppose the appeal. On September 30, 2016 Laclede Gas filed to increase its ISRS revenues by $5.0 for Laclede Gas’ eastern Missouri service territory and $3.4 for MGE, related to ISRS investments from March 2016 through October 2016. The MoPSC suspended the tariff until January 28, 2017 and directed the MoPSC Staff (Staff) to file a recommendation no later than November 29, 2016. Laclede Gas previously had authority from the MoPSC to issue debt securities and preferred stock, including on a private placement basis, as well as to issue common stock, receive paid-in capital, and enter into capital lease agreements, all for a total of up to $518.0 . This authority was scheduled to expire June 30, 2015. On April 15, 2015, Laclede Gas applied to the MoPSC for a new financing authorization in the amount of $550.0 , and on June 24, 2015, the MoPSC granted an extension of the current authorization until the pending application was resolved. On February 10, 2016, the MoPSC issued an order, by a 3-2 vote, authorizing Laclede financing authority for $300.0 for financings placed any time before September 30, 2018. Laclede Gas filed an application for rehearing, which was denied on March 9, 2016. On March 31, 2016, Laclede Gas filed an appeal with the Western District Court of Appeals concerning this matter. On July 20, 2016, Laclede Gas filed its initial brief before the Court. The MoPSC filed its reply brief on September 19, 2016. Laclede Gas filed its final brief on October 4, 2016. Oral arguments are scheduled for November 17, 2016. Laclede Gas issued no securities under this authorization since the decision and $300.0 remained available for issuance as of November 11, 2016. Alagasco Alagasco is subject to regulation by the APSC which established the Rate Stabilization and Equalization (RSE) rate-setting process in 1983. Alagasco’s current RSE order has a term extending beyond September 30, 2018, unless the APSC enters an order to the contrary in a manner consistent with law. In the event of unforeseen circumstances, whether physical or economic, of the nature of force majeure and including a change in control, the APSC and Alagasco will consult in good faith with respect to modifications, if any. Effective January 1, 2014, Alagasco’s allowed range of return on average common equity is 10.5% to 10.95% with an adjusting point of 10.8% . Alagasco is eligible to receive a performance-based adjustment of 5 basis points to the return on equity adjusting point, based on meeting certain customer satisfaction criteria. Under RSE, the APSC conducts quarterly reviews to determine whether Alagasco’s return on average common equity at the end of the rate year will be within the allowed range of return. Reductions in rates can be made quarterly to bring the projected return within the allowed range; increases, however, are allowed only once each rate year, effective December 1, and cannot exceed 4% of prior-year revenues. There was no RSE reduction for the January 31, 2016 quarterly point of test. Related to the April 30, 2016 quarterly point of test, Alagasco recorded a $5.8 RSE reduction to operating revenues, which the APSC directed, by order dated June 20, 2016, be applied to the Gas Supply Adjustment (GSA) balance. The RSE reduction for the July 31, 2016 quarterly point of test was $4.8 . As of September 30, 2016, Alagasco recorded a $2.7 RSE reduction to operating revenues to bring the expected rate of return on average common equity at the end of the year to within the allowed range of return. The quarterly point of test reductions from rate year 2016 went into effect October 1, 2016 for $4.8 and will go into effect December 1, 2016 for $2.7 . On October 26, 2016, as part of their annual update for RSE, Alagasco filed a $1.3 reduction for rate year 2017, which is subject to review by APSC Staff and becomes effective December 1, 2016 unless otherwise ordered by the APSC. The inflation-based Cost Control Mechanism (CCM), established by the APSC, allows for annual increases to operations and maintenance (O&M) expense. The CCM range is Alagasco’s 2007 actual rate year O&M expense (Base Year) inflation-adjusted using the June Consumer Price Index For All Urban Consumers each rate year plus or minus 1.75% (Index Range). If rate year O&M expense falls within the Index Range, no adjustment is required. If rate year O&M expense exceeds the Index Range, three-quarters of the difference is returned to customers through future rate adjustments. To the extent that rate year O&M is less than the Index Range, Alagasco benefits by one-half of the difference through future rate adjustments. Certain items that fluctuate based on situations demonstrated to be beyond Alagasco’s control may be excluded from the CCM calculation. A CCM benefit to the company for such cost saving of $7.8 related to 2016 will be reflected in rates effective December 1, 2016. The CCM benefit was $4.7 for 2015.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Commitments The Company and the Utilities have entered into contracts with various counterparties, expiring on dates through 2031, for the storage, transportation, and supply of natural gas. Minimum payments required by the Company under the contracts in place at September 30, 2016 are estimated at $1,647.8 . Minimum payments required for Laclede Gas and Alagasco under the contracts are estimated at $1,227.6 and $352.7 , respectively. Additional contracts are generally entered into prior to or during the heating season of November through April. The Missouri Utilities recover their costs from customers in accordance with their PGA clause and Alagasco recovers its cost through its GSA rider. Alagasco’s long-term contracts associated with the delivery and storage of natural gas include fixed charges of approximately $352.7 through August 2020. Alagasco also is committed to purchase minimum quantities of gas at market-related prices or to pay certain costs in the event the minimum quantities are not taken. These purchase commitments are approximately 93 Bcf through August 2020. Laclede Pipeline Company (Pipeline), a wholly owned subsidiary of Spire, is providing liquid propane transportation service to Laclede Gas pursuant to an approved FERC tariff and a contractual arrangement between Pipeline and Laclede Gas. In accordance with the terms of that agreement, Laclede Gas is obligated to pay Pipeline approximately $1.0 annually, at current rates. The agreement renews at the end of each contract year, unless terminated by either party upon provision of at least six months’ notice. Leases and Guarantees Aggregate rental expense and annual minimum rental commitments under all leases having an initial or remaining non-cancelable term of more than one year are shown below: Aggregate Rental Expense Minimum Rental Commitments 2016 2015 2014 2017 2018 2019 2020 2021 Later Total Spire $ 11.9 $ 14.1 $ 6.7 $ 10.5 $ 7.5 $ 7.3 $ 6.2 $ 6.0 $ 53.4 $ 90.9 Laclede Gas 4.3 7.6 6.3 2.5 0.9 0.9 0.3 0.1 — 4.7 Alagasco 3.7 4.0 2.0 3.9 2.5 2.5 2.1 2.1 4.9 18.0 The lease agreement covering the primary office space of Spire and its Missouri Utilities extends through February 2035. Laclede Gas has entered into various operating lease agreements for the rental of vehicles and power operated equipment. The lease agreement covering the primary office space of Alagasco extends through February 2018. Alagasco has an operating lease for additional office space that extends to January 31, 2024. Alagasco has subleased all of this office space to Energen pursuant to a sublease that expires on December 31, 2019 with an option to extend through January 31, 2024. Amounts in the table above have not been reduced for sublease rentals. For Alagasco and Spire, sublease rentals were $2.1 , $2.1 , and $0.2 for fiscal years 2016, 2015, and 2014, and minimum future rentals to be received in fiscal years 2017, 2018, 2019, and 2020 are $2.1 , $2.1 , $2.1 , and $0.5 , respectively. Laclede Gas, Alagasco and LER have other relatively minor rental arrangements that provide for minimum rental payments. A consolidated subsidiary is a general partner in an unconsolidated partnership that invests in real estate partnerships. The subsidiary and third parties are jointly and severally liable for the payment of mortgage loans in the aggregate outstanding amount of approximately $1.4 incurred in connection with various real estate ventures. Spire has no reason to believe that the other principal liable parties will not be able to meet their proportionate share of these obligations. Spire further believes that the asset values of the real estate properties are sufficient to support these mortgage loans. Contingencies The Company and Utilities account for environmental liabilities and other contingencies in accordance with accounting standards under the loss contingency guidance of ASC Topic 450, “Contingencies,” when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. 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. In addition to matters noted below, the Company, Laclede Gas, and Alagasco are involved in other litigation, claims, and investigations arising in the normal course of business. Management, after discussion with counsel, believes that the final outcome will not have a material effect on the consolidated statements of income, balance sheets, and statements of cash flows of the Company, Laclede Gas, or Alagasco. However, there is uncertainty in the valuation of pending claims and prediction of litigation results. 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. Laclede Gas Laclede Gas has identified three former MGP sites in eastern Missouri where costs have been incurred and claims have been asserted: one in Shrewsbury, Missouri and two in the City of St. Louis, Missouri. Laclede Gas has enrolled the two sites in the City of St. Louis in the Missouri Department of Natural Resources Brownfields/Voluntary Cleanup Program (BVCP). In Laclede Gas’ western service area, MGE has enrolled all of its owned former MGP sites in the BVCP. With regard to the former MGP site located in Shrewsbury, Missouri, Laclede Gas and state and federal environmental regulators agreed upon certain remedial actions to a portion of the site in a 1999 Administrative Order on Consent (AOC), which actions have been completed. On September 22, 2008, Environmental Protection Agency (EPA) Region VII issued a letter of Termination and Satisfaction terminating the AOC. However, if after this termination of the AOC, regulators require additional remedial actions, or additional claims are asserted, Laclede Gas may incur additional costs. In conjunction with redevelopment of one of the sites located in the City of St. Louis, Laclede Gas and another former owner of the site entered into an agreement (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 Missouri Department of Natural Resources (MDNR). The Remediation Agreement also provides for a release of Laclede Gas 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 Laclede Gas 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 Laclede Gas did not materially impact the financial condition, results of operations, or cash flows of the Company. Laclede Gas has not owned the other site located in the City of St. Louis for many years. In a letter dated June 29, 2011, the Attorney General for the state of Missouri informed Laclede Gas that the MDNR had completed an investigation of the site. The Attorney General requested that Laclede Gas participate in the follow up investigations of the site. In a letter dated January 10, 2012, Laclede Gas stated that it would participate in future environmental response activities at the site in conjunction with other potentially responsible parties (PRPs) that are willing to contribute to such efforts in a meaningful and equitable fashion. Accordingly, Laclede Gas entered into a cost sharing agreement for remedial investigation with other PRPs. Pending MDNR approval which has not occurred as of the date of filing, the remedial investigation of the site will begin. Laclede Gas 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, Laclede Gas continues to discuss potential reimbursements with them. On March 10, 2015, Laclede Gas received a Section 104(e) information request from EPA Region VII regarding the former Thompson Chemical/Superior Solvents site in St. Louis, Missouri. In turn, Laclede Gas 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. MGE 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, MGE 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 area. 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 Laclede Gas 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 potential responsible parties to pay, the successful completion of remediation efforts required by the Remediation Agreement described above, and any insurance recoveries. In 2013, Laclede Gas retained an outside consultant to conduct probabilistic cost modeling of 19 former MGP sites owned or operated by Laclede Gas in eastern Missouri or MGE in western 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. Laclede Gas has recorded its best estimate of the probable expenditures that relate to these matters. The amount is not material. Costs associated with environmental remediation activities are accrued when such costs are probable and reasonably estimable. To the extent such costs (less any amounts received from insurance proceeds or as contributions from other PRP’s), are incurred prior to a rate case, Laclede Gas would request from the MoPSC authority to defer such costs and collect them in the next rate case. Laclede Gas 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. Alagasco Alagasco 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. As of September 30, 2016, Alagasco does not foresee a probable or reasonably estimable loss associated with these nine sites. Alagasco and the Company do not expect potential liabilities that may arise from remediating these sites to have a material impact on their future financial conditions or results of operations. In 2012, Alagasco responded to an EPA Request for Information Pursuant to Section 104 of the Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) relating to the 35th Avenue Superfund Site located in North Birmingham, Jefferson County, Alabama. Alagasco 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, Alagasco 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. On December 17, 2013, an incident occurred at a Housing Authority apartment complex in Birmingham, Alabama which resulted in one fatality, personal injuries and property damage. Alagasco 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. Alagasco has been named as a defendant in several lawsuits arising from the incident, and additional lawsuits and claims may be filed against Alagasco. Mobile Gas Mobile Gas is in the chain of title of one former MGP site which it still owns in Mobile, Alabama. On September 15, 2010, Mobile Gas filed an application to enroll the site into the Alabama Department of Environmental Management’s (ADEM) Voluntary Cleanup Program (VCP). This application was accepted by ADEM on November 16, 2010. Investigation and testing have been completed. As of September 30, 2016, Mobile Gas has an approved remediation plan from ADEM which is currently in the process of being executed. Mobile Gas and the Company do not expect potential liabilities that may arise from remediating this site to have a material impact on their future financial conditions or results of operations. Since April 2012, a total of 14 lawsuits have been filed against Mobile Gas in Mobile County Circuit Court alleging that in the first half of 2008, Mobile Gas spilled tert-butyl mercaptan, an odorant added to natural gas for safety reasons, in Eight Mile, Alabama. Eleven of the lawsuits have been settled. The remaining three lawsuits, which include approximately 270 individual plaintiffs, allege nuisance, fraud and negligence causes of actions, and seek unspecified compensatory and punitive damages. A claim has been made against the insurance carriers for Mobile Gas requesting reimbursement for costs accrued in respect to this spill. Mobile Gas and the Company do not expect potential liabilities that may arise from these lawsuits to have a material impact on their future financial conditions or results of operations.

INTERIM FINANCIAL INFORMATION (

INTERIM FINANCIAL INFORMATION (UNAUDITED)	12 Months Ended
	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
INTERIM FINANCIAL INFORMATION (UNAUDITED)	INTERIM FINANCIAL INFORMATION (UNAUDITED) Spire In the opinion of Spire, the quarterly information presented below for fiscal years 2016 and 2015 includes all adjustments (consisting of only normal recurring accruals) necessary for a fair statement of the results of operations for such periods. Variations in consolidated operations reported on a quarterly basis primarily reflect the seasonal nature of the business of the Utilities. Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 399.4 $ 609.3 $ 249.3 $ 279.3 Operating Income (Loss) 87.0 167.7 35.3 (7.7 ) Net Income (Loss) 46.9 100.8 10.7 (14.2 ) Basic Earnings (Loss) Per Share of Common Stock $ 1.08 $ 2.32 $ 0.24 $ (0.31 ) Diluted Earnings (Loss) Per Share of Common Stock $ 1.08 $ 2.31 $ 0.24 $ (0.31 ) Fiscal Year 2015 Total Operating Revenues $ 619.6 $ 877.4 $ 275.2 $ 204.2 Operating Income (Loss) 87.3 157.7 36.0 (8.5 ) Net Income (Loss) 47.1 94.4 14.1 (18.7 ) Basic Earnings (Loss) Per Share of Common Stock $ 1.09 $ 2.18 $ 0.32 $ (0.43 ) Diluted Earnings (Loss) Per Share of Common Stock $ 1.09 $ 2.18 $ 0.32 $ (0.43 ) Laclede Gas In the opinion of Laclede Gas, the quarterly information presented below for fiscal years 2016 and 2015 includes all adjustments (consisting of only normal recurring accruals) necessary for a fair statement of the results of operations for such periods. Variations in operations reported on a quarterly basis primarily reflect their seasonal nature. Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 317.2 $ 446.7 $ 179.3 $ 144.3 Operating Income 65.1 87.0 29.4 5.4 Net Income (Loss) 39.4 54.3 13.9 (1.7 ) Fiscal Year 2015 Total Operating Revenues $ 462.4 $ 615.7 $ 187.5 $ 151.0 Operating Income 64.8 80.6 34.5 5.5 Net Income (Loss) 39.0 49.9 20.0 (3.6 ) Alagasco In the opinion of Alagasco, the quarterly information presented below for fiscal years 2016 and 2015 includes all adjustments (consisting of only normal recurring accruals) necessary for a fair statement of the results of operations for such periods. Variations in operations reported on a quarterly basis primarily reflect their seasonal nature. Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 82.3 $ 166.0 $ 74.0 $ 46.2 Operating Income (Loss) 18.9 80.4 9.3 (17.1 ) Net Income (Loss) 9.9 48.1 4.0 (8.8 ) Fiscal Year 2015 Total Operating Revenues $ 120.0 $ 233.3 $ 73.7 $ 52.2 Operating Income (Loss) 20.4 77.4 3.9 (12.5 ) Net Income (Loss) 10.6 46.3 0.7 (9.6 )

SUMMARY OF SIGNIFICANT ACCOUN29

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION – These notes are an integral part of the accompanying audited financial statements of Spire Inc. (Spire or the Company), as well as Laclede Gas Company (Laclede Gas or the Missouri Utilities) and Alabama Gas Corporation (Alagasco). Laclede Gas, which includes the operations of Missouri Gas Energy (MGE), and Alagasco are wholly owned subsidiaries of the Company. Laclede Gas, Alagasco and the subsidiaries of EnergySouth, Inc. (EnergySouth) are collectively referred to as the Utilities. The subsidiaries of EnergySouth are Mobile Gas Service Corporation (Mobile Gas) and Willmut Gas and Oil Company (Willmut Gas). The accompanying audited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The consolidated financial position, results of operations, and cash flows of Spire are primarily derived from the financial position, results of operations, and cash flows of the Utilities. In compliance with GAAP, transactions between Laclede Gas and Alagasco and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements. The Company’s September 12, 2016 acquisition of EnergySouth and the August 31, 2014 acquisition of Alagasco are included in the results of operations since their acquisition dates and impact the comparability of the financial statement periods presented for the Company. For a further discussion of the acquisitions, see Note 2 , Acquisitions. The Utilities are regulated natural gas distribution utilities. Due to the seasonal nature of the Utilities, the earnings of Spire, Laclede Gas and Alagasco are typically concentrated during the heating season of November through April each fiscal year. Effective September 2, 2014, Alagasco amended its bylaws to change Alagasco’s fiscal year from beginning January 1 and ending on December 31, to beginning October 1 and ending September 30. As a result, the financial statements covering the nine-month period from January 1, 2014 through September 30, 2014 (the “transition period”) were included in Alagasco’s transition report on Form 10-K/T for such period and are presented in the financial statements and notes herein.
USE OF ESTIMATES	USE OF ESTIMATES – The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
SYSTEM OF ACCOUNTS	SYSTEM OF ACCOUNTS – The accounts of the Utilities are maintained in accordance with the Uniform System of Accounts prescribed by the applicable state public service commissions, which systems substantially conform to that prescribed by the Federal Energy Regulatory Commission (FERC).
UTILITY PLANT, DEPRECIATION AND AMORTIZATION	UTILITY PLANT, DEPRECIATION AND AMORTIZATION – Utility plant is stated at original cost. The cost of additions to utility plant includes contracted work, direct labor and materials, allocable overheads, and an allowance for funds used during construction. The costs of units of property retired, replaced, or renewed are removed from utility plant and are charged to accumulated depreciation. Maintenance and repairs of property and replacement and renewal of items determined to be less than units of property are charged to maintenance expenses. For Laclede Gas, utility plant is depreciated on a straight-line basis at rates based on estimated service lives of the various classes of property. In fiscal years 2016 , 2015 and 2014 , annual depreciation and amortization expense averaged 3.0% of the original cost of depreciable and amortizable property. Laclede Gas’ capital expenditures were $197.8 , $198.6 and $163.0 for fiscal years 2016 , 2015 , and 2014 , respectively. Additionally, Laclede Gas had recorded accruals for capital expenditures totaling $14.8 at September 30, 2016 , $9.6 at September 30, 2015 , and $3.0 at September 30, 2014 . For Alagasco, depreciation is provided using the composite method of depreciation on a straight-line basis over the estimated useful lives of utility property at rates approved by the Alabama Public Service Commission (APSC).
ASSET RETIREMENT OBLIGATIONS	ASSET RETIREMENT OBLIGATIONS – Spire, Laclede Gas, and Alagasco record legal obligations associated with the retirement of long-lived assets in the period in which the obligations are incurred, if sufficient information exists to reasonably estimate the fair value of the obligations. Obligations are recorded as both a cost of the related long-lived asset and as a corresponding liability. Subsequently, the asset retirement costs are depreciated over the life of the asset and the asset retirement obligations are accreted to the expected settlement amounts. The Company, Laclede Gas and Alagasco record asset retirement obligations associated with certain safety requirements to purge and seal gas distribution mains upon retirement, the plugging and abandonment of storage wells and other storage facilities, specific service line obligations, and certain removal and disposal obligations related to components of Laclede Gas’, Alagasco’s and Mobile Gas’ distribution systems and general plant. Asset retirement obligations recorded by Spire’s other subsidiaries are not material. As authorized by the Missouri Public Service Commission (MoPSC) and APSC, Laclede Gas, Alagasco and Mobile Gas accrue future asset removal costs associated with their property, plant and equipment even if a legal obligation does not exist. Such accruals are provided for through depreciation expense and are recorded with corresponding credits to regulatory liabilities or assets. When those utilities retire depreciable utility plant and equipment, they charge the associated original costs to accumulated depreciation and amortization, and any related removal costs incurred are charged to regulatory liabilities or assets. The difference between removal costs recognized in depreciation rates and the accretion expense and depreciation expense recognized for financial reporting purposes is a timing difference between recovery of these costs in rates and their recognition for financial reporting purposes. Accordingly, these differences are deferred as regulatory liabilities or assets. In the rate setting process, the regulatory liability or asset is excluded from the rate base upon which those utilities have the opportunity to earn their allowed rates of return. The costs associated with asset retirement obligations of Laclede Gas, Alagasco and Mobile Gas are either currently being recovered in rates or are probable of recovery in future rates.
REGULATED OPERATIONS	REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, “Regulated Operations.” This Topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. See additional discussion on regulated operations in Note 15 , Regulatory Matters. As discussed below for Laclede Gas and Alagasco, 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 rider are both labeled Unamortized Purchased Gas Adjustments herein. Laclede Gas As authorized by the MoPSC, the PGA clause allows Laclede Gas to flow through to customers, subject to prudence review by the MoPSC, the cost of purchased gas supplies. To better match customer billings with market natural gas prices, Laclede Gas is allowed to file to modify, on a periodic basis, the level of gas costs in its PGA. Certain provisions of the PGA clause are included below: • Laclede Gas has a risk management policy that allows for the purchase of natural gas derivative instruments with the goal of managing price risk associated with purchasing natural gas on behalf of its customers. The MoPSC clarified that costs, cost reductions, and carrying costs associated with the Utility’s use of natural gas derivative instruments are gas costs recoverable through the PGA mechanism. • The tariffs allow Laclede Gas flexibility to make up to three discretionary PGA changes during each year, in addition to its mandatory November PGA change, so long as such changes are separated by at least two months . • Laclede Gas is authorized to apply carrying costs to all over- or under-recoveries of gas costs, including costs and cost reductions associated with the use of derivative instruments, including cash payments for margin deposits. Laclede Gas’ eastern Missouri service territory is also authorized to recover gas inventory carrying costs through its PGA rates to recover costs it incurs to finance its investment in gas supplies that are purchased during the storage injection season for sale during the heating season. • The MoPSC approved a plan applicable to Laclede Gas’ gas supply commodity costs under which it retains a portion of cost savings associated with the acquisition of natural gas below an established benchmark level. This gas supply cost management program allows Laclede Gas to retain 10% of cost savings, up to a maximum of $3.0 annually. Laclede Gas did not record any income under the plan during the three fiscal years reported. Income recorded under the plan, if any, is included in Gas Utility Operating Revenues on the Consolidated Statements of Income and under Operating Revenues on Laclede Gas’ Statements of Income. Pursuant to the provisions of the PGA clause, the difference between actual costs incurred and costs recovered through the application of the PGA clause are reflected as a deferred charge or credit at the end of the fiscal year. These costs include costs and cost reductions associated with the use of derivative instruments and gas inventory carrying costs, amounts due to or from customers related to operation of the gas supply cost management program, refunds received from the Company’s suppliers in connection with gas supply, transportation, and storage services, and carrying costs on such over- or under-recoveries. At that time, the balance is classified as a current asset or current liability and recovered from, or credited to, customers over an annual period commencing in November. The balance in the current account is amortized as amounts are reflected in customer billings. The PGA clause also provides for the treatment of income from off-system sales and capacity release revenues. Pre-tax income from off-system sales and capacity release revenues is shared with customers, with an estimated amount assumed in PGA rates. The difference between the actual amount allocated to customers for each fiscal year and the estimated amount assumed in PGA rates is recovered from, or credited to, customers over an annual period commencing in the subsequent November. The customer share of such income is determined in accordance with the following tables, shown for each service territory for which the PGA clauses were approved by the MoPSC. Customer Share Company Share Eastern Missouri First $2.0* 100% —% Next $2.0 80% 20% Next $2.0 75% 25% Amounts exceeding $6.0 70% 30% * Customer share reverts to 85% and company share reverts to 15% in 2017. Western Missouri First $1.2 85% 15% Next $1.2 80% 20% Next $1.2 75% 25% Amounts exceeding $3.6 70% 30% Alagasco Alagasco’s rate schedules for natural gas distribution charges contain a GSA rider, established in 1993, which permits the pass-through to customers of changes in the cost of gas supply. Alagasco’s tariff provides a temperature adjustment mechanism, also included in the GSA rider, which is designed to moderate the impact of departures from normal temperatures on Alagasco’s earnings. The temperature adjustment applies primarily to residential, small commercial and small industrial customers. Other non-temperature weather-related conditions that may affect customer usage are not included in the temperature adjustment.
NATURAL GAS AND PROPANE GAS	NATURAL GAS AND PROPANE GAS – For Laclede Gas’ eastern Missouri utility, inventory of natural gas in storage is priced on a last in, first out (LIFO) basis and inventory of propane gas in storage is priced on a first in, first out (FIFO) basis. For the rest of the Gas Utility segment, inventory of natural gas in storage is priced on the weighted average cost basis. The replacement cost of Laclede Gas’ natural gas for current use in eastern Missouri at September 30, 2016 and September 30, 2015 was less than the LIFO cost by $11.4 and $20.4 , respectively. The carrying value of Laclede Gas’ inventory is not adjusted to the lower of cost or market prices because, pursuant to the Missouri Utilities’ PGA clauses, actual gas costs are recovered in customer rates. Natural gas and propane gas storage inventory in Spire’s other operating segments is recorded at the lower of average cost or market.
BUSINESS COMBINATIONS	BUSINESS COMBINATIONS – The EnergySouth and Alagasco acquisitions are accounted for by Spire using business combination accounting. Under this method, the purchase price paid by the acquirer is allocated to the assets acquired and liabilities assumed as of the acquisition date based on their fair value.
GOODWILL	GOODWILL – Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the amount of acquisition-date identifiable assets acquired net of assumed liabilities. Spire and Laclede Gas evaluate goodwill for impairment as of July 1st of each year, or more frequently if events and circumstances indicate that goodwill might be impaired. At July 1, 2016, 2015 and 2014, Spire and Laclede Gas each applied a quantitative goodwill evaluation model to their reporting units and concluded goodwill was not impaired because the fair value exceeded the carrying amount.
IMPAIRMENT OF LONG-LIVED ASSETS	IMPAIRMENT OF LONG-LIVED ASSETS – Long-lived assets classified as held and used are evaluated for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Whether impairment has occurred is determined by comparing the estimated undiscounted cash flows attributable to the assets with the carrying value of the assets. If the carrying value exceeds the undiscounted cash flows, the Company recognizes an impairment charge equal to the amount of the carrying value that exceeds the estimated fair value of the assets. In the period in which the Company determines an asset meets held-for-sale criteria, an impairment charge is recorded to the extent the book value exceeds its fair value less cost to sell.
REVENUE RECOGNITION	REVENUE RECOGNITION – The Utilities read meters and bill customers on monthly cycles. The Missouri Utilities 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. The amounts of accrued unbilled revenues for Laclede Gas at September 30, 2016 and 2015 were $26.1 and $27.6 , respectively. Alagasco records natural gas distribution revenues in accordance with the tariff established by the APSC. The amount of accrued unbilled revenues, which are not recorded as revenues until billed, for Alagasco at September 30, 2016 and 2015 were $5.9 and $6.4 , respectively. All related costs and margins are also deferred. The subsidiaries of EnergySouth record natural gas revenues in accordance with tariffs established by the APSC and MSPSC. Unbilled revenues are accrued and related costs and margins are also deferred. Spire’s other subsidiaries, including LER, record revenues when earned, either when the product is delivered or when services are performed. In the course of its business, LER enters into commitments associated with the purchase or sale of natural gas. Certain of its derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of 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. For additional information on derivative instruments, refer to Note 10 , Derivative Instruments and Hedging Activities. Certain of LER’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 Consolidated Statements of Income. This net presentation has no effect on operating income or net income.
INCOME TAXES	INCOME TAXES – Spire and its subsidiaries account for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amount of existing assets and liabilities and the respective tax basis and for tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effects on deferred tax assets and liabilities of a change in enacted tax rates is recognized in income or loss for a non-regulated company, and in a regulatory asset or regulatory liability for a regulated company. A valuation allowance is established when it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with authoritative guidance. The authoritative guidance addresses the determination of whether tax benefits claimed, or expected to be claimed, on a tax return should be recorded in the financial statements. Spire may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by the taxing authority, based on the technical merits of the position. Tax-related interest and penalties, if any, are classified as a liability on the balance sheets.
CASH AND CASH EQUIVALENTS	CASH AND CASH EQUIVALENTS – All highly liquid debt instruments purchased with original maturities of three months or less are considered to be cash equivalents. Such instruments are carried at cost, which approximates market value. Outstanding checks on the Company’s and Utilities’ bank accounts in excess of funds on deposit create book overdrafts (which are funded at the time checks are presented for payment) and are classified as Other in the Current Liabilities section of the balance sheets. Changes in book overdrafts are reflected as Operating Activities in the statements of cash flows.
NATURAL GAS RECEIVABLE	ACCOUNTS RECEIVABLE AND ALLOWANCE FOR DOUBTFUL ACCOUNTS – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Estimates of the collectability of trade accounts receivable are based on historical trends, age of receivables, economic conditions, credit risk of specific customers, and other factors. Accounts receivable are written off against the allowance for doubtful accounts when they are deemed to be uncollectible. Spire’s provision for uncollectible accounts includes the amortization of previously deferred uncollectible expenses for Laclede Gas and Alagasco, as approved by the MoPSC and the APSC. NATURAL GAS RECEIVABLE – LER enters into natural gas transactions with natural gas pipeline companies known as park and loan arrangements. Under the terms of the arrangements, LER purchases natural gas from a third party and delivers that natural gas to the pipeline company for the right to receive the same quantity of natural gas from the pipeline company at the same location in a future period. These arrangements are accounted for as non-monetary transactions under GAAP and are recorded at the carrying amount. As such, natural gas receivables are reflected on the Consolidated Balance Sheets at cost, which includes related pipeline fees associated with the transactions. In the period that the natural gas is returned to LER, concurrent with the sale of the natural gas to a third party, the related natural gas receivable is expensed in the Consolidated Statements of Income. In conjunction with these transactions, LER usually enters into New York Mercantile Exchange (NYMEX) and Intercontinental Exchange (ICE) natural gas futures, options, and swap contracts or fixed price sales agreements to protect against market changes in future sales prices.
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE – GAAP requires dual presentation of basic and diluted earnings per share (EPS). EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareholders. Certain of the Company’s stock-based compensation awards pay non-forfeitable dividends to the participants during the vesting period and, as such, are deemed participating securities. Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding that are increased for additional shares that would be outstanding if potentially dilutive non-participating securities were converted to common shares, pursuant to the treasury stock method. Shares attributable to equity units, non-participating stock options and time-vested restricted stock/units are excluded from the calculation of diluted earnings per share if the effect would be antidilutive. Shares attributable to non-participating performance-contingent restricted stock awards are only included in the calculation of diluted earnings per share to the extent the underlying performance and/or market conditions are satisfied (a) prior to the end of the reporting period or (b) would be satisfied if the end of the reporting period were the end of the related contingency period and the result would be dilutive.
GROSS RECEIPTS AND SALES TAXES	GROSS RECEIPTS AND SALES TAXES – Gross receipts taxes associated with the Company’s natural gas utility services are imposed on the Company, Laclede Gas, and Alagasco 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: 2016 2015 2014 Spire $ 75.5 $ 97.3 $ 77.5 Laclede Gas 57.4 74.5 76.3 Alagasco 17.9 22.6 20.6 Sales taxes imposed on applicable Alagasco and Laclede Gas 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.
TRANSACTIONS WITH AFFILIATES	TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire.
GROUP MEDICAL AND WORKERS' COMPENSATION RESERVES	GROUP MEDICAL AND WORKERS’ COMPENSATION RESERVES – The Company self-insures its group medical and workers’ compensation costs and carries stop-loss coverage in relation to medical claims and workers’ compensation claims. Reserves for amounts incurred but not reported are established based on historical cost levels and lags between occurrences and reporting.
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS – Certain assets and liabilities are recognized or disclosed at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The levels of the hierarchy are described below: • Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2 – Pricing inputs other than quoted prices included within Level 1, which are either directly or indirectly observable for the asset or liability as of the reporting date. These inputs are derived principally from, or corroborated by, observable market data. • Level 3 – Pricing that is based upon inputs that are generally unobservable that are based on the best information available and reflect management’s assumptions about how market participants would price the asset or liability. Assessment of the significance of a particular input to the fair value measurements may require judgment and may affect the valuation of the asset or liability and its placement within the fair value hierarchy.
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION – The Company measures stock-based compensation awards at fair value at the date of grant and recognizes the compensation cost of the awards over the requisite service period. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if the actual forfeitures differ from those estimates.
NEW ACCOUNTING STANDARDS	NEW ACCOUNTING PRONOUNCEMENTS – In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. The core principle of the standard is when an entity transfers goods or services to customers it will recognize revenue in an amount that reflects the consideration the entity expects to be entitled to for those goods or services. ASU No. 2014-09 also requires disclosures that will enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which made the guidance in ASU No. 2014-09 effective for fiscal years beginning after December 15, 2017 and interim periods within those years, but companies may choose to adopt it one year earlier. In 2016, the FASB issued related ASU Nos. 2016-08, 2016-10, 2016-11 and 2016-12, which further modified the standards for accounting for revenue. The Company, Laclede Gas and Alagasco are currently assessing the available transition methods and the potential impacts of the updates, which must be adopted by the first quarter of fiscal year 2019. In April 2015, the FASB issued ASU No. 2015-03, Interest – Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs. Currently, debt issuance costs are recorded as a deferred charge (asset), while debt discount and debt premium costs are recorded as a liability adjustment. This amendment will require debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. ASU No. 2015-15 clarified that ASU No. 2015-03 does not address the presentation of debt issuance costs related to line-of-credit arrangements, and the Company intends to continue to report such costs as deferred charges. The new guidance is effective for the Company, Laclede Gas and Alagasco beginning in the first quarter of fiscal 2017. The application of this standard will be retrospective, wherein each balance sheet presented will be adjusted to reflect the impacts of applying the new guidance. If this ASU had been adopted as of September 30, 2016, the amounts reclassified from other deferred charges to reduce long-term debt at September 30, 2016 and 2015, respectively, would have been $13.2 and $13.0 for Spire, $4.2 and $4.8 for Laclede Gas, and $2.6 and $2.4 for Alagasco. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes: Balance Sheet classification of Deferred Taxes, to require that deferred tax liabilities and assets be classified entirely as noncurrent. This was part of the FASB’s simplification initiative intended to reduce cost and complexity in financial reporting while improving or maintaining the usefulness of the information reported to investors. The Company, Laclede Gas and Alagasco adopted this ASU in the fourth quarter of fiscal 2016. Prior periods were not retrospectively adjusted. The adoption of this accounting standard was not material to the financial statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, which provides revised guidance concerning certain matters involving the recognition, measurement, and disclosure of financial instruments. It is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company, Laclede Gas and Alagasco are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of fiscal year 2019. In February 2016, the FASB issued ASU No. 2016-02, Leases. The new standard requires lessees to recognize a right-of-use asset and lease liability for almost all lease contracts based on the present value of lease payments. There is an exemption for short-term leases. The ASU provides new guidelines for identifying and classifying a lease, and classification affects the pattern and income statement line item for the related expense. The ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company, Laclede Gas and Alagasco are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of fiscal year 2020. In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation: Improvements to Employee Share-Based Payment Accounting. The standard is intended to simplify several areas of accounting for share-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. The ASU is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. The Company, Laclede Gas and Alagasco are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of fiscal year 2018. On June 16, 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments. The standard introduces new guidance for the accounting for credit losses on instruments within its scope, including trade receivables. It is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, but may be adopted up to two years earlier. The Company, Laclede Gas and Alagasco are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of fiscal year 2021.

SUMMARY OF SIGNIFICANT ACCOUN30

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Asset retirement obligations	The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets. Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Asset retirement obligations, beginning of year $ 159.2 $ 99.2 $ 72.4 $ 71.2 $ 86.6 $ 27.7 Liabilities incurred during the period 4.1 2.3 1.2 0.6 2.9 1.7 Liabilities settled during the period (9.5 ) (2.0 ) (1.9 ) (1.9 ) (6.8 ) (0.1 ) Accretion 13.2 4.5 3.5 3.4 9.7 1.1 Revisions in estimated cash flows 27.5 55.2 — (0.9 ) 27.7 56.2 Addition of EnergySouth asset retirement obligations 11.9 — — — — — Asset retirement obligations, end of year $ 206.4 $ 159.2 $ 75.2 $ 72.4 $ 120.1 $ 86.6
Off-system sales	Pre-tax income from off-system sales and capacity release revenues is shared with customers, with an estimated amount assumed in PGA rates. The difference between the actual amount allocated to customers for each fiscal year and the estimated amount assumed in PGA rates is recovered from, or credited to, customers over an annual period commencing in the subsequent November. The customer share of such income is determined in accordance with the following tables, shown for each service territory for which the PGA clauses were approved by the MoPSC. Customer Share Company Share Eastern Missouri First $2.0* 100% —% Next $2.0 80% 20% Next $2.0 75% 25% Amounts exceeding $6.0 70% 30% * Customer share reverts to 85% and company share reverts to 15% in 2017. Western Missouri First $1.2 85% 15% Next $1.2 80% 20% Next $1.2 75% 25% Amounts exceeding $3.6 70% 30%
Changes in the carrying amount of goodwill by reportable segment	The changes in the carrying amount of goodwill by reportable segment were as follows: Gas Utility Gas Marketing Other Total Balance as of September 30, 2013 $ 247.1 $ — $ — $ 247.1 Adjustments to finalize the 2013 acquisition of MGE (36.9 ) — — (36.9 ) Acquisition of Alagasco — — 727.6 727.6 Balance as of September 30, 2014 210.2 — 727.6 937.8 Adjustments to finalize the acquisition of Alagasco — — 8.2 8.2 Balance as of September 30, 2015 210.2 — 735.8 946.0 Acquisition of EnergySouth — — 218.9 218.9 Balance as of September 30, 2016 $ 210.2 $ — $ 954.7 $ 1,164.9
Schedule of gross receipts taxes	The following table presents gross receipts taxes recorded: 2016 2015 2014 Spire $ 75.5 $ 97.3 $ 77.5 Laclede Gas 57.4 74.5 76.3 Alagasco 17.9 22.6 20.6
Schedule of inter-company transactions	Laclede Gas had the following transactions with affiliates: 2016 2015 2014 Purchases of natural gas from LER $ 46.3 $ 74.1 $ 89.1 Sales of natural gas to LER 1.9 4.0 5.1 Services received from Laclede Insurance Risk Services, Inc. 1.8 1.0 0.6

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Schedule of consideration paid and amounts of assets acquired and liabilities assumed	The following table summarizes the consideration paid and the amounts of the assets acquired and liabilities assumed at the acquisition dates. Measurement period adjustments were immaterial. Alagasco EnergySouth Recognized amounts of identifiable assets acquired and liabilities assumed: Utility plant $ 892.7 $ 199.5 Cash 12.1 2.0 Other current assets 99.4 17.5 Deferred tax assets 282.0 — Other assets 143.4 79.8 Long-term debt (249.8 ) (67.0 ) Current portion of long-term debt (15.0 ) — Other current liabilities (173.4 ) (42.7 ) Deferred tax liabilities — (35.5 ) Other liabilities (130.4 ) (52.8 ) Total identifiable net assets 861.0 100.8 Goodwill 735.8 218.9 Deferred tax elimination (Spire) (271.3 ) — Consideration (cash) $ 1,325.5 $ 319.7
Schedule of Pro Forma Information	The results of operations of each of the acquisitions are included in the Spire statements of income from the date of acquisition, as shown in the following table. Alagasco EnergySouth 2016 2015 2014 2016 Total Operating Revenues $ 368.5 $ 479.2 $ 19.7 $ 3.3 Net Income (Loss) 53.2 48.0 (2.9 ) (0.2 ) Earnings (Loss) Per Share $ 1.20 $ 1.11 $ (0.08 ) $ — The following unaudited pro forma financial information presents Spire’s combined results of operations as though the EnergySouth acquisition had occurred as of the beginning of fiscal year 2015 and the Alagasco acquisition had occurred as of the beginning of fiscal year 2013. The unaudited pro forma financial information is not necessarily indicative of either future results of operations or results that would have been achieved if the acquisitions had occurred as of those earlier dates. It does not reflect the costs of any integration activities. It includes estimates and assumptions which management believes are reasonable. 2016 2015 2014 Total Operating Revenues $ 1,632.4 $ 2,081.6 $ 2,187.1 Net Income 153.9 143.6 133.5 Basic Earnings Per Share $ 3.48 $ 3.32 $ 3.11 Diluted Earnings Per Share 3.46 3.31 3.10

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Restricted stock and restricted stock unit activity	Fiscal year 2016 activity of restricted stock and restricted stock units subject to performance and/or market conditions is presented below: Shares/ Units Weighted Average Grant Date Fair Value Per Share Nonvested at September 30, 2015 397,270 $ 36.28 Granted (maximum shares that can be earned) 199,140 $ 45.95 Vested (62,593 ) $ 35.29 Forfeited (23,234 ) $ 30.96 Nonvested at September 30, 2016 510,583 $ 40.37 Time-vested restricted stock and stock unit activity for fiscal year 2016 is presented below: Shares/ Units Weighted Average Grant Date Fair Value Per Share Nonvested at September 30, 2015 129,304 $ 44.89 Granted 48,730 $ 60.65 Vested (44,645 ) $ 47.30 Forfeited (610 ) $ 53.12 Nonvested at September 30, 2016 132,779 $ 49.83
Stock option awards activity	No stock options were granted during fiscal years 2016 , 2015 , and 2014 . Stock option activity for fiscal year 2016 is presented below: Stock Options Weighted Average Exercise Price Per Share Outstanding at September 30, 2015 28,500 $ 33.65 Exercised (27,750 ) $ 33.66 Forfeited (750 ) $ 33.45 Outstanding at September 30, 2016 — $ —
Significant assumptions used in the Monte Carlo simulations	The significant assumptions used in the Monte Carlo simulations are as follows: 2016 2015 2014 Risk free interest rate 1.14% 0.83% 0.53% Expected dividend yield of stock — — — Expected volatility of stock 15.0% 14.0% 18.0% Vesting period 2.8 years 2.8 years 2.8 years
Compensation cost recognized for share-based compensation arrangements	The amounts of compensation cost recognized for share-based compensation arrangements are presented below: 2016 2015 2014 Total equity compensation cost $ 6.7 $ 6.7 $ 5.8 Compensation cost capitalized (2.2 ) (1.8 ) (1.8 ) Compensation cost recognized in net income $ 4.5 $ 4.9 $ 4.0 Income tax benefit recognized in net income (1.7 ) (1.9 ) (1.5 ) Compensation cost recognized in net income, net of income tax $ 2.8 $ 3.0 $ 2.5

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	12 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share	2016 2015 2014 Basic EPS: Net Income $ 144.2 $ 136.9 $ 84.6 Less: Income allocated to participating securities 0.5 0.5 0.3 Net Income Available to Common Shareholders $ 143.7 $ 136.4 $ 84.3 Weighted Average Shares Outstanding (millions) 44.1 43.2 35.8 Earnings Per Share of Common Stock $ 3.26 $ 3.16 $ 2.36 Diluted EPS: Net Income $ 144.2 $ 136.9 $ 84.6 Less: Income allocated to participating securities 0.5 0.5 0.3 Net Income Available to Common Shareholders $ 143.7 $ 136.4 $ 84.3 Weighted Average Shares Outstanding (millions) 44.1 43.2 35.8 Dilutive Effect of Stock Options, Restricted Stock, and Restricted Stock Units (millions) 0.2 0.1 0.1 Weighted Average Diluted Shares (millions) 44.3 43.3 35.9 Earnings Per Share of Common Stock $ 3.24 $ 3.16 $ 2.35 Outstanding Shares (in millions) Excluded from the Calculation of Diluted EPS Attributable to: Restricted stock and stock units subject to performance and/or market conditions 0.3 0.3 0.3

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	12 Months Ended
	Sep. 30, 2016
Stockholders' Equity Note [Abstract]
Schedule of stock purchase obligation	The purchase price to be paid under the stock purchase contracts is fifty dollars per Corporate Unit and the number of shares to be purchased will be determined as follows: If the applicable market value per share of Spire common stock is: Number of shares to be purchased per purchase contract is: Equal to or greater than $57.8125 0.8649 Less than $57.8125, but greater than $46.25 $50 ÷ applicable market value Less than or equal to $46.25 1.0811
Schedule of Company's equity units	Selected information about the Company’s equity units is presented below: Issuance Date Units Issued (Millions) Total Net Proceeds Total Long-term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Contract Liability 6/11/2014 2.875 $139.4 $143.8 2.00% 4.75% $19.7
Schedule of accumulated other comprehensive income (loss)	The components of accumulated other comprehensive income (loss), net of income taxes, recognized in the balance sheets at September 30 were as follows: Net Unrealized Gains (Losses) on Cash Flow Hedges Defined Benefit Pension and Other Postretirement Benefit Plans Net Unrealized Losses on Available for Sale Securities Total Spire Balance at September 30, 2014 $ 0.2 $ (1.9 ) $ — $ (1.7 ) Other comprehensive (loss) income (0.6 ) 0.4 (0.1 ) (0.3 ) Balance at September 30, 2015 (0.4 ) (1.5 ) (0.1 ) (2.0 ) Other comprehensive (loss) income (1.9 ) (0.3 ) — (2.2 ) Balance at September 30, 2016 $ (2.3 ) $ (1.8 ) $ (0.1 ) $ (4.2 ) Laclede Gas Balance at September 30, 2014 $ — $ (1.9 ) $ — $ (1.9 ) Other comprehensive (loss) income (0.2 ) 0.4 — 0.2 Balance at September 30, 2015 (0.2 ) (1.5 ) — (1.7 ) Other comprehensive income (loss) 0.3 (0.3 ) (0.1 ) (0.1 ) Balance at September 30, 2016 $ 0.1 $ (1.8 ) $ (0.1 ) $ (1.8 )

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of maturities of long-term debt by fiscal year	Maturities of long-term debt for Spire, Laclede Gas and Alagasco for the five fiscal years subsequent to September 30, 2016 are as follows: Spire Laclede Gas Alagasco 2017 $ 250.0 $ — $ — 2018 100.0 100.0 — 2019 180.0 50.0 — 2020 40.0 — 40.0 2021 55.0 — —

NOTES PAYABLE AND CREDIT AGRE36

NOTES PAYABLE AND CREDIT AGREEMENTS (Tables)	12 Months Ended
	Sep. 30, 2016
Short-term Debt [Line Items]
Short-term borrowings	Information about Spire’s short-term borrowings (excluding intercompany borrowings) during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Laclede Gas Commercial Paper Borrowings Spire Bank Line Borrowings* Alagasco Bank Line Borrowings Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $201.0 $42.7 $30.2 $273.9 Weighted average interest rate 0.7% 1.6% 1.4% 0.9% Range of borrowings outstanding $43.0 - $307.2 $0.0 - $82.0 $0.0 - $82.0 $73.1 - $427.2 As of September 30, 2016 Borrowings outstanding at end of period $243.7 $73.0 $82.0 $398.7 Weighted average interest rate 0.8% 1.8% 1.5% 1.1% Year Ended September 30, 2015 Weighted average borrowings outstanding $212.7 $65.6 $22.3 $300.6 Weighted average interest rate 0.4% 1.4% 1.1% 0.7% Range of borrowings outstanding $ 102.1 - $341.0 $32.5 - $80.0 $0.0 - $69.5 $180.1 - $488.5 As of September 30, 2015 Borrowings outstanding at end of period $233.0 $74.0 $31.0 $338.0 Weighted average interest rate 0.5% 1.5% 1.2% 0.8% * Spire Inc., excluding its wholly owned subsidiaries.
Laclede Gas
Short-term Debt [Line Items]
Short-term borrowings	Information about Laclede Gas’ short-term borrowings during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Commercial Paper Borrowings Borrowings from Spire Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $201.0 $14.7 $215.7 Weighted average interest rate 0.7% 0.8% 0.7% Range of borrowings outstanding $43.0 - $307.2 $0.0 - $114.2 $127.8 - $ 307.2 As of September 30, 2016 Borrowings outstanding at end of period $243.7 $— $243.7 Weighted average interest rate 0.8% —% 0.8% Year Ended September 30, 2015 Weighted average borrowings outstanding $212.7 $0.3 $213.0 Weighted average interest rate 0.4% 0.5% 0.4% Range of borrowings outstanding $102.1 - $341.0 $0.0 - $10.4 $104.2 - $ 341.0 As of September 30, 2015 Borrowings outstanding at end of period $233.0 $— $233.0 Weighted average interest rate 0.5% —% 0.5%
Alagasco
Short-term Debt [Line Items]
Short-term borrowings	Information about Alagasco’s short-term borrowings during the twelve months ended September 30, and as of September 30, is presented below for 2016 and 2015 : Bank Line Borrowings Borrowings from Spire Total Short-Term Borrowings Year Ended September 30, 2016 Weighted average borrowings outstanding $30.2 $12.4 $42.6 Weighted average interest rate 1.4% 1.4% 1.4% Range of borrowings outstanding $0.0 - $82 $0.0 - $61.9 $19.0 - $82.0 As of September 30, 2016 Borrowings outstanding at end of period $82.0 $— $82.0 Weighted average interest rate 1.5% —% 1.5% Year Ended September 30, 2015 Weighted average borrowings outstanding $22.3 $— $22.3 Weighted average interest rate 1.1% —% 1.1% Range of borrowings outstanding $0.0 - $69.5 0 $0.0- $69.5 As of September 30, 2015 Borrowings outstanding at end of period $31.0 $— $31.0 Weighted average interest rate 1.2% —% 1.2%

FAIR VALUE OF FINANCIAL INSTR37

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Sep. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments	The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for the Company are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ 5.2 $ 5.2 $ 5.2 $ — $ — Short-term debt 398.7 398.7 — 398.7 — Long-term debt, including current portion 2,083.7 2,257.1 — 2,257.1 — As of September 30, 2015 Cash and cash equivalents $ 13.8 $ 13.8 $ 13.8 $ — $ — Short-term debt 338.0 338.0 — 338.0 — Long-term debt, including current portion 1,851.5 1,944.2 — 1,944.2 —
Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments	The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Laclede Gas are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ 2.1 $ 2.1 $ 2.1 $ — $ — Short-term debt 243.7 243.7 — 243.7 — Long-term debt 808.3 900.4 — 900.4 — As of September 30, 2015 Cash and cash equivalents $ 1.7 $ 1.7 $ 1.7 $ — $ — Short-term debt 233.0 233.0 — 233.0 — Long-term debt 808.1 880.2 — 880.2 —
Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments	The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Alagasco are as follows: Classification of Estimated Fair Value Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 30, 2016 Cash and cash equivalents $ — $ — $ — $ — $ — Short-term debt 82.0 82.0 — 82.0 — Long-term debt 250.0 275.5 — 275.5 — As of September 30, 2015 Cash and cash equivalents $ 7.2 $ 7.2 $ 7.2 $ — $ — Short-term debt 31.0 31.0 — 31.0 — Long-term debt, including current portion 250.0 263.2 — 263.2 —

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, 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 NYMEX. Derivative instruments classified as Level 2 include physical commodity derivatives that are valued using Over-the-Counter Bulletin Board (OTCBB), broker, or dealer quotation services whose prices are derived principally from, or are corroborated by, observable market inputs. Also included in Level 2 are certain derivative instruments that have values that are similar to, and correlate with, quoted prices for exchange-traded instruments in active markets. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. There were no material Level 3 balances as of September 30, 2016 or 2015 . 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 the “Other investments” line of the 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 exist between the Company or Laclede Gas and the counterparty to the derivative contract. For additional information on derivative instruments, see Note 10 , Derivative Instruments and Hedging Activities. 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, 2016 ASSETS Gas Utility US stock/bond mutual funds $ 16.8 $ 4.1 $ — $ — $ 20.9 NYMEX/ICE natural gas contracts 5.3 — — (0.4 ) 4.9 Gasoline and heating oil contracts 0.4 — — (0.3 ) 0.1 Subtotal 22.5 4.1 — (0.7 ) 25.9 Gas Marketing NYMEX/ICE natural gas contracts 0.4 3.4 — (3.4 ) 0.4 Natural gas commodity contracts — 8.7 0.2 (0.9 ) 8.0 Total $ 22.9 $ 16.2 $ 0.2 $ (5.0 ) $ 34.3 LIABILITIES Gas Utility NYMEX/ICE natural gas contracts $ 1.6 $ — $ — $ (1.6 ) $ — OTCBB natural gas contracts — 0.2 — — 0.2 Subtotal 1.6 0.2 — (1.6 ) 0.2 Gas Marketing NYMEX/ICE natural gas contracts 3.5 1.6 — (5.1 ) — Natural gas commodity contracts — 2.6 — (0.9 ) 1.7 Other Interest rate swaps — 3.0 — — 3.0 Total $ 5.1 $ 7.4 $ — $ (7.6 ) $ 4.9 As of September 30, 2015 ASSETS Gas Utility US stock/bond mutual funds $ 15.5 $ 4.0 $ — $ — $ 19.5 NYMEX/ICE natural gas contracts 1.3 — — (1.3 ) — Subtotal 16.8 4.0 — (1.3 ) 19.5 Gas Marketing NYMEX natural gas contracts 6.3 4.3 — (6.6 ) 4.0 Natural gas commodity contracts — 1.5 0.2 (0.5 ) 1.2 Total $ 23.1 $ 9.8 $ 0.2 $ (8.4 ) $ 24.7 LIABILITIES Gas Utility NYMEX/ICE natural gas contracts $ 16.4 $ — $ — $ (16.4 ) $ — OTCBB natural gas contracts — 5.9 — — 5.9 NYMEX gasoline and heating oil contracts 0.3 — — (0.3 ) — Subtotal 16.7 5.9 — (16.7 ) 5.9 Gas Marketing NYMEX/ICE natural gas contracts 1.2 3.9 — (5.1 ) — Natural gas commodity contracts — 2.2 — (0.5 ) 1.7 Total $ 17.9 $ 12.0 $ — $ (22.3 ) $ 7.6
Laclede Gas
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, 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 September 30, 2016 ASSETS US stock/bond mutual funds $ 16.8 $ 4.1 $ — $ — $ 20.9 NYMEX/ICE natural gas contracts 5.3 — — (0.4 ) 4.9 Gasoline and heating oil contracts 0.3 — — (0.3 ) — Total $ 22.4 $ 4.1 $ — $ (0.7 ) $ 25.8 LIABILITIES NYMEX/ICE natural gas contracts $ 1.6 $ — $ — $ (1.6 ) $ — OTCBB natural gas contracts — 0.2 — — 0.2 Total $ 1.6 $ 0.2 $ — $ (1.6 ) $ 0.2 As of September 30, 2015 ASSETS US stock/bond mutual funds $ 15.5 $ 4.0 $ — $ — $ 19.5 NYMEX/ICE natural gas contracts 1.3 — — (1.3 ) — Total $ 16.8 $ 4.0 $ — $ (1.3 ) $ 19.5 LIABILITIES NYMEX/ICE natural gas contracts $ 16.4 $ — $ — $ (16.4 ) $ — OTCBB natural gas contracts — 5.9 — — 5.9 NYMEX gasoline and heating oil contracts 0.3 — — (0.3 ) — Total $ 16.7 $ 5.9 $ — $ (16.7 ) $ 5.9

DERIVATIVE INSTRUMENTS AND HE39

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	12 Months Ended
	Sep. 30, 2016
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Open NYMEX/ICE and OTCBB natural gas futures and swap positions at September 30, 2016 were as follows: Gas Utility Gas Marketing MMBtu (millions) Avg. Price Per MMBtu MMBtu (millions) Avg. Price Per MMBtu NYMEX/ICE Open short futures positions Fiscal 2017 — $ — 12.20 $ 2.86 Fiscal 2018 — — 1.27 2.95 NYMEX/ICE Open long futures/swap positions Fiscal 2017 18.43 2.95 4.62 3.12 Fiscal 2018 0.33 2.83 0.45 3.02 Fiscal 2019 — — 0.04 2.89 ICE Open long basis swap positions Fiscal 2017 — — 16.62 0.34 Fiscal 2018 — — 2.01 0.43 Fiscal 2019 — — 0.08 0.40 ICE Open short basis swap positions Fiscal 2017 — — 11.88 0.19 Fiscal 2018 — — 0.93 0.27 Fiscal 2019 — — 2.27 0.13 OTC Open long futures/swap positions Fiscal 2017 0.32 3.64 — —
The Effect of Derivative Instruments on the Statements of Consolidated Income and Statements of Consolidated Comprehensive Income	Effect of Derivative Instruments on the Consolidated Statements of Income and Consolidated Statements of Comprehensive Income Location of Gain (Loss) Recorded in Income 2016 2015 2014 Derivatives in Cash Flow Hedging Relationships Effective portion of gain (loss) recognized in OCI on derivatives: Gas Marketing natural gas contracts $ (0.6 ) $ (4.3 ) $ (4.6 ) Gas Utility gasoline and heating oil contracts — (1.2 ) 0.1 Interest Rate Swaps (3.4 ) — — Total $ (4.0 ) $ (5.5 ) $ (4.5 ) Effective portion of gain (loss) reclassified from AOCI to income: Natural gas contracts Gas Marketing Operating Revenues $ 4.3 $ 1.7 $ 4.2 Gas Marketing Operating Expenses (4.9 ) (5.2 ) (1.5 ) Subtotal (0.6 ) (3.5 ) 2.7 Gasoline and heating oil contracts Gas Utility Other Operating Expenses (0.5 ) (0.9 ) (0.2 ) Total $ (1.1 ) $ (4.4 ) $ 2.5 Ineffective portion of gain (loss) on derivatives recognized in income: Natural gas contracts Gas Marketing Operating Revenues $ 0.1 $ — $ (0.1 ) Gas Marketing Operating Expenses 0.1 (0.5 ) 0.1 Subtotal 0.2 (0.5 ) — Gasoline and heating oil contracts Gas Utility Other Operating Expenses 0.1 0.1 (0.2 ) Total $ 0.3 $ (0.4 ) $ (0.2 ) Derivatives Not Designated as Hedging Instruments* Gain (loss) recognized in income on derivatives: Natural gas commodity contracts Gas Marketing Operating Revenues $ 12.3 $ (1.3 ) $ (8.7 ) NYMEX / ICE natural gas contracts Gas Marketing Operating Revenues (1.7 ) (9.6 ) 3.0 Gasoline and heating oil contracts Other Income and (Income Deductions) - Net — (0.2 ) — Total $ 10.6 $ (11.1 ) $ (5.7 ) * Gains and losses on Laclede Gas’ natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Missouri Utilities’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the statements of income. Such amounts are recognized in the statements of income as a component of Regulated Gas Distribution Natural and Propane Gas operating expenses when they are recovered through the PGA clause and reflected in customer billings.
Fair Value of Derivative Instruments in the Consolidated Balance Sheet	Fair Value of Derivative Instruments in the Consolidated Balance Sheet Asset Derivatives* Liability Derivatives* September 30, 2016 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gas Utility: Gasoline and heating oil contracts Derivative Instrument Assets $ 0.3 Derivative Instrument Assets $ — Gas Marketing: Natural gas contracts Derivative Instrument Assets 2.5 Derivative Instrument Assets 0.8 Deferred Charges – Other 0.4 Deferred Charges – Other 0.1 Other: Interest swaps Derivative Instrument Assets — Derivative Instrument Assets 3.0 Subtotal 3.2 3.9 Derivatives not designated as hedging instruments Gas Utility: Natural gas contracts Accounts Receivable – Other 5.4 Accounts Receivable – Other 1.6 Derivative Instrument Assets — Derivative Instrument Assets 0.2 Gas Marketing: NYMEX / ICE natural gas contracts Derivative Instrument Assets 0.8 Derivative Instrument Assets 4.1 Deferred Charges – Other — Deferred Charges – Other 0.1 Natural gas commodity Derivative Instrument Assets 6.5 Derivative Instrument Assets 0.2 Other Deferred Charges 2.1 Other Deferred Charges 0.3 Current Liabilities – Other 0.2 Current Liabilities – Other 2.0 Deferred Credits – Other 0.2 Deferred Credits – Other 0.1 Subtotal 15.2 8.6 Total derivatives $ 18.4 $ 12.5 September 30, 2015 Derivatives designated as hedging instruments Gas Utility: Gasoline and heating oil contracts Accounts Receivable – Other $ — Accounts Receivable – Other $ 0.3 Gas Marketing: Natural gas contracts Derivative Instrument Assets 4.1 Derivative Instrument Assets 3.2 Deferred Charges – Other 1.1 Deferred Charges – Other 0.5 Subtotal 5.2 4.0 Derivatives not designated as hedging instruments Gas Utility: Natural gas contracts Accounts Receivable – Other 1.2 Accounts Receivable – Other 16.4 Derivative Instrument Assets — Derivative Instrument Assets 5.7 Deferred Charges – Other — Deferred Charges – Other 0.2 Gas Marketing: NYMEX / ICE natural gas contracts Derivative Instrument Assets 4.7 Derivative Instrument Assets 0.6 Deferred Charges – Other 0.7 Deferred Charges – Other 0.7 Natural gas commodity Derivative Instrument Assets 1.4 Derivative Instrument Assets 0.1 Current Liabilities – Other 0.2 Current Liabilities – Other 1.4 Deferred Credits – Other 0.1 Deferred Credits – Other 0.7 Subtotal 8.3 25.8 Total derivatives $ 13.5 $ 29.8 * The fair values of Asset Derivatives and Liability Derivatives exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9 , Fair Value Measurements, for information on the valuation of derivative instruments.
Derivative instrument Reconciliation	Following is a reconciliation of the amounts in the tables above to the amounts presented in the Consolidated Balance Sheets: 2016 2015 Fair value of asset derivatives presented above $ 18.4 $ 13.5 Fair value of cash margin receivables offset with derivatives 2.5 13.9 Netting of assets and liabilities with the same counterparty (7.6 ) (22.2 ) Total $ 13.3 $ 5.2 Derivative Instrument Assets, per Consolidated Balance Sheets: Derivative instrument assets $ 11.4 $ 4.6 Deferred Charges – Other 1.9 0.6 Total $ 13.3 $ 5.2 Fair value of liability derivatives presented above $ 12.5 $ 29.8 Netting of assets and liabilities with the same counterparty (7.6 ) (22.2 ) Total $ 4.9 $ 7.6 Derivative Instrument Liabilities, per Consolidated Balance Sheets: Current Liabilities – Other $ 4.8 $ 6.8 Deferred Credits – Other 0.1 0.8 Total $ 4.9 $ 7.6
Laclede Gas
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Laclede Gas’ derivative instruments consist primarily of NYMEX and OTCBB positions. The NYMEX is the primary national commodities exchange on which natural gas derivatives are traded. Open NYMEX and OTCBB natural gas futures positions at September 30, 2016 were as follows: MMBtu (millions) Avg. Price Per MMBtu NYMEX/ICE Open long futures/swap positions Fiscal 2017 18.43 $ 2.95 Fiscal 2018 0.33 2.83 OTC Open long futures/swap positions Fiscal 2017 0.32 $ 3.64
The Effect of Derivative Instruments on the Statements of Consolidated Income and Statements of Consolidated Comprehensive Income	Effect of Derivative Instruments on the Statements of Income and Statements of Comprehensive Income Location of Gain (Loss) Recorded in Income 2016 2015 2014 Derivatives in Cash Flow Hedging Relationships Effective portion of gain (loss) recognized in OCI on derivatives: Gasoline and heating oil contracts $ — $ (1.2 ) $ 0.1 Effective portion of gain (loss) reclassified from AOCI to income: Gasoline and heating oil contracts Gas Utility Other Operating Expenses $ (0.5 ) $ (0.9 ) $ (0.2 ) Ineffective portion of gain (loss) on derivatives recognized in income: Gasoline and heating oil contracts Gas Utility Other Operating Expenses $ 0.1 $ 0.1 $ (0.2 ) Derivatives Not Designated as Hedging Instruments* Gain (loss) recognized in income on derivatives: Gasoline and heating oil contracts Other Income and (Income Deductions) - Net $ — $ (0.2 ) $ — * Gains and losses on Laclede Gas’ natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Laclede Gas’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the Statements of Income. Such amounts are recognized in the Statements of Income as a component of Regulated Gas Distribution Natural and Propane Gas operating expenses when they are recovered through the PGA clause and reflected in customer billings.
Fair Value of Derivative Instruments in the Consolidated Balance Sheet	Fair Value of Derivative Instruments in the Balance Sheet at September 30, 2016 Asset Derivatives* Liability Derivatives* Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gasoline and heating oil contracts Derivative Instrument Assets $ 0.3 Derivative Instrument Assets $ — Subtotal 0.3 — Derivatives not designated as hedging instruments Natural gas contracts Accounts Receivable – Other 5.4 Accounts Receivable – Other 1.6 OTCBB natural gas contracts Derivative Instrument Assets — Derivative Instrument Assets 0.2 Subtotal 5.4 1.8 Total derivatives $ 5.7 $ 1.8 Fair Value of Derivative Instruments in the Balance Sheet at September 30, 2015 Asset Derivatives Liability Derivatives* Balance Sheet Location Fair Value * Balance Sheet Location Fair Value Derivatives designated as hedging instruments Gasoline and heating oil contracts Accounts Receivable – Other $ — Accounts Receivable – Other $ 0.3 Subtotal — 0.3 Derivatives not designated as hedging instruments Natural gas contracts Accounts Receivable – Other 1.2 Accounts Receivable – Other 16.4 Derivative Instrument Assets — Derivative Instrument Assets 5.7 Deferred Charges - Other — Deferred Charges - Other 0.2 Subtotal 1.2 22.3 Total derivatives $ 1.2 $ 22.6 * The fair values of Asset Derivatives and Liability Derivatives exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the Balance Sheets. As such, the gross balances presented in the table above are not indicative of Laclede Gas’ net economic exposure. Refer to Note 9 , Fair Value Measurements, for information on the valuation of derivative instruments.
Derivative instrument Reconciliation	Following is a reconciliation of the amounts in the tables above to the amounts presented in Laclede Gas’ Balance Sheets: 2016 2015 Fair value of asset derivatives presented above $ 5.7 $ 1.2 Fair value of cash margin receivables offset with derivatives 0.8 15.5 Netting of assets and liabilities with the same counterparty (1.6 ) (16.7 ) Total $ 4.9 $ — Derivative Instrument Assets, per Balance Sheets: Derivative instrument assets $ 4.9 $ — Total $ 4.9 $ — Fair value of liability derivatives presented above $ 1.8 $ 22.6 Netting of assets and liabilities with the same counterparty (1.6 ) (16.7 ) Total $ 0.2 $ 5.9 Derivative Instrument Liabilities, per Balance Sheets: Current Liabilities – Other $ 0.2 $ 5.7 Deferred Credits – Other — 0.2 Total $ 0.2 $ 5.9

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Sep. 30, 2016
Income Tax Contingency [Line Items]
Net Provision For Income Tax	The Company’s provision for income taxes charged during the fiscal years ended September 30, 2016 , 2015 , and 2014 are as follows: 2016 2015 2014 Federal Current $ 0.1 $ (3.3 ) $ 0.3 Deferred 62.0 58.8 30.6 Investment tax credits (0.2 ) (0.2 ) (0.2 ) State and local Current 0.6 — 0.6 Deferred 7.0 6.9 1.0 Total income tax expense $ 69.5 $ 62.2 $ 32.3
Effective income tax rate variation from stated tax rate	The Company’s effective income tax rate varied from the federal statutory income tax rate for each year due to the following: 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 3.0 1.8 Certain expenses capitalized on books and deducted on tax return (3.4 ) (3.7 ) (4.9 ) Taxes related to prior years (0.2 ) (0.6 ) (0.7 ) Other items – net * (1.7 ) (2.5 ) (3.6 ) Effective income tax rate 32.5 % 31.2 % 27.6 % * Other consists primarily of property adjustments.
Significant Items in Net Deferred Tax Liability	The Company’s significant items comprising the net deferred tax liability recorded in the Consolidated Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 21.3 $ 14.8 Pension and other postretirement benefits 68.3 62.5 Operating losses 102.3 47.3 Other — 1.5 Deferred tax assets 191.9 126.1 Less: valuation allowance 0.9 — Total deferred tax assets 191.0 126.1 Deferred tax liabilities: Relating to property 623.1 472.1 Regulatory pension and other postretirement benefits 106.8 110.6 Deferred gas costs 20.0 8.1 Other 48.4 11.6 Total deferred tax liabilities 798.3 602.4 Net deferred tax liability 607.3 476.3 Net deferred tax asset – current — 5.8 Net deferred tax liability – noncurrent $ 607.3 $ 482.1
Unrecognized Tax Benefit Reconciliation	The following table presents a reconciliation of the beginning and ending balances of the Company’s unrecognized tax benefits: 2016 2015 2014 Unrecognized tax benefits, beginning of year $ 7.1 $ 4.6 $ 2.4 Increases related to tax positions taken in current year 3.4 2.9 2.6 Reductions due to lapse of applicable statute of limitations (0.5 ) (0.4 ) (0.4 ) Unrecognized tax benefits, end of year $ 10.0 $ 7.1 $ 4.6
Laclede Gas
Income Tax Contingency [Line Items]
Net Provision For Income Tax	Laclede Gas’ provision for income taxes charged during the fiscal years ended September 30, 2016 , 2015 , and 2014 are as follows: 2016 2015 2014 Federal Current $ — $ (2.1 ) $ (0.1 ) Deferred 37.5 40.9 34.3 Investment tax credits (0.2 ) (0.2 ) (0.2 ) State and local Current 0.1 (0.1 ) — Deferred 8.0 4.7 1.5 Total income tax expense $ 45.4 $ 43.2 $ 35.5
Effective income tax rate variation from stated tax rate	Laclede Gas’ effective income tax rate varied from the federal statutory income tax rate for each year due to the following: 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 2.8 1.8 Certain expenses capitalized on books and deducted on tax return (4.8 ) (4.9 ) (4.5 ) Taxes related to prior years (0.2 ) (0.8 ) (0.7 ) Other items – net * (2.8 ) (3.0 ) (3.3 ) Effective income tax rate 30.0 % 29.1 % 28.3 % * Other consists primarily of property adjustments.
Significant Items in Net Deferred Tax Liability	Laclede Gas’ significant items comprising the net deferred tax liability reported in the Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 14.9 $ 15.4 Pension and other postretirement benefits 56.9 62.5 Operating losses 29.9 3.7 Other — 1.5 Deferred tax assets 101.7 83.1 Less: valuation allowance 0.9 — Total deferred tax assets 100.8 83.1 Deferred tax liabilities: Relating to utility property 497.0 425.0 Regulatory pension and other postretirement benefits 106.8 120.2 Deferred gas costs 20.0 8.2 Other 33.9 14.5 Total deferred tax liabilities 657.7 567.9 Net deferred tax liability 556.9 484.8 Net deferred tax asset – current — 0.4 Net deferred tax liability – noncurrent $ 556.9 $ 485.2
Unrecognized Tax Benefit Reconciliation	The following table presents a reconciliation of the beginning and ending balances of Laclede Gas unrecognized tax benefits: 2016 2015 2014 Unrecognized tax benefits, beginning of year $ 6.9 $ 4.2 $ 2.0 Increases related to tax positions taken in current year 3.3 2.9 2.5 Reductions due to lapse of applicable statute of limitations (0.5 ) (0.2 ) (0.3 ) Unrecognized tax benefits, end of year $ 9.7 $ 6.9 $ 4.2
Alagasco
Income Tax Contingency [Line Items]
Net Provision For Income Tax	Alagasco’s provision for income taxes charged during the fiscal years ended September 30, 2016 and 2015 , and the nine months ended September 30, 2014 , are as follows: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Federal Current $ (0.8 ) $ — $ 14.1 Deferred 29.4 25.9 3.5 State and local Current — 0.1 1.8 Deferred 3.8 3.3 0.5 Total income tax expense $ 32.4 $ 29.3 $ 19.9
Effective income tax rate variation from stated tax rate	Alagasco’s effective income tax rate varied from the federal statutory income tax rate for each year due to the following: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of federal income tax benefits 2.8 2.8 2.8 Other items – net 0.1 0.1 (0.2 ) Effective income tax rate 37.9 % 37.9 % 37.6 %
Significant Items in Net Deferred Tax Liability	Alagasco’s significant items comprising the net deferred tax asset reported in the Balance Sheets as of September 30 are as follows: 2016 2015 Deferred tax assets: Reserves not currently deductible $ 6.3 $ 7.0 Pension and other postretirement benefits 11.4 9.6 Goodwill 233.4 251.5 Operating losses 60.2 32.4 Other — 1.4 Total deferred tax assets 311.3 301.9 Deferred tax liabilities: Relating to utility property 87.6 45.1 Other 2.3 2.2 Total deferred tax liabilities 89.9 47.3 Net deferred tax asset 221.4 254.6 Net deferred tax asset – current — 6.2 Net deferred tax asset – noncurrent $ 221.4 $ 248.4
Unrecognized Tax Benefit Reconciliation	The following table presents a reconciliation of the beginning and ending balances of Alagasco’s unrecognized tax benefits: Year Ended September 30, Year Ended September 30, Nine Months Ended September 30, 2016 2015 2014 Unrecognized tax benefits, beginning of period $ — $ — $ 0.3 Reduction for transfer of balance to Energen — — (0.3 ) Unrecognized tax benefits, end of period $ — $ — $ —

PENSION PLANS AND OTHER POSTR41

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Tables)	12 Months Ended
	Sep. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	The table below categorizes the fair value measurements of the Spire pension plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 51.2 $ — $ — $ 51.2 Stock/bond mutual fund 99.3 26.7 0.1 126.1 Debt Securities US bond mutual funds 23.0 126.0 — 149.0 US government 42.1 3.0 — 45.1 US corporate 137.4 — — 137.4 US municipal 6.3 — — 6.3 International 25.3 — — 25.3 Derivatives and margin (payable) (1.0 ) 1.1 — 0.1 Total $ 383.6 $ 156.8 $ 0.1 $ 540.5 As of September 30, 2015 Cash and cash equivalents $ 43.4 $ 0.2 $ — $ 43.6 Stock/bond mutual fund 46.4 74.6 9.6 130.6 Debt Securities US bond mutual funds — 9.3 — 9.3 US government 58.7 — — 58.7 US corporate 123.7 42.9 — 166.6 US municipal — 5.9 — 5.9 International — 31.3 — 31.3 Derivative instruments — 2.9 — 2.9 Total $ 272.2 $ 167.1 $ 9.6 $ 448.9 The table below categorizes the fair value measurements of Spire’s postretirement plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 4.8 $ — $ — $ 4.8 US stock/bond mutual fund 157.9 68.5 — 226.4 International fund 0.9 14.3 — 15.2 Total $ 163.6 $ 82.8 $ — $ 246.4 As of September 30, 2015 Cash and cash equivalents $ 1.6 $ — $ — $ 1.6 US stock/bond mutual fund 115.5 92.8 — 208.3 International fund — 13.4 — 13.4 Total $ 117.1 $ 106.2 $ — $ 223.3
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	The net periodic pension costs include the following components: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Service cost – benefits earned during the period $ 15.3 $ 17.3 $ 10.2 $ 10.0 $ 11.5 $ 9.7 $ 5.3 $ 5.8 $ 5.1 Interest cost on projected benefit obligation 28.0 29.5 24.5 21.7 23.3 24.0 6.3 6.2 4.1 Expected return on plan assets (34.9 ) (37.4 ) (27.2 ) (26.7 ) (29.2 ) (26.5 ) (8.2 ) (8.2 ) (5.2 ) Amortization of other comprehensive income — — 0.4 — — — — — — Amortization of prior service cost 0.4 0.5 0.5 0.4 0.5 0.5 — — 0.1 Amortization of actuarial loss 8.0 7.5 7.1 7.9 7.5 7.1 0.1 — 2.2 Loss on lump-sum settlements 3.3 19.6 1.5 — 18.0 1.5 3.3 1.6 10.1 Special termination benefits 1.6 — — 1.6 — — — — — Subtotal 21.7 37.0 17.0 14.9 31.6 16.3 6.8 5.4 16.4 Regulatory adjustment 17.8 (2.1 ) 10.4 11.7 (5.2 ) 10.4 6.1 3.1 0.4 Net pension cost $ 39.5 $ 34.9 $ 27.4 $ 26.6 $ 26.4 $ 26.7 $ 12.9 $ 8.5 $ 16.8 * Nine months ended September 30
Other changes in plan assets and benefit obligations recognized in other comprehensive income	Other changes in plan assets and pension benefit obligations recognized in other comprehensive income or loss (OCI) include the following: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Current year actuarial loss $ 46.8 $ 48.3 $ 15.7 $ 21.6 $ 26.0 $ 14.2 $ 25.2 $ 22.3 $ 1.5 Amortization of actuarial loss (8.0 ) (7.5 ) (7.1 ) (7.9 ) (7.5 ) (7.1 ) (0.1 ) — — Acceleration of loss recognized due to settlement (3.3 ) (19.6 ) (1.5 ) — (18.0 ) (1.5 ) (3.3 ) (1.6 ) — Amortization of current year service cost 5.0 — — 5.0 — — — — — Amortization of prior service cost (0.4 ) (0.5 ) (0.5 ) (0.4 ) (0.5 ) (0.5 ) — — — Subtotal 40.1 20.7 6.6 18.3 — 5.1 21.8 20.7 1.5 Regulatory adjustment (39.8 ) (21.2 ) (6.1 ) (18.0 ) (0.5 ) (4.7 ) (21.8 ) (20.7 ) (1.5 ) Total recognized in OCI $ 0.3 $ (0.5 ) $ 0.5 $ 0.3 $ (0.5 ) $ 0.4 $ — $ — $ — * Nine months ended September 30
Reconciliation of the beginning and ending balances of benefit obligation	The following table shows the reconciliation of the beginning and ending balances of the pension benefit obligation at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Benefit obligation, beginning of year $ 652.3 $ 692.4 $ 497.6 $ 543.6 $ 154.7 $ 148.8 Service cost 15.3 17.3 10.0 11.5 5.3 5.8 Interest cost 28.0 29.5 21.7 23.3 6.3 6.2 Actuarial loss (gain) 85.8 (12.8 ) 59.2 (20.7 ) 26.6 7.9 Plan amendments 5.1 — 5.1 — — — EnergySouth acquisition 60.4 — — — — — Settlement loss 1.1 16.5 — 14.5 1.1 2.0 Special termination benefits 1.6 — 1.6 — — — Settlement benefits paid (16.6 ) (71.1 ) — (58.2 ) (16.6 ) (12.9 ) Regular benefits paid (38.3 ) (19.5 ) (35.2 ) (16.4 ) (3.1 ) (3.1 ) Benefit obligation, end of year $ 794.7 $ 652.3 $ 560.0 $ 497.6 $ 174.3 $ 154.7 Accumulated benefit obligation, end of year 724.5 $ 591.4 517.7 $ 456.9 149.8 $ 134.5
Fair value of plan assets	The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Fair value of plan assets, beginning of year $ 448.9 $ 506.6 $ 339.9 $ 387.4 $ 109.0 $ 119.2 Actual return on plan assets 75.1 (7.2 ) 64.4 (3.0 ) 10.7 (4.2 ) Employer contributions 26.6 40.1 26.6 30.1 — 10.0 EnergySouth acquisition 44.8 — — — — — Settlement benefits paid (16.6 ) (71.1 ) — (58.2 ) (16.6 ) (12.9 ) Regular benefits paid (38.3 ) (19.5 ) (35.2 ) (16.4 ) (3.1 ) (3.1 ) Fair value of plan assets, end of year $ 540.5 $ 448.9 $ 395.7 $ 339.9 $ 100.0 $ 109.0 Funded status of plans, end of year $ (254.2 ) $ (203.4 ) $ (164.3 ) $ (157.7 ) $ (74.3 ) $ (45.7 )
Amounts recognized in consolidated balance sheets	The following table sets forth the amounts recognized in the balance sheets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Current liabilities $ (0.6 ) $ (0.5 ) $ (0.6 ) $ (0.5 ) $ — $ — Noncurrent liabilities (253.6 ) (202.9 ) (163.7 ) (157.2 ) (74.3 ) (45.7 ) Total $ (254.2 ) $ (203.4 ) $ (164.3 ) $ (157.7 ) $ (74.3 ) $ (45.7 ) Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic pension cost consist of: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 179.4 $ 143.9 $ 135.5 $ 121.9 $ 43.9 $ 22.0 Prior service costs 8.2 3.5 8.2 3.5 — — Subtotal 187.6 147.4 143.7 125.4 43.9 22.0 Adjustments for amounts included in regulatory assets (184.8 ) (144.9 ) (140.9 ) (122.9 ) (43.9 ) (22.0 ) Total $ 2.8 $ 2.5 $ 2.8 $ 2.5 $ — $ —
Pre-tax amounts amortized from accumulated other comprehensive income into net periodic cost	At September 30, 2016 , the following pre-tax amounts are expected to be amortized from accumulated other comprehensive loss into net periodic pension cost during fiscal year 2017 : Spire Laclede Gas Alagasco Amortization of net actuarial loss $ 13.5 $ 11.6 $ 1.9 Amortization of prior service cost 1.0 1.0 — Subtotal 14.5 12.6 1.9 Regulatory adjustment (14.2 ) (12.3 ) (1.9 ) Total $ 0.3 $ 0.3 $ —
Assumptions used to calculate net periodic cost and benefit obligations.	The assumptions used to calculate the benefit obligations are as follows: 2016 2015 Weighted average discount rate - Laclede Gas division 3.50% 4.40% Weighted average discount rate - MGE division 3.50% 4.50% Weighted average discount rate - Alagasco 3.45%/3.50% 4.25%/4.30% Weighted average rate of future compensation increase - Laclede Gas, Alagasco and MGE 3.00% 3.00% The assumptions used to calculate net periodic pension costs for Laclede Gas are as follows: 2016 2015 2014 Weighted average discount rate - Laclede Gas division plans 4.40% 4.30% 4.70% Weighted average discount rate - MGE division plans 4.50% 4.45% 5.00% Weighted average rate of future compensation increase * 3.00% 3.00% 3.00% Expected long-term rate of return on plan assets * 7.75% 7.75% 7.75% * Assumptions for weighted average rate of future compensation increase and expected long-term rate of return on plan assets are the same for both Laclede Gas and MGE plans. The assumptions used to calculate net periodic pension costs for Alagasco are as follows: 2016 2015 2014* Weighted average discount rate 4.25% /4.30% 4.15% /4.25% 4.00% / 4.05% Weighted average rate of future compensation increase 3.00% 2.92% 2.92% Expected long-term rate of return on plan assets 7.50% 7.00% / 7.25% 7.00% / 7.25% * Nine-month transition period ended September 30
Projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for plans that have projected benefit obligation and accumulated benefit obligation in excess of plan assets	Following are the projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for plans that have a projected benefit obligation and an accumulated benefit obligation in excess of plan assets: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Projected benefit obligation $ 794.8 $ 652.3 $ 560.0 $ 497.6 $ 174.3 $ 154.7 Accumulated benefit obligation 724.5 591.4 517.7 456.9 149.8 134.5 Fair value of plan assets 540.5 448.9 395.7 339.9 100.0 109.0
Targeted and actual plan assets by category	Following are the targeted and actual plan assets by category as of September 30 of each year for Laclede Gas and Alagasco: Laclede Gas 2016 Target 2016 Actual 2015 Target 2015 Actual Equity markets 56.2 % 56.9 % 52.0 % 48.4 % Debt securities 43.8 % 43.1 % 48.0 % 50.1 % Other* — % — % — % 1.5 % Total 100.0 % 100.0 % 100.0 % 100.0 % * Other investments in 2016 and 2015 consisted of cash equivalents. Alagasco 2016 Target 2016 Actual 2015 Target 2015 Actual Equity markets 60.0 % 59.2 % 60.0 % 52.9 % Debt securities 29.0 % 28.8 % 29.0 % 27.9 % Other* 11.0 % 12.0 % 11.0 % 19.2 % Total 100.0 % 100.0 % 100.0 % 100.0 % * Other investments in 2016 included cash, real estate, commodities, natural resources and TIPS. In 2015, this included cash and cash equivalents, hedge funds, real estate, and all asset funds, which can invest in equities or fixed income.
Expected benefit payments for the succeeding five fiscal years	Following are expected pension benefit payments for the succeeding five fiscal years, and in aggregate for the five years thereafter, for Spire, Laclede Gas, and Alagasco: 2017 2018 2019 2020 2021 2022- 2026 Spire $ 61.3 $ 56.2 $ 57.1 $ 56.6 $ 56.8 $ 286.3 Laclede Gas 48.2 43.3 43.5 42.2 40.4 196.6 Alagasco 10.9 10.6 11.2 11.9 13.7 74.5
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic cost	Net periodic postretirement benefit costs consist of the following components: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Service cost – benefits earned during the period $ 10.9 $ 12.8 $ 11.3 $ 10.6 $ 12.3 $ 11.2 $ 0.3 $ 0.5 $ 0.4 Interest cost on accumulated postretirement benefit obligation 10.2 11.2 8.9 8.1 8.6 8.7 2.1 2.6 1.9 Expected return on plan assets (13.5 ) (13.2 ) (7.3 ) (8.5 ) (8.1 ) (6.8 ) (5.0 ) (5.1 ) (3.6 ) Amortization of prior other comprehensive loss — — (0.2 ) — — — — — — Amortization of prior service cost 0.3 0.8 — 0.3 0.8 — — — — Amortization of actuarial loss (gain) 3.6 5.1 6.0 3.8 5.1 6.0 (0.2 ) — (1.0 ) Special termination benefits 2.6 — — 2.6 — — — — — Subtotal 14.1 16.7 18.7 16.9 18.7 19.1 (2.8 ) (2.0 ) (2.3 ) Regulatory adjustment (6.6 ) (11.0 ) (9.6 ) (4.8 ) (9.2 ) (9.6 ) (1.8 ) (1.8 ) (0.2 ) Net postretirement benefit cost $ 7.5 $ 5.7 $ 9.1 $ 12.1 $ 9.5 $ 9.5 $ (4.6 ) $ (3.8 ) $ (2.5 ) * Nine months ended September 30
Other changes in plan assets and benefit obligations recognized in other comprehensive income	Other changes in plan assets and postretirement benefit obligations recognized in OCI include the following: Spire Laclede Gas Alagasco 2016 2015 2014 2016 2015 2014 2016 2015 2014* Current year actuarial loss (gain) $ 0.8 $ (8.5 ) $ (3.1 ) $ 1.4 $ (2.4 ) $ (4.2 ) $ (0.6 ) $ (6.1 ) $ 1.1 Amortization of actuarial (loss) gain (3.6 ) (5.1 ) (6.0 ) (3.8 ) (5.1 ) (6.0 ) 0.2 — — Amortization of prior service (cost) credit (0.3 ) (0.8 ) 2.5 (0.3 ) (0.8 ) 2.5 — — — Current year prior service credit (1.8 ) (4.9 ) — — (4.9 ) — (1.8 ) — — Subtotal (4.9 ) (19.3 ) (6.6 ) (2.7 ) (13.2 ) (7.7 ) (2.2 ) (6.1 ) 1.1 Regulatory adjustment 4.9 19.3 6.6 2.7 13.2 7.7 2.2 6.1 (1.1 ) Total recognized in OCI $ — $ — $ — $ — $ — $ — $ — $ — $ — * Nine months ended September 30
Reconciliation of the beginning and ending balances of benefit obligation	The following table sets forth the reconciliation of the beginning and ending balances of the postretirement benefit obligation at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Benefit obligation, beginning of year $ 239.2 $ 258.5 $ 191.9 $ 197.9 $ 47.3 $ 60.6 Service cost 10.9 12.8 10.6 12.3 0.3 0.5 Interest cost 10.2 11.2 8.1 8.6 2.1 2.6 Actuarial loss (gain) 7.1 (23.7 ) 6.7 (10.9 ) 0.4 (12.8 ) Plan amendments (1.8 ) (4.9 ) — (4.9 ) (1.8 ) — EnergySouth acquisition 5.9 — — — — — Special termination benefits 2.6 — 2.6 — — — Retiree drug subsidy program 0.2 0.4 — — 0.2 0.4 Gross benefits paid (15.1 ) (15.1 ) (12.0 ) (11.1 ) (3.1 ) (4.0 ) Benefit obligation, end of year $ 259.2 $ 239.2 $ 207.9 $ 191.9 $ 45.4 $ 47.3
Fair value of plan assets	The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Fair value of plan assets at beginning of year $ 223.3 $ 222.5 $ 143.6 $ 137.2 $ 79.7 $ 85.3 Actual return on plan assets 19.9 (2.0 ) 13.8 (0.4 ) 6.2 (1.6 ) Employer contributions 14.3 17.9 14.3 17.9 — — EnergySouth acquisition 4.0 — — — — — Gross benefits paid (15.1 ) (15.1 ) (12.0 ) (11.1 ) (3.1 ) (4.0 ) Fair value of plan assets, end of year $ 246.4 $ 223.3 $ 159.7 $ 143.6 $ 82.8 $ 79.7 Funded status of plans, end of year $ (12.8 ) $ (15.9 ) $ (48.2 ) $ (48.3 ) $ 37.4 $ 32.4
Amounts recognized in consolidated balance sheets	The following table sets forth the amounts recognized in the balance sheets at September 30: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Current assets $ 0.3 $ — $ 0.3 $ — $ — $ — Noncurrent assets 37.4 35.5 — 3.1 37.4 32.4 Current liabilities (0.4 ) (0.3 ) (0.4 ) (0.3 ) — — Noncurrent liabilities (50.1 ) (51.1 ) (48.1 ) (51.1 ) — — Total $ (12.8 ) $ (15.9 ) $ (48.2 ) $ (48.3 ) $ 37.4 $ 32.4 Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic postretirement benefit cost consist of: Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 38.0 $ 40.8 $ 43.4 $ 45.8 $ (5.4 ) $ (5.0 ) Prior service credit (5.2 ) (3.1 ) (3.4 ) (3.1 ) (1.8 ) — Subtotal 32.8 37.7 40.0 42.7 (7.2 ) (5.0 ) Adjustments for amounts included in regulatory assets (32.8 ) (37.7 ) (40.0 ) (42.7 ) 7.2 5.0 Total $ — $ — $ — $ — $ — $ —
Pre-tax amounts amortized from accumulated other comprehensive income into net periodic cost	At September 30, 2016 , the following pre-tax amounts are expected to be amortized from accumulated other comprehensive loss into net periodic postretirement benefit cost during fiscal year 2017: Spire Laclede Gas Alagasco Amortization of net actuarial loss (gain) $ 2.4 $ 2.5 $ (0.1 ) Amortization of prior service cost 0.1 0.3 (0.2 ) Subtotal 2.5 2.8 (0.3 ) Regulatory adjustment (2.5 ) (2.8 ) 0.3 Total $ — $ — $ —
Assumptions used to calculate net periodic cost and benefit obligations.	The assumptions used to calculate the accumulated postretirement benefit obligations for Laclede Gas are as follows: 2016 2015 Weighted average discount rate - Laclede Gas division plans 3.15 % 4.00 % Weighted average discount rate - MGE division plans 3.45 % 4.30 % Weighted average rate of future compensation increase 3.00 % 3.00 % The assumptions used to calculate the accumulated postretirement benefit obligations for Alagasco are as follows: 2016 2015 Weighted average discount rate 3.60 % 4.50 % Weighted average rate of future compensation increase n/a n/a The assumptions used to calculate net periodic postretirement benefit costs for Laclede Gas are as follows: 2016 2015 2014 Weighted average discount rate Laclede Gas division plans 4.00 % 4.15 % 4.60 % Weighted average discount rate MGE division plans 4.30 % 4.40 % 4.95 % Weighted average rate of future compensation increase - Laclede Gas plans 3.00 % 3.00 % 3.00 % Expected long-term rate of return on plan assets - Laclede Gas division plans 6.00% / 7.75% 6.25% / 7.75% 6.25% / 7.75% Expected long-term rate of return on plan assets - MGE division plans 4.75 % 5.00 % 3.75% / 5.75% The assumptions used to calculate net periodic postretirement benefit costs for Alagasco are as follows: 2016 2015 2014 Weighted average discount rate 4.50 % 4.40 % 4.25 % Weighted average rate of future compensation increase n/a n/a 2.92 % Expected long-term rate of return on plan assets 4.50% / 7.25% 4.75% / 7.50% 4.75% / 7.25%
Targeted and actual plan assets by category	Following are the targeted and actual plan assets by category as of September 30 of each year for Laclede Gas and Alagasco: Laclede Gas Target 2016 Actual 2015 Actual Equity securities 60.0 % 59.1 % 59.6 % Debt securities 40.0 % 39.4 % 39.7 % Other (cash and cash equivalents) — % 1.5 % 0.7 % Total 100.0 % 100.0 % 100.0 % Alagasco Target 2016 Actual 2015 Actual Equity securities 60.0 % 60.5 % 59.7 % Debt securities 40.0 % 39.5 % 40.3 % Total 100.0 % 100.0 % 100.0 %
Expected benefit payments for the succeeding five fiscal years	Following are expected postretirement benefit payments for the succeeding five fiscal years, and in aggregate for the five years thereafter for Spire, Laclede Gas, and Alagasco: 2017 2018 2019 2020 2021 2022- 2026 Spire $ 15.4 $ 16.7 $ 17.9 $ 19.1 $ 20.1 $ 108.6 Laclede Gas 12.3 13.7 14.8 15.8 16.8 92.5 Alagasco 2.9 2.8 2.8 2.9 2.9 14.1
Assumed medical cost trend rates and effect of an assumed 1% changed in assumed medical cost trend.	The assumed medical cost trend rates at September 30 are as follows: 2016 2015 Medical cost trend assumed for next year - Laclede Gas 7.50 % 7.00 % Medical cost trend assumed for next year - Alagasco 7.50 % 7.00 % Rate to which the medical cost trend rate is assumed to decline (the ultimate medical cost trend rate) 5.00 % 5.00 % Year the rate reaches the ultimate trend 2023 2020 The following table presents the effects of an assumed 1% change in the assumed medical cost trend rate: Spire Laclede Gas Alagasco 1% Increase 1% Decrease 1% Increase 1% Decrease 1% Increase 1% Decrease Net periodic postretirement benefit cost $ 1.5 $ (1.4 ) $ 1.5 $ (1.4 ) $ — $ — Accumulated postretirement benefit obligation 11.0 (10.2 ) 9.0 (8.4 ) 1.3 (1.2 )
Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	The table below categorizes the fair value measurements of Laclede Gas’ pension plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 46.5 $ — $ — $ 46.5 Stock/bond mutual fund — 14.8 0.1 14.9 Debt Securities US bond mutual funds — 120.2 — 120.2 US government 42.1 3.0 — 45.1 US corporate 137.4 — — 137.4 US municipal 6.3 — — 6.3 International 25.2 — — 25.2 Derivatives and margin (payable) (1.0 ) 1.1 — 0.1 Total $ 256.5 $ 139.1 $ 0.1 $ 395.7 As of September 30, 2015 Cash and cash equivalents $ 31.8 $ — $ — $ 31.8 Stock/bond mutual funds — 67.6 0.1 67.7 Debt Securities US government 37.7 — — 37.7 US corporate 123.7 42.9 — 166.6 US municipal — 5.9 — 5.9 International — 27.3 — 27.3 Derivative instruments — 2.9 — 2.9 Total $ 193.2 $ 146.6 $ 0.1 $ 339.9 The table below categorizes the fair value measurements of Laclede Gas’ postretirement plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 4.6 $ — $ — $ 4.6 US stock/bond mutual funds 155.1 — — 155.1 Total $ 159.7 $ — $ — $ 159.7 As of September 30, 2015 Cash and cash equivalents $ 1.6 $ — $ — $ 1.6 US stock/bond mutual funds 115.5 26.5 — 142.0 Total $ 117.1 $ 26.5 $ — $ 143.6 Alagasco The table below categorizes the fair value measurements of Alagasco’s pension plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 Cash and cash equivalents $ 0.4 $ — $ — $ 0.4 Stock/bond mutual funds 59.0 11.9 — 70.9 Debt Securities US bond mutual funds 23.0 5.7 — 28.7 Total $ 82.4 $ 17.6 $ — $ 100.0 As of September 30, 2015 Cash and cash equivalents $ 11.6 $ 0.2 $ — $ 11.8 Stock/bond mutual fund 46.4 7.0 9.5 62.9 Debt Securities US bond mutual funds — 9.3 — 9.3 US government — 21.0 — 21.0 International — 4.0 — 4.0 Derivative instruments (b) — — — — Total $ 58.0 $ 41.5 $ 9.5 $ 109.0 The table below categorizes the fair value measurements of Alagasco’s postretirement plan assets: Quoted Prices in Active Markets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total As of September 30, 2016 US stock/bond mutual fund $ — $ 68.5 $ — $ 68.5 International fund — 14.3 — 14.3 Total $ — $ 82.8 $ — $ 82.8 As of September 30, 2015 US stock/bond mutual fund — 66.3 — 66.3 International fund — 13.4 — 13.4 Total $ — $ 79.7 $ — $ 79.7

INFORMATION BY OPERATING SEGM42

INFORMATION BY OPERATING SEGMENT (Tables)	12 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Schedule of operating segment information	Gas Utility Gas Marketing Other Eliminations Consolidated 2016 Revenues from external customers $ 1,457.2 $ 78.5 $ 1.6 $ — $ 1,537.3 Intersegment revenues 2.2 — 3.2 (5.4 ) — Total Operating Revenues 1,459.4 78.5 4.8 (5.4 ) 1,537.3 Operating Expenses Gas Utility Natural and propane gas 539.7 — — (47.5 ) 492.2 Other operation and maintenance 379.3 — — (1.8 ) 377.5 Depreciation and amortization 136.9 — — — 136.9 Taxes, other than income taxes 125.2 — — — 125.2 Total Gas Utility Operating Expenses 1,181.1 — — (49.3 ) 1,131.8 Gas Marketing and Other — 66.7 (a) 12.6 (b) 43.9 123.2 Total Operating Expenses 1,181.1 66.7 12.6 (5.4 ) 1,255.0 Operating Income (Loss) 278.3 11.8 (7.8 ) — 282.3 Net Economic Earnings (Loss) 160.3 6.4 (17.6 ) — 149.1 Capital Expenditures 291.7 — 1.6 — 293.3 Gas Utility Gas Marketing Other Eliminations Consolidated 2015 Revenues from external customers $ 1,891.8 $ 82.9 $ 1.7 $ — $ 1,976.4 Intersegment revenues 4.0 70.5 2.0 (76.5 ) — Total Operating Revenues 1,895.8 153.4 3.7 (76.5 ) 1,976.4 Operating Expenses Gas Utility Natural and propane gas 957.6 — — (75.2 ) 882.4 Other operation and maintenance 391.6 — — (1.0 ) 390.6 Depreciation and amortization 129.9 — — — 129.9 Taxes, other than income taxes 142.1 — — — 142.1 Total Gas Utility Operating Expenses 1,621.2 — — (76.2 ) 1,545.0 Gas Marketing and Other — 146.6 (a) 12.6 (b) (0.3 ) 158.9 Total Operating Expenses 1,621.2 146.6 12.6 (76.5 ) 1,703.9 Operating Income (Loss) 274.6 6.8 (8.9 ) — 272.5 Net Economic Earnings (Loss) 150.4 4.2 (16.3 ) — 138.3 Capital Expenditures 284.4 — 5.4 — 289.8 Gas Utility Gas Marketing Other Eliminations Consolidated 2014 Revenues from external customers $ 1,462.6 $ 162.6 $ 2.0 $ — $ 1,627.2 Intersegment revenues 5.2 84.0 1.8 (91.0 ) — Total Operating Revenues 1,467.8 246.6 3.8 (91.0 ) 1,627.2 Operating Expenses Gas Utility Natural and propane gas 821.8 — — (90.1 ) 731.7 Other operation and maintenance 288.7 — — (0.9 ) 287.8 Depreciation and amortization 82.4 — — — 82.4 Taxes, other than income taxes 112.0 — — — 112.0 Total Gas Utility Operating Expenses 1,304.9 — — (91.0 ) 1,213.9 Gas Marketing and Other — 226.4 (a) 20.5 (b) — 246.9 Total Operating Expenses 1,304.9 226.4 20.5 (91.0 ) 1,460.8 Operating Income (Loss) 162.9 20.2 (16.7 ) — 166.4 Net Economic Earnings (Loss) 92.8 10.2 (2.9 ) — 100.1 Capital Expenditures 168.6 — 2.4 — 171.0 (a) Depreciation and amortization for Gas Marketing are included in Gas Marketing Expenses on the Consolidated Statements of Income ( $0.1 for 2016 , $0.3 for 2015 , and $0.4 for 2014 ). (b) Depreciation, amortization, and accretion for Other are included in the Other Operating Expenses on the Consolidated Statements of Income ( $0.5 for 2016 , $0.6 for 2015 , and $0.5 for 2014 ). Total Assets at End of Year 2016 2015 2014 Gas Utility $ 5,191.9 $ 4,686.2 $ 4,520.0 Gas Marketing 205.0 160.6 156.7 Other 1,842.4 1,560.2 1,575.7 Eliminations (1,161.9 ) (1,116.8 ) (1,178.4 ) Total Assets $ 6,077.4 $ 5,290.2 $ 5,074.0
Schedule of the reconciliation of consolidated net economic earnings to consolidated net income	Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings 2016 2015 2014 Net Income (GAAP) $ 144.2 $ 136.9 $ 84.6 Unrealized gain on energy-related derivatives (0.1 ) (2.8 ) (1.6 ) Lower of cost or market inventory adjustments 0.2 0.4 (1.1 ) Realized (gain) loss on economic hedges prior to the sale of the physical commodity (1.6 ) 2.4 (0.4 ) Acquisition, divestiture and restructuring activities 9.2 9.8 29.5 Gain on sale of property — (7.6 ) — Income tax effect of adjustments (2.8 ) (0.8 ) (10.9 ) Net Economic Earnings $ 149.1 $ 138.3 $ 100.1

REGULATORY MATTERS (Tables)

REGULATORY MATTERS (Tables)	12 Months Ended
	Sep. 30, 2016
Regulated Operations [Abstract]
Schedule of regulatory assets	The following regulatory assets and regulatory liabilities were reflected in the Balance Sheets as of September 30, 2016 and 2015 . Unamortized Purchased Gas Adjustments are also included below, which are reported separately in the current assets and liabilities sections of each balance sheet. Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Regulatory Assets: Current: Pension and postretirement benefit costs $ 27.0 $ 22.0 $ 20.2 $ 15.5 $ 6.8 $ 6.5 Unamortized purchased gas adjustments 49.7 12.9 43.1 12.9 5.6 — Other 17.2 5.6 3.7 0.7 8.1 4.9 Total Current Regulatory Assets 93.9 40.5 67.0 29.1 20.5 11.4 Noncurrent: Future income taxes due from customers 151.3 134.5 151.3 134.5 — — Pension and postretirement benefit costs 487.9 448.7 375.7 368.0 98.9 80.7 Cost of removal 130.6 78.9 — — 130.6 78.9 Purchased gas costs 12.6 24.1 12.6 24.1 — — Energy efficiency 25.5 22.3 25.5 22.3 — — Other 30.1 29.1 24.7 24.7 1.2 4.0 Total Noncurrent Regulatory Assets 838.0 737.6 589.8 573.6 230.7 163.6 Total Regulatory Assets $ 931.9 $ 778.1 $ 656.8 $ 602.7 $ 251.2 $ 175.0 Regulatory Liabilities: Current: RSE adjustment $ 7.5 $ 12.2 $ — $ — $ 5.0 $ 12.2 Unbilled service margin 5.9 6.4 — — 5.9 6.4 Refundable negative salvage 9.3 10.8 — — 9.3 10.8 Unamortized purchased gas adjustments 1.7 28.2 — — — 28.2 Other 6.2 3.0 1.3 0.6 2.5 2.4 Total Current Regulatory Liabilities 30.6 60.6 1.3 0.6 22.7 60.0 Noncurrent: Postretirement liabilities 28.9 28.9 — — 28.9 28.9 Refundable negative salvage 9.4 16.2 — — 9.4 16.2 Accrued cost of removal 74.8 58.7 55.1 58.7 — — Other 17.6 15.5 12.2 11.9 3.4 3.6 Total Noncurrent Regulatory Liabilities 130.7 119.3 67.3 70.6 41.7 48.7 Total Regulatory Liabilities $ 161.3 $ 179.9 $ 68.6 $ 71.2 $ 64.4 $ 108.7 A portion of the Company’s regulatory assets are not earning a return and are shown in the schedule below: Spire Laclede Gas 2016 2015 2016 2015 Future income taxes due from customers $ 151.3 $ 134.5 $ 151.3 $ 134.5 Pension and postretirement benefit costs 240.6 223.7 240.6 223.7 Compensated absences — — — — Other 12.9 14.2 12.9 14.2 Total Regulatory Assets Not Earning a Return $ 404.8 $ 372.4 $ 404.8 $ 372.4
Schedule of regulatory liabilities	The following regulatory assets and regulatory liabilities were reflected in the Balance Sheets as of September 30, 2016 and 2015 . Unamortized Purchased Gas Adjustments are also included below, which are reported separately in the current assets and liabilities sections of each balance sheet. Spire Laclede Gas Alagasco 2016 2015 2016 2015 2016 2015 Regulatory Assets: Current: Pension and postretirement benefit costs $ 27.0 $ 22.0 $ 20.2 $ 15.5 $ 6.8 $ 6.5 Unamortized purchased gas adjustments 49.7 12.9 43.1 12.9 5.6 — Other 17.2 5.6 3.7 0.7 8.1 4.9 Total Current Regulatory Assets 93.9 40.5 67.0 29.1 20.5 11.4 Noncurrent: Future income taxes due from customers 151.3 134.5 151.3 134.5 — — Pension and postretirement benefit costs 487.9 448.7 375.7 368.0 98.9 80.7 Cost of removal 130.6 78.9 — — 130.6 78.9 Purchased gas costs 12.6 24.1 12.6 24.1 — — Energy efficiency 25.5 22.3 25.5 22.3 — — Other 30.1 29.1 24.7 24.7 1.2 4.0 Total Noncurrent Regulatory Assets 838.0 737.6 589.8 573.6 230.7 163.6 Total Regulatory Assets $ 931.9 $ 778.1 $ 656.8 $ 602.7 $ 251.2 $ 175.0 Regulatory Liabilities: Current: RSE adjustment $ 7.5 $ 12.2 $ — $ — $ 5.0 $ 12.2 Unbilled service margin 5.9 6.4 — — 5.9 6.4 Refundable negative salvage 9.3 10.8 — — 9.3 10.8 Unamortized purchased gas adjustments 1.7 28.2 — — — 28.2 Other 6.2 3.0 1.3 0.6 2.5 2.4 Total Current Regulatory Liabilities 30.6 60.6 1.3 0.6 22.7 60.0 Noncurrent: Postretirement liabilities 28.9 28.9 — — 28.9 28.9 Refundable negative salvage 9.4 16.2 — — 9.4 16.2 Accrued cost of removal 74.8 58.7 55.1 58.7 — — Other 17.6 15.5 12.2 11.9 3.4 3.6 Total Noncurrent Regulatory Liabilities 130.7 119.3 67.3 70.6 41.7 48.7 Total Regulatory Liabilities $ 161.3 $ 179.9 $ 68.6 $ 71.2 $ 64.4 $ 108.7

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Aggregate Rental Expense and Annual Minimum Rental Commitments	Aggregate rental expense and annual minimum rental commitments under all leases having an initial or remaining non-cancelable term of more than one year are shown below: Aggregate Rental Expense Minimum Rental Commitments 2016 2015 2014 2017 2018 2019 2020 2021 Later Total Spire $ 11.9 $ 14.1 $ 6.7 $ 10.5 $ 7.5 $ 7.3 $ 6.2 $ 6.0 $ 53.4 $ 90.9 Laclede Gas 4.3 7.6 6.3 2.5 0.9 0.9 0.3 0.1 — 4.7 Alagasco 3.7 4.0 2.0 3.9 2.5 2.5 2.1 2.1 4.9 18.0

INTERIM FINANCIAL INFORMATION45

INTERIM FINANCIAL INFORMATION (UNAUDITED) (Tables)	12 Months Ended
	Sep. 30, 2016
Quarterly Financial Information [Line Items]
Schedule of Quarterly Financial Information	Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 399.4 $ 609.3 $ 249.3 $ 279.3 Operating Income (Loss) 87.0 167.7 35.3 (7.7 ) Net Income (Loss) 46.9 100.8 10.7 (14.2 ) Basic Earnings (Loss) Per Share of Common Stock $ 1.08 $ 2.32 $ 0.24 $ (0.31 ) Diluted Earnings (Loss) Per Share of Common Stock $ 1.08 $ 2.31 $ 0.24 $ (0.31 ) Fiscal Year 2015 Total Operating Revenues $ 619.6 $ 877.4 $ 275.2 $ 204.2 Operating Income (Loss) 87.3 157.7 36.0 (8.5 ) Net Income (Loss) 47.1 94.4 14.1 (18.7 ) Basic Earnings (Loss) Per Share of Common Stock $ 1.09 $ 2.18 $ 0.32 $ (0.43 ) Diluted Earnings (Loss) Per Share of Common Stock $ 1.09 $ 2.18 $ 0.32 $ (0.43 )
Laclede Gas
Quarterly Financial Information [Line Items]
Schedule of Quarterly Financial Information	Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 317.2 $ 446.7 $ 179.3 $ 144.3 Operating Income 65.1 87.0 29.4 5.4 Net Income (Loss) 39.4 54.3 13.9 (1.7 ) Fiscal Year 2015 Total Operating Revenues $ 462.4 $ 615.7 $ 187.5 $ 151.0 Operating Income 64.8 80.6 34.5 5.5 Net Income (Loss) 39.0 49.9 20.0 (3.6 )
Alagasco
Quarterly Financial Information [Line Items]
Schedule of Quarterly Financial Information	Three Months Ended Dec. 31 March 31 June 30 Sept. 30 Fiscal Year 2016 Total Operating Revenues $ 82.3 $ 166.0 $ 74.0 $ 46.2 Operating Income (Loss) 18.9 80.4 9.3 (17.1 ) Net Income (Loss) 9.9 48.1 4.0 (8.8 ) Fiscal Year 2015 Total Operating Revenues $ 120.0 $ 233.3 $ 73.7 $ 52.2 Operating Income (Loss) 20.4 77.4 3.9 (12.5 ) Net Income (Loss) 10.6 46.3 0.7 (9.6 )

SUMMARY OF SIGNIFICANT ACCOUN46

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	Jun. 01, 2010	Sep. 30, 2014USD ($)	Sep. 30, 2016USD ($)operating_segmentchange	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Related Party Transaction [Line Items]
Number of operating segments | operating_segment			2
Utility Plant, Depreciation and Amortization [Abstract]
Capital expenditures			$ 293,300,000	$ 289,800,000	$ 171,000,000
Amount by which the replacement cost exceeds (less than) the cost basis value of stored gas inventories			$ 11,400,000	20,400,000
Number of months of the original maturity of debt instruments purchased			3 months
Finance receivable, net			$ 11,800,000	11,200,000
Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Other Deferred Charges
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			(13,200,000)	(13,000,000)
Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Long-Term Debt
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			$ 13,200,000	$ 13,000,000
Laclede Gas
Utility Plant, Depreciation and Amortization [Abstract]
Average annual depreciation and amortization expense percentage		3.00%	3.00%	3.00%	3.00%
Capital expenditures			$ 197,800,000	$ 198,600,000	$ 163,000,000
Accruals for capital expenditures			$ 14,800,000	9,600,000	3,000,000
Number of PGA discretionary changes | change			3
Months between PGA discretionary changes			2 months
Cost savings retention percentage			10.00%
Maximum amount of cost savings allowable			$ 3,000,000
Accrued unbilled revenues			26,100,000	27,600,000
Laclede Gas | Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Other Deferred Charges
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			(4,200,000)	(4,800,000)
Laclede Gas | Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Long-Term Debt
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			4,200,000	4,800,000
Alagasco
Utility Plant, Depreciation and Amortization [Abstract]
Capital expenditures		$ 46,200,000	93,400,000	85,800,000	$ 46,200,000
Accruals for capital expenditures		$ 5,000,000	$ 6,800,000	3,100,000
Composite depreciation rate	3.10%		3.10%
Current refundable negative salvage costs to customers			$ 9,300,000
Noncurrent refundable negative salvage costs to customers			$ 18,700,000
Noncurrent refundable negative salvage costs period			3 years
Accrued unbilled revenues			$ 5,900,000	6,400,000
Threshold period past due for collection			90 days
Threshold period past due for write-off of financing receivable			12 months
Write off on an allowance for credit losses			$ 400,000	400,000
Alagasco | Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Other Deferred Charges
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			(2,600,000)	(2,400,000)
Alagasco | Retrospective Effect is ASU had been Adopted | ASU 2015-03 | New Accounting Pronouncement, Early Adoption, Effect | Long-Term Debt
Utility Plant, Depreciation and Amortization [Abstract]
Deferred finance costs			2,600,000	2,400,000
Alagasco | Financing Receivables, Equal to Greater than 90 Days Past Due
Utility Plant, Depreciation and Amortization [Abstract]
Finance receivable 90 days past due			$ 400,000	$ 400,000

SUMMARY OF SIGNIFICANT ACCOUN47

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Asset retirement obligations [Roll forward]
Asset retirement obligations, beginning of year	$ 159.2	$ 99.2
Liabilities incurred during the period	4.1	2.3
Liabilities settled during the period	(9.5)	(2)
Accretion	13.2	4.5
Revisions in estimated cash flows	27.5	55.2
Asset retirement obligations, end of year	206.4	159.2
Laclede Gas
Asset retirement obligations [Roll forward]
Asset retirement obligations, beginning of year	72.4	71.2
Liabilities incurred during the period	1.2	0.6
Liabilities settled during the period	(1.9)	(1.9)
Accretion	3.5	3.4
Revisions in estimated cash flows	0	(0.9)
Asset retirement obligations, end of year	75.2	72.4
Alagasco
Asset retirement obligations [Roll forward]
Asset retirement obligations, beginning of year	86.6	27.7
Liabilities incurred during the period	2.9	1.7
Liabilities settled during the period	(6.8)	(0.1)
Accretion	9.7	1.1
Revisions in estimated cash flows	27.7	56.2
Asset retirement obligations, end of year	120.1	86.6
EnergySouth
Asset retirement obligations [Roll forward]
Addition of EnergySouth asset retirement obligations	11.9	0
EnergySouth | Laclede Gas
Asset retirement obligations [Roll forward]
Addition of EnergySouth asset retirement obligations	0	0
EnergySouth | Alagasco
Asset retirement obligations [Roll forward]
Addition of EnergySouth asset retirement obligations	$ 0	$ 0

SUMMARY OF SIGNIFICANT ACCOUN48

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Off System Sales (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2017
Eastern Missouri | First $2.0
Off System Sales [Line Items]
Pre-tax Income	$ 2
Customer Share	100.00%
Company Share	0.00%
Eastern Missouri | First $2.0 | Scenario, Forecast
Off System Sales [Line Items]
Customer Share		85.00%
Company Share		15.00%
Eastern Missouri | Next $2.0
Off System Sales [Line Items]
Pre-tax Income	$ 2
Customer Share	80.00%
Company Share	20.00%
Eastern Missouri | Next $2.0
Off System Sales [Line Items]
Pre-tax Income	$ 2
Customer Share	75.00%
Company Share	25.00%
Eastern Missouri | Amounts exceeding $6.0
Off System Sales [Line Items]
Pre-tax Income	$ 6
Customer Share	70.00%
Company Share	30.00%
Western Missouri | First $1.2
Off System Sales [Line Items]
Pre-tax Income	$ 1.2
Customer Share	85.00%
Company Share	15.00%
Western Missouri | Next $1.2
Off System Sales [Line Items]
Pre-tax Income	$ 1.2
Customer Share	80.00%
Company Share	20.00%
Western Missouri | Next $1.2
Off System Sales [Line Items]
Pre-tax Income	$ 1.2
Customer Share	75.00%
Company Share	25.00%
Western Missouri | Amounts exceeding $3.6
Off System Sales [Line Items]
Pre-tax Income	$ 3.6
Customer Share	70.00%
Company Share	30.00%

SUMMARY OF SIGNIFICANT ACCOUN49

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Changes in Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Goodwill [Roll Forward]
Beginning balance	$ 946	$ 937.8	$ 247.1
Adjustments to finalize acquisition		8.2	(36.9)
Acquisition	218.9		727.6
Ending balance	1,164.9	946	937.8
Operating Segments | Gas Utility
Goodwill [Roll Forward]
Beginning balance	210.2	210.2	247.1
Adjustments to finalize acquisition		0	(36.9)
Acquisition	0		0
Ending balance	210.2	210.2	210.2
Operating Segments | Gas Marketing
Goodwill [Roll Forward]
Beginning balance	0	0	0
Adjustments to finalize acquisition		0	0
Acquisition	0		0
Ending balance	0	0	0
Other
Goodwill [Roll Forward]
Beginning balance	735.8	727.6	0
Adjustments to finalize acquisition		8.2	0
Acquisition	218.9		727.6
Ending balance	$ 954.7	$ 735.8	$ 727.6

SUMMARY OF SIGNIFICANT ACCOUN50

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Gross Receipts and Sales Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	$ 75.5	$ 97.3	$ 77.5
Laclede Gas
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	57.4	74.5	76.3
Alagasco
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	$ 17.9	$ 22.6	$ 20.6

SUMMARY OF SIGNIFICANT ACCOUN51

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Transactions with Affiliates (Details) - Affiliated Entity - Regulated Operation - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Laclede Gas | Laclede Energy Resources
Related Party Transaction [Line Items]
Revenue from related parties	$ 1.9	$ 4	$ 5.1
Laclede Energy Resources | Laclede Gas
Related Party Transaction [Line Items]
Revenue from related parties	46.3	74.1	89.1
Laclede Risk Services | Laclede Gas
Related Party Transaction [Line Items]
Revenue from related parties	$ 1.8	$ 1	$ 0.6

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Details) - USD ($) $ in Millions	Sep. 12, 2016	Jan. 06, 2015	Aug. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired				$ (317.7)	$ 0	$ 0
Goodwill				$ 1,164.9	$ 946	$ 937.8	$ 247.1
Alagasco
Business Acquisition [Line Items]
Percentage of voting interest acquired			100.00%
Payments to acquire businesses, net of cash acquired		$ (1,313.4)	$ (1,305.2)
Payments for final reconciliation of acquisition		$ (8.2)
Goodwill			735.8
Goodwill, expected to be tax deductible			$ 717.6
EnergySouth
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Payments to acquire businesses, net of cash acquired	$ (317.7)
Goodwill	$ 218.9

ACQUISITIONS - Summary of Consi

ACQUISITIONS - Summary of Consideration Paid, Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 12, 2016	Sep. 30, 2015	Sep. 30, 2014	Aug. 31, 2014	Sep. 30, 2013
Business Acquisition [Line Items]
Goodwill	$ 1,164.9		$ 946	$ 937.8		$ 247.1
Alagasco
Business Acquisition [Line Items]
Utility plant					$ 892.7
Cash					12.1
Other current assets					99.4
Deferred tax assets					282
Other assets					143.4
Long-term debt					(249.8)
Current portion of long-term debt					(15)
Other current liabilities					(173.4)
Deferred tax liabilities					0
Other liabilities					(130.4)
Total identifiable net assets					861
Goodwill					735.8
Deferred tax elimination (Spire)					(271.3)
Consideration (cash)					$ 1,325.5
EnergySouth
Business Acquisition [Line Items]
Utility plant		$ 199.5
Cash		2
Other current assets		17.5
Deferred tax assets		0
Other assets		79.8
Long-term debt		(67)
Current portion of long-term debt		0
Other current liabilities		(42.7)
Deferred tax liabilities		(35.5)
Other liabilities		(52.8)
Total identifiable net assets		100.8
Goodwill		218.9
Deferred tax elimination (Spire)		0
Consideration (cash)		$ 319.7

ACQUISITIONS - Pro Forma Inform

ACQUISITIONS - Pro Forma Information, Revenues and Earnings (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Alagasco and EnergySouth
Business Acquisition [Line Items]
Total Operating Revenues	$ 1,632.4	$ 2,081.6	$ 2,187.1
Net Income	$ 153.9	$ 143.6	$ 133.5
Basic earnings (loss) per share (in dollars per share)	$ 3.48	$ 3.32	$ 3.11
Diluted earnings (loss) per share (in dollars per share)	$ 3.46	$ 3.31	$ 3.10
Alagasco
Business Acquisition [Line Items]
Pro forma, Total Operating Revenues	$ 368.5	$ 479.2	$ 19.7
Pro forma, Net Income (Loss)	$ 53.2	$ 48	$ (2.9)
Pro forma, Earnings (Loss) Per Share (in dollars per share)	$ 1.20	$ 1.11	$ (0.08)
EnergySouth
Business Acquisition [Line Items]
Pro forma, Total Operating Revenues	$ 3.3
Pro forma, Net Income (Loss)	$ (0.2)
Pro forma, Earnings (Loss) Per Share (in dollars per share)	$ 0

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, minimum	3 years
Number of shares of common stock that may be issued (in shares)	1,000,000
Stock Option Awards [Abstract]
Closing price of common stock (in dollars per share)	$ 63.74
Total unrecognized compensation costs	$ 9.2
Weighted average period for recognition of unrecognized compensation costs	1 year 9 months 18 days
Restricted Stock Awards
Restricted Stock Awards [Abstract]
Vested (in shares)	107,238	128,135	88,533
Vested restricted stock withheld for tax withholding obligations (in shares)	30,712	31,688	23,776
Vested restricted stock withheld for tax withholding obligations, weighted average price (in dollars per share)	$ 57.29	$ 50.65	$ 45.96
Fair value, restricted stock	$ 6.3	$ 6.4	$ 4.1
Actual tax benefit realized	$ 2.4	$ 2.4	$ 1.6
Restricted Stock Awards | Performance Vesting
Restricted Stock Awards [Abstract]
Granted (in shares)	199,140
Granted, weighted average grant date fair value (in dollars per share)	$ 45.95
Vested (in shares)	62,593
Restricted Stock Awards | Performance Vesting | Executive Officers and Key Employees
Restricted Stock Awards [Abstract]
Granted, weighted average grant date fair value (in dollars per share)		$ 36.69	$ 37.21
Restricted Stock Awards | Time Vesting
Restricted Stock Awards [Abstract]
Granted (in shares)	48,730
Granted, weighted average grant date fair value (in dollars per share)	$ 60.65
Vested (in shares)	44,645
Restricted Stock Awards | Time Vesting | Executive Officers and Key Employees
Restricted Stock Awards [Abstract]
Granted (in shares)	35,210
Granted, weighted average grant date fair value (in dollars per share)	$ 59.40	50.90	45.66
Restricted Stock Awards | Time Vesting | Non Employee Directors
Restricted Stock Awards [Abstract]
Granted (in shares)	13,520
Granted, weighted average grant date fair value (in dollars per share)	$ 63.93	$ 54.66	$ 46.02
Stock Option Awards
Stock Option Awards [Abstract]
Cash received from the exercise of stock options	$ 0.7	$ 1.5	$ 1.7
Intrinsic value of exercised	$ 0.7	$ 0.9	$ 0.9

STOCK-BASED COMPENSATION - Rest

STOCK-BASED COMPENSATION - Restricted Stock and Restricted Stock Unit Activity (Details) - Restricted Stock Awards - $ / shares	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Shares/ Units
Vested (in shares)	(107,238)	(128,135)	(88,533)
Performance Vesting
Shares/ Units
Nonvested at beginning of period (in shares)	397,270
Granted (in shares)	199,140
Vested (in shares)	(62,593)
Forfeited (in shares)	(23,234)
Nonvested at end of period (in shares)	510,583	397,270
Weighted Average Grant Date Fair Value Per Share
Nonvested at beginning of period (in dollars per share)	$ 36.28
Granted (in dollars per share)	45.95
Vested (in dollars per share)	35.29
Forfeited (in dollars per share)	30.96
Nonvested at end of period (in dollars per share)	$ 40.37	$ 36.28
Time Vesting
Shares/ Units
Nonvested at beginning of period (in shares)	129,304
Granted (in shares)	48,730
Vested (in shares)	(44,645)
Forfeited (in shares)	(610)
Nonvested at end of period (in shares)	132,779	129,304
Weighted Average Grant Date Fair Value Per Share
Nonvested at beginning of period (in dollars per share)	$ 44.89
Granted (in dollars per share)	60.65
Vested (in dollars per share)	47.30
Forfeited (in dollars per share)	53.12
Nonvested at end of period (in dollars per share)	$ 49.83	$ 44.89

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Awards Activity (Details) - Stock Option Awards	12 Months Ended
	Sep. 30, 2016$ / sharesshares
Stock Options
Outstanding at beginning of period (in shares) | shares	28,500
Exercised (in shares) | shares	(27,750)
Forfeited (in shares) | shares	(750)
Outstanding at end of period (in shares) | shares	0
Weighted Average Exercise Price Per Share
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 33.65
Exercised (in dollars per share) | $ / shares	33.66
Forfeited (in dollars per share) | $ / shares	33.45
Outstanding at end of period (in dollars per share) | $ / shares	$ 0

STOCK-BASED COMPENSATION - Fair

STOCK-BASED COMPENSATION - Fair Value Measurement Assumptions (Details)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk free interest rate	1.14%	0.83%	0.53%
Expected dividend yield of stock	0.00%	0.00%	0.00%
Expected volatility of stock	15.00%	14.00%	18.00%
Vesting period	2 years 9 months 18 days	2 years 9 months 18 days	2 years 9 months 18 days

STOCK-BASED COMPENSATION - Comp

STOCK-BASED COMPENSATION - Compensation Costs Recognized (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total equity compensation cost	$ 6.7	$ 6.7	$ 5.8
Compensation cost capitalized	(2.2)	(1.8)	(1.8)
Compensation cost recognized in net income	4.5	4.9	4
Income tax benefit recognized in net income	(1.7)	(1.9)	(1.5)
Compensation cost recognized in net income, net of income tax	$ 2.8	$ 3	$ 2.5

EARNINGS PER COMMON SHARE (Deta

EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Jun. 11, 2014	Jun. 30, 2014	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Basic EPS:
Net income			$ (14.2)	$ 10.7	$ 100.8	$ 46.9	$ (18.7)	$ 14.1	$ 94.4	$ 47.1	$ 144.2	$ 136.9	$ 84.6
Less: Income allocated to participating securities											0.5	0.5	0.3
Net Income Available to Common Shareholders											$ 143.7	$ 136.4	$ 84.3
Weighted Average Shares Outstanding, Basic (in Shares)											44.1	43.2	35.8
Earnings Per Share of Common Stock (in dollars per share)			$ (0.31)	$ 0.24	$ 2.32	$ 1.08	$ (0.43)	$ 0.32	$ 2.18	$ 1.09	$ 3.26	$ 3.16	$ 2.36
Diluted EPS:
Net income			$ (14.2)	$ 10.7	$ 100.8	$ 46.9	$ (18.7)	$ 14.1	$ 94.4	$ 47.1	$ 144.2	$ 136.9	$ 84.6
Less: Income allocated to participating securities											0.5	0.5	0.3
Net Income Available to Common Shareholders											$ 143.7	$ 136.4	$ 84.3
Weighted Average Shares Outstanding, Basic (in Shares)											44.1	43.2	35.8
Dilutive Effect of Stock Options, Restricted Stock, and Restricted Stock Units (in shares)											0.2	0.1	0.1
Weighted Average Diluted Shares (in shares)											44.3	43.3	35.9
Earnings Per Share of Common Stock (in dollars per share)			$ (0.31)	$ 0.24	$ 2.31	$ 1.08	$ (0.43)	$ 0.32	$ 2.18	$ 1.09	$ 3.24	$ 3.16	$ 2.35
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equity units, contract annual rate	4.75%	2.00%
Restricted stock and stock units subject to performance and/or market conditions
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding shares excluded from calculation of diluted EPS (in shares)											0.3	0.3	0.3

STOCKHOLDERS' EQUITY - Narrativ

STOCKHOLDERS' EQUITY - Narrative (Details) $ / shares in Units, Equity_Security in Thousands	May 17, 2016USD ($)shares	Jun. 11, 2014USD ($)Equity_Security	Apr. 30, 2017shares	Jun. 30, 2014USD ($)shares$ / shares	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2015USD ($)$ / sharesshares	Sep. 30, 2014USD ($)shares	Nov. 11, 2016shares	Feb. 10, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 20, 2014shares
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Number of equity units issued (in shares)		2,875		2,875,000
Proceeds from convertible debt | $		$ 143,800,000
Stated value per Corporate Unit (in dollars per share) | $ / shares				$ 50
Common stock, par value (in dollars per share) | $ / shares				$ 1	$ 1	$ 1
Percentage of beneficial ownership interest in Subordinated Notes				5.00%
Stated principal amount of Subordinated Notes | $				$ 1,000
Interest rate on Subordinated borrowing				2.00%
Issuance of stock (in shares)	2,185,000
Shares reserved for issuance under the stock purchase contracts (in shares)					4,200,000
SEC effective shelf registration Form S-3 sale and issuance authorization under the dividend reinvestment and stock purchase program (in shares)					168,698						168,698
SEC effective shelf registration Form S-3 remaining and available for issuance under the dividend reinvestment and stock purchase program (in shares)					106,535
Issuance of common stock | $	$ 133,200,000				$ 133,200,000		$ 456,800,000
Preferred stock shares authorized (in shares)					5,000,000	5,000,000
Preferred stock shares issued (in shares)					0	0
Preferred stock shares outstanding (in shares)					0	0
Dividend payment restriction formula component - fixed amount | $					$ 8,000,000
Retained earnings available to pay dividends in period | $					$ 916,800,000	$ 891,700,000
Laclede Gas
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Common stock, par value (in dollars per share) | $ / shares					$ 1	$ 1
Issuance of common stock | $							$ 1,100,000
Preferred stock shares authorized (in shares)					1,480,000	1,480,000
Regulatory preferred stock and debt securities issuance, amount authorized | $					$ 300,000,000				$ 300,000,000	$ 518,000,000
Laclede Gas | Affiliated Entity
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Issuance of stock (in shares)					0	0	28
Issuance of common stock | $							$ 1,100,000
Alagasco
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Common stock, par value (in dollars per share) | $ / shares					$ 0.01	$ 0.01
Preferred stock shares authorized (in shares)					120,000	120,000
Preferred stock shares issued (in shares)					0	0
Preferred stock shares outstanding (in shares)					0	0
Subsequent Event
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
SEC effective shelf registration Form S-3 remaining and available for issuance under the dividend reinvestment and stock purchase program (in shares)								101,439
Scenario, Forecast | Minimum
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Issuance of stock (in shares)			2,500,000
Scenario, Forecast | Maximum
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Issuance of stock (in shares)			3,100,000
Junior Subordinated Debt
Accumulated other comprehensive income (loss), net of income taxes [Line Items]
Proceeds from convertible debt | $				$ 143,800,000

STOCKHOLDERS' EQUITY - Stock Pu

STOCKHOLDERS' EQUITY - Stock Purchase Obligation (Details)	12 Months Ended
	Sep. 30, 2016shares / contract$ / shares	Jun. 30, 2014$ / shares
Stock Purchase Obligation [Line Items]
Stated value per Corporate Unit (in dollars per share)		$ 50
Equal to or greater than $57.8125
Stock Purchase Obligation [Line Items]
Market value per share of common stock (in dollars per share)	$ 57.8125
Number of shares to be purchased per purchase contract | shares / contract	0.8649
Less than $57.8125, but greater than $46.25 | Minimum
Stock Purchase Obligation [Line Items]
Market value per share of common stock (in dollars per share)	$ 46.25
Less than $57.8125, but greater than $46.25 | Maximum
Stock Purchase Obligation [Line Items]
Market value per share of common stock (in dollars per share)	57.8125
Less than or equal to $46.25
Stock Purchase Obligation [Line Items]
Market value per share of common stock (in dollars per share)	$ 46.25
Number of shares to be purchased per purchase contract | shares / contract	1.0811

STOCKHOLDERS' EQUITY - Schedule

STOCKHOLDERS' EQUITY - Schedule of Company's Equity Units (Details) shares in Thousands, Equity_Security in Thousands, $ in Millions	Jun. 11, 2014USD ($)Equity_Security	Jun. 30, 2014shares	Sep. 30, 2014USD ($)
Stockholders' Equity Note [Abstract]
Number of equity units issued (in shares)	2,875	2,875
Total Net Proceeds	$ 139.4
Total Long-term Debt	$ 143.8
RSN Annual Interest Rate	2.00%
Stock Purchase Contract Annual Rate	4.75%	2.00%
Stock Purchase Contract Liability	$ 19.7		$ 19.7

STOCKHOLDERS' EQUITY - Schedu64

STOCKHOLDERS' EQUITY - Schedule of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	$ 1,573.6	$ 1,508.4	$ 1,046.3
Other comprehensive (loss) income	(2.2)	(0.3)	(0.9)
BALANCE	1,768.2	1,573.6	1,508.4
Laclede Gas
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	1,037.8	1,007.8	973.9
Other comprehensive (loss) income	(0.1)	0.2	0.2
BALANCE	1,068.5	1,037.8	1,007.8
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(0.4)	0.2
Other comprehensive (loss) income	(1.9)	(0.6)
BALANCE	(2.3)	(0.4)	0.2
Net Unrealized Gains (Losses) on Cash Flow Hedges | Laclede Gas
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(0.2)	0
Other comprehensive (loss) income	0.3	(0.2)
BALANCE	0.1	(0.2)	0
Defined Benefit Pension and Other Postretirement Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(1.5)	(1.9)
Other comprehensive (loss) income	(0.3)	0.4
BALANCE	(1.8)	(1.5)	(1.9)
Defined Benefit Pension and Other Postretirement Benefit Plans | Laclede Gas
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(1.5)	(1.9)
Other comprehensive (loss) income	(0.3)	0.4
BALANCE	(1.8)	(1.5)	(1.9)
Net Unrealized Losses on Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(0.1)	0
Other comprehensive (loss) income	0	(0.1)
BALANCE	(0.1)	(0.1)	0
Net Unrealized Losses on Available for Sale Securities | Laclede Gas
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	0	0
Other comprehensive (loss) income	(0.1)	0
BALANCE	(0.1)	0	0
AOCI
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(2)	(1.7)	(0.8)
Other comprehensive (loss) income	(2.2)	(0.3)	(0.9)
BALANCE	(4.2)	(2)	(1.7)
AOCI | Laclede Gas
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE	(1.7)	(1.9)	(2.1)
Other comprehensive (loss) income	(0.1)	0.2	0.2
BALANCE	$ (1.8)	$ (1.7)	$ (1.9)

LONG-TERM DEBT - Maturities of

LONG-TERM DEBT - Maturities of Long-term Debt (Details) $ in Millions	Sep. 30, 2016USD ($)
Maturities on long-term debt [Abstract]
2,017	$ 250
2,018	100
2,019	180
2,020	40
2,021	55
Laclede Gas
Maturities on long-term debt [Abstract]
2,017	0
2,018	100
2,019	50
2,020	0
2,021	0
Alagasco
Maturities on long-term debt [Abstract]
2,017	0
2,018	0
2,019	0
2,020	40
2,021	$ 0

LONG-TERM DEBT - Narrative (Det

LONG-TERM DEBT - Narrative (Details) - USD ($)

Dec. 01, 2015

Sep. 15, 2015

Jan. 15, 2015

Sep. 30, 2016

Nov. 11, 2016

Sep. 09, 2016

Feb. 10, 2016

Sep. 30, 2015

Jun. 30, 2015

Feb. 03, 2015

Nov. 03, 2014

Aug. 19, 2014

Jun. 20, 2014

Jun. 11, 2014

Debt Instrument [Line Items]

Long-term debt issued amount

$ 625,000,000

Stated interest rate on debt issued

2.00%

Long-term debt amount bearing variable interest rate

$ 250,000,000

Long-term debt

$ 2,085,800,000

SEC effective shelf registration Form S-3 sale and issuance authorization under the dividend reinvestment and stock purchase program (in shares)

168,698

168,698

SEC effective shelf registration Form S-3 remaining and available for issuance under the dividend reinvestment and stock purchase program (in shares)

106,535

Percent of common stock equity

49.10%

47.00%

Percent of long-term debt

50.90%

53.00%

Debt instrument, principal outstanding, excluding current portion

$ 1,833,700,000

$ 1,771,500,000

Subsequent Event

Debt Instrument [Line Items]

SEC effective shelf registration Form S-3 remaining and available for issuance under the dividend reinvestment and stock purchase program (in shares)

101,439

Senior Notes

Debt Instrument [Line Items]

Long-term debt

1,942,000,000

Senior Notes | Unsecured Series 2016 Senior Notes

Debt Instrument [Line Items]

Long-term debt issued amount

$ 165,000,000

Senior Notes | Unsecured Series 2016 Senior Notes, Tranche A

Debt Instrument [Line Items]

Long-term debt issued amount

$ 35,000,000

Stated interest rate on debt issued

2.52%

Senior Notes | Unsecured Series 2016 Senior Notes, Tranche B

Debt Instrument [Line Items]

Long-term debt issued amount

$ 130,000,000

Stated interest rate on debt issued

3.13%

Senior Notes | No Call Options

Debt Instrument [Line Items]

Long-term debt

25,000,000

Senior Notes | Make Whole Call Options

Debt Instrument [Line Items]

Long-term debt

937,000,000

Senior Notes | One to six months prior to maturity | Subject to Callable at Par

Debt Instrument [Line Items]

Long-term debt

$ 730,000,000

Redemption period prior to maturity, minimum

1 month

Redemption period prior to maturity, maximum

6 months

Senior Notes | One year prior to maturity | Subject to Callable at Par

Debt Instrument [Line Items]

Long-term debt

$ 250,000,000

Junior Subordinated Debt | 2.0% Series A Remarketable Subordinated Notes, due April 1, 2022

Debt Instrument [Line Items]

Stated interest rate on debt issued

2.00%

Long-term debt

$ 143,800,000

Laclede Gas

Debt Instrument [Line Items]

Long-term debt

$ 810,000,000

Percent of common stock equity

56.90%

56.20%

Percent of long-term debt

43.10%

43.80%

Regulatory preferred stock and debt securities issuance, amount authorized

$ 300,000,000

$ 300,000,000

$ 518,000,000

Debt instrument, principal outstanding, excluding current portion

808,300,000

$ 808,100,000

Laclede Gas | No Call Options

Debt Instrument [Line Items]

Long-term debt

25,000,000

Laclede Gas | Make Whole Call Options

Debt Instrument [Line Items]

Long-term debt

435,000,000

Laclede Gas | Three to six months prior to maturity | Subject to Callable at Par

Debt Instrument [Line Items]

Long-term debt

$ 350,000,000

Redemption period prior to maturity, minimum

3 months

Redemption period prior to maturity, maximum

6 months

Laclede Gas | Subsequent Event

Debt Instrument [Line Items]

Regulatory preferred stock and debt securities issuance, authorized debt issuance - remaining available

$ 300,000,000

Alagasco

Debt Instrument [Line Items]

Long-term debt

$ 250,000,000

Percent of common stock equity

77.60%

83.70%

Percent of long-term debt

22.40%

16.30%

Long-term debt reclassified to current

$ 250,000,000

Long-term debt amount authorized

$ 80,000,000

$ 35,000,000

Debt instrument, principal outstanding, excluding current portion

250,000,000

$ 170,000,000

Debt instrument redeemed

$ 34,800,000

Alagasco | Make Whole Call Options

Debt Instrument [Line Items]

Long-term debt

$ 250,000,000

Alagasco | 5.7% Notes, due January 15, 2035

Debt Instrument [Line Items]

Stated interest rate on debt issued

5.70%

Debt instrument, principal outstanding, excluding current portion

$ 34,800,000

Alagasco | 5.368% Notes, due December 1, 2015

Debt Instrument [Line Items]

Long-term debt issued amount

$ 80,000,000

Alagasco | 3.21% Notes, due September 15, 2025

Debt Instrument [Line Items]

Stated interest rate on debt issued

3.21%

3.21%

Alagasco | Notes 4.31%, Due December 1, 2045

Debt Instrument [Line Items]

Stated interest rate on debt issued

4.31%

4.31%

Alagasco | Unsecured notes

Debt Instrument [Line Items]

Long-term debt issued amount

$ 115,000,000

Alagasco | Unsecured notes | 3.21% Notes, due September 15, 2025

Debt Instrument [Line Items]

Long-term debt issued amount

$ 35,000,000

Stated interest rate on debt issued

3.21%

Debt issued, maturity term

10 years

Alagasco | Unsecured notes | Notes 4.31%, Due December 1, 2045

Debt Instrument [Line Items]

Long-term debt issued amount

$ 80,000,000

Stated interest rate on debt issued

4.31%

Debt issued, maturity term

30 years

Other subsidiaries

Debt Instrument [Line Items]

Long-term debt

$ 67,000,000

NOTES PAYABLE AND CREDIT AGRE67

NOTES PAYABLE AND CREDIT AGREEMENTS - Narrative (Details)	Sep. 02, 2014USD ($)bank	Sep. 30, 2016USD ($)bank
Line of Credit Facility [Line Items]
Speculative interest rate increase percent		1.00%
Decrease in cash flow with an impact of 100 basis point interest rate increase		$ 2,700,000
Laclede Gas
Line of Credit Facility [Line Items]
Speculative interest rate increase percent		1.00%
Decrease in cash flow with an impact of 100 basis point interest rate increase		$ 2,200,000
Alagasco
Line of Credit Facility [Line Items]
Speculative interest rate increase percent		1.00%
Decrease in cash flow with an impact of 100 basis point interest rate increase		$ 400,000
Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity		$ 150,000,000
Banks in syndicated line of credit facility | bank		9
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		0.585
Line of Credit | Laclede Gas
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity		$ 450,000,000
Banks in syndicated line of credit facility | bank		10
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		0.497
Line of Credit | Alagasco
Line of Credit Facility [Line Items]
Line of credit facility borrowing capacity	$ 150,000,000
Banks in syndicated line of credit facility | bank	12
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		0.278
Line of Credit | Liabilities | Lender Concentration Risk
Line of Credit Facility [Line Items]
Percent of debt by a singe bank		15.60%
Line of Credit | Liabilities | Lender Concentration Risk | Laclede Gas
Line of Credit Facility [Line Items]
Percent of debt by a singe bank		15.60%
Line of Credit | Liabilities | Lender Concentration Risk | Alagasco
Line of Credit Facility [Line Items]
Percent of debt by a singe bank	10.00%

NOTES PAYABLE AND CREDIT AGRE68

NOTES PAYABLE AND CREDIT AGREEMENTS - Spire Short-term Borrowings (Details) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 273,900,000	$ 300,600,000
Weighted average interest rate		0.90%	0.70%
Minimum borrowing outstanding		$ 73,100,000	$ 180,100,000
Maximum borrowing outstanding		427,200,000	488,500,000
Short-term debt		$ 398,700,000	$ 338,000,000
Weighted average interest rate		1.10%	0.80%
Line of Credit
Short-term Debt [Line Items]
Minimum borrowing outstanding		$ 0	$ 32,500,000
Maximum borrowing outstanding		82,000,000	80,000,000
Laclede Gas
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 215,700,000	$ 213,000,000
Weighted average interest rate		0.70%	0.40%
Minimum borrowing outstanding		$ 127,800,000	$ 104,200,000
Maximum borrowing outstanding		307,200,000	341,000,000
Short-term debt		$ 243,700,000	$ 233,000,000
Weighted average interest rate		0.80%	0.50%
Laclede Gas | Commercial Paper
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 201,000,000	$ 212,700,000
Weighted average interest rate		0.70%	0.40%
Minimum borrowing outstanding		$ 43,000,000	$ 102,100,000
Maximum borrowing outstanding		307,200,000	341,000,000
Short-term debt		$ 243,700,000	$ 233,000,000
Weighted average interest rate		0.80%	0.50%
Spire | Line of Credit
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 42,700,000	$ 65,600,000
Weighted average interest rate		1.60%	1.40%
Short-term debt		$ 73,000,000	$ 74,000,000
Weighted average interest rate		1.80%	1.50%
Alagasco
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 42,600,000	$ 22,300,000
Weighted average interest rate		1.40%	1.10%
Minimum borrowing outstanding		$ 19,000,000	$ 0
Maximum borrowing outstanding		82,000,000	69,500,000
Short-term debt		$ 82,000,000	$ 31,000,000
Weighted average interest rate		1.50%	1.20%
Alagasco | Line of Credit
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 22,300,000	$ 30,200,000	$ 22,300,000
Weighted average interest rate	1.10%	1.40%	1.10%
Minimum borrowing outstanding		$ 0	$ 0
Maximum borrowing outstanding		82,000,000	69,500,000
Short-term debt		$ 82,000,000	$ 31,000,000
Weighted average interest rate		1.50%	1.20%

NOTES PAYABLE AND CREDIT AGRE69

NOTES PAYABLE AND CREDIT AGREEMENTS - Laclede Gas' Short-term Borrowings (Details) - USD ($)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 273,900,000	$ 300,600,000
Weighted average interest rate	0.90%	0.70%
Minimum borrowing outstanding	$ 73,100,000	$ 180,100,000
Maximum borrowing outstanding	427,200,000	488,500,000
Short-term debt	$ 398,700,000	$ 338,000,000
Weighted average interest rate	1.10%	0.80%
Laclede Gas
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 215,700,000	$ 213,000,000
Weighted average interest rate	0.70%	0.40%
Minimum borrowing outstanding	$ 127,800,000	$ 104,200,000
Maximum borrowing outstanding	307,200,000	341,000,000
Short-term debt	$ 243,700,000	$ 233,000,000
Weighted average interest rate	0.80%	0.50%
Laclede Gas | Commercial Paper
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 201,000,000	$ 212,700,000
Weighted average interest rate	0.70%	0.40%
Minimum borrowing outstanding	$ 43,000,000	$ 102,100,000
Maximum borrowing outstanding	307,200,000	341,000,000
Short-term debt	$ 243,700,000	$ 233,000,000
Weighted average interest rate	0.80%	0.50%
Laclede Gas | Notes Payable to Related Party
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 14,700,000	$ 300,000
Weighted average interest rate	0.80%	0.50%
Minimum borrowing outstanding	$ 0	$ 0
Maximum borrowing outstanding	114,200,000	10,400,000
Short-term debt	$ 0	$ 0
Weighted average interest rate	0.00%	0.00%

NOTES PAYABLE AND CREDIT AGRE70

NOTES PAYABLE AND CREDIT AGREEMENTS - Alagasco's Short-term Borrowings (Details) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 273,900,000	$ 300,600,000
Weighted average interest rate		0.90%	0.70%
Minimum borrowing outstanding		$ 73,100,000	$ 180,100,000
Maximum borrowing outstanding		427,200,000	488,500,000
Short-term debt		$ 398,700,000	$ 338,000,000
Weighted average interest rate		1.10%	0.80%
Line of Credit
Short-term Debt [Line Items]
Minimum borrowing outstanding		$ 0	$ 32,500,000
Maximum borrowing outstanding		82,000,000	80,000,000
Alagasco
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 42,600,000	$ 22,300,000
Weighted average interest rate		1.40%	1.10%
Minimum borrowing outstanding		$ 19,000,000	$ 0
Maximum borrowing outstanding		82,000,000	69,500,000
Short-term debt		$ 82,000,000	$ 31,000,000
Weighted average interest rate		1.50%	1.20%
Alagasco | Line of Credit
Short-term Debt [Line Items]
Weighted average borrowings outstanding	$ 22,300,000	$ 30,200,000	$ 22,300,000
Weighted average interest rate	1.10%	1.40%	1.10%
Minimum borrowing outstanding		$ 0	$ 0
Maximum borrowing outstanding		82,000,000	69,500,000
Short-term debt		$ 82,000,000	$ 31,000,000
Weighted average interest rate		1.50%	1.20%
Alagasco | Notes Payable to Related Party
Short-term Debt [Line Items]
Weighted average borrowings outstanding		$ 12,400,000	$ 0
Weighted average interest rate		1.40%	0.00%
Minimum borrowing outstanding		$ 0	$ 0
Maximum borrowing outstanding		61,900,000	0
Short-term debt		$ 0	$ 0
Weighted average interest rate		0.00%	0.00%

FAIR VALUE OF FINANCIAL INSTR71

FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 5.2	$ 13.8	$ 16.1		$ 53
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	5.2	13.8
Short-term debt	398.7	338
Long-term debt, including current portion	2,083.7	1,851.5
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	5.2	13.8
Short-term debt	398.7	338
Long-term debt, including current portion	2,257.1	1,944.2
Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2.1	1.7	3.7		$ 23.9
Laclede Gas | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2.1	1.7
Short-term debt	243.7	233
Long-term debt, including current portion	808.3	808.1
Laclede Gas | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2.1	1.7
Short-term debt	243.7	233
Long-term debt, including current portion	900.4	880.2
Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	7.2	$ 5.6	$ 3
Alagasco | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	7.2
Short-term debt	82	31
Long-term debt, including current portion	250	250
Alagasco | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	7.2
Short-term debt	82	31
Long-term debt, including current portion	275.5	263.2
Quoted Prices in Active Markets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	5.2	13.8
Short-term debt	0	0
Long-term debt, including current portion	0	0
Quoted Prices in Active Markets (Level 1) | Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2.1	1.7
Short-term debt	0	0
Long-term debt, including current portion	0	0
Quoted Prices in Active Markets (Level 1) | Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	7.2
Short-term debt	0	0
Long-term debt, including current portion	0	0
Significant Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	398.7	338
Long-term debt, including current portion	2,257.1	1,944.2
Significant Observable Inputs (Level 2) | Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	243.7	233
Long-term debt, including current portion	900.4	880.2
Significant Observable Inputs (Level 2) | Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	82	31
Long-term debt, including current portion	275.5	263.2
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	0	0
Long-term debt, including current portion	0	0
Significant Unobservable Inputs (Level 3) | Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	0	0
Long-term debt, including current portion	0	0
Significant Unobservable Inputs (Level 3) | Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Short-term debt	0	0
Long-term debt, including current portion	$ 0	$ 0

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
ASSETS
Derivative asset after the effects of netting	$ 13.3	$ 5.2
LIABILITIES
Derivative liability after the effects of netting	4.9	7.6
Laclede Gas
ASSETS
Derivative asset after the effects of netting	4.9	0
LIABILITIES
Derivative liability after the effects of netting	0.2	5.9
Fair Value, Measurements, Recurring
ASSETS
Effects of netting and cash margin receivables/payables	(5)	(8.4)
Derivative asset after the effects of netting	34.3	24.7
LIABILITIES
Effects of netting and cash margin receivables/payables	(7.6)
Derivative liability after the effects of netting	4.9
Fair Value, Measurements, Recurring | Laclede Gas
ASSETS
Effects of netting and cash margin receivables/payables	(0.7)	(1.3)
Derivative asset after the effects of netting	25.8	19.5
LIABILITIES
Effects of netting and cash margin receivables/payables	(1.6)	(16.7)
Derivative liability after the effects of netting	0.2	5.9
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	22.9	23.1
LIABILITIES
Derivative liability before effects of netting	5.1
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) | Laclede Gas
ASSETS
Derivative asset before effects of netting	22.4	16.8
LIABILITIES
Derivative liability before effects of netting	1.6	16.7
Fair Value, Measurements, Recurring | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	16.2	9.8
LIABILITIES
Derivative liability before effects of netting	7.4
Fair Value, Measurements, Recurring | Significant Observable Inputs (Level 2) | Laclede Gas
ASSETS
Derivative asset before effects of netting	4.1	4
LIABILITIES
Derivative liability before effects of netting	0.2	5.9
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0.2	0.2
LIABILITIES
Derivative liability before effects of netting	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Fair Value, Measurements, Recurring | US stock/bond mutual funds | Laclede Gas
ASSETS
Effects of netting and cash margin receivables/payables	0	0
Derivative asset after the effects of netting	20.9	19.5
Fair Value, Measurements, Recurring | US stock/bond mutual funds | Quoted Prices in Active Markets (Level 1) | Laclede Gas
ASSETS
Derivative asset before effects of netting	16.8	15.5
Fair Value, Measurements, Recurring | US stock/bond mutual funds | Significant Observable Inputs (Level 2) | Laclede Gas
ASSETS
Derivative asset before effects of netting	4.1	4
Fair Value, Measurements, Recurring | US stock/bond mutual funds | Significant Unobservable Inputs (Level 3) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0	0
Fair Value, Measurements, Recurring | NYMEX/ICE natural gas contracts | Laclede Gas
ASSETS
Effects of netting and cash margin receivables/payables	(0.4)	(1.3)
Derivative asset after the effects of netting	4.9	0
LIABILITIES
Effects of netting and cash margin receivables/payables	(1.6)	(16.4)
Derivative liability after the effects of netting	0	0
Fair Value, Measurements, Recurring | NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas
ASSETS
Derivative asset before effects of netting	5.3	1.3
LIABILITIES
Derivative liability before effects of netting	1.6	16.4
Fair Value, Measurements, Recurring | NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Fair Value, Measurements, Recurring | NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Fair Value, Measurements, Recurring | OTCBB natural gas contracts | Laclede Gas
LIABILITIES
Effects of netting and cash margin receivables/payables	0	0
Derivative liability after the effects of netting	0.2	5.9
Fair Value, Measurements, Recurring | OTCBB natural gas contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting	0	0
Fair Value, Measurements, Recurring | OTCBB natural gas contracts | Significant Observable Inputs (Level 2) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting	0.2	5.9
Fair Value, Measurements, Recurring | OTCBB natural gas contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting	0	0
Fair Value, Measurements, Recurring | Gasoline and heating oil contracts | Laclede Gas
ASSETS
Effects of netting and cash margin receivables/payables	(0.3)
Derivative asset after the effects of netting	0
Fair Value, Measurements, Recurring | Gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0.3
Fair Value, Measurements, Recurring | Gasoline and heating oil contracts | Significant Observable Inputs (Level 2) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0
Fair Value, Measurements, Recurring | Gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas
ASSETS
Derivative asset before effects of netting	0
Fair Value, Measurements, Recurring | NYMEX gasoline and heating oil contracts | Laclede Gas
LIABILITIES
Effects of netting and cash margin receivables/payables		(0.3)
Derivative liability after the effects of netting		0
Fair Value, Measurements, Recurring | NYMEX gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting		0.3
Fair Value, Measurements, Recurring | NYMEX gasoline and heating oil contracts | Significant Observable Inputs (Level 2) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting		0
Fair Value, Measurements, Recurring | NYMEX gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas
LIABILITIES
Derivative liability before effects of netting		0
Fair Value, Measurements, Recurring | Gas Marketing
LIABILITIES
Effects of netting and cash margin receivables/payables		(22.3)
Derivative liability after the effects of netting		7.6
Fair Value, Measurements, Recurring | Gas Marketing | Quoted Prices in Active Markets (Level 1)
LIABILITIES
Derivative liability before effects of netting		17.9
Fair Value, Measurements, Recurring | Gas Marketing | Significant Observable Inputs (Level 2)
LIABILITIES
Derivative liability before effects of netting		12
Fair Value, Measurements, Recurring | Gas Marketing | Significant Unobservable Inputs (Level 3)
LIABILITIES
Derivative liability before effects of netting		0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility
ASSETS
Effects of netting and cash margin receivables/payables	(0.7)	(1.3)
Derivative asset after the effects of netting	25.9	19.5
LIABILITIES
Effects of netting and cash margin receivables/payables	(1.6)	(16.7)
Derivative liability after the effects of netting	0.2	5.9
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	22.5	16.8
LIABILITIES
Derivative liability before effects of netting	1.6	16.7
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	4.1	4
LIABILITIES
Derivative liability before effects of netting	0.2	5.9
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | US stock/bond mutual funds
ASSETS
Effects of netting and cash margin receivables/payables	0	0
Derivative asset after the effects of netting	20.9	19.5
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | US stock/bond mutual funds | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	16.8	15.5
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | US stock/bond mutual funds | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	4.1	4
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | US stock/bond mutual funds | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(0.4)	(1.3)
Derivative asset after the effects of netting	4.9	0
LIABILITIES
Effects of netting and cash margin receivables/payables	(1.6)	(16.4)
Derivative liability after the effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	5.3	1.3
LIABILITIES
Derivative liability before effects of netting	1.6	16.4
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | OTCBB natural gas contracts
LIABILITIES
Effects of netting and cash margin receivables/payables	0	0
Derivative liability after the effects of netting	0.2	5.9
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | OTCBB natural gas contracts | Quoted Prices in Active Markets (Level 1)
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | OTCBB natural gas contracts | Significant Observable Inputs (Level 2)
LIABILITIES
Derivative liability before effects of netting	0.2	5.9
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | OTCBB natural gas contracts | Significant Unobservable Inputs (Level 3)
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Gasoline and heating oil contracts
ASSETS
Effects of netting and cash margin receivables/payables	(0.3)
Derivative asset after the effects of netting	0.1
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	0.4
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Gasoline and heating oil contracts | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | Gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX gasoline and heating oil contracts
LIABILITIES
Effects of netting and cash margin receivables/payables		(0.3)
Derivative liability after the effects of netting		0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1)
LIABILITIES
Derivative liability before effects of netting		0.3
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX gasoline and heating oil contracts | Significant Observable Inputs (Level 2)
LIABILITIES
Derivative liability before effects of netting		0
Operating Segments | Fair Value, Measurements, Recurring | Gas Utility | NYMEX gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3)
LIABILITIES
Derivative liability before effects of netting		0
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX/ICE natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables	(3.4)
Derivative asset after the effects of netting	0.4
LIABILITIES
Effects of netting and cash margin receivables/payables	(5.1)	(5.1)
Derivative liability after the effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	0.4
LIABILITIES
Derivative liability before effects of netting	3.5	1.2
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	3.4
LIABILITIES
Derivative liability before effects of netting	1.6	3.9
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX natural gas contracts
ASSETS
Effects of netting and cash margin receivables/payables		(6.6)
Derivative asset after the effects of netting		4
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX natural gas contracts | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting		6.3
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX natural gas contracts | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting		4.3
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | NYMEX natural gas contracts | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting		0
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | Natural gas commodity contracts
ASSETS
Effects of netting and cash margin receivables/payables	(0.9)	(0.5)
Derivative asset after the effects of netting	8	1.2
LIABILITIES
Effects of netting and cash margin receivables/payables	(0.9)	(0.5)
Derivative liability after the effects of netting	1.7	1.7
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | Natural gas commodity contracts | Quoted Prices in Active Markets (Level 1)
ASSETS
Derivative asset before effects of netting	0	0
LIABILITIES
Derivative liability before effects of netting	0	0
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | Natural gas commodity contracts | Significant Observable Inputs (Level 2)
ASSETS
Derivative asset before effects of netting	8.7	1.5
LIABILITIES
Derivative liability before effects of netting	2.6	2.2
Operating Segments | Fair Value, Measurements, Recurring | Gas Marketing | Natural gas commodity contracts | Significant Unobservable Inputs (Level 3)
ASSETS
Derivative asset before effects of netting	0.2	0.2
LIABILITIES
Derivative liability before effects of netting	0	$ 0
Other | Fair Value, Measurements, Recurring | Interest rate swaps
LIABILITIES
Effects of netting and cash margin receivables/payables	0
Derivative liability after the effects of netting	3
Other | Fair Value, Measurements, Recurring | Interest rate swaps | Quoted Prices in Active Markets (Level 1)
LIABILITIES
Derivative liability before effects of netting	0
Other | Fair Value, Measurements, Recurring | Interest rate swaps | Significant Observable Inputs (Level 2)
LIABILITIES
Derivative liability before effects of netting	3
Other | Fair Value, Measurements, Recurring | Interest rate swaps | Significant Unobservable Inputs (Level 3)
LIABILITIES
Derivative liability before effects of netting	$ 0

DERIVATIVE INSTRUMENTS AND HE73

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Narrative (Details) gal in Millions, MMBTU in Millions	Jun. 03, 2016USD ($)	May 21, 2015USD ($)	Aug. 06, 2014USD ($)	Sep. 30, 2016USD ($)MMBTU$ / galgal	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Sep. 30, 2016USD ($)MMBTU$ / galgal	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	May 05, 2016USD ($)	Dec. 01, 2015USD ($)	Sep. 15, 2015USD ($)	Apr. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Aug. 19, 2014USD ($)	Jul. 08, 2014USD ($)
Derivative [Line Items]
Notional amount of non-exchange traded natural gas commodity contracts (in MMBtu) | MMBTU				122.7			122.7
Notional amount of non-exchange traded natural gas commodity contracts to be settled during fiscal 2016 | MMBTU				110.8			110.8
Notional amount of non-exchange traded natural gas commodity contracts to be settled during fiscal 2017 | MMBTU				11.4			11.4
Notional amount of non-exchange traded natural gas commodity to be settled during fiscal 2018 | MMBTU				0.2			0.2
Notional amount of non-exchange traded natural gas commodity to be settled during fiscal 2019 | MMBTU				0.3			0.3
Notional amount					$ 120,000,000
Long-term debt issued amount															$ 625,000,000
Term of contract					7 years
Derivative average fixed interest rate					1.501%
Unrealized gain on energy-related derivatives							$ 100,000	$ 2,800,000	$ 1,600,000
Gain (loss) to be reclassified within twelve months							0
Cash margin receivables not offset with derivatives				$ 2,900,000			$ 2,900,000	5,900,000
Alagasco
Derivative [Line Items]
Unsecured debt														$ 115,000,000
Gasoline futures contracts notional amount (in gallons) | gal				0.6			0.6
Average price of future contracts (dollars per gallon) | $ / gal				1.53			1.53
Alagasco | 3.21% Notes, due September 15, 2025
Derivative [Line Items]
Unsecured debt												$ 35,000,000
Alagasco | Notes 4.31%, Due December 1, 2045
Derivative [Line Items]
Unsecured debt											$ 80,000,000
Laclede Gas
Derivative [Line Items]
MMBtu (millions) | MMBTU							19.8
Gain (loss) to be reclassified within twelve months							$ 0
Cash margin receivables not offset with derivatives				$ 500,000			$ 500,000	$ 5,900,000
Gasoline futures contracts notional amount (in gallons) | gal				1.8			1.8
Average price of future contracts (dollars per gallon) | $ / gal				1.37			1.37
Interest rate swaps
Derivative [Line Items]
Notional amount						$ 105,000,000
Derivative fixed interest rate						1.776%
Term of contract						5 years
Unrealized gain on energy-related derivatives				$ 1,000,000			$ (3,000,000)
Designated as Hedging Instrument | Interest rate swaps | Alagasco
Derivative [Line Items]
Gain on settlement of derivative		$ 2,700,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swaps
Derivative [Line Items]
Notional amount										$ 85,000,000			$ 24,000,000			$ 375,000,000
Loss on termination and settlement of interest rate swap			$ 19,000,000
Effective portion of gain (loss) recognized in OCI on derivatives	$ (400,000)
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swaps | Alagasco
Derivative [Line Items]
Notional amount													$ 24,000,000	$ 80,500,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swaps | Alagasco | Minimum
Derivative [Line Items]
Derivative fixed interest rate														2.18%
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swaps | Alagasco | Maximum
Derivative [Line Items]
Derivative fixed interest rate														2.85%

DERIVATIVE INSTRUMENTS AND HE74

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Exchange-Traded/Cleared Derivatives (Details) MMBTU in Thousands	12 Months Ended
	Sep. 30, 2016MMBTU$ / gal$ / MMBTU
Laclede Gas
Derivative [Line Items]
MMBtu (millions)	19,800
Avg. Price Per MMBtu | $ / gal	1.37
Short | Gas Utility | Natural gas contracts | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Short | Gas Utility | Natural gas contracts | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Short | Gas Utility | ICE Open basis swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Short | Gas Utility | ICE Open basis swap positions | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Short | Gas Utility | ICE Open basis swap positions | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Short | Gas Marketing | Natural gas contracts | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	12,200
Avg. Price Per MMBtu | $ / MMBTU	2.86
Short | Gas Marketing | Natural gas contracts | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	1,270
Avg. Price Per MMBtu | $ / MMBTU	2.95
Short | Gas Marketing | ICE Open basis swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	11,880
Avg. Price Per MMBtu | $ / MMBTU	0.19
Short | Gas Marketing | ICE Open basis swap positions | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	930
Avg. Price Per MMBtu | $ / MMBTU	0.27
Short | Gas Marketing | ICE Open basis swap positions | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	2,270
Avg. Price Per MMBtu | $ / MMBTU	0.13
Long | Gas Utility | Natural gas contracts | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	18,430
Avg. Price Per MMBtu | $ / MMBTU	2.95
Long | Gas Utility | Natural gas contracts | Fiscal 2017 | Laclede Gas
Derivative [Line Items]
MMBtu (millions)	18,430
Avg. Price Per MMBtu | $ / MMBTU	2.95
Long | Gas Utility | Natural gas contracts | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	330
Avg. Price Per MMBtu | $ / MMBTU	2.83
Long | Gas Utility | Natural gas contracts | Fiscal 2018 | Laclede Gas
Derivative [Line Items]
MMBtu (millions)	330
Avg. Price Per MMBtu | $ / MMBTU	2.83
Long | Gas Utility | Natural gas contracts | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Long | Gas Utility | ICE Open basis swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Long | Gas Utility | ICE Open basis swap positions | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Long | Gas Utility | ICE Open basis swap positions | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0
Long | Gas Utility | OTC Open long futures/swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	320
Avg. Price Per MMBtu | $ / MMBTU	3.64
Long | Gas Utility | OTC Open long futures/swap positions | Fiscal 2017 | Laclede Gas
Derivative [Line Items]
MMBtu (millions)	320
Avg. Price Per MMBtu | $ / MMBTU	3.64
Long | Gas Marketing | Natural gas contracts | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	4,620
Avg. Price Per MMBtu | $ / MMBTU	3.12
Long | Gas Marketing | Natural gas contracts | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	450
Avg. Price Per MMBtu | $ / MMBTU	3.02
Long | Gas Marketing | Natural gas contracts | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	40
Avg. Price Per MMBtu | $ / MMBTU	2.89
Long | Gas Marketing | ICE Open basis swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	16,620
Avg. Price Per MMBtu | $ / MMBTU	0.34
Long | Gas Marketing | ICE Open basis swap positions | Fiscal 2018
Derivative [Line Items]
MMBtu (millions)	2,010
Avg. Price Per MMBtu | $ / MMBTU	0.43
Long | Gas Marketing | ICE Open basis swap positions | Fiscal 2019
Derivative [Line Items]
MMBtu (millions)	80
Avg. Price Per MMBtu | $ / MMBTU	0.40
Long | Gas Marketing | OTC Open long futures/swap positions | Fiscal 2017
Derivative [Line Items]
MMBtu (millions)	0
Avg. Price Per MMBtu | $ / MMBTU	0

DERIVATIVE INSTRUMENTS AND HE75

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Gains (Losses) on Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 03, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Designated as Hedging Instrument | Cash Flow Hedging
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		$ (1.1)	$ (4.4)	$ 2.5
Ineffective portion of gain (loss) on derivatives recognized in income		0.3	(0.4)	(0.2)
Designated as Hedging Instrument | Cash Flow Hedging | Other Comprehensive Income (Loss)
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives		(4)	(5.5)	(4.5)
Designated as Hedging Instrument | Cash Flow Hedging | Natural gas contracts
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		(0.6)	(3.5)	2.7
Ineffective portion of gain (loss) on derivatives recognized in income		0.2	(0.5)	0
Designated as Hedging Instrument | Cash Flow Hedging | Natural gas contracts | Other Comprehensive Income (Loss)
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives		(0.6)	(4.3)	(4.6)
Designated as Hedging Instrument | Cash Flow Hedging | Natural gas contracts | Gas Marketing Operating Revenues
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		4.3	1.7	4.2
Ineffective portion of gain (loss) on derivatives recognized in income		0.1	0	(0.1)
Designated as Hedging Instrument | Cash Flow Hedging | Natural gas contracts | Gas Marketing Operating Expenses
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		(4.9)	(5.2)	(1.5)
Ineffective portion of gain (loss) on derivatives recognized in income		0.1	(0.5)	0.1
Designated as Hedging Instrument | Cash Flow Hedging | Gasoline and heating oil contracts | Other Comprehensive Income (Loss)
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives		0	(1.2)	0.1
Designated as Hedging Instrument | Cash Flow Hedging | Gasoline and heating oil contracts | Gas Utility Other Operating Expenses
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		(0.5)	(0.9)	(0.2)
Ineffective portion of gain (loss) on derivatives recognized in income		0.1	0.1	(0.2)
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives	$ (0.4)
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Other Comprehensive Income (Loss)
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives		(3.4)	0	0
Not Designated as Hedging Instrument
Derivatives Not Designated as Hedging Instruments [Abstract]
Gain (loss) recognized in income on derivatives		10.6	(11.1)	(5.7)
Not Designated as Hedging Instrument | Gasoline and heating oil contracts | Other Income and (Income Deductions) - Net
Derivatives Not Designated as Hedging Instruments [Abstract]
Gain (loss) recognized in income on derivatives		0	(0.2)	0
Not Designated as Hedging Instrument | Natural gas commodity contracts | Gas Marketing Operating Revenues
Derivatives Not Designated as Hedging Instruments [Abstract]
Gain (loss) recognized in income on derivatives		12.3	(1.3)	(8.7)
Not Designated as Hedging Instrument | NYMEX / ICE natural gas contracts | Gas Marketing Operating Revenues
Derivatives Not Designated as Hedging Instruments [Abstract]
Gain (loss) recognized in income on derivatives		(1.7)	(9.6)	3
Laclede Gas | Designated as Hedging Instrument | Cash Flow Hedging | Gasoline and heating oil contracts | Other Comprehensive Income (Loss)
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) recognized in OCI on derivatives		0	(1.2)	0.1
Laclede Gas | Designated as Hedging Instrument | Cash Flow Hedging | Gasoline and heating oil contracts | Gas Utility Other Operating Expenses
Derivatives in Cash Flow Hedging Relationships [Abstract]
Effective portion of gain (loss) reclassified from AOCI to income		(0.5)	(0.9)	(0.2)
Ineffective portion of gain (loss) on derivatives recognized in income		0.1	0.1	(0.2)
Laclede Gas | Not Designated as Hedging Instrument | Gasoline and heating oil contracts | Other Income and (Income Deductions) - Net
Derivatives Not Designated as Hedging Instruments [Abstract]
Gain (loss) recognized in income on derivatives		$ 0	$ (0.2)	$ 0

DERIVATIVE INSTRUMENTS AND HE76

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	$ 18.4	$ 13.5
Fair value of liability derivatives presented above	12.5	29.8
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	3.2
Fair value of liability derivatives presented above	3.9
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	15.2	8.3
Fair value of liability derivatives presented above	8.6	25.8
Other | Interest rate swaps | Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0
Gas Utility | Operating Segments | Gasoline and heating oil contracts | Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.3
Fair value of liability derivatives presented above	0
Gas Utility | Operating Segments | Gasoline and heating oil contracts | Designated as Hedging Instrument | Accounts Receivable – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		0
Fair value of liability derivatives presented above		0.3
Gas Utility | Operating Segments | Natural gas contracts | Not Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0	0
Fair value of liability derivatives presented above	0.2	5.7
Gas Utility | Operating Segments | Natural gas contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	5.4	1.2
Fair value of liability derivatives presented above	1.6	16.4
Gas Utility | Operating Segments | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		0
Fair value of liability derivatives presented above		0.2
Gas Marketing | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		5.2
Fair value of liability derivatives presented above		4
Gas Marketing | Operating Segments | Natural gas contracts | Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	2.5	4.1
Fair value of liability derivatives presented above	0.8	3.2
Gas Marketing | Operating Segments | Natural gas contracts | Designated as Hedging Instrument | Deferred Charges – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.4	1.1
Fair value of liability derivatives presented above	0.1	0.5
Gas Marketing | Operating Segments | NYMEX / ICE natural gas contracts | Not Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.8	4.7
Fair value of liability derivatives presented above	4.1	0.6
Gas Marketing | Operating Segments | NYMEX / ICE natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0	0.7
Fair value of liability derivatives presented above	0.1	0.7
Gas Marketing | Operating Segments | Natural gas commodity contracts | Not Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	6.5	1.4
Fair value of liability derivatives presented above	0.2	0.1
Gas Marketing | Operating Segments | Natural gas commodity contracts | Not Designated as Hedging Instrument | Deferred Charges – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	2.1
Fair value of liability derivatives presented above	0.3
Gas Marketing | Operating Segments | Natural gas commodity contracts | Not Designated as Hedging Instrument | Current Liabilities – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.2	0.2
Fair value of liability derivatives presented above	2	1.4
Gas Marketing | Operating Segments | Natural gas commodity contracts | Not Designated as Hedging Instrument | Deferred Credits – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.2	0.1
Fair value of liability derivatives presented above	0.1	0.7
Other Segments | Other | Interest rate swaps | Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of liability derivatives presented above	3
Laclede Gas
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	5.7	1.2
Fair value of liability derivatives presented above	1.8	22.6
Laclede Gas | Gas Utility
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	5.7	1.2
Fair value of liability derivatives presented above	1.8	22.6
Laclede Gas | Gas Utility | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.3	0
Fair value of liability derivatives presented above	0	0.3
Laclede Gas | Gas Utility | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	5.4	1.2
Fair value of liability derivatives presented above	1.8	22.3
Laclede Gas | Gas Utility | Gasoline and heating oil contracts | Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0.3
Fair value of liability derivatives presented above	0
Laclede Gas | Gas Utility | Gasoline and heating oil contracts | Designated as Hedging Instrument | Accounts Receivable – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		0
Fair value of liability derivatives presented above		0.3
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		0
Fair value of liability derivatives presented above		5.7
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	5.4	1.2
Fair value of liability derivatives presented above	1.6	16.4
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges – Other
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above		0
Fair value of liability derivatives presented above		$ 0.2
Laclede Gas | Gas Utility | OTCBB natural gas contracts | Not Designated as Hedging Instrument | Derivative Instrument Assets
Derivatives, Fair Value [Line Items]
Fair value of asset derivatives presented above	0
Fair value of liability derivatives presented above	$ 0.2

DERIVATIVE INSTRUMENTS AND HE77

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Instruments Reconciliation (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Offsetting Derivative Assets [Abstract]
Fair value of asset derivatives presented above	$ 18.4	$ 13.5
Fair value of cash margin receivables offset with derivatives	2.5	13.9
Netting of assets and liabilities with the same counterparty	(7.6)	(22.2)
Derivative asset after the effects of netting	13.3	5.2
Derivative instrument assets	11.4	4.6
Deferred Charges – Other	1.9	0.6
Offsetting Derivative Liabilities [Abstract]
Fair value of liability derivatives presented above	12.5	29.8
Netting of assets and liabilities with the same counterparty	(7.6)	(22.2)
Derivative liability after the effects of netting	4.9	7.6
Current Liabilities – Other	4.8	6.8
Deferred Credits – Other	0.1	0.8
Laclede Gas
Offsetting Derivative Assets [Abstract]
Fair value of asset derivatives presented above	5.7	1.2
Fair value of cash margin receivables offset with derivatives	0.8	15.5
Netting of assets and liabilities with the same counterparty	(1.6)	(16.7)
Derivative asset after the effects of netting	4.9	0
Derivative instrument assets	4.9	0
Offsetting Derivative Liabilities [Abstract]
Fair value of liability derivatives presented above	1.8	22.6
Netting of assets and liabilities with the same counterparty	(1.6)	(16.7)
Derivative liability after the effects of netting	0.2	5.9
Current Liabilities – Other	0.2	5.7
Deferred Credits – Other	$ 0	$ 0.2

CONCENTRATIONS OF CREDIT RISK (

CONCENTRATIONS OF CREDIT RISK (Details) $ in Millions	Sep. 30, 2016USD ($)counterparty
Concentration Risk [Line Items]
Number of large counterparties for which credit risk is disclosed | counterparty	5
Energy Producers And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	$ 15.8
Net receivable amount	12.4
Utility Companies And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	52.8
Net receivable amount	50.5
Largest Counterparties
Concentration Risk [Line Items]
Accounts receivable	31.2
Net receivable amount	$ 27.2

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	Sep. 30, 2016	Sep. 30, 2015
Tax Credit Carryforward [Line Items]
Federal and state loss carryforwards	$ 297,000,000
Contribution carryforwards	12,200,000
Valuation allowance	900,000	$ 0
Tax credit carryforwards	3,500,000
Unrecognized tax benefits affect on the Company's effective tax rate	3,300,000	3,100,000
Income taxes accrued	0	0
income tax penalties accrued	0
Laclede Gas
Tax Credit Carryforward [Line Items]
Federal and state loss carryforwards	105,000,000
Contribution carryforwards	12,000,000
Valuation allowance	900,000	0
Tax credit carryforwards	2,000,000
Unrecognized tax benefits affect on the Company's effective tax rate	3,100,000	2,900,000
Income taxes accrued	0	0
income tax penalties accrued	0	$ 0
Alagasco
Tax Credit Carryforward [Line Items]
Federal and state loss carryforwards	$ 159,000,000

INCOME TAXES - Net Provisions f

INCOME TAXES - Net Provisions for Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Federal
Current		$ 0.1	$ (3.3)	$ 0.3
Deferred		62	58.8	30.6
Investment tax credits		(0.2)	(0.2)	(0.2)
State and local
Current		0.6	0	0.6
Deferred		7	6.9	1
Total income tax expense		69.5	62.2	32.3
Laclede Gas
Federal
Current		0	(2.1)	(0.1)
Deferred		37.5	40.9	34.3
Investment tax credits		(0.2)	(0.2)	(0.2)
State and local
Current		0.1	(0.1)	0
Deferred		8	4.7	1.5
Total income tax expense		45.4	43.2	$ 35.5
Alagasco
Federal
Current	$ 14.1	(0.8)	0
Deferred	3.5	29.4	25.9
State and local
Current	1.8	0	0.1
Deferred	0.5	3.8	3.3
Total income tax expense	$ 19.9	$ 32.4	$ 29.3

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Variation from Stated Tax Rate (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Tax Contingency [Line Items]
Federal income tax statutory rate		35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefits		2.80%	3.00%	1.80%
Certain expenses capitalized on books and deducted on tax return		(3.40%)	(3.70%)	(4.90%)
Taxes related to prior years		(0.20%)	(0.60%)	(0.70%)
Other items – net		(1.70%)	(2.50%)	(3.60%)
Effective income tax rate		32.50%	31.20%	27.60%
Laclede Gas
Income Tax Contingency [Line Items]
Federal income tax statutory rate		35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefits		2.80%	2.80%	1.80%
Certain expenses capitalized on books and deducted on tax return		(4.80%)	(4.90%)	(4.50%)
Taxes related to prior years		(0.20%)	(0.80%)	(0.70%)
Other items – net		(2.80%)	(3.00%)	(3.30%)
Effective income tax rate		30.00%	29.10%	28.30%
Alagasco
Income Tax Contingency [Line Items]
Federal income tax statutory rate	35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefits	2.80%	2.80%	2.80%
Other items – net	(0.20%)	0.10%	0.10%
Effective income tax rate	37.60%	37.90%	37.90%

INCOME TAXES - Significant Item

INCOME TAXES - Significant Items in Net Deferred Tax Liability (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Deferred tax assets:
Reserves not currently deductible	$ 21.3	$ 14.8
Pension and other postretirement benefits	68.3	62.5
Operating losses	102.3	47.3
Other	0	1.5
Deferred tax assets	191.9	126.1
Less: valuation allowance	0.9	0
Total deferred tax assets	191	126.1
Deferred tax liabilities:
Relating to property	623.1	472.1
Regulatory pension and other postretirement benefits	106.8	110.6
Deferred gas costs	20	8.1
Other	48.4	11.6
Total deferred tax liabilities	798.3	602.4
Net deferred tax liability	607.3	476.3
Net deferred tax asset – current	0	5.8
Net deferred tax liability	607.3
Det deferred tax asset (liability) - noncurrent		482.1
Laclede Gas
Deferred tax assets:
Reserves not currently deductible	14.9	15.4
Pension and other postretirement benefits	56.9	62.5
Operating losses	29.9	3.7
Other	0	1.5
Deferred tax assets	101.7	83.1
Less: valuation allowance	0.9	0
Total deferred tax assets	100.8	83.1
Deferred tax liabilities:
Relating to property	497	425
Regulatory pension and other postretirement benefits	106.8	120.2
Deferred gas costs	20	8.2
Other	33.9	14.5
Total deferred tax liabilities	657.7	567.9
Net deferred tax liability	556.9	484.8
Net deferred tax asset – current	0	0.4
Net deferred tax liability	556.9
Det deferred tax asset (liability) - noncurrent		485.2
Alagasco
Deferred tax assets:
Reserves not currently deductible	6.3	7
Pension and other postretirement benefits	11.4	9.6
Goodwill	233.4	251.5
Operating losses	60.2	32.4
Other	0	1.4
Deferred tax assets	311.3	301.9
Deferred tax liabilities:
Relating to property	87.6	45.1
Other	2.3	2.2
Total deferred tax liabilities	89.9	47.3
Net deferred tax asset	221.4	254.6
Net deferred tax asset – current	0	6.2
Deferred income tax	$ 221.4
Deferred income tax		$ 248.4

INCOME TAXES - Unrecognized Tax

INCOME TAXES - Unrecognized Tax Benefit Reconciliation (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Unrecognized tax benefits [Roll Forward]
Unrecognized tax benefits, beginning of year		$ 7.1	$ 4.6	$ 2.4
Increases related to tax positions taken in current year		3.4	2.9	2.6
Reductions due to lapse of applicable statute of limitations		(0.5)	(0.4)	(0.4)
Unrecognized tax benefits, end of year	$ 4.6	10	7.1	4.6
Laclede Gas
Unrecognized tax benefits [Roll Forward]
Unrecognized tax benefits, beginning of year		6.9	4.2	2
Increases related to tax positions taken in current year		3.3	2.9	2.5
Reductions due to lapse of applicable statute of limitations		(0.5)	(0.2)	(0.3)
Unrecognized tax benefits, end of year	4.2	9.7	6.9	4.2
Alagasco
Unrecognized tax benefits [Roll Forward]
Unrecognized tax benefits, beginning of year	0.3	0	0
Reductions due to lapse of applicable statute of limitations	(0.3)	0	0
Unrecognized tax benefits, end of year	$ 0	$ 0	$ 0	$ 0

PENSION PLANS AND OTHER POSTR84

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Jan. 01, 2011	Feb. 20, 2010
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Extent of Lump-sum payments recognized, percentage	100.00%
Implementation period used to calculate return on plan assets	4 years
Gains or losses includible in cost amortized to extent exceeds benefit obligations or market-related value of plan assets, percentage	10.00%
Anticipated Contributions to pension plans for qualified trust	$ 29
Anticipated contributions to pension plans for non-qualified plans	$ 0.6
Medical insurance available until age is reached after early retirement	65 years
Recovery in rates for postretirement benefit				$ 9.5
Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Recovery in rates for the qualified pension plans base allowance				$ 15.5
Other Plans [Abstract]
401(K) plans, cost of defined contributions	$ 8.2	$ 8	$ 6.7
Alagasco
Other Plans [Abstract]
401(K) plans, cost of defined contributions	2.3	3	4.7
Missouri Gas Energy (MGE)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Recovery in rates for the qualified pension plans base allowance					$ 10
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement benefits paid	$ 16.6	$ 71.1	$ 22.1
Pension Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	100.00%	100.00%
Settlement benefits paid	$ 0	$ 58.2
Pension Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	100.00%	100.00%
Settlement benefits paid	$ 16.6	$ 12.9
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to the postretirement plans for qualified trusts	10.3
Anticipated payment directly to participants in postretirement plan	$ 0.4
Postretirement Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	100.00%
Postretirement Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	100.00%
Equity markets | Pension Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	56.20%	52.00%
Equity markets | Pension Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	60.00%	60.00%
Equity markets | Postretirement Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	60.00%
Equity markets | Postretirement Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	60.00%
Debt securities | Pension Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	43.80%	48.00%
Debt securities | Postretirement Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	40.00%
Debt securities | Postretirement Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Targeted allocation of plan assets	40.00%

PENSION PLANS AND OTHER POSTR85

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Net Periodic Cost (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period		$ 15.3	$ 17.3	$ 10.2
Interest cost on projected benefit obligation		28	29.5	24.5
Expected return on plan assets		(34.9)	(37.4)	(27.2)
Amortization of other comprehensive income		0	0	0.4
Amortization of prior service cost		0.4	0.5	0.5
Amortization of actuarial loss		8	7.5	7.1
Loss on lump-sum settlements		3.3	19.6	1.5
Special termination benefits		1.6	0	0
Subtotal		21.7	37	17
Regulatory adjustment		17.8	(2.1)	10.4
Net benefit cost		39.5	34.9	27.4
Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period		10.9	12.8	11.3
Interest cost on projected benefit obligation		10.2	11.2	8.9
Expected return on plan assets		(13.5)	(13.2)	(7.3)
Amortization of other comprehensive income		0	0	(0.2)
Amortization of prior service cost		0.3	0.8	0
Amortization of actuarial loss		3.6	5.1	6
Special termination benefits		2.6	0	0
Subtotal		14.1	16.7	18.7
Regulatory adjustment		(6.6)	(11)	(9.6)
Net benefit cost		7.5	5.7	9.1
Laclede Gas | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period		10	11.5	9.7
Interest cost on projected benefit obligation		21.7	23.3	24
Expected return on plan assets		(26.7)	(29.2)	(26.5)
Amortization of other comprehensive income		0	0	0
Amortization of prior service cost		0.4	0.5	0.5
Amortization of actuarial loss		7.9	7.5	7.1
Loss on lump-sum settlements		0	18	1.5
Special termination benefits		1.6	0	0
Subtotal		14.9	31.6	16.3
Regulatory adjustment		11.7	(5.2)	10.4
Net benefit cost		26.6	26.4	26.7
Laclede Gas | Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period		10.6	12.3	11.2
Interest cost on projected benefit obligation		8.1	8.6	8.7
Expected return on plan assets		(8.5)	(8.1)	(6.8)
Amortization of other comprehensive income		0	0	0
Amortization of prior service cost		0.3	0.8	0
Amortization of actuarial loss		3.8	5.1	6
Special termination benefits		2.6	0	0
Subtotal		16.9	18.7	19.1
Regulatory adjustment		(4.8)	(9.2)	(9.6)
Net benefit cost		12.1	9.5	$ 9.5
Alagasco | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period	$ 5.1	5.3	5.8
Interest cost on projected benefit obligation	4.1	6.3	6.2
Expected return on plan assets	(5.2)	(8.2)	(8.2)
Amortization of other comprehensive income	0	0	0
Amortization of prior service cost	0.1	0	0
Amortization of actuarial loss	2.2	0.1	0
Loss on lump-sum settlements	10.1	3.3	1.6
Special termination benefits	0	0	0
Subtotal	16.4	6.8	5.4
Regulatory adjustment	0.4	6.1	3.1
Net benefit cost	16.8	12.9	8.5
Alagasco | Postretirement Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost – benefits earned during the period	0.4	0.3	0.5
Interest cost on projected benefit obligation	1.9	2.1	2.6
Expected return on plan assets	(3.6)	(5)	(5.1)
Amortization of other comprehensive income	0	0	0
Amortization of prior service cost	0	0	0
Amortization of actuarial loss	(1)	(0.2)	0
Special termination benefits	0	0	0
Subtotal	(2.3)	(2.8)	(2)
Regulatory adjustment	(0.2)	(1.8)	(1.8)
Net benefit cost	$ (2.5)	$ (4.6)	$ (3.8)

PENSION PLANS AND OTHER POSTR86

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Changes in Plan Assets and Benefit Obligations (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amortization of actuarial loss		$ 0.3	$ (0.4)	$ (0.5)
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss		46.8	48.3	15.7
Amortization of actuarial loss		(8)	(7.5)	(7.1)
Acceleration of loss recognized due to settlement		(3.3)	(19.6)	(1.5)
Current year prior service credit		5	0	0
Amortization of prior service cost		(0.4)	(0.5)	(0.5)
Subtotal		40.1	20.7	6.6
Regulatory adjustment		(39.8)	(21.2)	(6.1)
Total recognized in OCI		0.3	(0.5)	0.5
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss		0.8	(8.5)	(3.1)
Amortization of actuarial loss		(3.6)	(5.1)	(6)
Current year prior service credit		(1.8)	(4.9)	0
Amortization of prior service cost		(0.3)	(0.8)	2.5
Subtotal		(4.9)	(19.3)	(6.6)
Regulatory adjustment		4.9	19.3	6.6
Total recognized in OCI		0	0	0
Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amortization of actuarial loss		0.3	(0.4)	(0.4)
Laclede Gas | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss		21.6	26	14.2
Amortization of actuarial loss		(7.9)	(7.5)	(7.1)
Acceleration of loss recognized due to settlement		0	(18)	(1.5)
Current year prior service credit		5	0	0
Amortization of prior service cost		(0.4)	(0.5)	(0.5)
Subtotal		18.3	0	5.1
Regulatory adjustment		(18)	(0.5)	(4.7)
Total recognized in OCI		0.3	(0.5)	0.4
Laclede Gas | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss		1.4	(2.4)	(4.2)
Amortization of actuarial loss		(3.8)	(5.1)	(6)
Current year prior service credit		0	(4.9)	0
Amortization of prior service cost		(0.3)	(0.8)	2.5
Subtotal		(2.7)	(13.2)	(7.7)
Regulatory adjustment		2.7	13.2	7.7
Total recognized in OCI		0	0	$ 0
Alagasco | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss	$ 1.5	25.2	22.3
Amortization of actuarial loss	0	(0.1)	0
Acceleration of loss recognized due to settlement	0	(3.3)	(1.6)
Current year prior service credit	0	0	0
Amortization of prior service cost	0	0	0
Subtotal	1.5	21.8	20.7
Regulatory adjustment	(1.5)	(21.8)	(20.7)
Total recognized in OCI	0	0	0
Alagasco | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current year actuarial loss	1.1	(0.6)	(6.1)
Amortization of actuarial loss	0	0.2	0
Current year prior service credit	0	(1.8)	0
Amortization of prior service cost	0	0	0
Subtotal	1.1	(2.2)	(6.1)
Regulatory adjustment	(1.1)	2.2	6.1
Total recognized in OCI	$ 0	$ 0	$ 0

PENSION PLANS AND OTHER POSTR87

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Benefit Obligation Rollforward (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		$ 652.3	$ 692.4
Service cost		15.3	17.3	$ 10.2
Interest cost		28	29.5	24.5
Actuarial loss (gain)		85.8	(12.8)
Plan amendments		5.1	0
EnergySouth acquisition		60.4	0
Settlement loss		1.1	16.5
Special termination benefits		1.6	0
Settlement benefits paid		(16.6)	(71.1)	(22.1)
Regular benefits paid		(38.3)	(19.5)
Benefit obligation, end of year	$ 692.4	794.7	652.3	692.4
Accumulated benefit obligation, end of year		724.5	591.4
Postretirement Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		239.2	258.5
Service cost		10.9	12.8	11.3
Interest cost		10.2	11.2	8.9
Actuarial loss (gain)		7.1	(23.7)
Plan amendments		(1.8)	(4.9)
EnergySouth acquisition		5.9	0
Special termination benefits		2.6	0
Retiree drug subsidy program		0.2	0.4
Regular benefits paid		(15.1)	(15.1)
Benefit obligation, end of year	258.5	259.2	239.2	258.5
Laclede Gas | Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		497.6	543.6
Service cost		10	11.5	9.7
Interest cost		21.7	23.3	24
Actuarial loss (gain)		59.2	(20.7)
Plan amendments		5.1	0
EnergySouth acquisition		0	0
Settlement loss		0	14.5
Special termination benefits		1.6
Settlement benefits paid		0	(58.2)
Regular benefits paid		(35.2)	(16.4)
Benefit obligation, end of year	543.6	560	497.6	543.6
Accumulated benefit obligation, end of year		517.7	456.9
Laclede Gas | Postretirement Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		191.9	197.9
Service cost		10.6	12.3	11.2
Interest cost		8.1	8.6	8.7
Actuarial loss (gain)		6.7	(10.9)
Plan amendments		0	(4.9)
EnergySouth acquisition		0	0
Special termination benefits		2.6	0
Retiree drug subsidy program		0	0
Regular benefits paid		(12)	(11.1)
Benefit obligation, end of year	197.9	207.9	191.9	197.9
Alagasco | Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		154.7	148.8
Service cost	5.1	5.3	5.8
Interest cost	4.1	6.3	6.2
Actuarial loss (gain)		26.6	7.9
Plan amendments		0	0
EnergySouth acquisition		0	0
Settlement loss		1.1	2
Special termination benefits			0
Settlement benefits paid		(16.6)	(12.9)
Regular benefits paid		(3.1)	(3.1)
Benefit obligation, end of year	148.8	174.3	154.7	148.8
Accumulated benefit obligation, end of year		149.8	134.5
Alagasco | Postretirement Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		47.3	60.6
Service cost	0.4	0.3	0.5
Interest cost	1.9	2.1	2.6
Actuarial loss (gain)		0.4	(12.8)
Plan amendments		(1.8)	0
EnergySouth acquisition		0	0
Special termination benefits		0	0
Retiree drug subsidy program		0.2	0.4
Regular benefits paid		(3.1)	(4)
Benefit obligation, end of year	$ 60.6	$ 45.4	$ 47.3	$ 60.6

PENSION PLANS AND OTHER POSTR88

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Fair Value of Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	$ 448.9	$ 506.6
Actual return on plan assets	75.1	(7.2)
Employer contributions	26.6	40.1
EnergySouth acquisition	44.8	0
Settlement benefits paid	(16.6)	(71.1)	$ (22.1)
Regular benefits paid	(38.3)	(19.5)
Fair value of plan assets, end of year	540.5	448.9	506.6
Funded status of plans, end of year	(254.2)	(203.4)
Postretirement Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	223.3	222.5
Actual return on plan assets	19.9	(2)
Employer contributions	14.3	17.9
EnergySouth acquisition	4	0
Regular benefits paid	(15.1)	(15.1)
Fair value of plan assets, end of year	246.4	223.3	222.5
Funded status of plans, end of year	(12.8)	(15.9)
Laclede Gas | Pension Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	339.9	387.4
Actual return on plan assets	64.4	(3)
Employer contributions	26.6	30.1
EnergySouth acquisition	0	0
Settlement benefits paid	0	(58.2)
Regular benefits paid	(35.2)	(16.4)
Fair value of plan assets, end of year	395.7	339.9	387.4
Funded status of plans, end of year	(164.3)	(157.7)
Laclede Gas | Postretirement Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	143.6	137.2
Actual return on plan assets	13.8	(0.4)
Employer contributions	14.3	17.9
EnergySouth acquisition	0	0
Regular benefits paid	(12)	(11.1)
Fair value of plan assets, end of year	159.7	143.6	137.2
Funded status of plans, end of year	(48.2)	(48.3)
Alagasco | Pension Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	109	119.2
Actual return on plan assets	10.7	(4.2)
Employer contributions	0	10
EnergySouth acquisition	0	0
Settlement benefits paid	(16.6)	(12.9)
Regular benefits paid	(3.1)	(3.1)
Fair value of plan assets, end of year	100	109	119.2
Funded status of plans, end of year	(74.3)	(45.7)
Alagasco | Postretirement Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	79.7	85.3
Actual return on plan assets	6.2	(1.6)
Employer contributions	0	0
EnergySouth acquisition	0	0
Regular benefits paid	(3.1)	(4)
Fair value of plan assets, end of year	82.8	79.7	$ 85.3
Funded status of plans, end of year	$ 37.4	$ 32.4

PENSION PLANS AND OTHER POSTR89

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent liabilities	$ (303.7)	$ (253.4)
Pension Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current liabilities	(0.6)	(0.5)
Noncurrent liabilities	(253.6)	(202.9)
Total	(254.2)	(203.4)
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	179.4	143.9
Prior service costs	8.2	3.5
Subtotal	187.6	147.4
Adjustments for amounts included in regulatory assets	(184.8)	(144.9)
Total	2.8	2.5
Postretirement Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current assets	0.3	0
Noncurrent assets	37.4	35.5
Current liabilities	(0.4)	(0.3)
Noncurrent liabilities	(50.1)	(51.1)
Total	(12.8)	(15.9)
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	38	40.8
Prior service costs	(5.2)	(3.1)
Subtotal	32.8	37.7
Adjustments for amounts included in regulatory assets	(32.8)	(37.7)
Total	0	0
Laclede Gas
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent liabilities	(211.8)	(207.8)
Laclede Gas | Pension Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current liabilities	(0.6)	(0.5)
Noncurrent liabilities	(163.7)	(157.2)
Total	(164.3)	(157.7)
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	135.5	121.9
Prior service costs	8.2	3.5
Subtotal	143.7	125.4
Adjustments for amounts included in regulatory assets	(140.9)	(122.9)
Total	2.8	2.5
Laclede Gas | Postretirement Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current assets	0.3	0
Noncurrent assets	0	3.1
Current liabilities	(0.4)	(0.3)
Noncurrent liabilities	(48.1)	(51.1)
Total	(48.2)	(48.3)
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	43.4	45.8
Prior service costs	(3.4)	(3.1)
Subtotal	40	42.7
Adjustments for amounts included in regulatory assets	(40)	(42.7)
Total	0	0
Alagasco
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent liabilities	(74.3)	(45.6)
Alagasco | Pension Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current liabilities	0	0
Noncurrent liabilities	(74.3)	(45.7)
Total	(74.3)	(45.7)
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	43.9	22
Prior service costs	0	0
Subtotal	43.9	22
Adjustments for amounts included in regulatory assets	(43.9)	(22)
Total	0	0
Alagasco | Postretirement Plans
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Current assets	0	0
Noncurrent assets	37.4	32.4
Current liabilities	0	0
Noncurrent liabilities	0	0
Total	37.4	32.4
Pre-tax amounts recognized in accumulated other comprehensive income not yet recognized as components of net periodic pension cost consist of:
Net actuarial loss	(5.4)	(5)
Prior service costs	(1.8)	0
Subtotal	(7.2)	(5)
Adjustments for amounts included in regulatory assets	7.2	5
Total	$ 0	$ 0

PENSION PLANS AND OTHER POSTR90

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Pre-tax Amortization from AOCI (Details) $ in Millions	12 Months Ended
	Sep. 30, 2016USD ($)
Pension Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	$ 13.5
Amortization of prior service cost	1
Subtotal	14.5
Regulatory adjustment	(14.2)
Total	0.3
Postretirement Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	2.4
Amortization of prior service cost	0.1
Subtotal	2.5
Regulatory adjustment	(2.5)
Total	0
Laclede Gas | Pension Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	11.6
Amortization of prior service cost	1
Subtotal	12.6
Regulatory adjustment	(12.3)
Total	0.3
Laclede Gas | Postretirement Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	2.5
Amortization of prior service cost	0.3
Subtotal	2.8
Regulatory adjustment	(2.8)
Total	0
Alagasco | Pension Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	1.9
Amortization of prior service cost	0
Subtotal	1.9
Regulatory adjustment	(1.9)
Total	0
Alagasco | Postretirement Plans
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract]
Amortization of net actuarial loss (gain)	(0.1)
Amortization of prior service cost	(0.2)
Subtotal	(0.3)
Regulatory adjustment	0.3
Total	$ 0

PENSION PLANS AND OTHER POSTR91

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Assumptions Used to Calculate Net Periodic Cost and Benefit Obligations (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Alagasco | Pension Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average rate of future compensation increase	2.92%	3.00%	2.92%
Expected long-term rate of return on plan assets		7.50%
Alagasco | Pension Plans | Minimum
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate	4.00%	4.25%	4.15%
Expected long-term rate of return on plan assets	7.00%		7.00%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.45%	4.25%
Alagasco | Pension Plans | Maximum
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate	4.05%	4.30%	4.25%
Expected long-term rate of return on plan assets	7.25%		7.25%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.50%	4.30%
Alagasco | Postretirement Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate		4.50%	4.40%	4.25%
Weighted average rate of future compensation increase				2.92%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.60%	4.50%
Alagasco | Postretirement Plans | Minimum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets	4.75%	4.50%	4.75%
Alagasco | Postretirement Plans | Maximum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets	7.25%	7.25%	7.50%
Laclede Gas | Pension Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate		4.40%	4.30%	4.70%
Weighted average rate of future compensation increase		3.00%	3.00%	3.00%
Expected long-term rate of return on plan assets		7.75%	7.75%	7.75%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.50%	4.40%
Laclede Gas | Postretirement Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate		4.00%	4.15%	4.60%
Weighted average rate of future compensation increase		3.00%	3.00%	3.00%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.15%	4.00%
Weighted average rate of future compensation increase		3.00%	3.00%
Laclede Gas | Postretirement Plans | Minimum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets		6.00%	6.25%	6.25%
Laclede Gas | Postretirement Plans | Maximum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets		7.75%	7.75%	7.75%
Missouri Gas Energy (MGE) | Pension Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate		4.50%	4.45%	5.00%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.50%	4.50%
Missouri Gas Energy (MGE) | Postretirement Plans
Assumptions used to calculate net periodic cost [Abstract]
Weighted average discount rate		4.30%	4.40%	4.95%
Expected long-term rate of return on plan assets		4.75%	5.00%
Assumptions used to calculate benefit obligations [Abstract]
Weighted average discount rate		3.45%	4.30%
Missouri Gas Energy (MGE) | Postretirement Plans | Minimum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets				3.75%
Missouri Gas Energy (MGE) | Postretirement Plans | Maximum
Assumptions used to calculate net periodic cost [Abstract]
Expected long-term rate of return on plan assets				5.75%
Laclede Gas, Alabama Gas Company, And Missouri Gas Energy | Pension Plans
Assumptions used to calculate benefit obligations [Abstract]
Weighted average rate of future compensation increase		3.00%	3.00%

PENSION PLANS AND OTHER POSTR92

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Projected Benefit Obligation (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 794.8	$ 652.3
Accumulated benefit obligation	724.5	591.4
Fair value of plan assets	540.5	448.9
Laclede Gas
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	560	497.6
Accumulated benefit obligation	517.7	456.9
Fair value of plan assets	395.7	339.9
Alagasco
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	174.3	154.7
Accumulated benefit obligation	149.8	134.5
Fair value of plan assets	$ 100	$ 109

PENSION PLANS AND OTHER POSTR93

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Targeted and Actual Plan Assets by Category (Details)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Alagasco | Pension Plans
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	100.00%	100.00%
Actual allocation of plan assets	100.00%	100.00%
Alagasco | Pension Plans | Equity markets
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	60.00%	60.00%
Actual allocation of plan assets	59.20%	52.90%
Alagasco | Pension Plans | Commodity Contract [Member]
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	29.00%	29.00%
Actual allocation of plan assets	28.80%	27.90%
Alagasco | Pension Plans | Real Estate [Member]
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	11.00%	11.00%
Actual allocation of plan assets	12.00%	19.20%
Alagasco | Postretirement Plans
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	100.00%
Actual allocation of plan assets	100.00%	100.00%
Alagasco | Postretirement Plans | Equity markets
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	60.00%
Actual allocation of plan assets	60.50%	59.70%
Alagasco | Postretirement Plans | Debt securities
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	40.00%
Actual allocation of plan assets	39.50%	40.30%
Laclede Gas | Pension Plans
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	100.00%	100.00%
Actual allocation of plan assets	100.00%	100.00%
Laclede Gas | Pension Plans | Equity markets
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	56.20%	52.00%
Actual allocation of plan assets	56.90%	48.40%
Laclede Gas | Pension Plans | Debt securities
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	43.80%	48.00%
Actual allocation of plan assets	43.10%	50.10%
Laclede Gas | Pension Plans | Other
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	0.00%	0.00%
Actual allocation of plan assets	0.00%	1.50%
Laclede Gas | Postretirement Plans
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	100.00%
Actual allocation of plan assets	100.00%	100.00%
Laclede Gas | Postretirement Plans | Equity markets
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	60.00%
Actual allocation of plan assets	59.10%	59.60%
Laclede Gas | Postretirement Plans | Debt securities
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	40.00%
Actual allocation of plan assets	39.40%	39.70%
Laclede Gas | Postretirement Plans | Other
Targeted and actual plan assets by category [Abstract]
Targeted allocation of plan assets	0.00%
Actual allocation of plan assets	1.50%	0.70%

PENSION PLANS AND OTHER POSTR94

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Expected Future Benefit Payments (Details) $ in Millions	Sep. 30, 2016USD ($)
Pension Plans
Expected benefit payments [Abstract]
2,017	$ 61.3
2,018	56.2
2,019	57.1
2,020	56.6
2,021	56.8
2022 - 2026	286.3
Postretirement Plans
Expected benefit payments [Abstract]
2,017	15.4
2,018	16.7
2,019	17.9
2,020	19.1
2,021	20.1
2022 - 2026	108.6
Laclede Gas | Pension Plans
Expected benefit payments [Abstract]
2,017	48.2
2,018	43.3
2,019	43.5
2,020	42.2
2,021	40.4
2022 - 2026	196.6
Laclede Gas | Postretirement Plans
Expected benefit payments [Abstract]
2,017	12.3
2,018	13.7
2,019	14.8
2,020	15.8
2,021	16.8
2022 - 2026	92.5
Alagasco | Pension Plans
Expected benefit payments [Abstract]
2,017	10.9
2,018	10.6
2,019	11.2
2,020	11.9
2,021	13.7
2022 - 2026	74.5
Alagasco | Postretirement Plans
Expected benefit payments [Abstract]
2,017	2.9
2,018	2.8
2,019	2.8
2,020	2.9
2,021	2.9
2022 - 2026	$ 14.1

PENSION PLANS AND OTHER POSTR95

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Assumed Medical Cost Trend Rates and Effect of 1% Changed (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate to which the medical cost trend rate is assumed to decline (the ultimate medical cost trend rate)	5.00%	5.00%
Year the rate reaches the ultimate trend	2,023	2,020
Assumed 1% change in the assumed medical cost trend rate [Abstract]
Effect of 1% increase on net periodic postretirement benefit cost	$ 1.5
Effect of 1% decrease on net periodic postretirement benefit cost	(1.4)
Effect of 1% increase on accumulated postretirement benefit obligation	11
Effect of 1% decrease on accumulated postretirement benefit obligation	$ (10.2)
Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Medical cost trend assumed for next year	7.50%	7.00%
Assumed 1% change in the assumed medical cost trend rate [Abstract]
Effect of 1% increase on net periodic postretirement benefit cost	$ 1.5
Effect of 1% decrease on net periodic postretirement benefit cost	(1.4)
Effect of 1% increase on accumulated postretirement benefit obligation	9
Effect of 1% decrease on accumulated postretirement benefit obligation	$ (8.4)
Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Medical cost trend assumed for next year	7.50%	7.00%
Assumed 1% change in the assumed medical cost trend rate [Abstract]
Effect of 1% increase on net periodic postretirement benefit cost	$ 0
Effect of 1% decrease on net periodic postretirement benefit cost	0
Effect of 1% increase on accumulated postretirement benefit obligation	1.3
Effect of 1% decrease on accumulated postretirement benefit obligation	$ (1.2)

PENSION PLANS AND OTHER POSTR96

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Fair Value Measurements of Plan Assets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	$ 540.5	$ 448.9	$ 506.6
Pension Plans | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	51.2	43.6
Pension Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	126.1	130.6
Pension Plans | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	149	9.3
Pension Plans | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	45.1	58.7
Pension Plans | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	137.4	166.6
Pension Plans | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	6.3	5.9
Pension Plans | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	25.3	31.3
Pension Plans | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1	2.9
Pension Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	383.6	272.2
Pension Plans | Quoted Prices in Active Markets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	51.2	43.4
Pension Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	99.3	46.4
Pension Plans | Quoted Prices in Active Markets (Level 1) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	23	0
Pension Plans | Quoted Prices in Active Markets (Level 1) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	42.1	58.7
Pension Plans | Quoted Prices in Active Markets (Level 1) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	137.4	123.7
Pension Plans | Quoted Prices in Active Markets (Level 1) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	6.3	0
Pension Plans | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	25.3	0
Pension Plans | Quoted Prices in Active Markets (Level 1) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	(1)	0
Pension Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	156.8	167.1
Pension Plans | Significant Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0.2
Pension Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	26.7	74.6
Pension Plans | Significant Observable Inputs (Level 2) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	126	9.3
Pension Plans | Significant Observable Inputs (Level 2) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	3	0
Pension Plans | Significant Observable Inputs (Level 2) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	42.9
Pension Plans | Significant Observable Inputs (Level 2) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	5.9
Pension Plans | Significant Observable Inputs (Level 2) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	31.3
Pension Plans | Significant Observable Inputs (Level 2) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	1.1	2.9
Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1	9.6
Pension Plans | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1	9.6
Pension Plans | Significant Unobservable Inputs (Level 3) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Pension Plans | Significant Unobservable Inputs (Level 3) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	246.4	223.3	222.5
Postretirement Plans | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	4.8	1.6
Postretirement Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	226.4	208.3
Postretirement Plans | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	15.2	13.4
Postretirement Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	163.6	117.1
Postretirement Plans | Quoted Prices in Active Markets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	4.8	1.6
Postretirement Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	157.9	115.5
Postretirement Plans | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.9	0
Postretirement Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	82.8	106.2
Postretirement Plans | Significant Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Postretirement Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	68.5	92.8
Postretirement Plans | Significant Observable Inputs (Level 2) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	14.3	13.4
Postretirement Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Postretirement Plans | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Postretirement Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Postretirement Plans | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	395.7	339.9	387.4
Laclede Gas | Pension Plans | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	46.5	31.8
Laclede Gas | Pension Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	14.9	67.7
Laclede Gas | Pension Plans | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	120.2
Laclede Gas | Pension Plans | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	45.1	37.7
Laclede Gas | Pension Plans | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	137.4	166.6
Laclede Gas | Pension Plans | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	6.3	5.9
Laclede Gas | Pension Plans | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	25.2	27.3
Laclede Gas | Pension Plans | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		2.9
Laclede Gas | Pension Plans | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	256.5	193.2
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	46.5	31.8
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	42.1	37.7
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	137.4	123.7
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	6.3	0
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	25.2	0
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Laclede Gas | Pension Plans | Quoted Prices in Active Markets (Level 1) | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	(1)
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	139.1	146.6
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	14.8	67.6
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	120.2
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	3	0
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	42.9
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	5.9
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	27.3
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		2.9
Laclede Gas | Pension Plans | Significant Observable Inputs (Level 2) | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	1.1
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1	0.1
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.1	0.1
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | US corporate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | US municipal
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Laclede Gas | Pension Plans | Significant Unobservable Inputs (Level 3) | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0
Laclede Gas | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	159.7	143.6	137.2
Laclede Gas | Postretirement Plans | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	4.6	1.6
Laclede Gas | Postretirement Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	155.1	142
Laclede Gas | Postretirement Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	159.7	117.1
Laclede Gas | Postretirement Plans | Quoted Prices in Active Markets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	4.6	1.6
Laclede Gas | Postretirement Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	155.1	115.5
Laclede Gas | Postretirement Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	26.5
Laclede Gas | Postretirement Plans | Significant Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Postretirement Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	26.5
Laclede Gas | Postretirement Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Postretirement Plans | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Laclede Gas | Postretirement Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	100	109	119.2
Alagasco | Pension Plans | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.4	11.8
Alagasco | Pension Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	70.9	62.9
Alagasco | Pension Plans | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	28.7	9.3
Alagasco | Pension Plans | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		21
Alagasco | Pension Plans | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		4
Alagasco | Pension Plans | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	82.4	58
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0.4	11.6
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	59	46.4
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	23	0
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Quoted Prices in Active Markets (Level 1) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	17.6	41.5
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0.2
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	11.9	7
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	5.7	9.3
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		21
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		4
Alagasco | Pension Plans | Significant Observable Inputs (Level 2) | Derivative instruments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	9.5
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	9.5
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3) | US bond mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3) | US government
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Pension Plans | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets		0
Alagasco | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	82.8	79.7	$ 85.3
Alagasco | Postretirement Plans | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	68.5	66.3
Alagasco | Postretirement Plans | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	14.3	13.4
Alagasco | Postretirement Plans | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Postretirement Plans | Quoted Prices in Active Markets (Level 1) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Postretirement Plans | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Postretirement Plans | Significant Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	82.8	79.7
Alagasco | Postretirement Plans | Significant Observable Inputs (Level 2) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	68.5	66.3
Alagasco | Postretirement Plans | Significant Observable Inputs (Level 2) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	14.3	13.4
Alagasco | Postretirement Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Postretirement Plans | Significant Unobservable Inputs (Level 3) | Stock/bond mutual fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	0	0
Alagasco | Postretirement Plans | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value measurements of plan assets	$ 0	$ 0

INFORMATION BY OPERATING SEGM97

INFORMATION BY OPERATING SEGMENT - Schedule of Operating Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2016USD ($)operating_segment	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of operating segments | operating_segment									2
Operating Segment Information [Abstract]
Total Operating Revenues	$ 279.3	$ 249.3	$ 609.3	$ 399.4	$ 204.2	$ 275.2	$ 877.4	$ 619.6	$ 1,537.3	$ 1,976.4	$ 1,627.2
Gas Utility
Natural and propane gas									492.2	882.4	731.7
Other operation and maintenance expenses									377.5	390.6	287.8
Depreciation and amortization									136.9	129.9	82.4
Taxes, other than income taxes									125.2	142.1	112
Total Gas Utility Operating Expenses									1,131.8	1,545	1,213.9
Gas Marketing and other									123.2	158.9	246.9
Total Operating Expenses									1,255	1,703.9	1,460.8
Operating Income	(7.7)	$ 35.3	$ 167.7	$ 87	(8.5)	$ 36	$ 157.7	$ 87.3	282.3	272.5	166.4
Net Economic Earnings									149.1	138.3	100.1
Capital Expenditures									293.3	289.8	171
ASSETS
Total Assets	6,077.4				5,290.2				6,077.4	5,290.2	5,074
Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues									(5.4)	(76.5)	(91)
Gas Utility
Natural and propane gas									(47.5)	(75.2)	(90.1)
Other operation and maintenance expenses									(1.8)	(1)	(0.9)
Depreciation and amortization									0	0	0
Taxes, other than income taxes									0	0	0
Total Gas Utility Operating Expenses									(49.3)	(76.2)	(91)
Gas Marketing and other									43.9	(0.3)	0
Total Operating Expenses									(5.4)	(76.5)	(91)
Operating Income									0	0	0
Net Economic Earnings									0	0	0
Capital Expenditures									0	0	0
ASSETS
Total Assets	(1,161.9)				(1,116.8)				(1,161.9)	(1,116.8)	(1,178.4)
Other
Operating Segment Information [Abstract]
Total Operating Revenues									1.6	1.7	2
Gas Utility
Depreciation and amortization expense									0.5	0.6	0.5
ASSETS
Total Assets	1,842.4				1,560.2				1,842.4	1,560.2	1,575.7
Corporate Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues									3.2	2	1.8
Corporate And Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues									4.8	3.7	3.8
Gas Utility
Natural and propane gas									0	0	0
Other operation and maintenance expenses									0	0	0
Depreciation and amortization									0	0	0
Taxes, other than income taxes									0	0	0
Total Gas Utility Operating Expenses									0	0	0
Gas Marketing and other									12.6	12.6	20.5
Total Operating Expenses									12.6	12.6	20.5
Operating Income									(7.8)	(8.9)	(16.7)
Net Economic Earnings									(17.6)	(16.3)	(2.9)
Capital Expenditures									1.6	5.4	2.4
Gas Utility
Operating Segment Information [Abstract]
Total Operating Revenues									1,457.2	1,891.8	1,462.6
Gas Utility | Operating Segments
Operating Segment Information [Abstract]
Total Operating Revenues									1,459.4	1,895.8	1,467.8
Gas Utility
Natural and propane gas									539.7	957.6	821.8
Other operation and maintenance expenses									379.3	391.6	288.7
Depreciation and amortization									136.9	129.9	82.4
Taxes, other than income taxes									125.2	142.1	112
Total Gas Utility Operating Expenses									1,181.1	1,621.2	1,304.9
Gas Marketing and other									0	0	0
Total Operating Expenses									1,181.1	1,621.2	1,304.9
Operating Income									278.3	274.6	162.9
Net Economic Earnings									160.3	150.4	92.8
Capital Expenditures									291.7	284.4	168.6
ASSETS
Total Assets	5,191.9				4,686.2				5,191.9	4,686.2	4,520
Gas Utility | Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues									2.2	4	5.2
Gas Marketing
Operating Segment Information [Abstract]
Total Operating Revenues									78.5	82.9	162.6
Gas Marketing | Operating Segments
Operating Segment Information [Abstract]
Total Operating Revenues									78.5	153.4	246.6
Gas Utility
Natural and propane gas									0	0	0
Other operation and maintenance expenses									0	0	0
Depreciation and amortization									0	0	0
Taxes, other than income taxes									0	0	0
Total Gas Utility Operating Expenses									0	0	0
Gas Marketing and other									66.7	146.6	226.4
Total Operating Expenses									66.7	146.6	226.4
Operating Income									11.8	6.8	20.2
Net Economic Earnings									6.4	4.2	10.2
Capital Expenditures									0	0	0
Depreciation and amortization expense									0.1	0.3	0.4
ASSETS
Total Assets	$ 205				$ 160.6				205	160.6	156.7
Gas Marketing | Eliminations
Operating Segment Information [Abstract]
Total Operating Revenues									$ 0	$ 70.5	$ 84

INFORMATION BY OPERATING SEGM98

INFORMATION BY OPERATING SEGMENT - Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting [Abstract]
Net Income	$ (14.2)	$ 10.7	$ 100.8	$ 46.9	$ (18.7)	$ 14.1	$ 94.4	$ 47.1	$ 144.2	$ 136.9	$ 84.6
Unrealized gain on energy-related derivatives									(0.1)	(2.8)	(1.6)
Lower of cost or market inventory adjustments									0.2	0.4	(1.1)
Realized (gain) loss on economic hedges prior to the sale of the physical commodity									(1.6)	2.4	(0.4)
Acquisition, divestiture and restructuring activities									9.2	9.8	29.5
Gain on sale of property									0	(7.6)	0
Income tax effect of adjustments									(2.8)	(0.8)	(10.9)
Net Economic Earnings									$ 149.1	$ 138.3	$ 100.1

REGULATORY MATTERS - Schedule

REGULATORY MATTERS - Schedule of Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Regulatory Assets [Line Items]
Regulatory assets, current	$ 93.9	$ 40.5
Regulatory assets, non current	838	737.6
Total Regulatory Assets	931.9	778.1
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	30.6	60.6
Regulatory liabilities, noncurrent	130.7	119.3
Total Regulatory Liabilities	161.3	179.9
RSE adjustment
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	7.5	12.2
Unbilled service margin
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	5.9	6.4
Pension and postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	9.3	10.8
Regulatory liabilities, noncurrent	9.4	16.2
Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	1.7	28.2
Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	28.9	28.9
Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	74.8	58.7
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	6.2	3
Regulatory liabilities, noncurrent	17.6	15.5
Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets, current	27	22
Regulatory assets, non current	487.9	448.7
Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory assets, current	49.7	12.9
Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory assets, non current	151.3	134.5
Accrued cost of removal
Regulatory Assets [Line Items]
Regulatory assets, non current	130.6	78.9
Purchased gas costs
Regulatory Assets [Line Items]
Regulatory assets, non current	12.6	24.1
Energy efficiency
Regulatory Assets [Line Items]
Regulatory assets, non current	25.5	22.3
Other
Regulatory Assets [Line Items]
Regulatory assets, current	17.2	5.6
Regulatory assets, non current	30.1	29.1
Laclede Gas
Regulatory Assets [Line Items]
Regulatory assets, current	67	29.1
Regulatory assets, non current	589.8	573.6
Total Regulatory Assets	656.8	602.7
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	1.3	0.6
Regulatory liabilities, noncurrent	67.3	70.6
Total Regulatory Liabilities	68.6	71.2
Laclede Gas | RSE adjustment
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	0	0
Laclede Gas | Unbilled service margin
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	0	0
Laclede Gas | Pension and postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	0	0
Regulatory liabilities, noncurrent	0	0
Laclede Gas | Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	0	0
Laclede Gas | Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	0	0
Laclede Gas | Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	55.1	58.7
Laclede Gas | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	1.3	0.6
Regulatory liabilities, noncurrent	12.2	11.9
Laclede Gas | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets, current	20.2	15.5
Regulatory assets, non current	375.7	368
Laclede Gas | Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory assets, current	43.1	12.9
Laclede Gas | Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory assets, non current	151.3	134.5
Laclede Gas | Accrued cost of removal
Regulatory Assets [Line Items]
Regulatory assets, non current	0	0
Laclede Gas | Purchased gas costs
Regulatory Assets [Line Items]
Regulatory assets, non current	12.6	24.1
Laclede Gas | Energy efficiency
Regulatory Assets [Line Items]
Regulatory assets, non current	25.5	22.3
Laclede Gas | Other
Regulatory Assets [Line Items]
Regulatory assets, current	3.7	0.7
Regulatory assets, non current	24.7	24.7
Alagasco
Regulatory Assets [Line Items]
Regulatory assets, current	20.5	11.4
Regulatory assets, non current	230.7	163.6
Total Regulatory Assets	251.2	175
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	22.7	60
Regulatory liabilities, noncurrent	41.7	48.7
Total Regulatory Liabilities	64.4	108.7
Alagasco | RSE adjustment
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	5	12.2
Alagasco | Unbilled service margin
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	5.9	6.4
Alagasco | Pension and postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	9.3	10.8
Regulatory liabilities, noncurrent	9.4	16.2
Alagasco | Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	0	28.2
Alagasco | Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	28.9	28.9
Alagasco | Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent	0	0
Alagasco | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities, current	2.5	2.4
Regulatory liabilities, noncurrent	3.4	3.6
Alagasco | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets, current	6.8	6.5
Regulatory assets, non current	98.9	80.7
Alagasco | Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory assets, current	5.6	0
Alagasco | Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory assets, non current	0	0
Alagasco | Accrued cost of removal
Regulatory Assets [Line Items]
Regulatory assets, non current	130.6	78.9
Alagasco | Purchased gas costs
Regulatory Assets [Line Items]
Regulatory assets, non current	0	0
Alagasco | Energy efficiency
Regulatory Assets [Line Items]
Regulatory assets, non current	0	0
Alagasco | Other
Regulatory Assets [Line Items]
Regulatory assets, current	8.1	4.9
Regulatory assets, non current	$ 1.2	$ 4

REGULATORY MATTERS - Schedule o

REGULATORY MATTERS - Schedule of Regulatory Assets Not Earnings a Return (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 404.8	$ 372.4
Future income taxes due from customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	151.3	134.5
Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	240.6	223.7
Compensated absences
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	0	0
Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	12.9	14.2
Laclede Gas
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	404.8	372.4
Laclede Gas | Future income taxes due from customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	151.3	134.5
Laclede Gas | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	240.6	223.7
Laclede Gas | Compensated absences
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	0	0
Laclede Gas | Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$ 12.9	$ 14.2

REGULATORY MATTERS - Narrative

REGULATORY MATTERS - Narrative (Details) - USD ($)

Oct. 01, 2017

Dec. 01, 2016

Oct. 26, 2016

Sep. 30, 2016

Jul. 31, 2016

May 31, 2016

May 19, 2016

Apr. 30, 2016

Jan. 31, 2016

Dec. 01, 2015

Nov. 12, 2015

Jan. 01, 2014

Sep. 30, 2016

Sep. 30, 2015

Nov. 11, 2016

Apr. 15, 2016

Feb. 10, 2016

Jun. 30, 2015

Public Utilities, General Disclosures [Line Items]

Regulatory assets for which no return on investment during recovery period is provided

$ 404,800,000

$ 404,800,000

$ 372,400,000

Remaining recovery period for regulatory assets for which no return on investment during recovery period is provided

15 years

Laclede Gas

Public Utilities, General Disclosures [Line Items]

Regulatory assets for which no return on investment during recovery period is provided

404,800,000

$ 404,800,000

372,400,000

Regulatory preferred stock and debt securities issuance, amount authorized

300,000,000

$ 300,000,000

$ 300,000,000

$ 518,000,000

Regulatory preferred stock and debt securities issuance, amount requested

$ 550,000,000

Alagasco

Public Utilities, General Disclosures [Line Items]

Potential performance-based adjustment

0.05%

APSC | Alagasco

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease) amount

$ (2,700,000)

$ (4,800,000)

$ (5,800,000)

$ 0

$ 7,800,000

$ 4,700,000

Approved return rate on equity

10.80%

Maximum return on equity, percentage of prior year revenues

4.00%

Rate increase (decrease), margin of index range

1.75%

1.75%

Infrastructure System Replacement Surcharge | MoPSC | Laclede Gas

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease) amount

$ 25,000,000

$ 5,400,000

$ 4,400,000

Approved rate increase, annualized revenue

$ 19,600,000

Requested rate increase

$ 5,000,000

Infrastructure System Replacement Surcharge | MoPSC | Missouri Gas Energy (MGE)

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease) amount

$ 10,300,000

$ 3,600,000

$ 1,900,000

Approved rate increase, annualized revenue

$ 6,700,000

Requested rate increase

$ 3,400,000

Subsequent Event | Laclede Gas

Public Utilities, General Disclosures [Line Items]

Regulatory preferred stock and debt securities issuance, authorized debt issuance - remaining available

$ 300,000,000

Subsequent Event | APSC | Alagasco

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease) amount

$ (4,800,000)

$ (1,300,000)

Minimum | APSC | Alagasco

Public Utilities, General Disclosures [Line Items]

Approved return rate on equity

10.50%

Maximum | APSC | Alagasco

Public Utilities, General Disclosures [Line Items]

Approved return rate on equity

10.95%

Scenario, Forecast | APSC | Alagasco

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease) amount

$ (2,700,000)

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Commitments (Details) MMcf in Thousands, $ in Millions	12 Months Ended
	Sep. 30, 2016USD ($)MMcf
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 1,647.8
Laclede Gas
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	1,227.6
Laclede Gas | Purchase Commitment | Subsidiary of Common Parent
Long-term Purchase Commitment [Line Items]
Annual purchase commitment	$ 1
Commitment termination minimum required notification period	6 months
Alagasco
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 352.7
Alagasco | Inventories
Long-term Purchase Commitment [Line Items]
Minimum volume purchase commitment required (in Mmcf) | MMcf	93

COMMITMENTS AND CONTINGENCIE103

COMMITMENTS AND CONTINGENCIES - Leases and Guarantees (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Loss Contingencies [Line Items]
Aggregate rental expense	$ 11.9	$ 14.1	$ 6.7
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Minimum rental commitments - in fiscal year 2017	10.5
Minimum rental commitments - due in fiscal year 2018	7.5
Minimum rental commitments - due in fiscal year 2019	7.3
Minimum rental commitments - due in fiscal year 2020	6.2
Minimum rental commitments - due in fiscal year 2021	6
Minimum rental commitments - due later	53.4
Minimum rental commitments - total	90.9
Sublease rentals	2.1	2.1	0.2
Minimum future sublease rentals to be received - fiscal year 2017	2.1
Minimum future sublease rentals to be received - fiscal year 2018	2.1
Minimum future sublease rentals to be received - fiscal year 2019	2.1
Minimum future sublease rentals to be received - fiscal year 2020	0.5
Outstanding mortgage loans incurred in connection with various real estate ventures with general partners	1.4
Laclede Gas
Loss Contingencies [Line Items]
Aggregate rental expense	4.3	7.6	6.3
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Minimum rental commitments - in fiscal year 2017	2.5
Minimum rental commitments - due in fiscal year 2018	0.9
Minimum rental commitments - due in fiscal year 2019	0.9
Minimum rental commitments - due in fiscal year 2020	0.3
Minimum rental commitments - due in fiscal year 2021	0.1
Minimum rental commitments - due later	0
Minimum rental commitments - total	4.7
Alagasco
Loss Contingencies [Line Items]
Aggregate rental expense	3.7	4	2
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Minimum rental commitments - in fiscal year 2017	3.9
Minimum rental commitments - due in fiscal year 2018	2.5
Minimum rental commitments - due in fiscal year 2019	2.5
Minimum rental commitments - due in fiscal year 2020	2.1
Minimum rental commitments - due in fiscal year 2021	2.1
Minimum rental commitments - due later	4.9
Minimum rental commitments - total	18
Sublease rentals	2.1	$ 2.1	$ 0.2
Minimum future sublease rentals to be received - fiscal year 2017	2.1
Minimum future sublease rentals to be received - fiscal year 2018	2.1
Minimum future sublease rentals to be received - fiscal year 2019	2.1
Minimum future sublease rentals to be received - fiscal year 2020	$ 0.5

COMMITMENTS AND CONTINGENCIE104

COMMITMENTS AND CONTINGENCIES - Contingencies (Details)	Dec. 17, 2013fatality	Sep. 30, 2016plaintiffsitelawsuit	Sep. 30, 2016sitelawsuit	Sep. 30, 2014site
Site Contingency [Line Items]
Number of incident fatalities | fatality	1
Laclede Gas
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP) sites in Missouri		3	3
Number of former manufactured gas plant (MGP) sites in Shrewsbury, Missouri		1	1
Number of former manufactured gas plant (MGP) sites in the City of St. Louis		2	2
Laclede Gas | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)				19
Missouri Gas Energy (MGE) | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		7	7
Alagasco
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		9	9
Number of former manufactured gas distribution		5	5
Alagasco | Current Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)		4	4
Number of former manufactured gas distribution		1	1
Mobile Gas
Site Contingency [Line Items]
Number of lawsuits | lawsuit			14
Number of lawsuits settled | lawsuit			11
Number of lawsuits pending | lawsuit		3	3
Mobile Gas | Pending Litigation
Site Contingency [Line Items]
Number of plaintiffs | plaintiff		270
Mobile Gas | Previous Ownership
Site Contingency [Line Items]
Number of former manufactured gas plant (MGP)				1

INTERIM FINANCIAL INFORMATIO105

INTERIM FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								9 Months Ended	12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Quarterly Financial Information [Line Items]
Total Operating Revenues	$ 279.3	$ 249.3	$ 609.3	$ 399.4	$ 204.2	$ 275.2	$ 877.4	$ 619.6		$ 1,537.3	$ 1,976.4	$ 1,627.2
Operating Income (Loss)	(7.7)	35.3	167.7	87	(8.5)	36	157.7	87.3		282.3	272.5	166.4
Net Income (Loss)	$ (14.2)	$ 10.7	$ 100.8	$ 46.9	$ (18.7)	$ 14.1	$ 94.4	$ 47.1		$ 144.2	$ 136.9	$ 84.6
Basic Earnings Per Share of Common Stock (in dollars per share)	$ (0.31)	$ 0.24	$ 2.32	$ 1.08	$ (0.43)	$ 0.32	$ 2.18	$ 1.09		$ 3.26	$ 3.16	$ 2.36
Diluted Earnings Per Share of Common Stock (in dollars per share)	$ (0.31)	$ 0.24	$ 2.31	$ 1.08	$ (0.43)	$ 0.32	$ 2.18	$ 1.09		$ 3.24	$ 3.16	$ 2.35
Laclede Gas
Quarterly Financial Information [Line Items]
Total Operating Revenues	$ 144.3	$ 179.3	$ 446.7	$ 317.2	$ 151	$ 187.5	$ 615.7	$ 462.4		$ 1,087.5	$ 1,416.6	$ 1,448.2
Operating Income (Loss)	5.4	29.4	87	65.1	5.5	34.5	80.6	64.8		186.9	185.4	166.4
Net Income (Loss)	(1.7)	13.9	54.3	39.4	(3.6)	20	49.9	39		105.9	105.3	$ 90.1
Alagasco
Quarterly Financial Information [Line Items]
Total Operating Revenues	46.2	74	166	82.3	52.2	73.7	233.3	120	$ 417.2	368.5	479.2
Operating Income (Loss)	(17.1)	9.3	80.4	18.9	(12.5)	3.9	77.4	20.4	62.2	91.5	89.2
Net Income (Loss)	$ (8.8)	$ 4	$ 48.1	$ 9.9	$ (9.6)	$ 0.7	$ 46.3	$ 10.6	$ 33	$ 53.2	$ 48