Spire Missouri 10-Q 6 May 15 2015 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	LACLEDE GROUP INC
Entity Central Index Key	1126956
Current Fiscal Year End Date	-21
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		43,318,933
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Laclede Gas
Entity Information [Line Items]
Entity Registrant Name	LACLEDE GAS CO
Entity Central Index Key	57183
Current Fiscal Year End Date	-21
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		24,577
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Alagasco
Entity Information [Line Items]
Entity Registrant Name	ALABAMA GAS CORP
Entity Central Index Key	3146
Current Fiscal Year End Date	-21
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		1,972,052
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Operating Revenues:
Gas utility	$847	$634.40	$1,428.40	$1,069.60
Gas marketing and other	30.4	60.1	68.6	93.5
Total Operating Revenues	877.4	694.5	1,497	1,163.10
Gas utility
Natural and propane gas	482.8	405.3	787.1	647.1
Other operation and maintenance expenses	103.8	72	200.9	134.3
Depreciation and amortization	32.2	20.1	64.2	40.1
Taxes, other than income taxes	55.7	41.8	93.7	70.4
Total Gas Utility Operating Expenses	674.5	539.2	1,145.90	891.9
Gas marketing and other	45.2	68.1	106.1	121.1
Total Operating Expenses	719.7	607.3	1,252	1,013
Operating Income	157.7	87.2	245	150.1
Other Income – Net	0.7	-0.3	2.1	1.4
Interest Charges:
Interest on long-term debt	16.5	8.6	33.7	18.3
Other interest charges	2.6	0.7	4.6	1.5
Total Interest Charges	19.1	9.3	38.3	19.8
Income Before Income Taxes	139.3	77.6	208.8	131.7
Income Tax Expense	44.9	25.4	67.3	43.9
Net Income	94.4	52.2	141.5	87.8
Weighted Average Number of Common Shares Outstanding:
Basic (in shares)	43.1	32.6	43.1	32.6
Diluted (in shares)	43.2	32.6	43.2	32.7
Basic Earnings Per Share of Common Stock (in dollars per share)	$2.18	$1.59	$3.27	$2.68
Diluted Earnings Per Share of Common Stock (in dollars per share)	$2.18	$1.59	$3.26	$2.68
Dividends Declared, Common stock (in dollars per share)	$0.46	$0.44	$0.92	$0.88
Laclede Gas
Operating Revenues:
Gas utility	615.7	638.7	1,078.10	1,073.90
Other	0	0.1	0	0.1
Total Operating Revenues	615.7	638.8	1,078.10	1,074
Gas utility
Natural and propane gas	402.7	430.5	686.1	692.1
Other operation and maintenance expenses	69.6	72.2	134.4	134.7
Depreciation and amortization	20.5	20.1	40.7	40.1
Taxes, other than income taxes	42.3	41.8	71.5	70.4
Total Gas Utility Operating Expenses	535.1	564.6	932.7	937.3
Gas marketing and other	0	-0.3	0	-0.1
Total Operating Expenses	535.1	564.3	932.7	937.2
Operating Income	80.6	74.5	145.4	136.8
Other Income – Net	0.4	-0.7	1.3	1
Interest Charges:
Interest on long-term debt	8.3	8.4	16.6	17.9
Other interest charges	1.2	0.7	2.2	1.5
Total Interest Charges	9.5	9.1	18.8	19.4
Income Before Income Taxes	71.5	64.7	127.9	118.4
Income Tax Expense	21.6	20.5	39	38.9
Net Income	49.9	44.2	88.9	79.5
Alagasco
Operating Revenues:
Gas utility	233.3	263.9	353.3	406.7
Total Operating Revenues	233.3	263.9	353.3	406.7
Gas utility
Natural and propane gas	96.4	128.1	142.8	180.1
Other operation and maintenance expenses	34.4	36.2	67	71.7
Depreciation and amortization	11.7	11.4	23.5	22.6
Taxes, other than income taxes	13.4	15.8	22.2	25.1
Total Operating Expenses	155.9	191.5	255.5	299.5
Operating Income	77.4	72.4	97.8	107.2
Other Income – Net	0.6	1.2	1	1.9
Interest Charges:
Interest on long-term debt	2.8	3.4	6	6.8
Other interest charges	0.7	0.6	1.3	1.1
Total Interest Charges	3.5	4	7.3	7.9
Income Before Income Taxes	74.5	69.6	91.5	101.2
Income Tax Expense	28.2	26.5	34.6	38.3
Net Income	$46.30	$43.10	$56.90	$62.90

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Net Income	$94.40	$52.20	$141.50	$87.80
Net gains (losses) on cash flow hedging derivative instruments:
Net hedging gains (losses) arising during the period	-0.6	-3.5	-6.5	-5.1
Reclassification adjustment for losses (gains) included in net income	2.3	3.2	2.2	2
Net unrealized gains (losses) on cash flow hedging derivative instruments	1.7	-0.3	-4.3	-3.1
Defined benefit pension and other postretirement plans:
Amortization of actuarial loss included in net periodic pension and postretirement benefit cost	0.1	0.1	0.2	0.2
Other Comprehensive Income (Loss), Before Tax	1.8	-0.2	-4.1	-2.9
Income Tax Expense (Benefit) Related to Items of Other Comprehensive Income	0.6	-0.1	-1.6	-1.1
Other Comprehensive Income (Loss), Net of Tax	1.2	-0.1	-2.5	-1.8
Comprehensive Income	95.6	52.1	139	86
Laclede Gas
Net Income	49.9	44.2	88.9	79.5
Net gains (losses) on cash flow hedging derivative instruments:
Net hedging gains (losses) arising during the period	0.1	0.1	-1.3	0.1
Reclassification adjustment for losses (gains) included in net income	0.3	0	0.4	-0.1
Net unrealized gains (losses) on cash flow hedging derivative instruments	0.4	0.1	-0.9	0
Defined benefit pension and other postretirement plans:
Amortization of actuarial loss included in net periodic pension and postretirement benefit cost	0	0.1	0.1	0.2
Other Comprehensive Income (Loss), Before Tax	0.4	0.2	-0.8	0.2
Income Tax Expense (Benefit) Related to Items of Other Comprehensive Income	0.1	0.1	-0.3	0.1
Other Comprehensive Income (Loss), Net of Tax	0.3	0.1	-0.5	0.1
Comprehensive Income	$50.20	$44.30	$88.40	$79.60

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $)	Mar. 31, 2015	Sep. 30, 2014
In Millions, unless otherwise specified
ASSETS
Utility Plant	$4,037.80	$3,928.30
Less: Accumulated depreciation and amortization	1,213.10	1,168.60
Net Utility Plant	2,824.70	2,759.70
Non-utility Property (net of accumulated depreciation and amortization, $7.2 and $6.7 at March 31, 2015 and September 30, 2014, respectively)	10.5	9.2
Goodwill	946	937.8
Other Property and Investments	60.8	60
Total Other Property and Investments	1,017.30	1,007
Current Assets:
Cash and cash equivalents	46.9	16.1
Accounts receivable:
Utility	303.8	148.2
Other	70.1	86.5
Allowance for doubtful accounts	-18.6	-15.9
Delayed customer billings	61.7	10.8
Inventories:
Natural gas	90.8	245.5
Propane gas	11.9	11.7
Materials and supplies	14.3	13
Natural gas receivable	5.9	7.3
Derivative instrument assets	3	2.4
Unamortized purchased gas adjustments	0	54
Regulatory assets	27.4	26.8
Prepayments and other	20	21.6
Total Current Assets	637.2	628
Deferred Charges:
Regulatory assets	632.9	614.3
Other	68.6	65
Total Deferred Charges	701.5	679.3
Total Assets	5,180.70	5,074
Capitalization:
Common stock	43.3	43.2
Paid-in capital	1,033.30	1,029.40
Retained earnings	539.2	437.5
Accumulated other comprehensive loss	-4.2	-1.7
Total Common Stock Equity	1,611.60	1,508.40
Long-term debt (less current portion)	1,736.30	1,851
Total Capitalization	3,347.90	3,359.40
Current Liabilities:
Current portion of long-term debt	80	0
Notes payable	247.6	287.1
Accounts payable	160.1	176.7
Advance customer billings	8.4	32.2
Wages and compensation accrued	30.9	36
Dividends payable	20.5	19.9
Customer deposits	36.2	34
Interest accrued	14.9	15.1
Unamortized purchased gas adjustments	76.7	22.4
Taxes accrued	85.2	63.4
Deferred income taxes	0	9.9
Regulatory liabilities	38.5	41.3
Other	54.7	47.8
Total Current Liabilities	853.7	785.8
Deferred Credits and Other Liabilities:
Deferred income taxes	438.7	383.8
Pension and postretirement benefit costs	243.9	244.9
Asset retirement obligations	101.5	99.2
Regulatory liabilities	114.3	125.8
Other	80.7	75.1
Total Deferred Credits and Other Liabilities	979.1	928.8
Commitments and Contingencies
Total Capitalization and Liabilities	5,180.70	5,074
Laclede Gas
ASSETS
Utility Plant	2,479.80	2,403.30
Less: Accumulated depreciation and amortization	566.2	542.3
Net Utility Plant	1,913.60	1,861
Goodwill	210.2	210.2
Other Property and Investments	56.5	55.7
Total Other Property and Investments	266.7	265.9
Current Assets:
Cash and cash equivalents	9.3	3.7
Accounts receivable:
Utility	224.1	111.1
Other	19.4	19.2
Allowance for doubtful accounts	-14	-10.7
Delayed customer billings	61.7	10.8
Receivables from associated companies	2.3	11.4
Inventories:
Natural gas	60.8	191.1
Propane gas	12	11.7
Materials and supplies	9.2	7.8
Unamortized purchased gas adjustments	0	54
Regulatory assets	17.4	18
Prepayments and other	16.2	15.5
Total Current Assets	418.4	443.6
Deferred Charges:
Regulatory assets	545.3	523.7
Other	11.9	10.8
Total Deferred Charges	557.2	534.5
Total Assets	3,155.90	3,105
Capitalization:
Common stock and Paid-in capital	746.3	744.1
Retained earnings	314.7	265.6
Accumulated other comprehensive loss	-2.4	-1.9
Total Common Stock Equity	1,058.60	1,007.80
Long-term debt (less current portion)	808	807.9
Total Capitalization	1,866.60	1,815.70
Current Liabilities:
Notes payable	142.6	238.6
Notes payable – associated companies	10.4	0
Accounts payable	77.3	70.1
Accounts payable – associated companies	5.7	6
Advance customer billings	0	15.5
Wages and compensation accrued	26.9	30.3
Dividends payable	19.9	19
Customer deposits	15.2	14.8
Interest accrued	8.1	8.1
Unamortized purchased gas adjustments	39.1	0
Taxes accrued	79.2	43.9
Other	36.3	41.9
Total Current Liabilities	460.7	488.2
Deferred Credits and Other Liabilities:
Deferred income taxes	424.3	399.8
Pension and postretirement benefit costs	212.4	215.3
Asset retirement obligations	72.9	71.2
Regulatory liabilities	71.7	72.1
Other	47.3	42.7
Total Deferred Credits and Other Liabilities	828.6	801.1
Commitments and Contingencies
Total Capitalization and Liabilities	3,155.90	3,105
Alagasco
ASSETS
Utility Plant	1,558	1,525.10
Less: Accumulated depreciation and amortization	646.9	626.4
Net Utility Plant	911.1	898.7
Current Assets:
Cash and cash equivalents	35.4	5.6
Accounts receivable:
Utility	79.6	39
Other	5.2	5.1
Allowance for doubtful accounts	-4.6	-5.1
Inventories:
Natural gas	27.6	48
Materials and supplies	4.9	5.1
Regulatory assets	10	8.8
Deferred income taxes	0	2.3
Prepayments and other	3.3	1.6
Total Current Assets	161.4	110.4
Deferred Charges:
Regulatory assets	87.6	90.6
Deferred income taxes	249.1	277.8
Other	50.4	47.1
Total Deferred Charges	387.1	415.5
Total Assets	1,459.60	1,424.60
Capitalization:
Common stock	0	0
Paid-in capital	506.3	503.9
Retained earnings	402.6	345.7
Total Common Stock Equity	908.9	849.6
Long-term debt (less current portion)	135	249.8
Total Capitalization	1,043.90	1,099.40
Current Liabilities:
Current portion of long-term debt	80	0
Notes payable	25	16
Accounts payable	37.9	34.2
Accounts payable – associated companies	1.2	0.4
Advance customer billings	8.4	16.7
Wages and compensation accrued	4	5.7
Customer deposits	21	19.1
Interest accrued	3.6	3.9
Unamortized purchased gas adjustments	37.6	22.4
Taxes accrued	23	30
Regulatory liabilities	37.9	40.7
Other	11.1	6.8
Total Current Liabilities	290.7	195.9
Deferred Credits and Other Liabilities:
Pension and postretirement benefit costs	31.5	29.6
Asset retirement obligations	28.4	27.7
Regulatory liabilities	42.8	53.7
Other	22.3	18.3
Total Deferred Credits and Other Liabilities	125	129.3
Total Capitalization and Liabilities	$1,459.60	$1,424.60

CONSOLIDATED_BALANCE_SHEETS_UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) (USD $)	Mar. 31, 2015	Sep. 30, 2014
In Millions, except Share data, unless otherwise specified
Assets
Non-utility property (net of accumulated depreciation and amortization)	$7.20	$6.70
Capitalization:
Common stock, par value (in dollars per share)	$1	$1
Common stock, authorized (in shares)	70,000,000	70,000,000
Common stock, issued (in shares)	43,300,000	43,200,000
Common stock, outstanding (in shares)	43,300,000	43,200,000
Laclede Gas
Capitalization:
Common stock, par value (in dollars per share)	$1	$1
Common stock, authorized (in shares)	50,000	50,000
Common stock, issued (in shares)	24,577	24,577
Common stock, outstanding (in shares)	24,577	24,577
Alagasco
Capitalization:
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, issued (in shares)	2,000,000	2,000,000
Common stock, outstanding (in shares)	2,000,000	2,000,000

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDER'S EQUITY (UNAUDITED) (USD $)	Total	Common Stock Issued	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Laclede Gas	Laclede Gas	Laclede Gas	Laclede Gas	Laclede Gas	Alagasco	Alagasco	Alagasco	Alagasco
In Millions, except Share data, unless otherwise specified							Common Stock Issued	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss		Common Stock Issued	Paid-in Capital	Retained Earnings
BALANCE at Sep. 30, 2013	$1,046.30	$32.70	$594.30	$420.10	($0.80)	$973.90	$0.10	$738.10	$237.80	($2.10)	$364.70	$0	$34.50	$330.20
BALANCE (in shares) at Sep. 30, 2013		32,696,836					24,549					1,972,052
Stockholders' Equity Rollforward
Net Income	87.8			87.8		79.5			79.5		62.9			62.9
Dividend reinvestment plan (in shares)		15,994
Dividend reinvestment plan	0.7		0.7
Stock-based compensation costs	2.4		2.4			1.8		1.8
Equity Incentive Plan (in shares)		63,765
Equity Incentive Plan	0.7	0.1	0.6
Employees’ taxes paid associated with restricted shares withheld upon vesting	-1.1		-1.1
Tax benefit - stock compensation	0.5		0.5			0.4		0.4
Dividends declared	-28.9			-28.9		-28.8			-28.8		-10.8			-10.8
Issuance of common stock to Laclede Group (in shares)							18
Issuance of common stock to Laclede Group						0.7		0.7
Other comprehensive loss, net of tax	-1.8				-1.8	0.1				0.1
BALANCE at Mar. 31, 2014	1,106.60	32.8	597.4	479	-2.6	1,027.60	0.1	741	288.5	-2	416.8	0	34.5	382.3
BALANCE (in shares) at Mar. 31, 2014		32,776,595					24,567					1,972,052
BALANCE at Dec. 31, 2013
Stockholders' Equity Rollforward
Net Income	52.2					44.2					43.1
Other comprehensive loss, net of tax	-0.1					0.1
BALANCE at Mar. 31, 2014	1,106.60					1,027.60					416.8	0	34.5
BALANCE (in shares) at Mar. 31, 2014												1,972,052
BALANCE at Sep. 30, 2014	1,508.40	43.2	1,029.40	437.5	-1.7	1,007.80	0.1	744	265.6	-1.9	849.6	0	503.9	345.7
BALANCE (in shares) at Sep. 30, 2014		43,178,405					24,577					1,972,052
Stockholders' Equity Rollforward
Net Income	141.5			141.5		88.9			88.9		56.9			56.9
Dividend reinvestment plan (in shares)		9,494
Dividend reinvestment plan	0.9		0.9
Stock-based compensation costs	-0.4		-0.4			1.7		1.7
Equity Incentive Plan (in shares)		125,949
Equity Incentive Plan	2.9	0.1	2.8
Tax benefit - stock compensation	0.6		0.6			0.5		0.5
Dividends declared	-39.8			-39.8		-39.8			-39.8
Purchase accounting adjustments											2.4		2.4
Other comprehensive loss, net of tax	-2.5				-2.5	-0.5				-0.5
BALANCE at Mar. 31, 2015	1,611.60	43.3	1,033.30	539.2	-4.2	1,058.60	0.1	746.2	314.7	-2.4	908.9	0	506.3	402.6
BALANCE (in shares) at Mar. 31, 2015		43,313,848					24,577					1,972,052
BALANCE at Dec. 31, 2014
Stockholders' Equity Rollforward
Net Income	94.4					49.9					46.3
Other comprehensive loss, net of tax	1.2					0.3
BALANCE at Mar. 31, 2015	$1,611.60					$1,058.60	$0.10				$908.90	$0
BALANCE (in shares) at Mar. 31, 2015							24,577					1,972,052

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Activities:
Net Income	$141.50	$87.80
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion	64.7	40.5
Changes in assets and liabilities:
Accounts receivable	-139.4	-211.7
Unamortized purchased gas adjustments	108.2	15.9
Deferred purchased gas costs	-14.3	27.8
Accounts payable	-12.1	79.4
Delayed/advance customer billings – net	-74.7	-53.4
Taxes accrued	21.5	38.1
Inventories	153.1	114.2
Other assets and liabilities	-2.1	-1.3
Other	33.5	5.5
Net cash provided by operating activities	279.9	142.8
Investing Activities:
Capital expenditures	-129.5	-68.2
Proceeds from sale of right to acquire New England Gas Company	0	11
(Payments for) proceeds from final reconciliation of acquisitions	-8.6	23.9
Other	-0.4	-5.1
Net cash used in investing activities	-138.5	-38.4
Financing Activities:
Redemption and maturity of long-term debt	-34.7	-80
Repayment of short-term debt – net	-39.6	-38
Issuance of common stock	2.8	1.4
Dividends paid	-39.2	-28.5
Employees’ taxes paid associated with restricted shares withheld upon vesting	-1.6	-1.1
Other	1.7	-0.3
Net cash used in financing activities	-110.6	-146.5
Net Increase (Decrease) in Cash and Cash Equivalents	30.8	-42.1
Cash and Cash Equivalents at Beginning of Year	16.1	53
Cash and Cash Equivalents at End of Year	46.9	10.9
Supplemental disclosure of cash flow information:
Interest paid	-36.1	-19.7
Income taxes (paid) refunded	0.3	2.6
Laclede Gas
Operating Activities:
Net Income	88.9	79.5
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion	40.7	40.1
Changes in assets and liabilities:
Accounts receivable	-100.9	-170.7
Unamortized purchased gas adjustments	93	15.9
Deferred purchased gas costs	-14.3	27.8
Accounts payable	11.4	55.3
Delayed/advance customer billings – net	-66.4	-53.4
Taxes accrued	35.4	36.8
Inventories	128.7	105.1
Other assets and liabilities	12.8	2.7
Other	-6.1	5.4
Net cash provided by operating activities	223.2	144.5
Investing Activities:
Capital expenditures	-93.4	-67.1
Proceeds from final reconciliation of acquisition of Missouri Gas Energy	0	23.9
Other	0	-4.8
Net cash used in investing activities	-93.4	-48
Financing Activities:
Redemption and maturity of first mortgage bonds	0	-80
Repayment of short-term debt – net	-96.1	-38
Borrowings from Laclede Group	16.8	121.8
Repayment of borrowings from Laclede Group	-6.4	-91.2
Issuance of common stock	0	0.7
Dividends paid	-38.9	-28.3
Other	0.4	-0.4
Net cash used in financing activities	-124.2	-115.4
Net Increase (Decrease) in Cash and Cash Equivalents	5.6	-18.9
Cash and Cash Equivalents at Beginning of Year	3.7	23.9
Cash and Cash Equivalents at End of Year	9.3	5
Supplemental disclosure of cash flow information:
Interest paid	-18.4	-19.5
Income taxes (paid) refunded	0.6	1.2
Alagasco
Operating Activities:
Net Income	56.9	62.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion	23.5	22.6
Changes in assets and liabilities:
Accounts receivable	-44	-64.5
Unamortized purchased gas adjustments	15.2	23.8
Accounts payable	4.2	19.9
Advance customer billings	-8.3	-13.6
Taxes accrued	-7	18.5
Inventories	20.5	21.9
Other assets and liabilities	-7	29
Other	35.2	-3.7
Net cash provided by operating activities	89.2	116.8
Investing Activities:
Capital expenditures	-34.2	-34.4
Proceeds from sale of assets	0	0
Other	-0.2	3.1
Net cash used in investing activities	-34.4	-31.3
Financing Activities:
Redemption and maturity of long-term debt	-34.7	0
Issuance (repayment) of short-term debt – net	9	-49
Borrowings from Laclede Group	0.8	0
Dividends paid	0	-10.8
Other	-0.1	-0.1
Net cash used in financing activities	-25	-59.9
Net Increase (Decrease) in Cash and Cash Equivalents	29.8	25.6
Cash and Cash Equivalents at Beginning of Year	5.6	8.5
Cash and Cash Equivalents at End of Year	35.4	34.1
Supplemental disclosure of cash flow information:
Interest paid	-6.7	-6.8
Income taxes (paid) refunded	$0	($5.30)

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Mar. 31, 2015
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 unaudited financial statements of The Laclede Group, Inc. (Laclede Group or the Company), as well as Laclede Gas Company (Laclede Gas or the Missouri Utilities) and Alabama Gas Corporation (Alagasco or the Alabama Utility). Laclede Gas, which includes the operations of Missouri Gas Energy (MGE), and Alagasco are wholly owned subsidiaries of the Company. Collectively, Laclede Gas and Alagasco are referred to as the Utilities. The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the disclosures required for complete financial statements. In the opinion of management, the accompanying unaudited financial statements include all adjustments (consisting of only normal recurring accruals) necessary for the fair presentation of the results of operations for the periods presented. This Form 10-Q should be read in conjunction with the Notes to the Financial Statements contained in Laclede Group's, Laclede Gas' and Alagasco's Annual Reports on Form 10-K or 10-KT for the fiscal year or transition period, as applicable, ended September 30, 2014.
	The consolidated financial position, results of operations, and cash flows of Laclede Group are primarily derived from the financial position, results of operations, and cash flows of the Utilities. In compliance with GAAP, transactions between the Utilities and their affiliates, as well as intercompany balances on the Utilities' Balance Sheets, have not been eliminated from the Utilities' financial statements. As a result of the Company's August 31, 2014 acquisition of Alagasco, the Company's results of operations for the three and six months ended March 31, 2015 include Alagasco, which impacts the comparability of the current year financial statements to prior years. For a further discussion of the acquisition, see Note 2, Alagasco Acquisition.
	The Utilities are regulated natural gas distribution utilities. Due to the seasonal nature of the Utilities, Laclede Group’s earnings are typically concentrated during the heating season of November through April each fiscal year. As a result, the interim statements of income for Laclede Group are not necessarily indicative of annual results or representative of succeeding quarters of the fiscal year.
	NATURE OF OPERATIONS - Laclede Group, headquartered in St. Louis, Missouri, is a public utility holding company. It has two key operating segments: Gas Utility and Gas Marketing. The Gas Utility segment is comprised of the operations of the Missouri Utilities and the Alabama Utility and serves St. Louis and eastern Missouri through legacy Laclede Gas, serves Kansas City and western Missouri through MGE, and serves central and northern Alabama through Alagasco. Laclede Group’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 9, Information by Operating Segment, and are reported as Other. The Company's earnings are primarily derived from its Gas Utility segment.
	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 March 31, 2015 and September 30, 2014 were $63.5 and $29.4, respectively.
	Alagasco records natural gas distribution revenues in accordance with the tariff established by the Alabama Public Service Commission (APSC). The amount of accrued unbilled revenues, which is not recorded as revenue until billed, for Alagasco at March 31, 2015 and September 30, 2014 were $15.0 and $5.2, respectively.
	Laclede Group'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 LER’s derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 815, “Derivatives and Hedging.” Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded using a gross presentation. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of LER’s wholesale purchase and sale transactions entered on or after January 1, 2012 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 in the Condensed Consolidated Statements of Income. This net presentation has no effect on operating income or net income.
	GROSS RECEIPTS TAXES - Gross receipts taxes associated with the Utilities' services are imposed on the Utilities and billed to customers. These amounts are recorded gross in the Operating Revenues line in the Company's Condensed Consolidated Statements of Income and the Utilities' Condensed Statements of Income. Gross receipts taxes are expensed by the Utilities and are included in the "Taxes, other than income taxes" line in the Company's Condensed Consolidated Statements of Income and the Utilities' Condensed Statements of Income.
	The following table presents gross receipts taxes recorded:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group	$	44.7		$	34.3		$	72.4		$	54.3
	Laclede Gas	33.9			34.3			55.8			54.3
	Alagasco	10.8			13			16.6			19.4
	REGULATED OPERATIONS - The Utilities account for their regulated operations in accordance with FASB ASC Topic 980, “Regulated Operations.” This Topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. As authorized by the MoPSC, the Purchased Gas Adjustment (PGA) clauses allow the Missouri Utilities to flow through to customers, subject to prudence review by the MoPSC, the cost of purchased gas supplies. Similarly, Alagasco's rate schedules for natural gas distribution charges contain a Gas Supply Adjustment (GSA) rider, which permits the pass-through to customers of changes in the cost of gas supply. Regulatory assets and liabilities related to the PGA clauses and GSA rider are both labeled Unamortized Purchased Gas Adjustments herein. See additional discussion on regulated operations in Note 4, Regulatory Matters.
	TRANSACTIONS WITH AFFILIATES - Transactions between the Company and its affiliates have been eliminated from the consolidated financial statements of Laclede Group. Alagasco had no significant transactions with affiliates. Laclede Gas had the following transactions with affiliates:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Sales of natural gas from Laclede Gas to LER	$	1.9		$	4.2		$	2.9		$	4.3
	Sales of natural gas from LER to Laclede Gas	16			25			41.3			44.5
	Transportation services provided by Laclede Pipeline Company to Laclede Gas	0.2			0.2			0.5			0.5
	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. The following table represents total goodwill of Laclede Group and Laclede Gas, by acquisition, all included in the Gas Utility segment:
			Laclede Group						Laclede Gas
	($ Millions)		31-Mar-15			30-Sep-14			31-Mar-15			September 30, 2014
	Acquisition of MGE		$	210.2		$	210.2		$	210.2		$	210.2
	Acquisition of Alagasco		735.8			727.6			—			—
	Total		$	946		$	937.8		$	210.2		$	210.2
	Alagasco has no goodwill on its balance sheet as push down accounting was not applied. As part of the Alagasco acquisition, the Company initially recorded $727.6 of goodwill. As part of the final reconciliation of net assets, $8.6 was paid by the Company to Energen Corporation (Energen) on January 6, 2015. This payment, offset partly by other immaterial purchase price adjustments in the second quarter of 2015, resulted in goodwill of $735.8 as of March 31, 2015 related to the Alagasco acquisition.
	UTILITY PLANT - Laclede Gas had accrued capital expenditures of $4.2 and $3.0 as of March 31, 2015 and September 30, 2014. Alagasco had accrued capital expenditures of $4.7 and $5.0 as of March 31, 2015 and September 30, 2014.
	REVISIONS TO PRIOR FINANCIAL STATEMENTS - In the Statements of Shareholder’s Equity in Alagasco's most recent Annual Report on Form 10-KT, $31.7 was misclassified between common stock and paid-in capital, with no impact on total shareholder’s equity. The prior period balances have been corrected in this filing. In addition, certain current and noncurrent assets and liabilities in the prior period have been adjusted to conform with the current period presentation for Laclede Group, Laclede Gas and Alagasco.
	NEW ACCOUNTING PRONOUNCEMENTS - In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. This standard is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principles-based approach to the recognition of revenue. 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. The standard outlines a five-step model and related application guidance, which replaces most existing revenue recognition guidance. ASU 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. The guidance is currently effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, with early adoption not permitted. In April 2015, the FASB proposed (for public comment) a one-year deferral of the effective date (which also would permit early application as of the standard's original effective date). The Company, Laclede Gas and Alagasco are currently assessing the available transition methods and the potential impacts of the standard, which must be adopted by the first quarter of fiscal 2018 (or fiscal 2019, if the effective date is delayed as proposed).

ALAGASCO_ACQUISITION

ALAGASCO ACQUISITION	6 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
ALAGASCO ACQUISITION	ALAGASCO ACQUISITION
	The Company completed the acquisition of 100% of the common stock of Alagasco (Alagasco Transaction) from Energen for $1,600.0, including cash and assumed debt. The acquisition date (Closing Date) was September 2, 2014, with an effective time under the Stock Purchase Agreement of 11:59 p.m. on August 31, 2014. The Alagasco Transaction was subject to certain post-closing adjustments for cash, indebtedness and working capital as discussed below. 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 $8.6 was paid by the Company to Energen on January 6, 2015, effectively increasing the total net consideration to $1,313.8. This payment, offset partly by other immaterial purchase price adjustments in the second quarter of 2015, increased goodwill related to the transaction from $727.6 recorded as of September 30, 2014, to $735.8 as of March 31, 2015. The Alagasco Transaction was accounted for under the acquisition method of accounting in accordance with FASB ASC Topic 805, “Business Combinations.” The Company determined that the Alagasco Transaction met the scope exceptions for pushdown accounting, and as such the excess consideration transferred over the fair value of assets acquired was recorded at Laclede Group. 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 Transaction as a deemed purchase and sale of assets for tax purposes. As a result, the existing deferred tax assets and liabilities were re-measured as of the Closing Date.

EARNINGS_PER_COMMON_SHARE

EARNINGS PER COMMON SHARE	6 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE
		Three Months Ended March 31,				Six Months Ended March 31,
	(Millions, except per share amounts)	2015		2014		2015		2014
	Basic EPS:
	Net Income	$	94.4	$	52.2	$	141.5	$	87.8
	Less: Income allocated to participating securities	0.3		0.2		0.5		0.3
	Net Income Available to Common Shareholders	$	94.1	$	52	$	141	$	87.5
	Weighted Average Shares Outstanding	43.1		32.6		43.1		32.6
	Basic Earnings Per Share of Common Stock	$	2.18	$	1.59	$	3.27	$	2.68
	Diluted EPS:
	Net Income	$	94.4	$	52.2	$	141.5	$	87.8
	Less: Income allocated to participating securities	0.3		0.2		0.5		0.3
	Net Income Available to Common Shareholders	$	94.1	$	52	$	141	$	87.5
	Weighted Average Shares Outstanding	43.1		32.6		43.1		32.6
	Dilutive Effect of Stock Options, Restricted Stock	0.1		—		0.1		0.1
	and Restricted Stock Units
	Weighted Average Diluted Shares	43.2		32.6		43.2		32.7
	Diluted Earnings Per Share of Common Stock	$	2.18	$	1.59	$	3.26	$	2.68
	There were 0.4 and 0.3 shares of restricted stock and stock units subject to performance or market conditions for the three and six months ended March 31, 2015 and 2014, respectively, excluded from the calculation of diluted EPS. Also, Laclede Group's 2014 2.0% Series Equity Units issued in June 2014 are potentially dilutive securities but were anti-dilutive for the three and six months ended March 31, 2015; accordingly, they were excluded from the calculation of weighted average diluted shares for those periods.

REGULATORY_MATTERS

REGULATORY MATTERS	6 Months Ended
	Mar. 31, 2015
Regulated Operations [Abstract]
REGULATORY MATTERS	REGULATORY MATTERS
	As explained in Note 1, Summary of Significant Accounting Policies, Laclede Gas and Alagasco account for regulated operations in accordance with FASB ASC Topic 980, "Regulated Operations." The following regulatory assets and regulatory liabilities, including purchase gas adjustments, were reflected in the balance sheets of the Company and the Utilities as of March 31, 2015 and September 30, 2014.
		Laclede Group				Laclede Gas				Alagasco
		March 31,		September 30,		March 31,		September 30,		March 31,		September 30,
	($ Millions)	2015		2014		2015		2014		2015		2014
	Regulatory Assets:
	Current:
	Pension and postretirement benefit costs	$	21.4	$	21.4	$	15	$	15	$	6.4	$	6.4
	Unamortized purchased gas adjustments	—		54		—		54		—		—
	Other	6		5.4		2.4		3		3.6		2.4
	Total Regulatory Assets (current)	27.4		80.8		17.4		72		10		8.8
	Non-current:
	Future income taxes due from customers	125.6		117		125.6		117		—		—
	Pension and postretirement benefit costs	420.8		431.5		357.9		365.4		62.9		66.1
	Accretion and depreciation of asset retirement obligations	19.1		18.4		—		—		19.1		18.4
	Purchased gas costs	18.6		4.3		18.6		4.3		—		—
	Energy efficiency	20.4		18.9		20.4		18.9		—		—
	Other	28.4		24.2		22.8		18.1		5.6		6.1
	Total Regulatory Assets (non-current)	632.9		614.3		545.3		523.7		87.6		90.6
	Total Regulatory Assets	$	660.3	$	695.1	$	562.7	$	595.7	$	97.6	$	99.4
	Regulatory Liabilities:
	Current:
	RSE adjustment	$	9.9	$	19.8	$	—	$	—	$	9.9	$	19.8
	Unbilled service margin	15		5.2		—		—		15		5.2
	Refundable negative salvage	10.8		13.4		—		—		10.8		13.4
	Unamortized purchased gas adjustments	76.7		22.4		39.1		—		37.6		22.4
	Other	2.8		2.9		0.6		0.6		2.2		2.3
	Total Regulatory Liabilities (current)	115.2		63.7		39.7		0.6		75.5		63.1
	Non-current:
	Postretirement liabilities	25.1		26.2		—		—		25.1		26.2
	Refundable negative salvage	17		26.8		—		—		17		26.8
	Accrued cost of removal	59.9		60.5		59.9		60.5		—		—
	Other	12.3		12.3		11.8		11.6		0.7		0.7
	Total Regulatory Liabilities (non-current)	114.3		125.8		71.7		72.1		42.8		53.7
	Total Regulatory Liabilities	$	229.5	$	189.5	$	111.4	$	72.7	$	118.3	$	116.8
	A portion of the Company's and Laclede Gas' regulatory assets are not earning a return, as shown in the schedule below:
		Laclede Group				Laclede Gas
		March 31,		September 30,		March 31,		September 30,
	($ Millions)	2015		2014		2015		2014
	Regulatory Assets Not Earning a Return:
	Future income taxes due from customers	$	125.6	$	117	$	125.6	$	117
	Pension and postretirement benefit costs	232.3		240.9		232.3		240.9
	Other	15.2		16		15.2		16
	Total Regulatory Assets Not Earning a Return	$	373.1	$	373.9	$	373.1	$	373.9
	Like all the Company's regulatory assets, these regulatory assets are expected to be recovered from customers in future rates. The Company and Laclede Gas expect these items to be recovered over a period not to exceed 15 years consistent with precedent set by the Missouri Public Service Commission (MoPSC). The portion of regulatory assets related to pensions and other postemployment benefits that pertains to unfunded differences between the projected benefit obligation and plan assets also does not earn a rate of return. Alagasco does not have any regulatory assets that are not earning a return.

FAIR_VALUE_OF_FINANCIAL_INSTRU

FAIR VALUE OF FINANCIAL INSTRUMENTS	6 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS
	The carrying amounts of cash and cash equivalents and short-term debt approximate fair value due to the short maturity of these instruments. The fair values of long-term debt are estimated based on market prices for similar issues. Refer to Note 6, Fair Value Measurements, for information on financial instruments measured at fair value on a recurring basis.
	Laclede Group
	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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	46.9	$	46.9	$	46.9	$	—	$	—
	Short-term debt	247.6		247.6		—		247.6		—
	Long-term debt, including current portion	1,816.30		1,971.00		—		1,971.00		—
	As of September 30, 2014
	Cash and cash equivalents	$	16.1	$	16.1	$	16.1	$	—	$	—
	Short-term debt	287.1		287.1		—		287.1		—
	Long-term debt	1,851.00		1,937.30		—		1,937.30		—
	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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	9.3	$	9.3	$	9.3	$	—	$	—
	Short-term debt	153		—		—		153		—
	Long-term debt	808		909.5		—		909.5		—
	As of September 30, 2014
	Cash and cash equivalents	$	3.7	$	3.7	$	3.7	$	—	$	—
	Short-term debt	238.6		238.6		—		238.6		—
	Long-term debt	807.9		876.2		—		876.2		—
	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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	35.4	$	35.4	$	35.4	$	—	$	—
	Short-term debt	25		25		—		25		—
	Long-term debt, including current portion	215		235.1		—		235.1		—
	As of September 30, 2014
	Cash and cash equivalents	$	5.6	$	5.6	$	5.6	$	—	$	—
	Short-term debt	16		16		—		16		—
	Long-term debt	249.8		266.4		—		266.4		—

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS
	The following tables for Laclede Group, Laclede Gas, and Alagasco categorize the assets and liabilities in the balance sheets that are accounted for at fair value on a recurring basis in periods subsequent to initial recognition.
	The mutual funds included in Level 1 are valued based on exchange-quoted market prices of individual securities. The mutual funds included in Level 2 are valued based on the closing net asset value per unit.
	Derivative instruments included in Level 1 are valued using quoted market prices on the New York Mercantile Exchange (NYMEX). Derivative instruments classified in 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. The Alagasco interest rate swaps fall into this latter Level 2 classification. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. The Level 3 balances as of March 31, 2015 and September 30, 2014 consisted of gas commodity contracts. The Company’s and the Utilities' policy is to recognize transfers between the levels of the fair value hierarchy, if any, as of the beginning of the interim reporting period in which circumstances change or events occur to cause the transfer.
	The mutual funds are included in 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 exists between the Company or Laclede Gas and the counterparty to a derivative contract.
	Laclede Group
	($ Millions)	Quoted		Significant		Significant		Effects of Netting and Cash Margin Receivables			Total
		Prices in		Observable		Unobservable		/Payables
		Active		Inputs		Inputs
		Markets		(Level 2)		(Level 3)
		(Level 1)
	As of March 31, 2015
	ASSETS
	Gas Utility
	U. S. stock/bond mutual funds	$	16.4	$	3.9	$	—	$	—		$	20.3
	NYMEX natural gas contracts	0.6		—		—		(0.6		)	—
	Subtotal	17		3.9		—		(0.6		)	20.3
	Gas Marketing
	NYMEX natural gas contracts	3.4		1.7		—		(4.3		)	0.8
	Natural gas commodity contracts	—		2.7		0.5		(0.5		)	2.7
	Total	$	20.4	$	8.3	$	0.5	$	(5.4	)	$	23.8
	LIABILITIES
	Gas Utility
	NYMEX/ICE natural gas contracts	$	14.1	$	—	$	—	$	(14.1	)	$	—
	OTCBB natural gas contracts	—		14.5		—		—			14.5
	NYMEX gasoline and heating oil contracts	1		—		—		(1.0		)	—
	Interest rate swaps	—		2.9		—		—			2.9
	Subtotal	15.1		17.4		—		(15.1		)	17.4
	Gas Marketing
	NYMEX natural gas contracts	1.9		3.5		—		(5.4		)	—
	Natural gas commodity contracts	—		0.8		—		(0.5		)	0.3
	Total	$	17	$	21.7	$	—	$	(21.0	)	$	17.7
	As of September 30, 2014
	ASSETS
	Gas Utility
	U. S. stock/bond mutual funds	$	15.7	$	3.9	$	—	$	—		$	19.6
	NYMEX natural gas contracts	2.4		—		—		(2.4		)	—
	OTCBB natural gas contracts	—		0.1		—		(0.1		)	—
	Subtotal	18.1		4		—		(2.5		)	19.6
	Gas Marketing
	NYMEX natural gas contracts	1		1.2		—		(1.8		)	0.4
	Natural gas commodity contracts	—		2.7		0.2		(0.2		)	2.7
	Total	$	19.1	$	7.9	$	0.2	$	(4.5	)	$	22.7
	LIABILITIES
	Gas Utility
	NYMEX/ICE natural gas contracts	$	5.2	$	—	$	—	$	(5.2	)	$	—
	OTCBB natural gas contracts	—		4.1		—		(0.1		)	4
	Gasoline and heating oil contracts	0.2		—		—		(0.2		)	—
	Subtotal	5.4		4.1		—		(5.5		)	4
	Gas Marketing
	NYMEX natural gas contracts	1.1		0.7		—		(1.8		)	—
	Natural gas commodity contracts	—		0.7		—		(0.2		)	0.5
	Total	$	6.5	$	5.5	$	—	$	(7.5	)	$	4.5
	Laclede Gas
	($ Millions)	Quoted		Significant		Significant		Effects of Netting and Cash Margin Receivables			Total
		Prices in		Observable		Unobservable		/Payables
		Active		Inputs		Inputs
		Markets		(Level 2)		(Level 3)
		(Level 1)
	As of March 31, 2015
	ASSETS
	U. S. stock/bond mutual funds	$	16.4	$	3.9	$	—	$	—		$	20.3
	NYMEX natural gas contracts	0.6		—		—		(0.6		)	—
	Total	17		3.9		—		(0.6		)	20.3
LIABILITIES
NYMEX natural gas contracts	14.1		—		—		(14.1		)	—
OTCBB natural gas contracts	—		14.5		—		—			14.5
Gasoline and heating oil contracts	1		—		—		(1.0		)	—
Total	$	15.1	$	14.5	$	—	$	(15.1	)	$	14.5
As of September 30, 2014
ASSETS
U. S. stock/bond mutual funds	$	15.7	$	3.9	$	—	$	—		$	19.6
NYMEX natural gas contracts	2.4		—		—		(2.4		)	—
OTCBB natural gas contracts	—		0.1		—		(0.1		)	—
Total	18.1		4		—		(2.5		)	19.6
LIABILITIES
NYMEX/ICE natural gas contracts	5.2		—		—		(5.2		)	—
OTCBB natural gas contracts	—		4.1		—		(0.1		)	4
NYMEX gasoline and heating oil contracts	0.2		—		—		(0.2		)	—
Total	$	5.4	$	4.1	$	—	$	(5.5	)	$	4
Alagasco
($ Millions)	Quoted		Significant		Significant		Effects of Netting and Cash Margin Receivables			Total
	Prices in		Observable		Unobservable		/Payables
	Active		Inputs		Inputs
	Markets		(Level 2)		(Level 3)
	(Level 1)
As of March 31, 2015
LIABILITIES
Interest rate swaps	$	—	$	2.9	$	—	$	—		$	2.9
Total	$	—	$	2.9	$	—	$	—		$	2.9
As of September 30, 2014
LIABILITIES
Interest rate swaps	$	—	$	—	$	—	$	—		$	—
Total	$	—	$	—	$	—	$	—		$	—

CONCENTRATIONS_OF_CREDIT_RISK

CONCENTRATIONS OF CREDIT RISK	6 Months Ended
	Mar. 31, 2015
Risks and Uncertainties [Abstract]
CONCENTRATION OF CREDIT RISK	CONCENTRATIONS OF CREDIT RISK
	Other than in LER (the Gas Marketing segment), Laclede Group has no significant concentrations of credit risk.
	A significant portion of LER’s transactions are with (or are associated with) energy producers, utility companies, and pipelines. The concentration of transactions with these counterparties has the potential to affect the Company’s overall exposure to credit risk, either positively or negatively, in that each of these three groups may be affected similarly by changes in economic, industry, or other conditions. To manage this risk, as well as credit risk from significant counterparties in these and other industries, 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 LER's accounts receivable attributable to energy producers and their marketing affiliates totaled $7.5 at March 31, 2015. Net receivable amounts from these customers on the same date, reflecting netting arrangements, were $5.7. LER's accounts receivable attributable to utility companies and their marketing affiliates comprised $15.6 of total accounts receivable at March 31, 2015, while net receivable amounts from these customers, reflecting netting arrangements, were $14.1.
	LER also has concentrations of credit risk with certain individually significant counterparties and with pipeline companies associated with its natural gas receivable amounts. At March 31, 2015, the amounts included in accounts receivable from LER’s five largest counterparties (in terms of net accounts receivable exposure) totaled $9.8. These five counterparties are either investment-grade rated or owned by investment-grade rated companies. Net receivable amounts from these five customers on the same date, reflecting netting arrangements, were $9.3.

PENSION_PLANS_AND_OTHER_POSTRE

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	6 Months Ended
	Mar. 31, 2015
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS
	This footnote includes all pension plans of the Company whether historical plans or those acquired as part of the purchase of certain assets and liabilities of MGE on September 1, 2013 or those acquired in the Alagasco Transaction effective August 31, 2014. The net pension and postretirement obligations were re-measured at the applicable acquisition dates as well as at the fiscal year end.
	Pension Plans
	The pension plans of Laclede Group consist of plans for employees at the Missouri Utilities and plans covering employees of Alagasco.
	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 cost included the following components:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group
	Service cost – benefits earned during the period	$	4.3		$	2.5		$	8.6		$	4.9
	Interest cost on projected benefit obligation	7.4			6			14.9			12
	Expected return on plan assets	(9.3		)	(6.7		)	(18.7		)	(13.3		)
	Amortization of prior service cost	0.1			0.1			0.2			0.2
	Amortization of actuarial loss	2			1.7			3.9			3.5
	Loss on lump-sum settlements	—			1.3			—			1.3
	Sub-total	4.5			4.9			8.9			8.6
	Regulatory adjustment	4.8			1.6			9.7			4.5
	Net pension cost	$	9.3		$	6.5		$	18.6		$	13.1
	Laclede Gas
	Service cost – benefits earned during the period	$	2.9		$	2.5		$	5.7		$	4.9
	Interest cost on projected benefit obligation	5.9			6			11.8			12
	Expected return on plan assets	(7.3		)	(6.7		)	(14.6		)	(13.3		)
	Amortization of prior service cost	0.1			0.1			0.2			0.2
	Amortization of actuarial loss	2			1.7			3.9			3.5
	Loss on lump-sum settlements	—			1.3			—			1.3
	Sub-total	3.6			4.9			7			8.6
	Regulatory adjustment	3.4			1.6			6.8			4.5
	Net pension cost	$	7		$	6.5		$	13.8		$	13.1
	Alagasco
	Service cost – benefits earned during the period	$	1.4		$	1.5		$	2.9		$	3.6
	Interest cost on projected benefit obligation	1.5			1.2			3.1			2.9
	Expected return on plan assets	(2.0		)	(1.5		)	(4.1		)	(3.7		)
	Amortization of prior service cost	—			0.1			—			0.1
	Amortization of actuarial loss	—			0.7			—			2
	Loss on lump-sum settlements	—			10.1			—			10.9
	Sub-total	0.9			12.1			1.9			15.8
	Regulatory adjustment	1.4			(9.8		)	2.9			(10.6		)
	Net pension cost	$	2.3		$	2.3		$	4.8		$	5.2
	Pursuant to the provisions of the Missouri Utilities' and Alagasco's pension plans, pension obligations may be satisfied by lump-sum cash payments. Pursuant to a MoPSC Order, 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. Lump-sum payments during the six months ended March 31, 2015 were $12.7 for the Missouri Utilities and $2.6 for Alagasco.
	The funding policy of the Utilities is to contribute an amount not less than the minimum required by government funding standards, nor more than the maximum deductible amount for federal income tax purposes. Fiscal year 2015 contributions to Laclede Gas' pension plans through March 31, 2015 were $9.1 to the qualified trusts and $0.2 to the non-qualified plans. There were no fiscal 2015 contributions to the Alagasco pension plans through March 31, 2015.
	Contributions to the Missouri Utilities' pension plans for the remaining six months of fiscal 2015 are anticipated to be approximately $17.3 to the qualified trusts and $0.3 to the non-qualified plans. There are no expected contributions to Alagasco's pension plans for the remaining six months of fiscal 2015.
	Postretirement Benefits
	The Utilities provide certain life insurance benefits at retirement. Laclede Gas plans provide for medical insurance after early retirement until age 65. For retirements prior to January 1, 2015, the MGE plans provided medical insurance after retirement until death. For retirements after January 1, 2015, the MGE plans provide medical insurance after early retirement until age 65. The transition obligation not yet included in postretirement benefit cost is being amortized over 20 years. Under the Alagasco plans, medical insurance is currently available upon retirement until death for certain retirees depending on the type of employee and the date the employee was originally hired.
	Net periodic postretirement benefit cost for the Company consisted of the following components:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group
	Service cost – benefits earned during the period	$	3.2		$	2.8		$	6.4		$	5.6
	Interest cost on accumulated postretirement benefit obligation	2.8			2.2			5.6			4.4
	Expected return on plan assets	(3.3		)	(1.7		)	(6.6		)	(3.4		)
	Amortization of prior service credit	0.2			—			0.4			—
	Amortization of actuarial loss	1.2			1.5			2.5			3
	Sub-total	4.1			4.8			8.3			9.6
	Regulatory adjustment	(2.7		)	(2.4		)	(5.4		)	(4.8		)
	Net postretirement benefit cost	$	1.4		$	2.4		$	2.9		$	4.8
	Laclede Gas
	Service cost – benefits earned during the period	$	3.1		$	2.8		$	6.2		$	5.6
	Interest cost on accumulated postretirement benefit obligation	2.2			2.2			4.3			4.4
	Expected return on plan assets	(2.1		)	(1.7		)	(4.1		)	(3.4		)
	Amortization of prior service cost	0.2			—			0.4			—
	Amortization of actuarial loss	1.2			1.5			2.5			3
Sub-total	4.6			4.8			9.3			9.6
Regulatory adjustment	(2.3		)	(2.4		)	(4.6		)	(4.8		)
Net postretirement benefit cost	$	2.3		$	2.4		$	4.7		$	4.8
Alagasco
Service cost – benefits earned during the period	$	0.1		$	0.1		$	0.2		$	0.4
Interest cost on accumulated postretirement benefit obligation	0.6			0.5			1.3			1.2
Expected return on plan assets	(1.2		)	(1.1		)	(2.5		)	(2.1		)
Amortization of actuarial loss and other	—			(0.4		)	—			(0.5		)
Amortization of transition obligation	—			0.1			—			0.3
Sub-total	(0.5		)	(0.8		)	(1.0		)	(0.7		)
Regulatory adjustment	(0.4		)	—			(0.8		)	—
Net postretirement benefit cost	$	(0.9	)	$	(0.8	)	$	(1.8	)	$	(0.7	)
Missouri and Alabama 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. The Missouri Utilities established Voluntary Employees’ Beneficiary Association (VEBA) and Rabbi Trusts as its external funding mechanisms. The assets of the VEBA and Rabbi Trusts consist primarily of money market securities and mutual funds invested in stocks and bonds.
The Utilities' funding policy is to contribute amounts to the trusts equal to the periodic benefit cost calculated pursuant to GAAP as recovered in rates. Fiscal year 2015 contributions to the postretirement plans through March 31, 2015 were $4.4 for the Missouri Utilities. Contributions to the postretirement plans for the remaining six months of fiscal year 2015 are anticipated to be $13.6 to the qualified trusts and $0.3 paid directly to participants from the Missouri Utilities' funds. For Alagasco, there were no contributions to the postretirement plans during the first six months of fiscal year 2015, and there are none expected for the remaining six months.

INFORMATION_BY_OPERATING_SEGME

INFORMATION BY OPERATING SEGMENT	6 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
INFORMATION BY OPERATING SEGMENT	INFORMATION BY OPERATING SEGMENT
	The Company has two key operating segments: Gas Utility and Gas Marketing. The Gas Utility segment comprises the regulated operations of the Utilities, consisting of Laclede Gas and Alagasco. Laclede Gas and Alagasco are public utilities engaged in the retail distribution and sale of natural gas serving an area in eastern Missouri through its legacy Laclede Gas assets, an area in western Missouri through its MGE assets, and central and northern Alabama through its Alagasco assets. 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 Laclede Group which operates a propane pipeline under Federal Energy Regulatory Commission (FERC) jurisdiction, and
	•	Laclede Group’s subsidiaries that are engaged in, among other activities, oil production, real estate development, compression of natural gas, and financial investments in other enterprises. All subsidiaries are wholly owned.
	Accounting policies and intersegment transactions are described in Note 1, Summary of Significant Accounting Policies.
	($ Millions)	Gas Utility			Gas Marketing			Other			Eliminations			Consolidated
	Three Months Ended March 31, 2015
	Operating Revenues:
	Revenues from external customers	$	847		$	30		$	0.4		$	—		$	877.4
	Intersegment revenues	2			14.1			0.5			(16.6		)	—
	Total Operating Revenues	849			44.1			0.9			(16.6		)	877.4
	Operating Expenses:
	Gas Utility
	Natural and propane gas	499.1			—			—			(16.3		)	482.8
	Other operation and maintenance	104			—			—			(0.2		)	103.8
	Depreciation and amortization	32.2			—			—			—			32.2
	Taxes, other than income taxes	55.7			—			—			—			55.7
	Total Gas Utility Operating Expenses	691			—			—			(16.5		)	674.5
	Gas Marketing	—			43.5			—			—			43.5
	Other	—			—			1.8			(0.1		)	1.7
	Total Operating Expenses	691			43.5			1.8			(16.6		)	719.7
	Operating Income (Loss)	$	158		$	0.6		$	(0.9	)	$	—		$	157.7
	Net Economic Earnings (Loss)	$	96.5		$	2.1		$	(1.0	)	$	—		$	97.6
	Three Months Ended March 31, 2014
	Operating Revenues:
	Revenues from external customers	$	634.4		$	59.9		$	0.2		$	—		$	694.5
	Intersegment revenues	4.2			20.6			0.6			(25.4		)	—
	Total Operating Revenues	638.6			80.5			0.8			(25.4		)	694.5
	Operating Expenses:
	Gas Utility
	Natural and propane gas	430.5			—			—			(25.2		)	405.3
	Other operation and maintenance	72.2			—			—			(0.2		)	72
	Depreciation and amortization	20.1			—			—			—			20.1
	Taxes, other than income taxes	41.8			—			—			—			41.8
	Total Gas Utility Operating Expenses	564.6			—			—			(25.4		)	539.2
	Gas Marketing	—			65			—			—			65
	Other	—			—			3.1			—			3.1
	Total Operating Expenses	564.6			65			3.1			(25.4		)	607.3
	Operating Income (Loss)	$	74		$	15.5		$	(2.3	)	$	—		$	87.2
	Net Economic Earnings (Loss)	$	44.7		$	7.1		$	(0.1	)	$	—		$	51.7
	($ Millions)	Gas Utility			Gas Marketing			Other			Eliminations			Consolidated
	Six Months Ended March 31, 2015
	Operating Revenues:
	Revenues from external customers	$	1,428.40		$	67.8		$	0.8		$	—		$	1,497.00
	Intersegment revenues	3			38.5			1			(42.5		)	—
	Total Operating Revenues	1,431.40			106.3			1.8			(42.5		)	1,497.00
	Operating Expenses:
	Gas Utility
	Natural and propane gas	828.9			—			—			(41.8		)	787.1
	Other operation and maintenance	201.4			—			—			(0.5		)	200.9
	Depreciation and amortization	64.2			—			—			—			64.2
	Taxes, other than income taxes	93.7			—			—			—			93.7
	Total Gas Utility Operating Expenses	1,188.20			—			—			(42.3		)	1,145.90
	Gas Marketing	—			102.1			—			—			102.1
	Other	—			—			4.2			(0.2		)	4
	Total Operating Expenses	1,188.20			102.1			4.2			(42.5		)	1,252.00
	Operating Income (Loss)	$	243.2		$	4.2		$	(2.4	)	$	—		$	245
	Net Economic Earnings (Loss)	$	146.3		$	2.5		$	(5.5	)	$	—		$	143.3
	Six Months Ended March 31, 2014
	Operating Revenues:
	Revenues from external customers	$	1,069.60		$	93.1		$	0.4		$	—		$	1,163.10
	Intersegment revenues	4.3			40.1			1			(45.4		)	—
	Total Operating Revenues	1,073.90			133.2			1.4			(45.4		)	1,163.10
Operating Expenses:
Gas Utility
Natural and propane gas	692.1			—			—			(45.0		)	647.1
Other operation and maintenance	134.7			—			—			(0.4		)	134.3
Depreciation and amortization	40.1			—			—			—			40.1
Taxes, other than income taxes	70.4			—			—			—			70.4
Total Gas Utility Operating Expenses	937.3			—			—			(45.4		)	891.9
Gas Marketing	—			116.8			—			—			116.8
Other	—			—			4.3			—			4.3
Total Operating Expenses	937.3			116.8			4.3			(45.4		)	1,013.00
Operating Income (Loss)	$	136.6		$	16.4		$	(2.9	)	$	—		$	150.1
Net Economic Earnings (Loss)	$	80.5		$	7.9		$	(0.4	)	$	—		$	88
The Company's total assets by segment were as follows:
	March 31,			September 30,
($ Millions)	2015			2014
Total Assets:
Gas Utility	$	4,615.60		$	4,520.00
Gas Marketing	131.7			156.7
Other	1,590.80			1,575.70
Eliminations	(1,157.4		)	(1,178.4		)
Total Assets	$	5,180.70		$	5,074.00
The following table reconciles the Company's Net Income (GAAP) to Net Economic Earnings (Non-GAAP):
	Three Months Ended March 31,						Six Months Ended March 31,
($ Millions)	2015			2014			2015			2014
Net income (GAAP)	$	94.4		$	52.2		$	141.5		$	87.8
Unrealized loss (gain) on energy-related derivative contracts	2.6			(1.7		)	(0.4		)	(1.3		)
Lower of cost or market inventory adjustments	(1.0		)	(0.5		)	0.2			(0.6		)
Realized loss (gain) on economic hedges prior to sale of the physical commodity	0.1			(0.1		)	0.1			(0.1		)
Acquisition, divestiture and restructuring activities	1.5			1.8			1.9			2.2
Net Economic Earnings (Non-GAAP)	$	97.6		$	51.7		$	143.3		$	88

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Mar. 31, 2015
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 2019, for the storage, transportation, and supply of natural gas. Minimum payments required under the contracts in place at March 31, 2015 are estimated at approximately $1,595.0, $750.4, and $521.5 for the Company, Laclede Gas, and Alagasco, 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.
	Contingencies
	Laclede Gas
	Similar to other natural gas utility companies, Laclede Gas owns and operates 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 Laclede Gas' financial position and results of operations. As environmental laws, regulations, and their interpretations change, however, the Company or Laclede Gas may incur additional environmental liabilities that may result in additional costs.
	In the natural gas industry, many gas distribution companies like Laclede Gas and MGE have incurred environmental liabilities associated with sites they or their predecessor companies formerly owned or operated where manufactured gas operations took place. At this time, Laclede Gas has identified three former manufactured gas plant (MGP) sites 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). MGE has enrolled all of its owned former manufactured gas plant 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, 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. 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 Missouri Department of Natural Resources 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 that are willing to contribute to such efforts in a meaningful and equitable fashion. Accordingly, Laclede Gas was able to enter into a cost sharing agreement for remedial investigation with other potentially responsible parties. Pending Missouri Department of Natural Resources approval, 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 Region 7 of the United States Environmental Protection Agency (EPA) in respect to the former Thompson Chemical/Superior Solvents site located at 60 Chouteau Avenue in St. Louis, Missouri. Laclede Gas is currently reviewing its records, and responses are due to the EPA on May 26, 2015. In turn, Laclede Gas has issued a Freedom of Information Act request to the EPA dated April 3, 2015, in an effort to identify the basis of the EPA’s inquiry.
	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, 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, which is in the early stages of site analysis and characterization. Remediation efforts at these sites are at various stages of completion, ranging from groundwater monitoring and sampling following source removal activities to early site characterization in 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.
	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 or MGE. 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 from $8.1 to $39.3 based upon current available facts, technology and laws and regulations.
	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 potential responsible parties), 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. The Company does not expect potential liabilities that may arise from remediating these sites to have a material impact on the future financial position or results of operations of Laclede Gas or the Company.
	Alagasco
	Alagasco owns and operates 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 Alagasco's financial position and results of operations. As environmental laws, regulations, and their interpretations change, however, Alagasco may be required to incur additional costs.
	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. Management expects that, should future remediation of the sites be required, Alagasco’s share of the remediation costs will not materially affect the financial position of Alagasco. During 2011, a removal action was completed at the Huntsville, Alabama MGP site pursuant to an Administrative Settlement Agreement and Order on Consent among the EPA, Alagasco and the current site owner.
	In 2012, Alagasco responded to an EPA Request for Information Pursuant to Section 104 of Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) relating to the 35th Avenue Superfund Site located in North Birmingham, Jefferson County, Alabama. The Request related to a former site of a manufactured gas distribution facility owned by Alagasco and located in the vicinity of the 35th Avenue Superfund Site. In September 2013, Alagasco received from the EPA a General Notice Letter and Invitation to Conduct a Removal Action at the 35th Avenue Superfund Site. The letter identifies Alagasco as a potentially responsible party (PRP) under CERCLA for the cleanup of the Site or costs the EPA incurs in cleaning up the site. The EPA also offered the PRP group the opportunity to conduct Phase I of the proposed removal action which involved removal activities at approximately 50 residences that purportedly exceed certain risk levels for contamination. All Phase I work was conducted by EPA without PRP participation, and is completed or close to completion. In August of 2014, EPA offered the PRP group the opportunity to conduct Phase II of the proposed removal action which involved removal activities at approximately 30 additional residences that purportedly exceed certain risk levels for contamination. Alagasco has not agreed to undertake any of the proposed removal activities.
	Alagasco has discussed its designation as a PRP with the EPA (including an in-person meeting in Atlanta), and Alagasco has requested additional information from the EPA regarding the testing and removal activities and its designation as a PRP. To 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.
	Alagasco has also been approached by a law firm regarding entry into an agreement to toll the statute of limitations with potential plaintiffs related to purported damages allegedly incurred by such potential plaintiffs in connection with the 35th Avenue Superfund Site, and is considering whether to enter into such a tolling arrangement.
	The EPA published a proposal to add the 35th Avenue Superfund Site to its National Priorities List (NPL). CERCLA requires that the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) include a list of national priorities among the known releases or threatened releases of hazardous substances, pollutants or contaminants throughout the United States. The NPL constitutes this list. Alagasco submitted comments in opposition to the proposed listing on January 20, 2015.
	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 potential responsible parties) are incurred, Alagasco would defer such costs and recover them over a period of time in accordance with Alagasco's Enhanced Stability Reserve (ESR). Alagasco does not expect potential liabilities that may arise from remediating these sites to have a material impact on the future financial position or results of operations of Alagasco or the Company.
	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 is cooperating with the National Transportation Safety Board which is investigating the incident. Alagasco has been named as a defendant in several lawsuits arising from the incident, and additional lawsuits and claims may be filed against Alagasco.
	Alagasco is, from time to time, a party to various pending or threatened legal proceedings and has accrued a provision for its estimated liability. Certain of these lawsuits include claims for punitive damages in addition to other specified relief. Alagasco recognizes its liability for contingencies when information available indicates both a loss is probable and the amount of the loss can be reasonably estimated. Based upon information presently available, and in light of available legal and other defenses, contingent liabilities arising from threatened and pending litigation are not considered material in relation to the financial position of Alagasco. It should be noted, however, that there is uncertainty in the valuation of pending claims and prediction of litigation results.
	Laclede Group
	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 outcomes of such matters will not have a material effect on the statements of income, balance sheets, and statements of cash flows of the Company, Laclede Gas, or Alagasco.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION - These notes are an integral part of the accompanying unaudited financial statements of The Laclede Group, Inc. (Laclede Group or the Company), as well as Laclede Gas Company (Laclede Gas or the Missouri Utilities) and Alabama Gas Corporation (Alagasco or the Alabama Utility). Laclede Gas, which includes the operations of Missouri Gas Energy (MGE), and Alagasco are wholly owned subsidiaries of the Company. Collectively, Laclede Gas and Alagasco are referred to as the Utilities. The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the disclosures required for complete financial statements. In the opinion of management, the accompanying unaudited financial statements include all adjustments (consisting of only normal recurring accruals) necessary for the fair presentation of the results of operations for the periods presented. This Form 10-Q should be read in conjunction with the Notes to the Financial Statements contained in Laclede Group's, Laclede Gas' and Alagasco's Annual Reports on Form 10-K or 10-KT for the fiscal year or transition period, as applicable, ended September 30, 2014.
	The consolidated financial position, results of operations, and cash flows of Laclede Group are primarily derived from the financial position, results of operations, and cash flows of the Utilities. In compliance with GAAP, transactions between the Utilities and their affiliates, as well as intercompany balances on the Utilities' Balance Sheets, have not been eliminated from the Utilities' financial statements. As a result of the Company's August 31, 2014 acquisition of Alagasco, the Company's results of operations for the three and six months ended March 31, 2015 include Alagasco, which impacts the comparability of the current year financial statements to prior years. For a further discussion of the acquisition, see Note 2, Alagasco Acquisition.
	The Utilities are regulated natural gas distribution utilities. Due to the seasonal nature of the Utilities, Laclede Group’s earnings are typically concentrated during the heating season of November through April each fiscal year. As a result, the interim statements of income for Laclede Group are not necessarily indicative of annual results or representative of succeeding quarters of the fiscal year.
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 March 31, 2015 and September 30, 2014 were $63.5 and $29.4, respectively.
	Alagasco records natural gas distribution revenues in accordance with the tariff established by the Alabama Public Service Commission (APSC). The amount of accrued unbilled revenues, which is not recorded as revenue until billed, for Alagasco at March 31, 2015 and September 30, 2014 were $15.0 and $5.2, respectively.
	Laclede Group'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 LER’s derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 815, “Derivatives and Hedging.” Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded using a gross presentation. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of LER’s wholesale purchase and sale transactions entered on or after January 1, 2012 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 in the Condensed Consolidated Statements of Income. This net presentation has no effect on operating income or net income.
GROSS RECEIPTS TAXES	GROSS RECEIPTS TAXES - Gross receipts taxes associated with the Utilities' services are imposed on the Utilities and billed to customers. These amounts are recorded gross in the Operating Revenues line in the Company's Condensed Consolidated Statements of Income and the Utilities' Condensed Statements of Income. Gross receipts taxes are expensed by the Utilities and are included in the "Taxes, other than income taxes" line in the Company's Condensed Consolidated Statements of Income and the Utilities' Condensed Statements of Income.
REGULATED OPERATIONS	REGULATED OPERATIONS - The Utilities account for their regulated operations in accordance with FASB ASC Topic 980, “Regulated Operations.” This Topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process.
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.
NEW ACCOUNTING PRONOUNCEMENTS	NEW ACCOUNTING PRONOUNCEMENTS - In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. This standard is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principles-based approach to the recognition of revenue. 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. The standard outlines a five-step model and related application guidance, which replaces most existing revenue recognition guidance. ASU 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. The guidance is currently effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, with early adoption not permitted. In April 2015, the FASB proposed (for public comment) a one-year deferral of the effective date (which also would permit early application as of the standard's original effective date). The Company, Laclede Gas and Alagasco are currently assessing the available transition methods and the potential impacts of the standard, which must be adopted by the first quarter of fiscal 2018 (or fiscal 2019, if the effective date is delayed as proposed).

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	6 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Schedule of gross receipts taxes	The following table presents gross receipts taxes recorded:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group	$	44.7		$	34.3		$	72.4		$	54.3
	Laclede Gas	33.9			34.3			55.8			54.3
	Alagasco	10.8			13			16.6			19.4
Schedule of inter-company transactions	Laclede Gas had the following transactions with affiliates:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Sales of natural gas from Laclede Gas to LER	$	1.9		$	4.2		$	2.9		$	4.3
	Sales of natural gas from LER to Laclede Gas	16			25			41.3			44.5
	Transportation services provided by Laclede Pipeline Company to Laclede Gas	0.2			0.2			0.5			0.5
Schedule of goodwill	The following table represents total goodwill of Laclede Group and Laclede Gas, by acquisition, all included in the Gas Utility segment:
			Laclede Group						Laclede Gas
	($ Millions)		31-Mar-15			30-Sep-14			31-Mar-15			September 30, 2014
	Acquisition of MGE		$	210.2		$	210.2		$	210.2		$	210.2
	Acquisition of Alagasco		735.8			727.6			—			—
	Total		$	946		$	937.8		$	210.2		$	210.2

EARNINGS_PER_COMMON_SHARE_Tabl

EARNINGS PER COMMON SHARE (Tables)	6 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Common Share
		Three Months Ended March 31,				Six Months Ended March 31,
	(Millions, except per share amounts)	2015		2014		2015		2014
	Basic EPS:
	Net Income	$	94.4	$	52.2	$	141.5	$	87.8
	Less: Income allocated to participating securities	0.3		0.2		0.5		0.3
	Net Income Available to Common Shareholders	$	94.1	$	52	$	141	$	87.5
	Weighted Average Shares Outstanding	43.1		32.6		43.1		32.6
	Basic Earnings Per Share of Common Stock	$	2.18	$	1.59	$	3.27	$	2.68
	Diluted EPS:
	Net Income	$	94.4	$	52.2	$	141.5	$	87.8
	Less: Income allocated to participating securities	0.3		0.2		0.5		0.3
	Net Income Available to Common Shareholders	$	94.1	$	52	$	141	$	87.5
	Weighted Average Shares Outstanding	43.1		32.6		43.1		32.6
	Dilutive Effect of Stock Options, Restricted Stock	0.1		—		0.1		0.1
	and Restricted Stock Units
	Weighted Average Diluted Shares	43.2		32.6		43.2		32.7
	Diluted Earnings Per Share of Common Stock	$	2.18	$	1.59	$	3.26	$	2.68

REGULATORY_MATTERS_Tables

REGULATORY MATTERS (Tables)	6 Months Ended
	Mar. 31, 2015
Regulated Operations [Abstract]
Schedule of regulatory assets	The following regulatory assets and regulatory liabilities, including purchase gas adjustments, were reflected in the balance sheets of the Company and the Utilities as of March 31, 2015 and September 30, 2014.
		Laclede Group				Laclede Gas				Alagasco
		March 31,		September 30,		March 31,		September 30,		March 31,		September 30,
	($ Millions)	2015		2014		2015		2014		2015		2014
	Regulatory Assets:
	Current:
	Pension and postretirement benefit costs	$	21.4	$	21.4	$	15	$	15	$	6.4	$	6.4
	Unamortized purchased gas adjustments	—		54		—		54		—		—
	Other	6		5.4		2.4		3		3.6		2.4
	Total Regulatory Assets (current)	27.4		80.8		17.4		72		10		8.8
	Non-current:
	Future income taxes due from customers	125.6		117		125.6		117		—		—
	Pension and postretirement benefit costs	420.8		431.5		357.9		365.4		62.9		66.1
	Accretion and depreciation of asset retirement obligations	19.1		18.4		—		—		19.1		18.4
	Purchased gas costs	18.6		4.3		18.6		4.3		—		—
	Energy efficiency	20.4		18.9		20.4		18.9		—		—
	Other	28.4		24.2		22.8		18.1		5.6		6.1
	Total Regulatory Assets (non-current)	632.9		614.3		545.3		523.7		87.6		90.6
	Total Regulatory Assets	$	660.3	$	695.1	$	562.7	$	595.7	$	97.6	$	99.4
	Regulatory Liabilities:
	Current:
	RSE adjustment	$	9.9	$	19.8	$	—	$	—	$	9.9	$	19.8
	Unbilled service margin	15		5.2		—		—		15		5.2
	Refundable negative salvage	10.8		13.4		—		—		10.8		13.4
	Unamortized purchased gas adjustments	76.7		22.4		39.1		—		37.6		22.4
	Other	2.8		2.9		0.6		0.6		2.2		2.3
	Total Regulatory Liabilities (current)	115.2		63.7		39.7		0.6		75.5		63.1
	Non-current:
	Postretirement liabilities	25.1		26.2		—		—		25.1		26.2
	Refundable negative salvage	17		26.8		—		—		17		26.8
	Accrued cost of removal	59.9		60.5		59.9		60.5		—		—
	Other	12.3		12.3		11.8		11.6		0.7		0.7
	Total Regulatory Liabilities (non-current)	114.3		125.8		71.7		72.1		42.8		53.7
	Total Regulatory Liabilities	$	229.5	$	189.5	$	111.4	$	72.7	$	118.3	$	116.8
	A portion of the Company's and Laclede Gas' regulatory assets are not earning a return, as shown in the schedule below:
		Laclede Group				Laclede Gas
		March 31,		September 30,		March 31,		September 30,
	($ Millions)	2015		2014		2015		2014
	Regulatory Assets Not Earning a Return:
	Future income taxes due from customers	$	125.6	$	117	$	125.6	$	117
	Pension and postretirement benefit costs	232.3		240.9		232.3		240.9
	Other	15.2		16		15.2		16
	Total Regulatory Assets Not Earning a Return	$	373.1	$	373.9	$	373.1	$	373.9
Schedule of regulatory liabilities	The following regulatory assets and regulatory liabilities, including purchase gas adjustments, were reflected in the balance sheets of the Company and the Utilities as of March 31, 2015 and September 30, 2014.
		Laclede Group				Laclede Gas				Alagasco
		March 31,		September 30,		March 31,		September 30,		March 31,		September 30,
	($ Millions)	2015		2014		2015		2014		2015		2014
	Regulatory Assets:
	Current:
	Pension and postretirement benefit costs	$	21.4	$	21.4	$	15	$	15	$	6.4	$	6.4
	Unamortized purchased gas adjustments	—		54		—		54		—		—
	Other	6		5.4		2.4		3		3.6		2.4
	Total Regulatory Assets (current)	27.4		80.8		17.4		72		10		8.8
	Non-current:
	Future income taxes due from customers	125.6		117		125.6		117		—		—
	Pension and postretirement benefit costs	420.8		431.5		357.9		365.4		62.9		66.1
	Accretion and depreciation of asset retirement obligations	19.1		18.4		—		—		19.1		18.4
	Purchased gas costs	18.6		4.3		18.6		4.3		—		—
	Energy efficiency	20.4		18.9		20.4		18.9		—		—
	Other	28.4		24.2		22.8		18.1		5.6		6.1
	Total Regulatory Assets (non-current)	632.9		614.3		545.3		523.7		87.6		90.6
	Total Regulatory Assets	$	660.3	$	695.1	$	562.7	$	595.7	$	97.6	$	99.4
	Regulatory Liabilities:
	Current:
	RSE adjustment	$	9.9	$	19.8	$	—	$	—	$	9.9	$	19.8
	Unbilled service margin	15		5.2		—		—		15		5.2
	Refundable negative salvage	10.8		13.4		—		—		10.8		13.4
	Unamortized purchased gas adjustments	76.7		22.4		39.1		—		37.6		22.4
	Other	2.8		2.9		0.6		0.6		2.2		2.3
	Total Regulatory Liabilities (current)	115.2		63.7		39.7		0.6		75.5		63.1
	Non-current:
	Postretirement liabilities	25.1		26.2		—		—		25.1		26.2
	Refundable negative salvage	17		26.8		—		—		17		26.8
	Accrued cost of removal	59.9		60.5		59.9		60.5		—		—
	Other	12.3		12.3		11.8		11.6		0.7		0.7
	Total Regulatory Liabilities (non-current)	114.3		125.8		71.7		72.1		42.8		53.7
	Total Regulatory Liabilities	$	229.5	$	189.5	$	111.4	$	72.7	$	118.3	$	116.8

FAIR_VALUE_OF_FINANCIAL_INSTRU1

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	6 Months Ended
	Mar. 31, 2015
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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	46.9	$	46.9	$	46.9	$	—	$	—
	Short-term debt	247.6		247.6		—		247.6		—
	Long-term debt, including current portion	1,816.30		1,971.00		—		1,971.00		—
	As of September 30, 2014
	Cash and cash equivalents	$	16.1	$	16.1	$	16.1	$	—	$	—
	Short-term debt	287.1		287.1		—		287.1		—
	Long-term debt	1,851.00		1,937.30		—		1,937.30		—
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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	9.3	$	9.3	$	9.3	$	—	$	—
	Short-term debt	153		—		—		153		—
	Long-term debt	808		909.5		—		909.5		—
	As of September 30, 2014
	Cash and cash equivalents	$	3.7	$	3.7	$	3.7	$	—	$	—
	Short-term debt	238.6		238.6		—		238.6		—
	Long-term debt	807.9		876.2		—		876.2		—
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
	($ Millions)	Carrying		Fair		Quoted		Significant Observable Inputs		Significant Unobservable Inputs
		Amount		Value		Prices in Active Markets		(Level 2)		(Level 3)
						(Level 1)
	As of March 31, 2015
	Cash and cash equivalents	$	35.4	$	35.4	$	35.4	$	—	$	—
	Short-term debt	25		25		—		25		—
	Long-term debt, including current portion	215		235.1		—		235.1		—
	As of September 30, 2014
	Cash and cash equivalents	$	5.6	$	5.6	$	5.6	$	—	$	—
	Short-term debt	16		16		—		16		—
	Long-term debt	249.8		266.4		—		266.4		—

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Mar. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Measured on Recurring Basis	The following tables for Laclede Group, Laclede Gas, and Alagasco categorize the assets and liabilities in the balance sheets that are accounted for at fair value on a recurring basis in periods subsequent to initial recognition.
	The mutual funds included in Level 1 are valued based on exchange-quoted market prices of individual securities. The mutual funds included in Level 2 are valued based on the closing net asset value per unit.
	Derivative instruments included in Level 1 are valued using quoted market prices on the New York Mercantile Exchange (NYMEX). Derivative instruments classified in 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. The Alagasco interest rate swaps fall into this latter Level 2 classification. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. The Level 3 balances as of March 31, 2015 and September 30, 2014 consisted of gas commodity contracts. The Company’s and the Utilities' policy is to recognize transfers between the levels of the fair value hierarchy, if any, as of the beginning of the interim reporting period in which circumstances change or events occur to cause the transfer.
	The mutual funds are included in 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 exists between the Company or Laclede Gas and the counterparty to a derivative contract.
	Laclede Group
	($ Millions)	Quoted		Significant		Significant		Effects of Netting and Cash Margin Receivables			Total
		Prices in		Observable		Unobservable		/Payables
		Active		Inputs		Inputs
		Markets		(Level 2)		(Level 3)
		(Level 1)
	As of March 31, 2015
	ASSETS
	Gas Utility
	U. S. stock/bond mutual funds	$	16.4	$	3.9	$	—	$	—		$	20.3
	NYMEX natural gas contracts	0.6		—		—		(0.6		)	—
	Subtotal	17		3.9		—		(0.6		)	20.3
	Gas Marketing
	NYMEX natural gas contracts	3.4		1.7		—		(4.3		)	0.8
	Natural gas commodity contracts	—		2.7		0.5		(0.5		)	2.7
	Total	$	20.4	$	8.3	$	0.5	$	(5.4	)	$	23.8
	LIABILITIES
	Gas Utility
	NYMEX/ICE natural gas contracts	$	14.1	$	—	$	—	$	(14.1	)	$	—
	OTCBB natural gas contracts	—		14.5		—		—			14.5
	NYMEX gasoline and heating oil contracts	1		—		—		(1.0		)	—
	Interest rate swaps	—		2.9		—		—			2.9
	Subtotal	15.1		17.4		—		(15.1		)	17.4
	Gas Marketing
	NYMEX natural gas contracts	1.9		3.5		—		(5.4		)	—
	Natural gas commodity contracts	—		0.8		—		(0.5		)	0.3
	Total	$	17	$	21.7	$	—	$	(21.0	)	$	17.7
	As of September 30, 2014
	ASSETS
	Gas Utility
	U. S. stock/bond mutual funds	$	15.7	$	3.9	$	—	$	—		$	19.6
	NYMEX natural gas contracts	2.4		—		—		(2.4		)	—
	OTCBB natural gas contracts	—		0.1		—		(0.1		)	—
	Subtotal	18.1		4		—		(2.5		)	19.6
	Gas Marketing
	NYMEX natural gas contracts	1		1.2		—		(1.8		)	0.4
	Natural gas commodity contracts	—		2.7		0.2		(0.2		)	2.7
	Total	$	19.1	$	7.9	$	0.2	$	(4.5	)	$	22.7
	LIABILITIES
	Gas Utility
	NYMEX/ICE natural gas contracts	$	5.2	$	—	$	—	$	(5.2	)	$	—
	OTCBB natural gas contracts	—		4.1		—		(0.1		)	4
	Gasoline and heating oil contracts	0.2		—		—		(0.2		)	—
	Subtotal	5.4		4.1		—		(5.5		)	4
	Gas Marketing
	NYMEX natural gas contracts	1.1		0.7		—		(1.8		)	—
	Natural gas commodity contracts	—		0.7		—		(0.2		)	0.5
	Total	$	6.5	$	5.5	$	—	$	(7.5	)	$	4.5
Laclede Gas
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Measured on Recurring Basis
	($ Millions)	Quoted		Significant		Significant		Effects of Netting and Cash Margin Receivables			Total
		Prices in		Observable		Unobservable		/Payables
		Active		Inputs		Inputs
		Markets		(Level 2)		(Level 3)
		(Level 1)
	As of March 31, 2015
	ASSETS
	U. S. stock/bond mutual funds	$	16.4	$	3.9	$	—	$	—		$	20.3
	NYMEX natural gas contracts	0.6		—		—		(0.6		)	—
	Total	17		3.9		—		(0.6		)	20.3
	LIABILITIES
	NYMEX natural gas contracts	14.1		—		—		(14.1		)	—
	OTCBB natural gas contracts	—		14.5		—		—			14.5
	Gasoline and heating oil contracts	1		—		—		(1.0		)	—
	Total	$	15.1	$	14.5	$	—	$	(15.1	)	$	14.5
	As of September 30, 2014
	ASSETS
	U. S. stock/bond mutual funds	$	15.7	$	3.9	$	—	$	—		$	19.6
	NYMEX natural gas contracts	2.4		—		—		(2.4		)	—
	OTCBB natural gas contracts	—		0.1		—		(0.1		)	—
	Total	18.1		4		—		(2.5		)	19.6
	LIABILITIES
	NYMEX/ICE natural gas contracts	5.2		—		—		(5.2		)	—
	OTCBB natural gas contracts	—		4.1		—		(0.1		)	4
	NYMEX gasoline and heating oil contracts	0.2		—		—		(0.2		)	—
	Total	$	5.4	$	4.1	$	—	$	(5.5	)	$	4

PENSION_PLANS_AND_OTHER_POSTRE1

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Tables)	6 Months Ended
	Mar. 31, 2015
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost	The net periodic pension cost included the following components:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group
	Service cost – benefits earned during the period	$	4.3		$	2.5		$	8.6		$	4.9
	Interest cost on projected benefit obligation	7.4			6			14.9			12
	Expected return on plan assets	(9.3		)	(6.7		)	(18.7		)	(13.3		)
	Amortization of prior service cost	0.1			0.1			0.2			0.2
	Amortization of actuarial loss	2			1.7			3.9			3.5
	Loss on lump-sum settlements	—			1.3			—			1.3
	Sub-total	4.5			4.9			8.9			8.6
	Regulatory adjustment	4.8			1.6			9.7			4.5
	Net pension cost	$	9.3		$	6.5		$	18.6		$	13.1
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost	Net periodic postretirement benefit cost for the Company consisted of the following components:
		Three Months Ended						Six Months Ended
		March 31,						March 31,
	($ Millions)	2015			2014			2015			2014
	Laclede Group
	Service cost – benefits earned during the period	$	3.2		$	2.8		$	6.4		$	5.6
	Interest cost on accumulated postretirement benefit obligation	2.8			2.2			5.6			4.4
	Expected return on plan assets	(3.3		)	(1.7		)	(6.6		)	(3.4		)
	Amortization of prior service credit	0.2			—			0.4			—
	Amortization of actuarial loss	1.2			1.5			2.5			3
	Sub-total	4.1			4.8			8.3			9.6
	Regulatory adjustment	(2.7		)	(2.4		)	(5.4		)	(4.8		)
	Net postretirement benefit cost	$	1.4		$	2.4		$	2.9		$	4.8
Laclede Gas | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost
	Laclede Gas
	Service cost – benefits earned during the period	$	2.9		$	2.5		$	5.7		$	4.9
	Interest cost on projected benefit obligation	5.9			6			11.8			12
	Expected return on plan assets	(7.3		)	(6.7		)	(14.6		)	(13.3		)
	Amortization of prior service cost	0.1			0.1			0.2			0.2
	Amortization of actuarial loss	2			1.7			3.9			3.5
	Loss on lump-sum settlements	—			1.3			—			1.3
	Sub-total	3.6			4.9			7			8.6
	Regulatory adjustment	3.4			1.6			6.8			4.5
	Net pension cost	$	7		$	6.5		$	13.8		$	13.1
Laclede Gas | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost
	Laclede Gas
	Service cost – benefits earned during the period	$	3.1		$	2.8		$	6.2		$	5.6
	Interest cost on accumulated postretirement benefit obligation	2.2			2.2			4.3			4.4
	Expected return on plan assets	(2.1		)	(1.7		)	(4.1		)	(3.4		)
	Amortization of prior service cost	0.2			—			0.4			—
	Amortization of actuarial loss	1.2			1.5			2.5			3
	Sub-total	4.6			4.8			9.3			9.6
	Regulatory adjustment	(2.3		)	(2.4		)	(4.6		)	(4.8		)
	Net postretirement benefit cost	$	2.3		$	2.4		$	4.7		$	4.8
Alagasco | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost
	Alagasco
	Service cost – benefits earned during the period	$	1.4		$	1.5		$	2.9		$	3.6
	Interest cost on projected benefit obligation	1.5			1.2			3.1			2.9
	Expected return on plan assets	(2.0		)	(1.5		)	(4.1		)	(3.7		)
	Amortization of prior service cost	—			0.1			—			0.1
	Amortization of actuarial loss	—			0.7			—			2
	Loss on lump-sum settlements	—			10.1			—			10.9
	Sub-total	0.9			12.1			1.9			15.8
	Regulatory adjustment	1.4			(9.8		)	2.9			(10.6		)
	Net pension cost	$	2.3		$	2.3		$	4.8		$	5.2
Alagasco | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Cost
	Alagasco
	Service cost – benefits earned during the period	$	0.1		$	0.1		$	0.2		$	0.4
	Interest cost on accumulated postretirement benefit obligation	0.6			0.5			1.3			1.2
	Expected return on plan assets	(1.2		)	(1.1		)	(2.5		)	(2.1		)
	Amortization of actuarial loss and other	—			(0.4		)	—			(0.5		)
	Amortization of transition obligation	—			0.1			—			0.3
	Sub-total	(0.5		)	(0.8		)	(1.0		)	(0.7		)
	Regulatory adjustment	(0.4		)	—			(0.8		)	—
	Net postretirement benefit cost	$	(0.9	)	$	(0.8	)	$	(1.8	)	$	(0.7	)

INFORMATION_BY_OPERATING_SEGME1

INFORMATION BY OPERATING SEGMENT (Tables)	6 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of operating segment information
	($ Millions)	Gas Utility			Gas Marketing			Other			Eliminations			Consolidated
	Three Months Ended March 31, 2015
	Operating Revenues:
	Revenues from external customers	$	847		$	30		$	0.4		$	—		$	877.4
	Intersegment revenues	2			14.1			0.5			(16.6		)	—
	Total Operating Revenues	849			44.1			0.9			(16.6		)	877.4
	Operating Expenses:
	Gas Utility
	Natural and propane gas	499.1			—			—			(16.3		)	482.8
	Other operation and maintenance	104			—			—			(0.2		)	103.8
	Depreciation and amortization	32.2			—			—			—			32.2
	Taxes, other than income taxes	55.7			—			—			—			55.7
	Total Gas Utility Operating Expenses	691			—			—			(16.5		)	674.5
	Gas Marketing	—			43.5			—			—			43.5
	Other	—			—			1.8			(0.1		)	1.7
	Total Operating Expenses	691			43.5			1.8			(16.6		)	719.7
	Operating Income (Loss)	$	158		$	0.6		$	(0.9	)	$	—		$	157.7
	Net Economic Earnings (Loss)	$	96.5		$	2.1		$	(1.0	)	$	—		$	97.6
	Three Months Ended March 31, 2014
	Operating Revenues:
	Revenues from external customers	$	634.4		$	59.9		$	0.2		$	—		$	694.5
	Intersegment revenues	4.2			20.6			0.6			(25.4		)	—
	Total Operating Revenues	638.6			80.5			0.8			(25.4		)	694.5
	Operating Expenses:
	Gas Utility
	Natural and propane gas	430.5			—			—			(25.2		)	405.3
	Other operation and maintenance	72.2			—			—			(0.2		)	72
	Depreciation and amortization	20.1			—			—			—			20.1
	Taxes, other than income taxes	41.8			—			—			—			41.8
	Total Gas Utility Operating Expenses	564.6			—			—			(25.4		)	539.2
	Gas Marketing	—			65			—			—			65
	Other	—			—			3.1			—			3.1
	Total Operating Expenses	564.6			65			3.1			(25.4		)	607.3
	Operating Income (Loss)	$	74		$	15.5		$	(2.3	)	$	—		$	87.2
	Net Economic Earnings (Loss)	$	44.7		$	7.1		$	(0.1	)	$	—		$	51.7
	($ Millions)	Gas Utility			Gas Marketing			Other			Eliminations			Consolidated
	Six Months Ended March 31, 2015
	Operating Revenues:
	Revenues from external customers	$	1,428.40		$	67.8		$	0.8		$	—		$	1,497.00
	Intersegment revenues	3			38.5			1			(42.5		)	—
	Total Operating Revenues	1,431.40			106.3			1.8			(42.5		)	1,497.00
	Operating Expenses:
	Gas Utility
	Natural and propane gas	828.9			—			—			(41.8		)	787.1
	Other operation and maintenance	201.4			—			—			(0.5		)	200.9
	Depreciation and amortization	64.2			—			—			—			64.2
	Taxes, other than income taxes	93.7			—			—			—			93.7
	Total Gas Utility Operating Expenses	1,188.20			—			—			(42.3		)	1,145.90
	Gas Marketing	—			102.1			—			—			102.1
	Other	—			—			4.2			(0.2		)	4
	Total Operating Expenses	1,188.20			102.1			4.2			(42.5		)	1,252.00
	Operating Income (Loss)	$	243.2		$	4.2		$	(2.4	)	$	—		$	245
	Net Economic Earnings (Loss)	$	146.3		$	2.5		$	(5.5	)	$	—		$	143.3
	Six Months Ended March 31, 2014
	Operating Revenues:
	Revenues from external customers	$	1,069.60		$	93.1		$	0.4		$	—		$	1,163.10
	Intersegment revenues	4.3			40.1			1			(45.4		)	—
	Total Operating Revenues	1,073.90			133.2			1.4			(45.4		)	1,163.10
	Operating Expenses:
	Gas Utility
	Natural and propane gas	692.1			—			—			(45.0		)	647.1
	Other operation and maintenance	134.7			—			—			(0.4		)	134.3
	Depreciation and amortization	40.1			—			—			—			40.1
Taxes, other than income taxes	70.4			—			—			—			70.4
Total Gas Utility Operating Expenses	937.3			—			—			(45.4		)	891.9
Gas Marketing	—			116.8			—			—			116.8
Other	—			—			4.3			—			4.3
Total Operating Expenses	937.3			116.8			4.3			(45.4		)	1,013.00
Operating Income (Loss)	$	136.6		$	16.4		$	(2.9	)	$	—		$	150.1
Net Economic Earnings (Loss)	$	80.5		$	7.9		$	(0.4	)	$	—		$	88
The Company's total assets by segment were as follows:
	March 31,			September 30,
($ Millions)	2015			2014
Total Assets:
Gas Utility	$	4,615.60		$	4,520.00
Gas Marketing	131.7			156.7
Other	1,590.80			1,575.70
Eliminations	(1,157.4		)	(1,178.4		)
Total Assets	$	5,180.70		$	5,074.00
Schedule of the reconciliation of consolidated net economic earnings to consolidated net income	The following table reconciles the Company's Net Income (GAAP) to Net Economic Earnings (Non-GAAP):
		Three Months Ended March 31,						Six Months Ended March 31,
	($ Millions)	2015			2014			2015			2014
	Net income (GAAP)	$	94.4		$	52.2		$	141.5		$	87.8
	Unrealized loss (gain) on energy-related derivative contracts	2.6			(1.7		)	(0.4		)	(1.3		)
	Lower of cost or market inventory adjustments	(1.0		)	(0.5		)	0.2			(0.6		)
	Realized loss (gain) on economic hedges prior to sale of the physical commodity	0.1			(0.1		)	0.1			(0.1		)
	Acquisition, divestiture and restructuring activities	1.5			1.8			1.9			2.2
	Net Economic Earnings (Non-GAAP)	$	97.6		$	51.7		$	143.3		$	88

SUMMARY_OF_SIGNIFICANT_ACCOUNT3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) (USD $)	6 Months Ended	12 Months Ended	0 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014	Jan. 06, 2015	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2013	Dec. 31, 2014
	Operating_Segment
Related Party Transaction [Line Items]
Number of operating segments	2
Goodwill	$946	$937.80		$946
Stockholders' Equity	1,611.60	1,508.40		1,611.60	1,106.60	1,046.30
Laclede Gas
Related Party Transaction [Line Items]
Accrued unbilled revenues	63.5	29.4		63.5
Goodwill	210.2	210.2		210.2
Accruals for capital expenditures	4.2	3
Stockholders' Equity	1,058.60	1,007.80		1,058.60	1,027.60	973.9
Alagasco
Related Party Transaction [Line Items]
Accrued unbilled revenues	15	5.2		15
Accruals for capital expenditures	4.7	5
Stockholders' Equity	908.9	849.6		908.9	416.8	364.7
Missouri Gas Energy (MGE)
Related Party Transaction [Line Items]
Goodwill	210.2	210.2		210.2
Missouri Gas Energy (MGE) | Laclede Gas
Related Party Transaction [Line Items]
Goodwill	210.2	210.2		210.2
Alagasco
Related Party Transaction [Line Items]
Goodwill	735.8	727.6		735.8			727.6
Final reconciliation of net assets payments to acquire businesses			8.6	8.6
Alagasco | Laclede Gas
Related Party Transaction [Line Items]
Goodwill	0	0		0
Common Stock Issued
Related Party Transaction [Line Items]
Stockholders' Equity	43.3	43.2		43.3	32.8	32.7
Common Stock Issued | Laclede Gas
Related Party Transaction [Line Items]
Stockholders' Equity	0.1	0.1		0.1	0.1	0.1
Common Stock Issued | Alagasco
Related Party Transaction [Line Items]
Stockholders' Equity	0	0		0	0	0
Common Stock Issued | Restatement Adjustment | Alagasco
Related Party Transaction [Line Items]
Stockholders' Equity	31.7			31.7
Paid-in Capital
Related Party Transaction [Line Items]
Stockholders' Equity	1,033.30	1,029.40		1,033.30	597.4	594.3
Paid-in Capital | Laclede Gas
Related Party Transaction [Line Items]
Stockholders' Equity	746.2	744		746.2	741	738.1
Paid-in Capital | Alagasco
Related Party Transaction [Line Items]
Stockholders' Equity	506.3	503.9		506.3	34.5	34.5
Paid-in Capital | Restatement Adjustment | Alagasco
Related Party Transaction [Line Items]
Stockholders' Equity	$31.70			$31.70

SUMMARY_OF_SIGNIFICANT_ACCOUNT4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Gross Receipts Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	$44.70	$34.30	$72.40	$54.30
Laclede Gas
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	33.9	34.3	55.8	54.3
Alagasco
Schedule of Gross Receipts Taxes [Line Items]
Gross Receipts taxes recorded in regulated gas distribution operating revenues	$10.80	$13	$16.60	$19.40

SUMMARY_OF_SIGNIFICANT_ACCOUNT5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Inter-company Transactions (Details) (Affiliated Entity, USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Regulated Operation | Laclede Gas | Laclede Energy Resources
Related Party Transaction [Line Items]
Revenue from related parties	$16	$25	$41.30	$44.50
Regulated Operation | Laclede Energy Resources | Laclede Gas
Related Party Transaction [Line Items]
Revenue from related parties	1.9	4.2	2.9	4.3
Unregulated Operation | Laclede Gas | Laclede Pipeline Company
Related Party Transaction [Line Items]
Revenue from related parties	$0.20	$0.20	$0.50	$0.50

SUMMARY_OF_SIGNIFICANT_ACCOUNT6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Goodwill (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014
In Millions, unless otherwise specified
Goodwill [Line Items]
Goodwill	$946		$937.80
Laclede Gas
Goodwill [Line Items]
Goodwill	210.2		210.2
Missouri Gas Energy (MGE)
Goodwill [Line Items]
Goodwill	210.2		210.2
Missouri Gas Energy (MGE) | Laclede Gas
Goodwill [Line Items]
Goodwill	210.2		210.2
Alagasco
Goodwill [Line Items]
Goodwill	735.8	727.6	727.6
Alagasco | Laclede Gas
Goodwill [Line Items]
Goodwill	$0		$0

ALAGASCO_ACQUISITION_Alabama_G

ALAGASCO ACQUISITION - Alabama Gas Corporation (Details) (USD $)	0 Months Ended		1 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Jan. 06, 2015	Sep. 02, 2014	Jan. 31, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 02, 2014
Business Acquisition [Line Items]
Goodwill				$946		$937.80
Alagasco
Business Acquisition [Line Items]
Percentage of voting interest acquired		100.00%					100.00%
Total consideration transferred		1,600
Payments to acquire businesses, net of cash acquired		1,305.20	1,313.80
Final reconciliation of net assets payments to acquire businesses	8.6			8.6
Goodwill				$735.80	$727.60	$727.60

EARNINGS_PER_COMMON_SHARE_Deta

EARNINGS PER COMMON SHARE (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Basic EPS:
Net Income	$94.40	$52.20	$141.50	$87.80
Less: Income allocated to participating securities	0.3	0.2	0.5	0.3
Net Income Available to Common Shareholders	94.1	52	141	87.5
Weighted Average Shares Outstanding, Basic (in Shares)	43.1	32.6	43.1	32.6
Basic Earnings Per Share of Common Stock (in dollars per share)	$2.18	$1.59	$3.27	$2.68
Diluted EPS:
Net Income	94.4	52.2	141.5	87.8
Less: Income allocated to participating securities	0.3	0.2	0.5	0.3
Net Income Available to Common Shareholders	$94.10	$52	$141	$87.50
Weighted Average Shares Outstanding, Basic (in Shares)	43.1	32.6	43.1	32.6
Dilutive Effect of Stock Options, Restricted Stock and Restricted Stock Units (in shares)	0.1	0	0.1	0.1
Weighted Average Diluted Shares (in shares)	43.2	32.6	43.2	32.7
Diluted Earnings Per Share of Common Stock (in dollars per share)	$2.18	$1.59	$3.26	$2.68
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)	0.4	0.3

REGULATORY_MATTERS_Schedule_of

REGULATORY MATTERS - Schedule of Regulatory Assets and Liabilities (Details) (USD $)	Mar. 31, 2015	Sep. 30, 2014
In Millions, unless otherwise specified
Regulatory Assets [Line Items]
Regulatory Assets: Current	$27.40	$26.80
Regulatory Assets: Non-current	632.9	614.3
Total Regulatory Assets	660.3	695.1
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	38.5	41.3
Regulatory Liabilities: Non-current	114.3	125.8
Total Regulatory Liabilities	229.5	189.5
RSE adjustment
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	9.9	19.8
Unbilled service margin
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	15	5.2
Refundable negative salvage
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	10.8	13.4
Regulatory Liabilities: Non-current	17	26.8
Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	76.7	22.4
Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	2.8	2.9
Regulatory Liabilities: Non-current	12.3	12.3
Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	25.1	26.2
Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	59.9	60.5
Total Regulatory Liabilities (current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	115.2	63.7
Total Regulatory Liabilities (non-current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	114.3	125.8
Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory Assets: Current	21.4	21.4
Regulatory Assets: Non-current	420.8	431.5
Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory Assets: Current	0	54
Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	125.6	117
Accretion and depreciation of asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	19.1	18.4
Purchased gas costs
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	18.6	4.3
Energy efficiency
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	20.4	18.9
Other
Regulatory Assets [Line Items]
Regulatory Assets: Current	6	5.4
Regulatory Assets: Non-current	28.4	24.2
Total Regulatory Assets (current)
Regulatory Assets [Line Items]
Regulatory Assets: Current	27.4	80.8
Total Regulatory Assets (non-current)
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	632.9	614.3
Laclede Gas
Regulatory Assets [Line Items]
Regulatory Assets: Current	17.4	18
Regulatory Assets: Non-current	545.3	523.7
Total Regulatory Assets	562.7	595.7
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	71.7	72.1
Total Regulatory Liabilities	111.4	72.7
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 | Refundable negative salvage
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	0	0
Regulatory Liabilities: Non-current	0	0
Laclede Gas | Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	39.1	0
Laclede Gas | Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	0.6	0.6
Regulatory Liabilities: Non-current	11.8	11.6
Laclede Gas | Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	0	0
Laclede Gas | Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	59.9	60.5
Laclede Gas | Total Regulatory Liabilities (current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	39.7	0.6
Laclede Gas | Total Regulatory Liabilities (non-current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	71.7	72.1
Laclede Gas | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory Assets: Current	15	15
Regulatory Assets: Non-current	357.9	365.4
Laclede Gas | Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory Assets: Current	0	54
Laclede Gas | Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	125.6	117
Laclede Gas | Accretion and depreciation of asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	0	0
Laclede Gas | Purchased gas costs
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	18.6	4.3
Laclede Gas | Energy efficiency
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	20.4	18.9
Laclede Gas | Other
Regulatory Assets [Line Items]
Regulatory Assets: Current	2.4	3
Regulatory Assets: Non-current	22.8	18.1
Laclede Gas | Total Regulatory Assets (current)
Regulatory Assets [Line Items]
Regulatory Assets: Current	17.4	72
Laclede Gas | Total Regulatory Assets (non-current)
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	545.3	523.7
Alagasco
Regulatory Assets [Line Items]
Regulatory Assets: Current	10	8.8
Regulatory Assets: Non-current	87.6	90.6
Total Regulatory Assets	97.6	99.4
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	37.9	40.7
Regulatory Liabilities: Non-current	42.8	53.7
Total Regulatory Liabilities	118.3	116.8
Alagasco | RSE adjustment
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	9.9	19.8
Alagasco | Unbilled service margin
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	15	5.2
Alagasco | Refundable negative salvage
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	10.8	13.4
Regulatory Liabilities: Non-current	17	26.8
Alagasco | Unamortized purchased gas adjustments
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	37.6	22.4
Alagasco | Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	2.2	2.3
Regulatory Liabilities: Non-current	0.7	0.7
Alagasco | Postretirement liabilities
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	25.1	26.2
Alagasco | Accrued cost of removal
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	0	0
Alagasco | Total Regulatory Liabilities (current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Current	75.5	63.1
Alagasco | Total Regulatory Liabilities (non-current)
Regulatory Liabilities [Line Items]
Regulatory Liabilities: Non-current	42.8	53.7
Alagasco | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory Assets: Current	6.4	6.4
Regulatory Assets: Non-current	62.9	66.1
Alagasco | Unamortized purchased gas adjustments
Regulatory Assets [Line Items]
Regulatory Assets: Current	0	0
Alagasco | Future income taxes due from customers
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	0	0
Alagasco | Accretion and depreciation of asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	19.1	18.4
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	3.6	2.4
Regulatory Assets: Non-current	5.6	6.1
Alagasco | Total Regulatory Assets (current)
Regulatory Assets [Line Items]
Regulatory Assets: Current	10	8.8
Alagasco | Total Regulatory Assets (non-current)
Regulatory Assets [Line Items]
Regulatory Assets: Non-current	$87.60	$90.60

REGULATORY_MATTERS_Schedule_of1

REGULATORY MATTERS - Schedule of Regulatory Assets Not Earnings a Return (Details) (USD $)	Mar. 31, 2015	Sep. 30, 2014
In Millions, unless otherwise specified
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$373.10	$373.90
Future income taxes due from customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	125.6	117
Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	232.3	240.9
Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	15.2	16
Laclede Gas
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	373.1	373.9
Laclede Gas | Future income taxes due from customers
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	125.6	117
Laclede Gas | Pension and postretirement benefit costs
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	232.3	240.9
Laclede Gas | Other
Regulatory Assets [Line Items]
Total Regulatory Assets Not Earning a Return	$15.20	$16

REGULATORY_MATTERS_Details

REGULATORY MATTERS (Details)	6 Months Ended
	Mar. 31, 2015
Regulated Operations [Abstract]
Remaining recovery period for regulatory assets for which no return on investment during recovery period is provided	15 years

FAIR_VALUE_OF_FINANCIAL_INSTRU2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $)	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$46.90	$16.10	$10.90	$53
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	46.9	16.1
Short-term debt	247.6	287.1
Long-term debt, including current portion	1,816.30	1,851
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	46.9	16.1
Short-term debt	247.6	287.1
Long-term debt, including current portion	1,971	1,937.30
Laclede Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	9.3	3.7	5	23.9
Laclede Gas | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	9.3	3.7
Short-term debt	153	238.6
Long-term debt, including current portion	808	807.9
Laclede Gas | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	9.3	3.7
Short-term debt	0	238.6
Long-term debt, including current portion	909.5	876.2
Alagasco
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	35.4	5.6	34.1	8.5
Alagasco | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	35.4	5.6
Short-term debt	25	16
Long-term debt, including current portion	215	249.8
Alagasco | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	35.4	5.6
Short-term debt	25	16
Long-term debt, including current portion	235.1	266.4
Quoted Prices in Active Markets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	46.9	16.1
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	9.3	3.7
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	35.4	5.6
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	247.6	287.1
Long-term debt, including current portion	1,971	1,937.30
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	153	238.6
Long-term debt, including current portion	909.5	876.2
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	25	16
Long-term debt, including current portion	235.1	266.4
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) (Fair Value, Measurements, Recurring, USD $)	Mar. 31, 2015	Sep. 30, 2014
In Millions, unless otherwise specified
ASSETS
Total	$23.80	$22.70
LIABILITIES
Total	17.7	4.5
Quoted Prices in Active Markets (Level 1)
ASSETS
Total	20.4	19.1
LIABILITIES
Total	17	6.5
Significant Observable Inputs (Level 2)
ASSETS
Total	8.3	7.9
LIABILITIES
Total	21.7	5.5
Significant Unobservable Inputs (Level 3)
ASSETS
Total	0.5	0.2
LIABILITIES
Total	0	0
Effects of Netting and Cash Margin Receivables /Payables
ASSETS
Total	-5.4	-4.5
LIABILITIES
Total	-21	-7.5
Gas Utility
ASSETS
U. S. Stock/Bond Mutual Funds	20.3	19.6
NYMEX natural gas contracts	0	0
OTCBB natural gas contracts		0
Total	20.3	19.6
LIABILITIES
NYMEX/ICE natural gas contracts	0	0
OTCBB natural gas contracts	14.5	4
NYMEX gasoline and heating oil contracts	0	0
Interest rate swaps	2.9
Total	17.4	4
Gas Utility | Quoted Prices in Active Markets (Level 1)
ASSETS
U. S. Stock/Bond Mutual Funds	16.4	15.7
NYMEX natural gas contracts	0.6	2.4
OTCBB natural gas contracts		0
Total	17	18.1
LIABILITIES
NYMEX/ICE natural gas contracts	14.1	5.2
OTCBB natural gas contracts	0	0
NYMEX gasoline and heating oil contracts	1	0.2
Interest rate swaps	0
Total	15.1	5.4
Gas Utility | Significant Observable Inputs (Level 2)
ASSETS
U. S. Stock/Bond Mutual Funds	3.9	3.9
NYMEX natural gas contracts	0	0
OTCBB natural gas contracts		0.1
Total	3.9	4
LIABILITIES
NYMEX/ICE natural gas contracts	0	0
OTCBB natural gas contracts	14.5	4.1
NYMEX gasoline and heating oil contracts	0	0
Interest rate swaps	2.9
Total	17.4	4.1
Gas Utility | Significant Unobservable Inputs (Level 3)
ASSETS
U. S. Stock/Bond Mutual Funds	0	0
NYMEX natural gas contracts	0	0
Total	0	0
LIABILITIES
NYMEX/ICE natural gas contracts	0	0
OTCBB natural gas contracts	0	0
NYMEX gasoline and heating oil contracts	0	0
Interest rate swaps	0
Total	0	0
Gas Utility | Effects of Netting and Cash Margin Receivables /Payables
ASSETS
U. S. Stock/Bond Mutual Funds	0	0
NYMEX natural gas contracts	-0.6	-2.4
OTCBB natural gas contracts		-0.1
Total	-0.6	-2.5
LIABILITIES
NYMEX/ICE natural gas contracts	-14.1	-5.2
OTCBB natural gas contracts	0	-0.1
NYMEX gasoline and heating oil contracts	-1	-0.2
Interest rate swaps	0
Total	-15.1	-5.5
Gas Marketing
ASSETS
NYMEX natural gas contracts	0.8	0.4
Natural gas commodity contracts	2.7	2.7
LIABILITIES
NYMEX natural gas contracts	0	0
Natural gas commodity contracts	0.3	0.5
Gas Marketing | Quoted Prices in Active Markets (Level 1)
ASSETS
NYMEX natural gas contracts	3.4	1
Natural gas commodity contracts	0	0
LIABILITIES
NYMEX natural gas contracts	1.9	1.1
Natural gas commodity contracts	0	0
Gas Marketing | Significant Observable Inputs (Level 2)
ASSETS
NYMEX natural gas contracts	1.7	1.2
Natural gas commodity contracts	2.7	2.7
LIABILITIES
NYMEX natural gas contracts	3.5	0.7
Natural gas commodity contracts	0.8	0.7
Gas Marketing | Significant Unobservable Inputs (Level 3)
ASSETS
NYMEX natural gas contracts	0	0
Natural gas commodity contracts	0.5	0.2
LIABILITIES
NYMEX natural gas contracts	0	0
Natural gas commodity contracts	0	0
Gas Marketing | Effects of Netting and Cash Margin Receivables /Payables
ASSETS
NYMEX natural gas contracts	-4.3	-1.8
Natural gas commodity contracts	-0.5	-0.2
LIABILITIES
NYMEX natural gas contracts	-5.4	-1.8
Natural gas commodity contracts	-0.5	-0.2
Laclede Gas
ASSETS
U. S. Stock/Bond Mutual Funds	20.3	19.6
NYMEX natural gas contracts	0	0
OTCBB natural gas contracts		0
Total	20.3	19.6
LIABILITIES
NYMEX/ICE natural gas contracts		0
OTCBB natural gas contracts	14.5	4
NYMEX gasoline and heating oil contracts	0	0
NYMEX natural gas contracts	0
Total	14.5	4
Laclede Gas | Quoted Prices in Active Markets (Level 1)
ASSETS
U. S. Stock/Bond Mutual Funds	16.4	15.7
NYMEX natural gas contracts	0.6	2.4
OTCBB natural gas contracts		0
Total	17	18.1
LIABILITIES
NYMEX/ICE natural gas contracts		5.2
OTCBB natural gas contracts	0	0
NYMEX gasoline and heating oil contracts	1	0.2
NYMEX natural gas contracts	14.1
Total	15.1	5.4
Laclede Gas | Significant Observable Inputs (Level 2)
ASSETS
U. S. Stock/Bond Mutual Funds	3.9	3.9
NYMEX natural gas contracts	0	0
OTCBB natural gas contracts		0.1
Total	3.9	4
LIABILITIES
NYMEX/ICE natural gas contracts		0
OTCBB natural gas contracts	14.5	4.1
NYMEX gasoline and heating oil contracts	0	0
NYMEX natural gas contracts	0
Total	14.5	4.1
Laclede Gas | Significant Unobservable Inputs (Level 3)
ASSETS
U. S. Stock/Bond Mutual Funds	0	0
NYMEX natural gas contracts	0	0
Total	0	0
LIABILITIES
NYMEX/ICE natural gas contracts		0
OTCBB natural gas contracts	0	0
NYMEX gasoline and heating oil contracts	0	0
NYMEX natural gas contracts	0
Total	0	0
Laclede Gas | Effects of Netting and Cash Margin Receivables /Payables
ASSETS
U. S. Stock/Bond Mutual Funds	0	0
NYMEX natural gas contracts	-0.6	-2.4
OTCBB natural gas contracts		-0.1
Total	-0.6	-2.5
LIABILITIES
NYMEX/ICE natural gas contracts		-5.2
OTCBB natural gas contracts	0	-0.1
NYMEX gasoline and heating oil contracts	-1	-0.2
NYMEX natural gas contracts	-14.1
Total	-15.1	-5.5
Alagasco
LIABILITIES
Interest rate swaps	2.9	0
Total	2.9	0
Alagasco | Quoted Prices in Active Markets (Level 1)
LIABILITIES
Interest rate swaps	0	0
Total	0	0
Alagasco | Significant Observable Inputs (Level 2)
LIABILITIES
Interest rate swaps	2.9	0
Total	2.9	0
Alagasco | Significant Unobservable Inputs (Level 3)
LIABILITIES
Interest rate swaps	0	0
Total	0	0
Alagasco | Effects of Netting and Cash Margin Receivables /Payables
LIABILITIES
Interest rate swaps	0	0
Total	$0	$0

CONCENTRATIONS_OF_CREDIT_RISK_

CONCENTRATIONS OF CREDIT RISK (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified	counterparty
Concentration Risk [Line Items]
Number of large counterparties for which credit risk is disclosed	5
Energy Producers And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	7.5
Net receivable amount	5.7
Utility Companies And Their Affiliates
Concentration Risk [Line Items]
Accounts receivable	15.6
Net receivable amount	14.1
Largest Counterparties
Concentration Risk [Line Items]
Accounts receivable	9.8
Net receivable amount	9.3

PENSION_PLANS_AND_OTHER_POSTRE2

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Extent of lump-sum payments recognized, percentage			100.00%
Medical insurance available until age is reached after early retirement			65 years
Amortization period for transition obligation excluded from postretirement benefit cost (in years)			20 years
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amortization of actuarial loss	$2,000,000	$1,700,000	$3,900,000	$3,500,000
Pension Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions made by employer			9,100,000
Pension Plans | Missouri Gas Energy (MGE)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Lump-sum payments recognized as settlements			12,700,000
Anticipated contributions to pension plans for qualified trust			17,300,000
Pension Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Lump-sum payments recognized as settlements			2,600,000
Contributions made by employer			0
Anticipated contributions to pension plans for qualified trust			0
Amortization of actuarial loss	0	700,000	0	2,000,000
Nonqualified Pension Plans | Laclede Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions made by employer			200,000
Nonqualified Pension Plans | Missouri Gas Energy (MGE)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to pension plans for qualified trust			300,000
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to pension plans for qualified trust			13,600,000
Amortization of actuarial loss	1,200,000	1,500,000	2,500,000	3,000,000
Anticipated payment directly to participants in postretirement plan			300,000
Postretirement Plans | Missouri Gas Energy (MGE)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions made by employer			4,400,000
Postretirement Plans | Alagasco
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amortization of actuarial loss	$0	($400,000)	$0	($500,000)

PENSION_PLANS_AND_OTHER_POSTRE3

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Net Periodic Cost (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	$4.30	$2.50	$8.60	$4.90
Interest cost on projected benefit obligation	7.4	6	14.9	12
Expected return on plan assets	-9.3	-6.7	-18.7	-13.3
Amortization of prior service cost	0.1	0.1	0.2	0.2
Amortization of actuarial loss	2	1.7	3.9	3.5
Loss on lump-sum settlements	0	1.3	0	1.3
Sub-total	4.5	4.9	8.9	8.6
Regulatory adjustment	4.8	1.6	9.7	4.5
Net pension cost	9.3	6.5	18.6	13.1
Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	3.2	2.8	6.4	5.6
Interest cost on projected benefit obligation	2.8	2.2	5.6	4.4
Expected return on plan assets	-3.3	-1.7	-6.6	-3.4
Amortization of prior service cost	0.2	0	0.4	0
Amortization of actuarial loss	1.2	1.5	2.5	3
Sub-total	4.1	4.8	8.3	9.6
Regulatory adjustment	-2.7	-2.4	-5.4	-4.8
Net pension cost	1.4	2.4	2.9	4.8
Laclede Gas | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	2.9	2.5	5.7	4.9
Interest cost on projected benefit obligation	5.9	6	11.8	12
Expected return on plan assets	-7.3	-6.7	-14.6	-13.3
Amortization of prior service cost	0.1	0.1	0.2	0.2
Amortization of actuarial loss	2	1.7	3.9	3.5
Loss on lump-sum settlements	0	1.3	0	1.3
Sub-total	3.6	4.9	7	8.6
Regulatory adjustment	3.4	1.6	6.8	4.5
Net pension cost	7	6.5	13.8	13.1
Laclede Gas | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	3.1	2.8	6.2	5.6
Interest cost on projected benefit obligation	2.2	2.2	4.3	4.4
Expected return on plan assets	-2.1	-1.7	-4.1	-3.4
Amortization of prior service cost	0.2	0	0.4	0
Amortization of actuarial loss	1.2	1.5	2.5	3
Sub-total	4.6	4.8	9.3	9.6
Regulatory adjustment	-2.3	-2.4	-4.6	-4.8
Net pension cost	2.3	2.4	4.7	4.8
Alagasco | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	1.4	1.5	2.9	3.6
Interest cost on projected benefit obligation	1.5	1.2	3.1	2.9
Expected return on plan assets	-2	-1.5	-4.1	-3.7
Amortization of prior service cost	0	0.1	0	0.1
Amortization of actuarial loss	0	0.7	0	2
Loss on lump-sum settlements	0	10.1	0	10.9
Sub-total	0.9	12.1	1.9	15.8
Regulatory adjustment	1.4	-9.8	2.9	-10.6
Net pension cost	2.3	2.3	4.8	5.2
Alagasco | Postretirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost – benefits earned during the period	0.1	0.1	0.2	0.4
Interest cost on projected benefit obligation	0.6	0.5	1.3	1.2
Expected return on plan assets	-1.2	-1.1	-2.5	-2.1
Amortization of transition obligation	0	0.1	0	0.3
Amortization of actuarial loss	0	-0.4	0	-0.5
Sub-total	-0.5	-0.8	-1	-0.7
Regulatory adjustment	-0.4	0	-0.8	0
Net pension cost	($0.90)	($0.80)	($1.80)	($0.70)

INFORMATION_BY_OPERATING_SEGME2

INFORMATION BY OPERATING SEGMENT - Schedule of Operating Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	$877.40	$694.50	$1,497	$1,163.10
Total Operating Revenues	877.4	694.5	1,497	1,163.10
Gas utility
Natural and propane gas	482.8	405.3	787.1	647.1
Other operation and maintenance expenses	103.8	72	200.9	134.3
Depreciation and amortization	32.2	20.1	64.2	40.1
Taxes, other than income taxes	55.7	41.8	93.7	70.4
Total Gas Utility Operating Expenses	674.5	539.2	1,145.90	891.9
Gas Marketing	43.5	65	102.1	116.8
Other	1.7	3.1	4	4.3
Total Operating Expenses	719.7	607.3	1,252	1,013
Operating Income	157.7	87.2	245	150.1
Net Economic Earnings (Loss)	97.6	51.7	143.3	88
ASSETS
Total Assets	5,180.70		5,180.70		5,074
Intersegment revenues
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	0	0	0	0
Gas Utility
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	847	634.4	1,428.40	1,069.60
Total Operating Revenues	849	638.6	1,431.40	1,073.90
Gas utility
Natural and propane gas	499.1	430.5	828.9	692.1
Other operation and maintenance expenses	104	72.2	201.4	134.7
Depreciation and amortization	32.2	20.1	64.2	40.1
Taxes, other than income taxes	55.7	41.8	93.7	70.4
Total Gas Utility Operating Expenses	691	564.6	1,188.20	937.3
Gas Marketing	0	0	0	0
Other	0	0	0	0
Total Operating Expenses	691	564.6	1,188.20	937.3
Operating Income	158	74	243.2	136.6
Net Economic Earnings (Loss)	96.5	44.7	146.3	80.5
ASSETS
Total Assets	4,615.60		4,615.60		4,520
Gas Utility | Intersegment revenues
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	2	4.2	3	4.3
Gas Marketing
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	30	59.9	67.8	93.1
Total Operating Revenues	44.1	80.5	106.3	133.2
Gas utility
Natural and propane gas	0	0	0	0
Other operation and maintenance expenses	0	0	0	0
Depreciation and amortization	0	0	0	0
Taxes, other than income taxes	0	0	0	0
Total Gas Utility Operating Expenses	0	0	0	0
Gas Marketing	43.5	65	102.1	116.8
Other	0	0	0	0
Total Operating Expenses	43.5	65	102.1	116.8
Operating Income	0.6	15.5	4.2	16.4
Net Economic Earnings (Loss)	2.1	7.1	2.5	7.9
ASSETS
Total Assets	131.7		131.7		156.7
Gas Marketing | Intersegment revenues
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	14.1	20.6	38.5	40.1
Other
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	0.4	0.2	0.8	0.4
Total Operating Revenues	0.9	0.8	1.8	1.4
Gas utility
Natural and propane gas	0	0	0	0
Other operation and maintenance expenses	0	0	0	0
Depreciation and amortization	0	0	0	0
Taxes, other than income taxes	0	0	0	0
Total Gas Utility Operating Expenses	0	0	0	0
Gas Marketing	0	0	0	0
Other	1.8	3.1	4.2	4.3
Total Operating Expenses	1.8	3.1	4.2	4.3
Operating Income	-0.9	-2.3	-2.4	-2.9
Net Economic Earnings (Loss)	-1	-0.1	-5.5	-0.4
ASSETS
Total Assets	1,590.80		1,590.80		1,575.70
Other | Intersegment revenues
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	0.5	0.6	1	1
Eliminations
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	0	0	0	0
Total Operating Revenues	-16.6	-25.4	-42.5	-45.4
Gas utility
Natural and propane gas	-16.3	-25.2	-41.8	-45
Other operation and maintenance expenses	-0.2	-0.2	-0.5	-0.4
Depreciation and amortization	0	0	0	0
Taxes, other than income taxes	0	0	0	0
Total Gas Utility Operating Expenses	-16.5	-25.4	-42.3	-45.4
Gas Marketing	0	0	0	0
Other	-0.1	0	-0.2	0
Total Operating Expenses	-16.6	-25.4	-42.5	-45.4
Operating Income	0	0	0	0
Net Economic Earnings (Loss)	0	0	0	0
ASSETS
Total Assets	-1,157.40		-1,157.40		-1,178.40
Eliminations | Intersegment revenues
Operating Segment Information [Abstract]
Total revenues including intersegment revenues	($16.60)	($25.40)	($42.50)	($45.40)

INFORMATION_BY_OPERATING_SEGME3

INFORMATION BY OPERATING SEGMENT - Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting [Abstract]
Net Income	$94.40	$52.20	$141.50	$87.80
Unrealized loss (gain) on energy-related derivative contracts	2.6	-1.7	-0.4	-1.3
Lower of cost or market inventory adjustments	-1	-0.5	0.2	-0.6
Realized loss (gain) on economic hedges prior to sale of the physical commodity	0.1	-0.1	0.1	-0.1
Acquisition, divestiture and restructuring activities	1.5	1.8	1.9	2.2
Net Economic Earnings (Non-GAAP)	$97.60	$51.70	$143.30	$88

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES - Commitments (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$1,595
Laclede Gas
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	750.4
Alagasco
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$521.50

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES - Contingencies (Details) (USD $)	Dec. 31, 2014	Aug. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	site		Resident
Loss Contingencies [Line Items]
Number of former manufactured gas plant (MGP) sites in Missouri	3
Number of former manufactured gas plant (MGP) sites in Shrewsbury, Missouri	1
Number of former manufactured gas plant (MGP) sites in the City of St. Louis	2
Minimum cost estimate for a one-time contractual transfer of risk		$8.10
Maximum cost estimate for a one-time contractual transfer of risk		$39.30
Alagasco
Loss Contingencies [Line Items]
Number of former manufactured gas plant (MGP)	9
Number of former manufactured gas distribution	5
Previous Ownership | Missouri Gas Energy (MGE)
Loss Contingencies [Line Items]
Number of former manufactured gas plant (MGP)	7
Previous Ownership | Laclede Gas
Loss Contingencies [Line Items]
Number of former manufactured gas plant (MGP)	19
Current Ownership | Alagasco
Loss Contingencies [Line Items]
Number of former manufactured gas plant (MGP)	4
Number of former manufactured gas distribution	1
Removal Action, Phase I | 35th Avenue Superfund Site
Loss Contingencies [Line Items]
Number of residents at high levels of contamination			50
Removal Action, Phase II | 35th Avenue Superfund Site
Loss Contingencies [Line Items]
Number of residents at high levels of contamination		30