CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock Issued	Paid-in Capital	Retained Earnings	Accum. Other Comp. Income (Loss)	Laclede Gas	Laclede Gas Common Stock Issued	Laclede Gas Paid-in Capital	Laclede Gas Retained Earnings	Laclede Gas Accum. Other Comp. Income (Loss)
BALANCE at Sep. 30, 2011	$ 573.3	$ 22.4	$ 163.7	$ 389.3	$ (2.1)	$ 434.0	$ 0.1	$ 212.9	$ 223.5	$ (2.5)
BALANCE (in shares) at Sep. 30, 2011		22,430,734					11,717
Stockholders' Equity Rollforward
Net income	62.6			62.6		49.9			49.9
Issuance of common stock to Laclede Group (in shares)							1,087
Issuance of common stock to Laclede Group						42.7		42.7
Dividend reinvestment plan	1.9	0.1	1.8
Dividend reinvestment plan (in shares)		46,107
Stock-based compensation costs	2.7		2.7			1.9		1.9
Equity Incentive Plan	2.5	0.1	2.4
Equity Incentive Plan (in shares)		62,590
Employees’ taxes paid associated with restricted shares withheld upon vesting	(1.2)		(1.2)
Non-employee directors’ restricted stock awards	(0.6)		(0.6)
Tax benefit - stock compensation	(0.2)		(0.2)			(0.2)		(0.2)
Dividends declared:
Common stock	(37.4)			(37.4)		(37.4)			(37.4)
Other comprehensive income, net of tax	(2.0)				(2.0)	0.4				0.4
BALANCE at Sep. 30, 2012	601.6	22.6	168.6	414.5	(4.1)	491.3	0.1	257.3	236.0	(2.1)
BALANCE (in shares) at Sep. 30, 2012		22,539,431					12,804
Stockholders' Equity Rollforward
Net income	25.6					25.7
BALANCE at Dec. 31, 2012
BALANCE at Sep. 30, 2012	601.6	22.6	168.6	414.5	(4.1)	491.3	0.1	257.3	236.0
BALANCE (in shares) at Sep. 30, 2012		22,539,431					12,804
Stockholders' Equity Rollforward
Net income	52.8			52.8		48.8			48.8
Issuance of common stock to Laclede Group (in shares)		10,005,000					11,745
Issuance of common stock to Laclede Group	427.2	10.0	417.2			477.2		477.2
Dividend reinvestment plan	1.8		1.8
Dividend reinvestment plan (in shares)	44,074	44,074
Stock-based compensation costs	4.4		4.4			3.1		3.1
Equity Incentive Plan	2.7	0.1	2.6
Equity Incentive Plan (in shares)		108,331
Employees’ taxes paid associated with restricted shares withheld upon vesting	(0.9)		(0.9)
Tax benefit - stock compensation	0.6		0.6			0.5		0.5
Dividends declared:
Common stock	(47.2)			(47.2)		(47.0)			(47.0)
Other comprehensive income, net of tax	3.3				3.3	0
BALANCE at Sep. 30, 2013	1,046.3	32.7	594.3	420.1	(0.8)	973.9	0.1	738.1	237.8
BALANCE (in shares) at Sep. 30, 2013	32,700,000	32,696,836				24,549	24,549
BALANCE at Jun. 30, 2013
Stockholders' Equity Rollforward
Net income	(9.6)					(10.5)
BALANCE at Sep. 30, 2013	1,046.3					973.9
BALANCE (in shares) at Sep. 30, 2013	32,700,000					24,549
Stockholders' Equity Rollforward
Net income	35.6					35.3
BALANCE at Dec. 31, 2013
BALANCE at Sep. 30, 2013	1,046.3	32.7	594.3	420.1	(0.8)	973.9	0.1	738.1	237.8	(2.1)
BALANCE (in shares) at Sep. 30, 2013	32,700,000	32,696,836				24,549	24,549
Stockholders' Equity Rollforward
Net income	84.6			84.6		90.1			90.1
Issuance of common stock to Laclede Group (in shares)		10,350,000					28
Issuance of common stock to Laclede Group	456.8	10.4	446.4			1.1		1.1
Equity units offering	(19.7)		(19.7)
Dividend reinvestment plan	1.5		1.5
Dividend reinvestment plan (in shares)		33,667
Stock-based compensation costs	5.8		5.8			4.2		4.2
Equity Incentive Plan	1.7	0.1	1.6
Equity Incentive Plan (in shares)		97,902
Employees’ taxes paid associated with restricted shares withheld upon vesting	(1.1)		(1.1)
Tax benefit - stock compensation	0.6		0.6			0.6		0.6
Dividends declared:
Common stock	(67.2)			(67.2)		(62.3)			(62.3)
Other comprehensive income, net of tax	(0.9)				(0.9)	0.2				0.2
BALANCE at Sep. 30, 2014	1,508.4	43.2	1,029.4	437.5	(1.7)	1,007.8	0.1	744.0	265.6	(1.9)
BALANCE (in shares) at Sep. 30, 2014	43,200,000	43,178,405				24,577	24,577
BALANCE at Jun. 30, 2014
Stockholders' Equity Rollforward
Net income	(14.9)					(1.4)
BALANCE at Sep. 30, 2014	$ 1,508.4					$ 1,007.8
BALANCE (in shares) at Sep. 30, 2014	43,200,000					24,577