CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Assets
Non-utility property (net of accumulated depreciation and amortization)	$ 7.4	$ 6.7
Capitalization:
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, authorized (in shares)	70,000,000.0	70,000,000.0
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)	$ 1.00	$ 1.00
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