Utility Regulatory Assets and Liabilities and Regulatory Matters (Tables)

6 Months Ended

Mar. 31, 2013

Regulated Operations [Abstract]

Regulatory assets and liabilities associated with Gas Utility and Electric Utility

The following regulatory assets and liabilities associated with Gas Utility and Electric Utility are included in our accompanying Condensed Consolidated Balance Sheets:

	March 31, 2013		September 30, 2012		March 31, 2012
Regulatory assets:
Income taxes recoverable	$	104.2	$	103.2	$	99.2
Underfunded pension and postretirement plans	181.3		188.2		146.6
Environmental costs	16.8		16.8		18.2
Deferred fuel and power costs	2.1		11.6		11.0
Removal costs, net	11.9		12.7		11.9
Other	6.0		5.9		8.8
Total regulatory assets	$	322.3	$	338.4	$	295.7
Regulatory liabilities:
Postretirement benefits	$	13.9	$	13.1	$	12.1
Environmental overcollections	3.0		2.9		3.8
Deferred fuel and power refunds	31.2		4.4		12.0
State tax benefits—distribution system repairs	7.9		7.4		6.7
Other	0.7		0.5		0.8
Total regulatory liabilities	$	56.7	$	28.3	$	35.4