Utility Regulatory Assets and Liabilities and Regulatory Matters (Tables)

3 Months Ended

Dec. 31, 2012

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:

	December 31, 2012		September 30, 2012		December 31, 2011
Regulatory assets:
Income taxes recoverable	$	103.7	$	103.2	$	98.7
Underfunded pension and postretirement plans	184.8		188.2		148.7
Environmental costs	17.1		16.8		19.4
Deferred fuel and power costs	7.8		11.6		14.8
Removal costs, net	11.5		12.7		11.9
Other	5.7		5.9		8.0
Total regulatory assets	$	330.6	$	338.4	$	301.5
Regulatory liabilities:
Postretirement benefits	$	13.5	$	13.1	$	11.8
Environmental overcollections	3.1		2.9		4.7
Deferred fuel and power refunds	1.9		4.4		5.0
State tax benefits—distribution system repairs	7.7		7.4		6.5
Other	0.6		0.5		0.4
Total regulatory liabilities	$	26.8	$	28.3	$	28.4