Utility Regulatory Assets and Liabilities and Regulatory Matters (Tables)

9 Months Ended

Jun. 30, 2011

Utility Regulatory Assets and Liabilities and Regulatory Matters [Abstract]

Regulatory assets and liabilities associated with Gas Utility and Electric Utility

	June 30,		September 30,		June 30,
	2011		2010		2010
Regulatory assets:
Income taxes recoverable	$	92.7	$	82.5	$	95.3
Underfunded pension and postretirement plans		116.0		159.2		10.3
Environmental costs		20.7		22.6		24.3
Deferred fuel and power costs		7.8		36.6		6.3
Other		8.9		5.8		5.5
Total regulatory assets	$	246.1	$	306.7	$	141.7
Regulatory liabilities:
Postretirement benefits	$	11.6	$	10.5	$	10.3
Environmental overcollections		6.2		7.2		8.3
Deferred fuel and power refunds		22.4		8.3		16.6
State tax benefits — distribution system repairs		6.2		6.7		11.0
Total regulatory liabilities	$	46.4	$	32.7	$	46.2