Regulatory Assets and Liabilities and Regulatory Matters (Tables)

9 Months Ended

Jun. 30, 2012

Regulatory Assets and Liabilities Disclosure [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:

	June 30, 2012		September 30, 2011		June 30, 2011
Regulatory assets:
Income taxes recoverable	$	99,891	$	97,947	$	92,695
Underfunded pension and postretirement plans	144,613		150,669		116,003
Environmental costs	16,562		19,547		20,712
Deferred fuel and power costs	9,829		12,163		7,836
Removal costs, net	11,840		12,313		11,240
Other	8,312		7,816		8,852
Total regulatory assets	$	291,047	$	300,455	$	257,338
Regulatory liabilities:
Postretirement benefits	$	12,342	$	11,476	$	11,558
Environmental overcollections	3,726		4,758		6,182
Deferred fuel and power refunds	10,324		6,578		22,451
State tax benefits — distribution system repairs	6,961		6,282		6,166
Other	625		736		—
Total regulatory liabilities	$	33,978	$	29,830	$	46,357