Regulatory Assets and Liabilities and Regulatory Matters (Tables)

3 Months Ended

Dec. 31, 2013

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:

	December 31, 2013		September 30, 2013		December 31, 2012
Regulatory assets:
Income taxes recoverable	$	106,435	$	106,069	$	103,665
Underfunded pension and postretirement plans	92,755		94,515		184,764
Environmental costs	14,910		17,054		17,119
Deferred fuel and power costs	427		8,283		7,797
Removal costs, net	13,748		13,333		11,541
Other	5,722		5,657		5,742
Total regulatory assets	$	233,997	$	244,911	$	330,628
Regulatory liabilities:
Postretirement benefits	$	16,846	$	16,497	$	13,486
Environmental overcollections	2,329		2,552		3,077
Deferred fuel and power refunds	7,524		8,283		1,916
State tax benefits — distribution system repairs	8,725		8,453		7,750
Other	1,332		1,502		570
Total regulatory liabilities	$	36,756	$	37,287	$	26,799