Regulatory Assets and Liabilities and Regulatory Matters (Tables)

9 Months Ended

Jun. 30, 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:

	June 30, 2013		September 30, 2012		June 30, 2012
Regulatory assets:
Income taxes recoverable	$	104,731	$	103,172	$	99,891
Underfunded pension and postretirement plans	177,846		188,222		144,613
Environmental costs	16,642		16,812		16,562
Deferred fuel and power costs	4,109		11,602		9,829
Removal costs, net	12,074		12,718		11,840
Other	5,561		5,879		8,312
Total regulatory assets	$	320,963	$	338,405	$	291,047
Regulatory liabilities:
Postretirement benefits	$	14,244	$	13,147	$	12,342
Environmental overcollections	2,906		2,883		3,726
Deferred fuel and power refunds	14,156		4,435		10,325
State tax benefits — distribution system repairs	8,024		7,385		6,961
Other	672		494		624
Total regulatory liabilities	$	40,002	$	28,344	$	33,978