INFORMATION BY OPERATING SEGMENT (Tables)

6 Months Ended

Mar. 31, 2013

Segment Reporting [Abstract]

Schedule of operating segment information

(Thousands)	Gas Utility		Other		Adjustments & Eliminations		Total
Three Months Ended
March 31, 2013
Operating revenues	$	363,912	$	233	$	—	$	364,145
Net Economic Earnings	30,197		207		—		30,404
Total assets	1,821,372		747		—		1,822,119
Six Months Ended
March 31, 2013
Operating revenues	$	614,703	$	1,376	$	—	$	616,079
Net Economic Earnings	55,538		667		—		56,205
Total assets	1,821,372		747		—		1,822,119
Three Months Ended
March 31, 2012
Operating revenues	$	298,623	$	274	$	—	$	298,897
Net Economic Earnings	25,772		136		—		25,908
Total assets	1,680,948		2,274		—		1,683,222
Six Months Ended
March 31, 2012
Operating revenues	$	549,525	$	1,355	$	—	$	550,880
Net Economic Earnings	46,851		751		—		47,602
Total assets	1,680,948		2,274		—		1,683,222

Schedule of the reconciliation of net economic earnings to net income

Reconciliation of Net Economic Earnings to Net Income
	Three Months Ended					Six Months Ended
	March 31,					March 31,
(Thousands)	2013			2012		2013			2012
Total Net Economic Earnings above	$	30,404		$	25,908	$	56,205		$	47,602
Add: Unrealized (loss) gain on energy-related  derivative contracts, net of tax	(32		)	17		(91		)	20
Add: Acquisition, divestiture, and restructuring costs,      net of tax	(597		)	—		(597		)	—
Net Income	$	29,775		$	25,925	$	55,517		$	47,622