Condensed Consolidated Statements of Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues	$ 143,644	$ 172,714	$ 770,087	$ 1,007,695
Costs and expenses:
Cost of sales — gas, fuel and purchased power (excluding depreciation shown below)	62,701	93,383	412,377	615,645
Operating and administrative expenses	37,689	42,910	124,380	134,103
Operating and administrative expenses - related parties	2,107	1,747	7,013	10,595
Taxes other than income taxes	3,919	3,523	12,903	13,350
Depreciation	12,425	12,058	37,132	37,347
Amortization	826	631	2,292	1,896
Other income, net	(1,323)	(1,024)	(4,362)	(7,716)
Total costs and expenses	118,344	153,228	591,735	805,220
Operating income	25,300	19,486	178,352	202,475
Interest expense	10,575	10,518	31,859	31,960
Income before income taxes	14,725	8,968	146,493	170,515
Income taxes	6,265	3,490	57,494	63,800
Net income	$ 8,460	$ 5,478	$ 88,999	$ 106,715