Condensed Consolidated Statements of Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Revenues	$ 273,797	$ 280,641
Costs and expenses:
Cost of sales — gas, fuel and purchased power (excluding depreciation shown below)	138,277	156,906
Operating and administrative expenses	44,235	40,942
Operating and administrative expenses - related parties	1,805	2,125
Taxes other than income taxes	4,276	4,127
Depreciation	12,753	12,379
Amortization	818	684
Other income, net	(931)	(1,127)
Total costs and expenses	201,233	216,036
Operating income	72,564	64,605
Interest expense	10,077	10,607
Income before income taxes	62,487	53,998
Income taxes	25,675	21,330
Net income	$ 36,812	$ 32,668