Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 102,098	$ 87,898	$ 105,196
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	55,716	52,792	52,546
Deferred income taxes, net	35,281	53,247	50,823
Pension expense, net of contributions paid	(4,450)	(17,431)	(6,292)
Provision for uncollectible accounts	9,584	6,286	9,137
Other, net	(1,560)	2,490	(4,526)
Net change in:
Accounts receivable and accrued utility revenues	(16,446)	5,461	(4,583)
Inventories	(22,327)	36,929	14,596
Deferred fuel costs, net of changes in unsettled derivatives	9,321	(8,190)	12,842
Accounts payable	7,511	(6,718)	9,229
Other current assets	13,598	(5,063)	(3,817)
Other current liabilities	(18,413)	2,041	(14,401)
Net cash provided by operating activities	169,913	209,742	220,750
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for property, plant and equipment	(151,090)	(114,090)	(98,856)
Net costs of property, plant and equipment disposals	(4,925)	(4,922)	(3,537)
(Increase) decrease in restricted cash	(3,181)	4,308	390
Net cash used by investing activities	(159,196)	(114,704)	(102,003)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of dividends	(58,975)	(70,615)	(99,490)
Increase (decrease) in bank loans	8,300	9,200	(17,000)
Issuances of long-term debt	175,000	0	0
Repayments of long-term debt	(133,000)	(40,000)	0
Excess tax benefits from equity-based payment arrangements	1,406	369	692
Net cash used by financing activities	(7,269)	(101,046)	(115,798)
Cash and cash equivalents increase (decrease)	3,448	(6,008)	2,949
CASH AND CASH EQUIVALENTS:
End of year	4,707	1,259	7,267
Beginning of year	1,259	7,267	4,318
Increase (decrease)	3,448	(6,008)	2,949
Cash paid for:
Interest	49,460	29,902	39,151
Income taxes	$ 18,376	$ 6,728	$ 13,856