Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 124,106	$ 102,098	$ 87,898
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	59,219	55,716	52,792
Deferred income taxes, net	33,588	35,281	53,247
Pension contributions, net of pension expense	(9,459)	(4,450)	(17,431)
Provision for uncollectible accounts	13,149	9,584	6,286
Other, net	3,998	(1,560)	2,490
Net change in:
Accounts receivable and accrued utility revenues	(19,718)	(16,446)	5,461
Inventories	(5,558)	(22,327)	36,929
Deferred fuel costs, net of changes in unsettled derivatives	(17,632)	9,321	(8,190)
Accounts payable	5,757	7,511	(6,718)
Other current assets	362	13,598	(5,063)
Other current liabilities	864	(18,413)	2,041
Net cash provided by operating activities	188,676	169,913	209,742
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for property, plant and equipment	(164,180)	(151,090)	(114,090)
Net costs of property, plant and equipment disposals	(8,214)	(4,925)	(4,922)
(Increase) decrease in restricted cash	(411)	(3,181)	4,308
Net cash used by investing activities	(172,805)	(159,196)	(114,704)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of dividends	(77,395)	(58,975)	(70,615)
Increase in short-term borrowings	68,800	8,300	9,200
Issuances of long-term debt	174,445	175,000	0
Repayments of long-term debt	(175,000)	(133,000)	(40,000)
Excess tax benefits from equity-based payment arrangements	973	1,406	369
Net cash used by financing activities	(8,177)	(7,269)	(101,046)
Cash and cash equivalents increase (decrease)	7,694	3,448	(6,008)
CASH AND CASH EQUIVALENTS:
End of year	12,401	4,707	1,259
Beginning of year	4,707	1,259	7,267
Increase (decrease)	7,694	3,448	(6,008)
Cash paid for:
Interest	34,781	49,460	29,902
Income taxes	$ 54,293	$ 18,376	$ 6,728