Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 23,351	$ 38,839
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	16,701	15,425
Deferred income taxes, net	15,607	3,921
Provision for uncollectible accounts	1,930	2,490
Other, net	4,331	3,534
Net change in:
Accounts receivable and accrued utility revenues	(46,757)	(92,313)
Inventories	2,351	9,790
Deferred fuel and power costs, net of changes in unsettled derivatives	(6,788)	4,393
Accounts payable	(3,642)	6,075
Other current assets	(4,767)	(4,821)
Other current liabilities	6,449	25,356
Net cash provided by operating activities	8,766	12,689
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for property, plant and equipment	(60,457)	(55,029)
Net costs of property, plant and equipment disposals	(3,150)	(2,028)
Decrease (increase) in restricted cash	278	(5,371)
Net cash used by investing activities	(63,329)	(62,428)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of dividends	(7,000)	(15,600)
Repayments of long-term debt	(72,000)	0
Increase in short-term borrowings	146,000	67,200
Other	49	5
Net cash provided by financing activities	67,049	51,605
Cash and cash equivalents increase	12,486	1,866
CASH AND CASH EQUIVALENTS:
End of period	15,585	14,267
Beginning of period	$ 3,099	$ 12,401