Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 36,812	$ 32,668
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	13,571	13,063
Deferred income taxes, net	6,554	(587)
Provision for uncollectible accounts	2,106	2,223
Other, net	514	2,505
Net change in:
Accounts receivable and accrued utility revenues	(97,349)	(86,309)
Inventories	5,473	6,812
Deferred fuel and power costs	4,845	1,552
Accounts payable	292	(12,190)
Other current assets	8,936	9,186
Other current liabilities	(7,126)	15,666
Net cash used by operating activities	(25,372)	(15,411)
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for property, plant and equipment	(29,728)	(22,858)
Net costs of property, plant and equipment disposals	(322)	(607)
(Increase) decrease in restricted cash	(2,106)	1,242
Net cash used by investing activities	(32,156)	(22,223)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of dividends	0	(23,199)
Increase in bank loans	63,900	57,700
Other	293	94
Net cash provided by financing activities	64,193	34,595
Cash and cash equivalents increase (decrease)	6,665	(3,039)
CASH AND CASH EQUIVALENTS:
End of period	7,924	4,228
Beginning of period	1,259	7,267
Increase (decrease)	$ 6,665	$ (3,039)