Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 139,421	$ 154,464
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	67,956	62,926
Deferred income tax expense (benefit), net	10,455	(6,024)
Provision for uncollectible accounts	13,297	16,462
Regulatory liability arising from tax reform	0	24,098
Other, net	2,799	(1,635)
Net change in:
Accounts receivable and accrued utility revenues	(34,658)	(70,726)
Inventories	20,150	18,646
Deferred fuel and power costs, net of changes in unsettled derivatives	(19,311)	39,657
Accounts payable	(9,981)	3,655
Other current assets	61,210	(2,650)
Other current liabilities	3,399	16,725
Net cash provided by operating activities	254,737	255,598
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(267,403)	(217,901)
Net costs of property, plant and equipment disposals	(4,487)	(5,682)
Net cash used by investing activities	(271,890)	(223,583)
CASH FLOWS FROM FINANCING ACTIVITIES
Payment of dividends	(15,000)	(45,000)
Decrease in short-term borrowings	(113,500)	(51,500)
Issuances of long-term debt, net of issuance costs	149,211	124,404
Repayments of long-term debt	(7,018)	(44,182)
Other, net	(732)	0
Net cash provided (used) by financing activities	12,961	(16,278)
CASH AND CASH EQUIVALENTS
Cash, cash equivalents, and restricted cash, period end	7,312	23,986
Cash, cash equivalents, and restricted cash, period beginning	11,504	8,249
Cash, cash equivalents and restricted cash (decrease) increase	$ (4,192)	$ 15,737