Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2015
Current assets:
Cash and cash equivalents	$ 82,449	$ 3,099	$ 16,522
Restricted cash	212	6,602	3,683
Accounts receivable (less allowances for doubtful accounts of $7,921, $5,599 and $12,534, respectively)	59,301	55,659	89,340
Accounts receivable — related parties	638	1,271	2,039
Accrued utility revenues	10,099	12,051	7,716
Inventories	27,009	51,716	33,376
Deferred income taxes	0	24,694	29,904
Income taxes receivable	0	10,026	0
Regulatory assets	3,263	4,105	2,763
Derivative instruments	5,384	934	1,285
Prepaid expenses & other current assets	33,724	23,903	13,551
Total current assets	222,079	194,060	200,179
Property, plant and equipment, at cost (less accumulated depreciation and amortization of $961,006, $929,130 and $918,311, respectively)	1,945,539	1,824,369	1,781,668
Goodwill	182,145	182,145	182,145
Regulatory assets	342,037	300,103	251,479
Derivative instruments	109	0	111
Other assets	7,989	7,501	7,623
Total assets	2,699,898	2,508,178	2,423,205
Current liabilities:
Current maturities of long-term debt	20,000	247,000	72,000
Short-term borrowings	130,000	71,700	2,700
Accounts payable	50,665	58,135	44,687
Accounts payable — related parties	5,838	4,430	5,477
Regulatory liability — deferred fuel and power refunds	34,432	36,638	45,564
Derivative instruments	507	12,591	4,412
Other current liabilities	113,011	103,265	151,760
Total current liabilities	354,453	533,759	326,600
Long-term debt	630,000	375,000	550,000
Deferred income taxes	545,614	512,497	478,108
Deferred investment tax credits	3,348	3,597	3,681
Pension and postretirement benefit obligations	128,932	135,003	91,804
Other noncurrent liabilities	98,652	57,702	50,752
Total liabilities	1,760,999	1,617,558	1,500,945
Commitments and contingencies
Common stockholder’s equity:
Common Stock, $2.25 par value (authorized — 40,000,000 shares; issued and outstanding — 26,781,785 shares)	60,259	60,259	60,259
Additional paid-in capital	473,295	471,904	471,796
Retained earnings	434,391	372,143	396,823
Accumulated other comprehensive loss	(29,046)	(13,686)	(6,618)
Total common stockholder’s equity	938,899	890,620	922,260
Total liabilities and stockholder’s equity	$ 2,699,898	$ 2,508,178	$ 2,423,205