Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015
Current assets:
Cash and cash equivalents	$ 26,406	$ 3,099	$ 16,040
Restricted cash	3,909	6,602	5,578
Accounts receivable (less allowances for doubtful accounts of $8,232, $5,599 and $11,889, respectively)	102,125	55,659	183,046
Accounts receivable — related parties	1,271	1,271	2,709
Accrued utility revenues	24,052	12,051	42,056
Inventories	16,685	51,716	19,533
Deferred income taxes	0	24,694	25,168
Income taxes receivable	0	10,026	0
Regulatory assets	3,229	4,105	625
Derivative instruments	881	934	612
Prepaid expenses & other current assets	27,632	23,903	15,648
Total current assets	206,190	194,060	311,015
Property, plant and equipment, at cost (less accumulated depreciation and amortization of $952,478, $929,130 and $911,289, respectively)	1,900,806	1,824,369	1,753,197
Goodwill	182,145	182,145	182,145
Regulatory assets	344,983	300,103	251,945
Other assets	7,463	7,501	7,741
Total assets	2,641,587	2,508,178	2,506,043
Current liabilities:
Current maturities of long-term debt	0	247,000	92,000
Short-term borrowings	155,000	71,700	30,500
Accounts payable	42,681	58,135	54,612
Accounts payable — related parties	6,710	4,430	14,979
Regulatory liability — deferred fuel and power refunds	30,838	36,638	40,542
Derivative instruments	3,370	12,591	5,464
Other current liabilities	152,479	103,265	166,879
Total current liabilities	391,078	533,759	404,976
Long-term debt	550,000	375,000	550,000
Deferred income taxes	526,937	512,497	472,343
Deferred investment tax credits	3,429	3,597	3,765
Pension and postretirement benefit obligations	130,915	135,003	94,332
Derivative instruments	0	0	75
Other noncurrent liabilities	99,029	57,702	51,262
Total liabilities	$ 1,701,388	$ 1,617,558	$ 1,576,753
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	472,715	471,904	471,653
Retained earnings	436,788	372,143	404,516
Accumulated other comprehensive loss	(29,563)	(13,686)	(7,138)
Total common stockholder’s equity	940,199	890,620	929,290
Total liabilities and stockholder’s equity	$ 2,641,587	$ 2,508,178	$ 2,506,043