Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018
Current assets:
Cash and cash equivalents	$ 3,057	$ 10,314	$ 23,181
Restricted cash	4,255	1,190	805
Accounts receivable (less allowances for doubtful accounts of $15,967, $9,760 and $16,261, respectively)	94,106	71,507	107,966
Accounts receivable — related parties	437	2,273	1,682
Accrued utility revenues	14,575	13,977	14,425
Inventories	32,263	52,413	34,663
Prepaid income taxes	127	53,857	41
Regulatory assets	3,549	7,475	2,180
Derivative instruments	851	3,004	1,874
Prepaid expenses	6,754	9,006	10,224
Other current assets	6,702	8,003	8,832
Total current assets	166,676	233,019	205,873
Property, plant and equipment, at cost (less accumulated depreciation of $1,115,273, $1,074,521 and $1,069,070, respectively)	2,709,194	2,541,768	2,430,893
Goodwill	182,145	182,145	182,145
Regulatory assets	297,128	293,527	357,881
Other assets	20,479	16,117	17,233
Total assets	3,375,622	3,266,576	3,194,025
Current liabilities:
Current maturities of long-term debt	8,494	9,001	9,474
Short-term borrowings	76,000	189,500	118,500
Accounts payable	44,665	87,861	56,297
Accounts payable — related parties	7,203	9,585	14,385
Regulatory liabilities	51,777	40,131	49,664
Other current liabilities	116,695	114,256	119,196
Total current liabilities	304,834	450,334	367,516
Long-term debt	972,716	828,995	830,982
Deferred income taxes	421,855	400,939	336,035
Pension and postretirement benefit obligations	71,946	81,590	133,235
Regulatory liabilities	324,393	350,044	362,787
Other noncurrent liabilities	66,855	61,386	63,665
Total liabilities	2,162,599	2,173,288	2,094,220
Commitments and contingencies (Note 9)
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	473,580	473,580	473,580
Retained earnings	705,724	579,778	590,321
Accumulated other comprehensive loss	(26,540)	(20,329)	(24,355)
Total common stockholder’s equity	1,213,023	1,093,288	1,099,805
Total liabilities and stockholder’s equity	$ 3,375,622	$ 3,266,576	$ 3,194,025