CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 13,539	$ 16,281
Certificates of deposit	3,460	4,413
Accounts and other receivables, net of allowance for doubtful accounts of: $34,000 at June 30, 2018; $46,000 at September 30, 2017	1,414	1,414
Income taxes receivable	2,231	1,145
Investment held for sale	1,000	1,037
Other current assets	1,269	852
Total current assets	22,913	25,142
Income taxes receivable, net of current portion	460	0
Deferred income tax assets	0	300
Investments	1,695	2,209
Property and equipment	58,858	79,231
Accumulated depletion, depreciation, and amortization	(55,385)	(73,862)
Property and equipment, net	3,473	5,369
Total assets	28,541	33,020
Current liabilities:
Accounts payable	1,158	1,185
Accrued capital expenditures	184	348
Accrued operating and other expenses	1,013	1,386
Accrued compensation	446	390
Current portion of asset retirement obligation	410	1,231
Other current liabilities	63	258
Total current liabilities	3,274	4,798
Deferred rent	86	21
Liability for retirement benefits	4,064	4,150
Asset retirement obligation	3,809	5,632
Deferred income tax liabilities	353	236
Total liabilities	11,586	14,837
Commitments and contingencies
Equity:
Common stock, par value $0.50 per share; authorized, 20,000,000 shares: 8,445,060 issued at June 30, 2018 and September 30, 2017	4,223	4,223
Additional paid-in capital	1,351	1,350
Retained earnings	14,311	15,023
Accumulated other comprehensive loss, net	(1,228)	(1,058)
Treasury stock, at cost: 167,900 shares at June 30, 2018 and September 30, 2017	(2,286)	(2,286)
Total stockholders' equity	16,371	17,252
Non-controlling interests	584	931
Total equity	16,955	18,183
Total liabilities and equity	$ 28,541	$ 33,020