Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Current assets:
Cash and cash equivalents	$ 110,031	$ 111,885
Restricted cash	529	375
Accounts receivable, net of allowance of $103 and $462, respectively	19,326	17,319
Inventory	16,792	17,130
Prepaid expenses and other current assets	4,362	4,976
Total current assets	151,040	151,685
Property, plant, and equipment, net	10,228	8,925
Other non-current assets, net of allowance of $0 and $3,561, respectively	298	297
Total assets	161,566	160,907
Current liabilities:
Accounts payable	8,150	7,189
Deferred gain associated with sale of assets	0	3,400
Accrued expenses and other current liabilities	9,859	13,102
Total current liabilities	18,009	23,691
Asset retirement obligations	1,540	1,774
Total liabilities	$ 19,549	$ 25,465
Commitments and contingencies (Note 11)
Shareholders’ equity:
Preferred stock, $0.0001 par value, 5,882 shares authorized; none issued or outstanding	$ 0	$ 0
Common stock, no par value, 50,000 shares authorized; 33,012 shares issued and 26,102 shares outstanding as of March 31, 2016; 32,586 shares issued and 25,676 shares outstanding as of September 30, 2015	763,654	762,003
Treasury stock at cost; 6,910 shares at March 31, 2016 and September 30, 2015	(47,721)	(47,721)
Accumulated other comprehensive income	802	847
Accumulated deficit	(574,718)	(579,687)
Total shareholders’ equity	142,017	135,442
Total liabilities and shareholders’ equity	$ 161,566	$ 160,907