Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Current assets:
Cash and cash equivalents	$ 66,094	$ 63,905
Restricted cash	423	965
Accounts receivable, net of allowance of $7 and $36, respectively	22,285	18,432
Inventory	26,147	24,150
Prepaid expenses and other current assets	6,633	3,764
Total current assets	121,582	111,216
Property, plant, and equipment, net	15,684	12,213
Non-current inventory	3,115	3,531
Other non-current assets	95	251
Total assets	140,476	127,211
Current liabilities:
Accounts payable	12,951	10,575
Accrued expenses and other current liabilities	8,687	7,684
Total current liabilities	21,638	18,259
Asset retirement obligations	1,620	1,573
Other long-term liabilities	55	62
Total liabilities	23,313	19,894
Commitments and contingencies (Note 12)
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; 33,781 shares issued and 26,871 shares outstanding as of June 30, 2017; 33,154 shares issued and 26,244 shares outstanding as of September 30, 2016	729,467	725,666
Treasury stock at cost; 6,910 shares	(47,721)	(47,721)
Accumulated other comprehensive income	594	579
Accumulated deficit	(565,177)	(571,207)
Total shareholders’ equity	117,163	107,317
Total liabilities and shareholders’ equity	$ 140,476	$ 127,211