Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 64,200	$ 68,333
Restricted cash	33	421
Accounts receivable, net of allowance of $39 and $22, respectively	23,130	22,265
Inventory	23,401	25,139
Prepaid expenses and other current assets	8,461	8,527
Total current assets	119,225	124,685
Property, plant, and equipment, net	17,157	16,635
Non-current inventory	2,510	2,686
Other non-current assets	576	78
Total assets	139,468	144,084
Current liabilities:
Accounts payable	7,414	11,818
Accrued expenses and other current liabilities	9,206	9,825
Total current liabilities	16,620	21,643
Asset retirement obligations	1,655	1,638
Other long-term liabilities	42	29
Total liabilities	18,317	23,310
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; 34,062 shares issued and 27,152 shares outstanding as of December 31, 2017; 33,938 shares issued and 27,028 shares outstanding as of September 30, 2017	731,112	730,906
Treasury stock at cost; 6,910 shares	(47,721)	(47,721)
Accumulated other comprehensive income	814	561
Accumulated deficit	(563,054)	(562,972)
Total shareholders’ equity	121,151	120,774
Total liabilities and shareholders’ equity	$ 139,468	$ 144,084