Selected Balance Sheet Data (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Accounts receivable, net:
Accounts receivable	$ 31,071	$ 30,885
Less allowance for doubtful accounts	344	209
Less reserve for future returns and pricing adjustments	2,166	1,991
Accounts receivable, net	28,561	28,685
Inventories:
Raw materials	26,391	21,116
Work in process	512	802
Finished goods	6,105	4,358
Inventories	$ 33,008	$ 26,276