CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016
Current assets:
Trade receivables, allowances for doubtful accounts	$ 227	$ 243
Stockholders' equity:
Convertible preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Convertible preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Convertible preferred stock, shares issued (in shares)	448,545	448,705
Convertible preferred stock, shares outstanding (in shares)	448,545	448,705
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	5,341,993	5,341,513
Common stock, shares outstanding (in shares)	5,341,993	5,341,513