Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Current assets:
Allowance, accounts receivable	$ 2,448	$ 2,540
Stockholders' equity:
Preferred stock, par value	$ 0.003	$ 0.003
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.001455	$ 0.001455
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	72,960,000	72,960,000
Treasury stock, shares	11,648,000	11,374,000
Treasury stock held for deferred compensation, shares	186,000	157,000