Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 1,857	$ 2,062
Preferred stock, par value (dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (dollars per share)	$ 0	$ 0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	63,544,000	65,315,000
Common stock, shares outstanding	63,544,000	65,315,000