Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 31, 2017	Jul. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 712	$ 692
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	62,764,824	62,597,110
Treasury, shares	10,070,459	10,011,069