Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2018	Jul. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 1,505	$ 1,808
Preferred Stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred Stock, authorized (in shares)	1,000,000	1,000,000
Preferred Stock, issued (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common Stock, authorized (in shares)	75,000,000	75,000,000
Common Stock, issued (in shares)	46,239,890	46,194,370
Common Stock, outstanding (in shares)	41,709,335	41,728,934
Treasury Stock (in shares)	4,530,555	4,465,440