Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2021	Jul. 31, 2020
Statement of Financial Position [Abstract]
Trade receivables, allowances	$ 7,621	$ 2,484
Inventories, net of reserves of $2,601 and $4,447, respectively	$ 2,601	$ 4,447
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	46,552,000	46,350,000
Exchangeable Shares Par Value Per Share	$ 0.01	$ 0.01
Exchangeable Shares, Shares, Issued	34,000	36,000
Treasury stock, shares	6,161,141	6,161,000