Consolidated Condensed Balance Sheets (Parenthetical) - $ / shares	Apr. 30, 2020	Jul. 31, 2019	Apr. 30, 2019
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized	25,000,000	25,000,000	25,000,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000	100,000,000
Common stock, shares issued	46,266,000	46,190,000	46,105,000
Exchangeable Shares, Par Value Per Share	$ 0.01	$ 0.01	$ 0.01
Exchangeable Shares, Shares, Issued	54,000	56,000	56,000
Treasury stock, shares	6,161,141	5,905,000	5,905,000