Consolidated Condensed Balance Sheets (Parenthetical) - $ / shares	Oct. 31, 2016	Jul. 31, 2016	Oct. 31, 2015
Preferred stock, par value (in dollars 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	45,060,893	41,614,432	41,566,094
Exchangeable Shares, Par Value Per Share	$ 0.01	$ 0.01	$ 0.01
Exchangeable Shares, Shares, Issued	418,095	0	0
Treasury stock, shares	5,434,977	5,434,977	5,326,941