Consolidated Condensed Balance Sheets (Parenthetical) - $ / shares	Jan. 31, 2017	Jul. 31, 2016	Jan. 31, 2016
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	45,419,228	41,614,432	41,578,019
Exchangeable Shares, Par Value Per Share	$ 0.01	$ 0.00	$ 0.00
Exchangeable Shares, Shares, Issued	73,047	0	0
Treasury stock, shares	5,436,294	5,434,977	5,326,941