Consolidated Balance Sheets (Parenthetical) (USD $)	Apr. 30, 2012	Jul. 31, 2011
Consolidated Balance Sheets [Abstract]
Preferred stock, par value	$ 0.01
Preferred stock, shares authorized	5,000,000
Preferred stock, shares issued	0
Common stock, par value	$ 0.01
Common stock, shares authorized	100,000,000
Common stock, shares issued	48,057,074	40,034,659
Common stock, shares outstanding	48,057,074	40,034,659