Consolidated Balance Sheets (Parenthetical) (USD $)	Apr. 30, 2012	Apr. 30, 2011
Consolidated Balance Sheets [Abstract]
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares issued	0	0
Common stock, no par value	$ 0	$ 0
Common stock, shares issued	38,140,309	37,966,709
Common stock, shares outstanding	38,140,309	37,966,709