Summary of Significant Accounting Policies - Goodwill (Details) (USD $)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Summary Of Significant Accounting Policies - Liquidity And Basis Of Presentation Details Narrative
Opening balance May 1	$ 1,453,000	$ 1,242,000
Impairment charge	438,000
Goodwill balance April 30	$ 1,083,000	$ 1,453,000