Major Customers (Details)	3 Months Ended
	Jul. 31, 2013	Jul. 31, 2013 Revenue [Member] Customer Concentration Risk [Member] From Unrelated Customers [Member] Gaming Business [Member] Customer	Jul. 31, 2012 Revenue [Member] Customer Concentration Risk [Member] From Unrelated Customers [Member] Voting Business [Member] Customer	Jul. 31, 2012 Revenue [Member] Customer Concentration Risk [Member] From Related Customers [Member] Gaming Business [Member] Customer	Jul. 31, 2013 Revenue [Member] Customer Concentration Risk [Member] From Related Customers [Member] No Individual Customer [Member] Customer
Concentration Risk [Line Items]
Number of major customers		1	1	2	0
Concentration risk, percentage (in hundredths)	10.00%	86.00%	19.00%	65.00%	10.00%