Major Customers (Details)	3 Months Ended		6 Months Ended
	Oct. 31, 2013 Customer	Oct. 31, 2012 Customer	Oct. 31, 2013 Customer	Oct. 31, 2012 Customer
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)			10.00%
Revenue [Member] | Customer Concentration Risk [Member] | From Unrelated Customers [Member] | Gaming Business [Member]
Concentration Risk [Line Items]
Number of major customers		1	1	1
Concentration risk, percentage (in hundredths)		10.00%	40.00%	10.00%
Revenue [Member] | Customer Concentration Risk [Member] | From Unrelated Customers [Member] | No Individual Customer [Member]
Concentration Risk [Line Items]
Number of major customers	0
Concentration risk, percentage (in hundredths)	10.00%
Revenue [Member] | Customer Concentration Risk [Member] | From Unrelated Customers [Member] | Voting Business [Member]
Concentration Risk [Line Items]
Number of major customers		1		1
Concentration risk, percentage (in hundredths)		41.00%		28.00%
Revenue [Member] | Customer Concentration Risk [Member] | From Related Customers [Member] | Gaming Business [Member]
Concentration Risk [Line Items]
Number of major customers	1	1	1	1
Concentration risk, percentage (in hundredths)	95.00%	36.00%	52.00%	50.00%