The Company And Summary Of Significant Accounting Policies (Schedule Detailling Activity For The Allowance For Doubtful Accounts And Long-Term Accounts Receivable) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010	Apr. 30, 2013
Allowance balance					$ 278
Allowance for Doubtful Accounts [Member]
Allowance balance					278
Allowance balance	345	503	262
Balance of allowances from acquistion				207
Charges (credits) to operation expenses	130	(14)	160
Write-offs of accounts	(197)	(144)	(126)
Allowance balance		345	503	262
Allowance For Long-Term Accounts Receivable [Member]
Allowance balance		91	82
Charges (credits) to operation expenses		8	9
Write-offs of accounts		(99)
Allowance balance			$ 91