Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Apr. 30, 2012
Income Taxes [Abstract]
Net operating loss carryforwards	$ 11,659	$ 12,010
Capital loss carryforward	8	92
Foreign tax credits	386	224
Domestic fixed assets and other intangibles	5,038	5,106
Reserves and other accruals	629	1,034
Deferred revenue	85	213
Allowance for losses on accounts receivable	107	131
Reserves and other accruals	466	412
Total deferred tax assets	18,378	19,222
Valuation allowance	(18,345)	(19,187)
Domestic fixed assets and other intangibles	(33)	(35)
Goodwill	(890)	(699)
Total deferred tax liabilities	(923)	(734)
Net deferred tax assets (liabilities)	$ (890)	$ (699)