Stockholders' Equity (Summary Of Remaining Unrecognized Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2013
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	$ 441
Cost recognition, weighted-average period, years	1 year 1 month 28 days
2014 [Member]
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	238
2015 [Member]
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	142
2016 [Member]
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	58
2017 [Member]
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	$ 3