Stock Compensation Information (Summary Of Remaining Unrecognized Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 31, 2013
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	$ 560
Cost recognition, weighted-average period, years	1 year 2 months 1 day
Remainder Of 2013 [Member]
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	102
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	249
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	147
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	59
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