Stock Compensation Information (Summary Of Remaining Unrecognized Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Oct. 31, 2012
Schedule Of Employee Service Share-Based Compensation, Allocation Of Not Yet Recognized Period Costs [Line Items]
Nonvested equity awards outstanding, unrecognized compensation expense	$ 943
Cost recognition, weighted-average period, years	1 year 2 months 9 days
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	285
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	371
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	211
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	74
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	$ 2