Loans Payable And Long-Term Debt (Schedule Of Debt Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Debt Instrument [Line Items]
2015	$ 1,146
2016	11,185
2017	1,116
2018	781
2019	2,783
2020 and thereafter	4,588
Total	21,599
Less current maturities	1,146	1,155
Total long-term debt	20,453	23,594
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
2015	0
2016	10,000
2017	0
2018	0
2019	0
2020 and thereafter	0
Total	10,000
Economic Development Loans [Member]
Debt Instrument [Line Items]
2015	0
2016	0
2017	0
2018	0
2019	2,190
2020 and thereafter	1,290
Total	3,480
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
2015	1,146
2016	1,185
2017	1,116
2018	781
2019	593
2020 and thereafter	3,298
Total	$ 8,119