BENEFIT PLANS (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017	Dec. 29, 2017
Defined Benefit Plan Disclosure [Line Items]
Share-based Compensation, Total			$ 136,000	$ 99,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total	$ 138,000		138,000
Pension Benefit Plan Accelerated Funding			4,535,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 225,000	$ 248,000	674,000	746,000
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 1,040,000	0
Board of Directors Chairman [Member]
Defined Benefit Plan Disclosure [Line Items]
Deferred Compensation Arrangement with Individual, Common Stock Reserved for Future Issuance	11,396		11,396
Non cash Director Fee Compensation			$ 60,000
Equity Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Share-based Compensation, Total	$ 31,000	$ 19,000	$ 76,000	$ 48,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			10,500
Stock Issued During Period, Shares, Restricted Stock Award, Gross			25,750
Stock Issued During Period, Shares, Restricted Stock Award, Forfeited			5,000
Two Thousand Six Equity Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	34,750		34,750
2016 Equity Plan [Member] | Board of Directors Chairman [Member]
Defined Benefit Plan Disclosure [Line Items]
Shares Issued, Price Per Share					$ 7.02
Non cash Director Compensation			$ 20,000