BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES, Identified Intangible Assets and Liabilities (Details) - USD ($)	3 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2016
Identified intangible assets (included in intangible assets) [Abstract]
Gross carrying amount	$ 8,088,000		$ 8,088,000
Accumulated amortization	(6,916,000)		(6,230,000)
Net carrying amount	1,172,000		1,858,000
Identified intangible liabilities (included in other liabilities) [Abstract]
Gross carrying amount	159,000		159,000
Accumulated amortization	(61,000)		(55,000)
Net carrying amount	98,000		$ 104,000
Amortization of above and below market leases	5,000	$ 6,000
Amortization of all other identified intangible assets	675,000	$ 192,000
Estimated annual amortization of acquired below-market leases, net of acquired above-market leases [Abstract]
2018	5,000
2019	(11,000)
2020	(20,000)
2021	(16,000)
2022	(13,000)
Estimated annual amortization [Abstract]
2018	1,171,000
2019	269,000
2020	170,000
2021	104,000
2022	$ 78,000