IDENTIFIED INTANGIBLE ASSETS AND LIABILITIES (Details) - USD ($)	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Identified intangible assets (included in intangible assets) [Roll Forward]
Gross carrying amount	$ 53,843,000	$ 56,710,000
Accumulated amortization	(26,576,000)	(24,071,000)
Net carrying amount	27,267,000	32,639,000
Identified intangible liabilities (included in other liabilities) [Abstract]
Gross carrying amount	134,000	173,000
Accumulated amortization	(110,000)	(127,000)
Net carrying amount	24,000	46,000
Other Identified Intangible Assets [Member]
Identified intangible liabilities (included in other liabilities) [Abstract]
Amortization of intangible assets	5,700,000	8,300,000	$ 5,300,000
Estimated annual amortization [Abstract]
2016	4,539,000
2017	4,032,000
2018	3,601,000
2019	3,477,000
2020	3,390,000
Leases, Acquired-in-Place, Market Adjustment [Member]
Identified intangible liabilities (included in other liabilities) [Abstract]
Amortization of intangible assets	23,000	$ 42,000	$ 38,000
Estimated annual amortization [Abstract]
2016	20,000
2017	12,000
2018	(1,000)
2019	(2,000)
2020	$ (1,000)