DISCONTINUED OPERATIONS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
DISCONTINUED OPERATIONS [Abstract]
Number of apartment complexes sold	2
Number of retail properties sold	1
REVENUE
Real estate rentals	$ 51,755	$ 48,826
Tenant reimbursement	10,655	10,731
TOTAL REVENUE	62,410	59,557
EXPENSES
Depreciation/amortization related to real estate investments	15,453	14,139
Utilities	4,231	3,985
Maintenance	7,422	6,821
Real estate taxes	8,387	7,799
Insurance	921	876
Property management expenses	4,107	5,378
Other expenses	519	315
Amortization related to non-real estate investments	833	734
TOTAL EXPENSES	43,969	42,228
Interest expense	(16,517)	(15,881)
Interest income	18	53
INCOME FROM DISCONTINUED OPERATIONS	(70)	(28)
Discontinued Operations [Member]
REVENUE
Real estate rentals	9	74
Tenant reimbursement	1	(3)
TOTAL REVENUE	10	71
EXPENSES
Depreciation/amortization related to real estate investments	0	27
Utilities	0	13
Maintenance	3	7
Real estate taxes	3	4
Insurance	1	1
Property management expenses	0	3
TOTAL EXPENSES	7	55
Interest expense	0	(44)
Income from discontinued operations before gain on sale	3	(28)
Gain on sale of discontinued operations	(73)	0
INCOME FROM DISCONTINUED OPERATIONS	$ (70)	$ (28)