SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Apr. 30, 2013	Apr. 30, 2012
Segment revenues and net operating income [Abstract]
Real estate revenue	$ 67,182	$ 60,975
Real estate expenses	27,591	24,685
Gain on Business Interruption Insurance Recovery	966	0
Net operating income	40,557	36,290
Depreciation/amortization	(19,518)	(15,885)
Administrative, advisory and trustee services	(2,753)	(2,096)
Impairment of real estate investments	(1,458)
Other expenses	(679)	(519)
Interest expense	(14,799)	(16,069)
Interest and other income	210	142
Income from continuing operations	1,560	1,863
Income from discontinued operations	1,656	133
Net income	3,216	1,996
Segment Assets [Abstract]
Property owned	2,016,523		2,032,970
Less accumulated depreciation	(429,376)		(420,421)
Net property owned	1,587,147		1,612,549
Real Estate Held-for-sale	3,969		0
Cash and cash equivalents	93,193	37,002	94,133	39,989
Other investments	640		639
Receivables and other assets	113,523		113,948
Development in progress	77,396		46,782
Unimproved land	20,774		21,503
Total Assets	1,896,642		1,889,554
Multi-Family Residential [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue	24,582	21,210
Real estate expenses	10,959	9,293
Gain on Business Interruption Insurance Recovery	966
Net operating income	14,589	11,917
Segment Assets [Abstract]
Property owned	670,573		659,696
Less accumulated depreciation	(145,276)		(140,354)
Net property owned	525,297		519,342
Commercial-Office [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue	19,744	18,778
Real estate expenses	9,985	9,336
Gain on Business Interruption Insurance Recovery	0
Net operating income	9,759	9,442
Segment Assets [Abstract]
Property owned	625,610		613,775
Less accumulated depreciation	(143,246)		(138,270)
Net property owned	482,364		475,505
Commercial-Healthcare [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue	16,072	15,073
Real estate expenses	4,282	4,080
Gain on Business Interruption Insurance Recovery	0
Net operating income	11,790	10,993
Segment Assets [Abstract]
Property owned	502,346		501,191
Less accumulated depreciation	(94,616)		(90,891)
Net property owned	407,730		410,300
Commercial-Industrial [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue	3,456	2,788
Real estate expenses	1,039	896
Gain on Business Interruption Insurance Recovery	0
Net operating income	2,417	1,892
Segment Assets [Abstract]
Property owned	100,204		125,772
Less accumulated depreciation	(19,968)		(23,688)
Net property owned	80,236		102,084
Commercial-Retail [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue	3,328	3,126
Real estate expenses	1,326	1,080
Gain on Business Interruption Insurance Recovery	0
Net operating income	2,002	2,046
Segment Assets [Abstract]
Property owned	117,790		132,536
Less accumulated depreciation	(26,270)		(27,218)
Net property owned	$ 91,520		$ 105,318