OPERATING SEGMENTS (Details) (USD $)	3 Months Ended									12 Months Ended
	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013		Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2014 Segment	Apr. 30, 2013		Apr. 30, 2012	Apr. 30, 2011
OPERATING SEGMENTS [Abstract]
Number of reportable segments										5
Segment revenues and net operating income [Abstract]
Real estate revenue	$ 66,983,000	$ 67,629,000	$ 65,772,000	$ 65,098,000	$ 64,184,000		$ 63,080,000	$ 61,864,000	$ 58,930,000	$ 265,482,000	$ 248,058,000		$ 228,671,000
Gain on involuntary conversion										2,480,000	5,084,000		274,000
Other expenses										(2,132,000)	(2,173,000)		(1,898,000)
Interest expense										(59,142,000)	(61,154,000)		(61,801,000)
Income (loss) before gain (loss) on sale of real estate and other investments and income (loss) from discontinued operations										(23,339,000)	20,677,000		8,644,000
Loss on sale of real estate and other investments										(51,000)	0		0
Income from continuing operations										(23,390,000)	20,677,000		8,644,000
Income (loss) from discontinued operations										6,450,000	9,295,000		1,062,000
Net Income										(16,940,000)	29,972,000		9,706,000
Segment Assets [Abstract]
Property owned	1,996,031,000				2,032,970,000	[1]				1,996,031,000	2,032,970,000	[1]
Less accumulated depreciation	(424,288,000)				(420,421,000)	[1]				(424,288,000)	(420,421,000)	[1]
Total property owned	1,571,743,000				1,612,549,000	[1]				1,571,743,000	1,612,549,000	[1]
Real estate held for sale	2,951,000				0	[1]				2,951,000	0	[1]
Cash and cash equivalents	47,267,000				94,133,000	[1]				47,267,000	94,133,000	[1]	39,989,000	41,191,000
Other investments	329,000				639,000	[1]				329,000	639,000	[1]
Development in progress	104,609,000				46,782,000	[1]				104,609,000	46,782,000	[1]
Unimproved land	22,864,000				21,503,000	[1]				22,864,000	21,503,000	[1]
Total Assets	1,869,221,000				1,889,554,000	[1]				1,869,221,000	1,889,554,000	[1]
Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										265,482,000	248,058,000		228,671,000
Real estate expenses										108,487,000	99,059,000		93,350,000
Gain on involuntary conversion										2,480,000	5,084,000		274,000
Net operating income										159,475,000	154,083,000		135,595,000
Depreciation/amortization										(70,918,000)	(62,333,000)		(56,650,000)
Administrative, advisory and trustee services										(10,743,000)	(8,494,000)		(7,381,000)
Other expenses										(2,132,000)	(2,173,000)		(1,898,000)
Impairment of real estate investments										(42,566,000)	0
Interest expense										(59,142,000)	(61,154,000)		(61,801,000)
Interest and other income										2,687,000	748,000		779,000
Income (loss) before gain (loss) on sale of real estate and other investments and income (loss) from discontinued operations										(23,339,000)
Loss on sale of real estate and other investments										(51,000)
Income from continuing operations										(23,390,000)	20,677,000		8,644,000
Income (loss) from discontinued operations										6,450,000	9,295,000		1,062,000
Net Income										(16,940,000)	29,972,000		9,706,000
Segment Assets [Abstract]
Property owned	1,996,031,000				2,032,970,000					1,996,031,000	2,032,970,000
Less accumulated depreciation	(424,288,000)				(420,421,000)					(424,288,000)	(420,421,000)
Total property owned	1,571,743,000				1,612,549,000					1,571,743,000	1,612,549,000		1,518,519,000
Real estate held for sale	2,951,000				0					2,951,000	0
Cash and cash equivalents	47,267,000				94,133,000					47,267,000	94,133,000
Other investments	329,000				639,000					329,000	639,000
Receivables and other assets	119,458,000				113,948,000					119,458,000	113,948,000
Development in progress	104,609,000				46,782,000					104,609,000	46,782,000
Unimproved land	22,864,000				21,503,000					22,864,000	21,503,000
Total Assets	1,869,221,000				1,889,554,000					1,869,221,000	1,889,554,000
Multi-Family Residential [Member] | Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										102,059,000	89,923,000		71,728,000
Real estate expenses										46,138,000	38,223,000		33,386,000
Gain on involuntary conversion										2,480,000	3,852,000		0
Net operating income										58,401,000	55,552,000		38,342,000
Segment Assets [Abstract]
Property owned	753,731,000				659,696,000					753,731,000	659,696,000
Less accumulated depreciation	(158,100,000)				(140,354,000)					(158,100,000)	(140,354,000)
Total property owned	595,631,000				519,342,000					595,631,000	519,342,000		410,949,000
Commercial-Office [Member] | Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										77,440,000	75,962,000		73,493,000
Real estate expenses										38,190,000	37,267,000		34,126,000
Gain on involuntary conversion										0	0		0
Net operating income										39,250,000	38,695,000		39,367,000
Segment Assets [Abstract]
Property owned	544,628,000				613,775,000					544,628,000	613,775,000
Less accumulated depreciation	(121,892,000)				(138,270,000)					(121,892,000)	(138,270,000)
Total property owned	422,736,000				475,505,000					422,736,000	475,505,000		494,881,000
Commercial Healthcare [Member] | Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										65,258,000	61,975,000		64,511,000
Real estate expenses										17,127,000	16,779,000		20,650,000
Gain on involuntary conversion										0	0		0
Net operating income										48,131,000	45,196,000		43,861,000
Segment Assets [Abstract]
Property owned	525,028,000				501,191,000					525,028,000	501,191,000
Less accumulated depreciation	(105,843,000)				(90,891,000)					(105,843,000)	(90,891,000)
Total property owned	419,185,000				410,300,000					419,185,000	410,300,000		421,524,000
Commercial-Industrial [Member] | Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										6,894,000	6,700,000		6,613,000
Real estate expenses										2,043,000	1,871,000		1,142,000
Gain on involuntary conversion										0	0		0
Net operating income										4,851,000	4,829,000		5,471,000
Segment Assets [Abstract]
Property owned	55,375,000				125,772,000					55,375,000	125,772,000
Less accumulated depreciation	(10,198,000)				(23,688,000)					(10,198,000)	(23,688,000)
Total property owned	45,177,000				102,084,000					45,177,000	102,084,000		98,309,000
Commercial Retail [Member] | Segment Operations [Member]
Segment revenues and net operating income [Abstract]
Real estate revenue										13,831,000	13,498,000		12,326,000
Real estate expenses										4,989,000	4,919,000		4,046,000
Gain on involuntary conversion										0	1,232,000		274,000
Net operating income										8,842,000	9,811,000		8,554,000
Segment Assets [Abstract]
Property owned	117,269,000				132,536,000					117,269,000	132,536,000
Less accumulated depreciation	(28,255,000)				(27,218,000)					(28,255,000)	(27,218,000)
Total property owned	$ 89,014,000				$ 105,318,000					$ 89,014,000	$ 105,318,000		$ 92,856,000

[1] (as revised)