DISCONTINUED OPERATIONS, Effect on Net Income from Properties Classified as Discontinued Operations (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Jan. 31, 2016 USD ($) Loan	Jan. 31, 2015 USD ($)	Jan. 31, 2016 USD ($) Loan	Jan. 31, 2015 USD ($)
REVENUE [Abstract]
Real estate rentals		$ 50,277	$ 46,753	$ 142,526	$ 135,621
Tenant reimbursement		4,492	5,223	13,466	15,122
TOTAL REVENUE		55,772	52,939	158,998	153,342
EXPENSES [Abstract]
Depreciation/amortization related to real estate investments		14,789	12,627	42,522	37,700
Utilities		3,427	3,564	9,757	9,533
Maintenance		5,821	5,033	16,979	15,081
Real estate taxes		5,029	5,284	14,948	15,052
Insurance		1,214	1,215	3,558	3,745
Property management expenses		4,676	3,825	13,182	10,970
Other property expenses		169	197	344	753
Amortization related to non-real estate investments		130	210	470	647
Impairment of real estate investments		162	540	3,320	4,663
TOTAL EXPENSES		39,344	36,562	117,603	111,373
Interest expense		(10,540)	(10,009)	(29,867)	(29,710)
Gain on extinguishment of debt		0	0	(106)	0
Other income		135	109	286	371
Gain on sale of discontinued operations				25,512	(811)
INCOME FROM DISCONTINUED OPERATIONS		35,408	1,162	50,181	1,322
Default interest		1,600		4,700
Non-recourse loan		$ 122,600		$ 122,600
Number of loan properties | Loan		9		9
Mendota Joint Venture Entity [Member]
EXPENSES [Abstract]
Income from discontinued operations attributable to noncontrolling interest				$ 51,400	1,700
Discontinued Operations [Member]
REVENUE [Abstract]
Real estate rentals		$ 3,576	13,687	21,966	40,780
Tenant reimbursement		718	6,290	8,268	18,309
TOTAL REVENUE		4,294	19,977	30,234	59,089
EXPENSES [Abstract]
Depreciation/amortization related to real estate investments		0	4,207	4,239	12,146
Utilities		416	1,803	3,016	5,608
Maintenance		588	2,766	4,784	8,310
Real estate taxes		756	3,532	5,341	10,531
Insurance		58	264	462	815
Property management expenses		468	921	1,941	2,761
Other property expenses		0	30	0	30
Amortization related to non-real estate investments		105	706	1,002	1,981
Impairment of real estate investments		0	0	440	1,442
TOTAL EXPENSES		2,391	14,229	21,225	43,624
Operating income (loss)		1,903	5,748	9,009	15,465
Interest expense	[1]	(3,436)	(4,586)	(12,832)	(14,148)
Gain on extinguishment of debt	[1]	36,456	0	29,336	0
Other income		154	0	427	5
Income from discontinued operations before gain on sale		35,077	1,162	25,940	1,322
Gain on sale of discontinued operations		331	0	24,241	0
INCOME FROM DISCONTINUED OPERATIONS	[2]	$ 35,408	$ 1,162	$ 50,181	$ 1,322

[1] Interest expense includes $1.6 million and $4.7 million for the three and nine months ended January 31, 2016, respectively, of default interest related to a $122.6 million non-recourse loan by one of our subsidiaries. Gain on extinguishment of debt in the three and nine months ended January 31, 2016, respectively, includes $36.5 million of gain on extinguishment of debt recognized in connection with our transfer of ownership to the mortgage lender of the nine properties serving as collateral for the $122.6 million non-recourse loan and the removal of the debt obligation and accrued interest from our balance sheet.

[2] Discontinued operations for the nine months ended January 31, 2016 and 2015 includes a noncontrolling interest for our Mendota joint venture entity. Income from discontinued operations attributable to us was $51.4 million and $1.7 million for the nine months ended January 31, 2016 and 2015, respectively