MORTGAGES PAYABLE AND LINE OF CREDIT (Details) $ in Thousands	6 Months Ended
	Oct. 31, 2015 USD ($) Property Loan	Apr. 30, 2015 USD ($)
Aggregate amount of required future principal payments on mortgages payable [Abstract]
Total payments	$ 728,973	$ 668,112
Mortgages Payable [Member]
Mortgages Payable [Abstract]
Interest rates on mortgages payable range, minimum	2.70%
Interest rates on mortgages payable range, maximum	8.25%
Mortgages maturity date	Jul. 01, 2036
Number of loans in default | Loan	1
Non-recourse loan	$ 122,600
Debt instrument maturity date	Oct. 31, 2016
Interest rate on mortgage payable	5.93%
Fixed rate mortgages	$ 639,100	629,800
Variable rate mortgages	$ 89,800	$ 38,300
Weighted average rate of interest on mortgage debt	5.04%	4.95%
Aggregate amount of required future principal payments on mortgages payable [Abstract]
2016 (remainder)	$ 58,971
2017	43,389
2018	41,008
2019	116,390
2020	110,690
Thereafter	358,525
Total payments	728,973
Mortgages Payable [Member] | Assets Held for Sale [Member]
Mortgages Payable [Abstract]
Minimum future principal payments	133,400
Line of Credit [Member]
Line of Credit [Abstract]
Lending commitments	$ 100,000
Number of properties securing line of credit | Property	16
Line of credit, current interest rate	4.75%
Line of credit, minimum outstanding principal balance	$ 17,500
Borrowed amount	$ 17,500	$ 60,500
Debt service coverage on aggregate assets	1.25
Debt service coverage on individual assets	1.00
Minimum depository accounts	$ 6,000
Non-interest bearing account	$ 1,500