MORTGAGES PAYABLE AND CONSTRUCTION DEBT (Details) $ in Thousands	12 Months Ended
	Apr. 30, 2017 USD ($) loan	Apr. 30, 2016 USD ($)
Aggregate amount of required future principal payments on mortgages payable [Abstract]
Total payments	$ 661,960	$ 812,393
Mortgages Payable [Member]
Debt Instrument [Line Items]
Mortgages maturity date range, start	May 28, 2017
Mortgages maturity date range, end	Jul. 01, 2036
Number of loans in default | loan	0
Fixed rate mortgages	$ 629,500	689,300
Variable rate mortgages	$ 57,700	$ 196,800
Weighted average interest rate (in hundredths)	4.71%	4.54%
Aggregate amount of required future principal payments on mortgages payable [Abstract]
2018	$ 40,777
2019	75,918
2020	93,678
2021	136,390
2022	87,654
Thereafter	231,023
Total payments	665,440
Mortgages Payable [Member] | Assets Held for Sale [Member]
Aggregate amount of required future principal payments on mortgages payable [Abstract]
2018	16,621
2019	1,870
2020	183
2021	193
2022	993
Thereafter	1,943
Total payments	$ 21,803
Mortgages Payable [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate on mortgages payable (in hundredths)	3.28%
Mortgages Payable [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate on mortgages payable (in hundredths)	6.66%
Construction Debt [Member]
Debt Instrument [Line Items]
Construction debt	$ 41,700	$ 82,000
Weighted average interest rate (in hundredths)	3.27%	2.74%
Amount available to be drawn under construction loans	$ 4,800