PROPERTY OWNED (Details) - USD ($)	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
PROPERTY OWNED [Abstract]
Property owned net	$ 1,337,064,000	$ 1,368,582,000
Capitalized interest during construction	431,000	$ 4,900,000	$ 4,900,000
Future minimum lease receipts to be received under non-cancellable leases [Abstract]
2017	25,922,000
2018	24,250,000
2019	22,695,000
2020	21,386,000
2021	19,601,000
Thereafter	120,772,000
Total	$ 234,626,000