DEBT - Narrative (Details)	3 Months Ended	12 Months Ended
	Jul. 31, 2018 USD ($) property extension	Apr. 30, 2018 USD ($)
Line of Credit Facility [Line Items]
Number of real estate properties, unencumbered by mortgages | property	41
Number of real estate properties, unencumbered used to provide credit support | property	30
Maximum borrowing capacity		$ 6,000,000
Revolving line of credit	$ 130,000,000	124,000,000
Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	370,000,000
Revolving line of credit	0	$ 0
Line of Credit [Member] | BMO Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	300,000,000
Current borrowing capacity	300,000,000
Remaining borrowing capacity	170,000,000
Revolving line of credit	$ 130,000,000
Line of Credit [Member] | BMO Line of Credit [Member]
Line of Credit Facility [Line Items]
Number of extensions | extension	1
Extension term	12 months
Minimum [Member] | Base Rate [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	600.00%
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.60%
Maximum [Member] | Base Rate [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1250.00%
Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.25%
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit facility, accordion feature, higher borrowing capacity option	$ 200,000,000
Term		1 year
Unsecured Debt [Member] | Term Loan Maturing 2024 [Member]
Line of Credit Facility [Line Items]
Debt instrument face amount	$ 70,000,000