FAIR VALUE MEASUREMENTS (Details) $ in Thousands	Dec. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Apr. 30, 2017 USD ($)
FINANCIAL LIABILITIES
Mortgages payable	$ 444,197	$ 509,919	$ 565,978
Carrying Amount
FINANCIAL ASSETS
Cash and cash equivalents	13,792	11,891	28,819
Mortgage and note receivables	26,809	25,809	0
FINANCIAL LIABILITIES
Other debt, including other debt related to assets held for sale	0	0	49,637
Revolving line of credit	57,500	124,000	57,050
Mortgages payable	445,974	509,919	665,440
Mortgages payable related to assets held for sale	0	0	21,803
Fair Value
FINANCIAL ASSETS
Cash and cash equivalents	13,792	11,891	28,819
Mortgage and note receivables	26,809	25,809	0
FINANCIAL LIABILITIES
Other debt, including other debt related to assets held for sale	0	0	49,637
Revolving line of credit	57,500	124,000	57,050
Mortgages payable	444,241	510,803	680,941
Mortgages payable related to assets held for sale	0	0	21,861
Nonrecurring
Fair Value Measurements on a Nonrecurring Basis [Abstract]
Real estate investments valued at fair value	3,049	52,145	506
Real estate held for sale			10,891
Nonrecurring \| Level 1
Fair Value Measurements on a Nonrecurring Basis [Abstract]
Real estate investments valued at fair value	0	0	0
Real estate held for sale			0
Nonrecurring \| Level 2
Fair Value Measurements on a Nonrecurring Basis [Abstract]
Real estate investments valued at fair value	0	0	0
Real estate held for sale			0
Nonrecurring \| Level 3
Fair Value Measurements on a Nonrecurring Basis [Abstract]
Real estate investments valued at fair value	3,049	52,145	506
Real estate held for sale			$ 10,891
Measurement Input, Cap Rate \| Nonrecurring
Fair Value Measurements on a Nonrecurring Basis [Abstract]
Capitalization rate (as a percent)			0.070
Term Loan Maturing 2024 \| Carrying Amount
FINANCIAL LIABILITIES
Term loan	70,000	70,000	$ 0
Term Loan Maturing 2024 \| Fair Value
FINANCIAL LIABILITIES
Term loan	70,000	70,000	0
Term Loan Maturing 2025 \| Carrying Amount
FINANCIAL LIABILITIES
Term loan	75,000	0	0
Term Loan Maturing 2025 \| Fair Value
FINANCIAL LIABILITIES
Term loan	$ 75,000	$ 0	$ 0

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