DISCONTINUED OPERATIONS - Properties Disposed of or Held for Sale (Details) - property	3 Months Ended		12 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Apr. 30, 2017	Apr. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold	28
Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties classified as held for sale in discontinued operations	27		0
Discontinued Operations, Held-for-sale [Member] | Senior Housing properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties classified as held for sale in discontinued operations				34
Discontinued Operations, Disposed of by Sale [Member] | Senior Housing properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold		2	32