DISCONTINUED OPERATIONS - Narrative (Details) $ in Thousands			12 Months Ended
	May 30, 2017 property	Dec. 17, 2015 USD ($)	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($) property	Dec. 31, 2016 USD ($)	Dec. 29, 2016 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on disposition of assets held for sale			$ 0	$ 0	$ 0
Number of multifamily properties sold | property			0
Lending
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Carrying value					27,587
Gain on disposition of assets held for sale					0
Lending | Discontinued operations, held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transaction costs from sales					$ 6
Lending segment, commercial mortgage loans | Discontinued operations, disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Carrying value		$ 77,121
Gain on disposition of assets held for sale		$ 5,151
Commercial real estate subsidiary | Discontinued operations, disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Carrying value						$ 27,587
Multifamily
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of multifamily properties sold | property	2			5