SEGMENT DISCLOSURE (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) property	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($) property
Segment disclosure
Number of types of commercial real estate properties | property									2	2	3
Revenues	$ 26,641	$ 29,215	$ 36,856	$ 47,277	$ 50,025	$ 47,607	$ 51,544	$ 48,294	$ 139,989	$ 197,470	$ 236,059
Revenues									35,633	35,672	35,576
Property and Lending expenses:
Interest expense									12,175	26,894	34,484
General and administrative									6,354	9,167	5,479
EXPENSES									226,690	195,403	263,023
Reportable segments
Property and Lending expenses:
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									67,251	109,457	128,452
Reportable segments | Office
Segment disclosure
Revenues									86,948	147,811	173,853
Property and Lending expenses:
Operating									36,638	54,654	68,650
General and administrative									521	2,350	981
EXPENSES									37,159	57,004	69,631
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									49,789	90,807	104,222
Reportable segments | Hotel
Segment disclosure
Revenues									38,748	38,789	38,585
Property and Lending expenses:
Operating									26,290	25,263	25,059
General and administrative									134	32	77
EXPENSES									26,424	25,295	25,136
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									12,324	13,494	13,449
Reportable segments | Multifamily
Segment disclosure
Revenues									0	0	13,400
Property and Lending expenses:
Operating									0	0	7,559
General and administrative									0	0	393
EXPENSES									0	0	7,952
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									0	0	5,448
Reportable segments | Lending
Segment disclosure
Revenues									10,964	10,870	10,221
Property and Lending expenses:
Interest expense									1,814	1,412	414
Fees to related party									2,382	2,445	3,464
General and administrative									1,630	1,857	1,010
EXPENSES									5,826	5,714	4,888
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									$ 5,138	$ 5,156	$ 5,333