SEGMENT DISCLOSURE (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($) property	Dec. 31, 2016 USD ($) property
Segment disclosure
Number of types of commercial real estate properties | property									2	3	3
Revenues	$ 50,127	$ 47,640	$ 51,559	$ 48,398	$ 52,744	$ 55,384	$ 61,299	$ 66,949	$ 197,724	$ 236,376	$ 265,931
Revenues									35,672	35,576	45,082
Property and Lending expenses:
Interest expense									27,702	36,338	34,385
General and administrative									9,167	5,479	7,961
EXPENSES									195,657	256,979	273,239
Reportable segments
Property and Lending expenses:
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									109,457	128,452	133,406
Reportable segments | Office
Segment disclosure
Revenues									148,065	174,004	187,435
Property and Lending expenses:
Operating									54,908	68,801	81,217
General and administrative									2,350	981	1,234
EXPENSES									57,258	69,782	82,451
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									90,807	104,222	104,984
Reportable segments | Hotel
Segment disclosure
Revenues									38,789	38,585	48,379
Property and Lending expenses:
Operating									25,263	25,059	32,177
General and administrative									32	77	282
EXPENSES									25,295	25,136	32,459
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									13,494	13,449	15,920
Reportable segments | Multifamily
Segment disclosure
Revenues									0	13,566	20,303
Property and Lending expenses:
Operating									0	7,725	11,309
General and administrative									0	393	1,048
EXPENSES									0	8,118	12,357
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									0	5,448	7,946
Reportable segments | Lending
Segment disclosure
Revenues									10,870	10,221	9,814
Property and Lending expenses:
Interest expense									1,412	414	537
Fees to related party									2,445	3,464	3,555
General and administrative									1,857	1,010	1,166
EXPENSES									5,714	4,888	5,258
INCOME FROM CONTINUING OPERATIONS BEFORE PROVISION FOR INCOME TAXES									$ 5,156	$ 5,333	$ 4,556