REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Real Estate Properties Sold (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property	Dec. 31, 2017 USD ($)
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			$ 90,806	$ 12,590
Net Book Value	$ 1,060,243		1,060,243		$ 1,032,041
Realized Gain/(Loss)	1,628	$ 2,232	32,637	4,563
2018 Disposal Properties
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			101,244
Net Book Value	68,607		68,607
Realized Gain/(Loss)			32,637
2018 Disposal Properties | Condominium | Las Vegas, NV
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			4,509
Net Book Value	$ 1,939		1,939
Realized Gain/(Loss)			$ 2,570
Properties | property	0		0
Units Sold | property			6
Units Remaining | property			7
2018 Disposal Properties | Condominium | Miami, FL
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			$ 3,296
Net Book Value	$ 2,662		2,662
Realized Gain/(Loss)			$ 634
Properties | property	0		0
Units Sold | property			12
Units Remaining | property			36
2018 Disposal Properties | Diversified | El Monte, CA
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			$ 71,807
Net Book Value	$ 52,610		52,610
Realized Gain/(Loss)			$ 19,197
Properties | property	1		1
Units Sold | property			0
Units Remaining | property			0
2018 Disposal Properties | Diversified | Richmond, VA
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds			$ 21,632
Net Book Value	$ 11,396		11,396
Realized Gain/(Loss)			$ 10,236
Properties | property	1		1
Units Sold | property			0
Units Remaining | property			0
2017 Disposal Properties
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds				12,590
Net Book Value		8,027		8,027
Realized Gain/(Loss)				4,563
2017 Disposal Properties | Condominium | Las Vegas, NV
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds				7,935
Net Book Value		$ 4,371		4,371
Realized Gain/(Loss)				$ 3,564
Properties | property		0		0
Units Sold | property				21
Units Remaining | property				38
2017 Disposal Properties | Condominium | Miami, FL
Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds				$ 4,655
Net Book Value		$ 3,656		3,656
Realized Gain/(Loss)				$ 999
Properties | property		0		0
Units Sold | property				16
Units Remaining | property				72