REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Unaudited Pro Forma (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Operating lease income	$ 19,085	$ 20,390	$ 38,379	$ 39,537
Net income	3,945	68,697	(7,500)	86,659
Net loss attributable to noncontrolling interest in consolidated joint ventures	(235)	684	(2)	493
Net (income) loss attributable to noncontrolling interest in operating partnership	(908)	(35,171)	4,765	(43,768)
Net income attributable to Class A common shareholders	2,802	34,210	(2,737)	43,384
Acquisitions
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Operating lease income	182	279	464	565
Net income	124	185	311	167
Net loss attributable to noncontrolling interest in consolidated joint ventures	0	0	0	0
Net (income) loss attributable to noncontrolling interest in operating partnership	(53)	(78)	(132)	(71)
Net income attributable to Class A common shareholders	72	107	179	96
Consolidated Pro Forma
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Operating lease income	19,267	20,669	38,843	40,102
Net income	4,069	68,882	(7,189)	86,826
Net loss attributable to noncontrolling interest in consolidated joint ventures	(235)	684	(2)	493
Net (income) loss attributable to noncontrolling interest in operating partnership	(961)	(35,249)	4,633	(43,839)
Net income attributable to Class A common shareholders	2,874	34,317	(2,558)	43,480
2016 Acquisitions
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenue recorded from acquisitions included in operating lease income	$ 100		$ 100
2015 Acquisitions
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenue recorded from acquisitions included in operating lease income		$ 3,100		$ 4,300