REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Gross intangible assets	$ 188.7		$ 188.7		$ 154.7
Accumulated amortization	57.5		57.5		48.1
Net intangible assets	131.1		131.1		106.6
Unamortized favorable/unfavorable lease intangibles	9.2		9.2		7.0
Net increase in operating lease income, amortization of below market lease intangibles	0.6	$ 0.4	1.3	$ 1.2
Unbilled rent receivables	0.5		0.5		0.7
Unencumbered real estates	179.3		$ 179.3		$ 70.3
Weighted average amortization period for intangible assets acquired			18 years 7 months 6 days	20 years 3 months 18 days
Revenue recorded from acquisitions	0.3	0.6	$ 5.6	$ 1.0
Earnings (losses) recorded from acquisitions	0.1	(0.3)	3.7	(0.2)
Above Market Leases
Business Acquisition [Line Items]
Net reduction in operating lease income, amortization of above market leases	$ (0.3)	$ (0.7)	$ (0.8)	$ (1.0)