REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Gross intangible assets	$ 162.0	$ 189.5
Accumulated amortization	57.7	60.9
Net intangible assets	104.3	128.6
Unamortized favorable/unfavorable lease intangibles	5.5	8.9
Increase in operating lease income, amortization of below market lease intangibles acquired	2.4	1.9	$ 1.4
Unbilled rent receivables	0.8	0.9
Unencumbered real estates	$ 58.6	$ 128.7
Weighted average amortization period for intangible assets acquired	25 years 1 month 6 days	19 years	19 years 6 months
Revenues from acquisitions	$ 5.3	$ 9.5	$ 2.8
Net earnings (loss)	2.4	6.8	(0.3)
Above Market Leases
Business Acquisition [Line Items]
Decrease in operating lease income, amortization of above market lease intangibles acquired	$ (0.6)	$ (1.1)	$ (1.3)