OTHER ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Straight-line rent receivables, net	$ 244,360	$ 267,764
Non-mortgage loans receivable, net	50,478	59,857
Debt securities, available-for-sale, carrying value	208,090	0
Other intangibles, net	5,804	6,496
Investment in unconsolidated operating entities	62,295	49,738
Other	211,359	189,924
Total other assets	$ 782,386	$ 573,779