OTHER ASSETS (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Straight-line rent receivables, net	$ 238,884	$ 267,764
Non-mortgage loans receivable, net	49,972	59,857
Marketable debt securities	203,760
Other intangibles, net	5,916	6,496
Investment in unconsolidated operating entities	62,816	49,738
Other	166,129	189,924
Total other assets	$ 727,477	$ 573,779