Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Straight-line rent receivables, net	$ 250,023	$ 267,764
Non-mortgage loans receivable, net	54,164	59,857
Senior unsecured notes	206,442	0
Other intangible assets, net	5,623	6,496
Investment in unconsolidated operating entities	56,820	49,738
Other	186,113	189,924
Total other assets	$ 759,185	$ 573,779