Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Investments in debt securities, net	$ 483,381	$ 378,545
Derivative instruments (Note 7)	137,238	57,612
Held for sale assets	69,238	46,814
Investment in unconsolidated joint venture	56,823	57,078
Prepaid expenses	38,108	37,869
Rent and other receivables, net	26,388	24,525
Corporate fixed assets, net	17,980	16,595
Deferred leasing costs, net	6,499	7,018
Deferred financing costs, net	6,319	7,504
In-place leases, net	4,624	37,517
Amounts deposited and held by others	4,619	12,598
Other	23,930	12,930
Total	$ 875,147	$ 696,605