Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Investment property, net	$ 6,471,256	$ 6,118,316
Other assets	220,214	176,162
Secured debt	2,879,017	2,815,957
Other liabilities	$ 179,461	$ 157,862
Common Stock, Par Value	$ 0.01	$ 0.01
Common Stock, Shares Authorized	180,000	180,000
Common Stock, Shares Issued	86,463	86,357
Common Stock, Shares Outstanding	86,463	86,357
Series A-4 Preferred Stock
Series A-4 Preferred Stock, Par Value	$ 0.01	$ 0.01
Series A-4 Preferred Stock, Shares Issued	1,063	1,063
Series A-4 Preferred Stock, Shares Outstanding	1,063	1,063
Variable Interest Entity, Primary Beneficiary [Member]
Investment property, net	$ 314,669	$ 308,171
Other assets	22,369	19,809
Secured debt	43,913	44,172
Preferred OP units - mandatorily redeemable	35,249	35,277
Other liabilities	$ 21,049	$ 6,914