Consolidated Variable Interest Entities Consolidated Variable Interest Entities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Investment property, net	$ 5,469,481	$ 3,721,115
Other assets	146,450	213,030
Variable Interest Entity, Consolidated, Carrying Amount, Assets	92,041	95,832
Secured debt	2,819,567	2,125,267
Other liabilities	279,667	184,859
Consolidated variable interest entities	(2,982)	(1,767)
Variable Interest Entities, Consolidated, Total Liabilities and Stockholder's Equity	$ 61,127	$ 66,406
VIE Percent of Consolidated Assets	1.60%	2.30%
VIE Percent of Consolidated Liabilities	1.90%	2.70%
VIE Percent of Total Equity	1.00%	1.00%
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investment property, net	$ 88,987	$ 92,009
Other assets	3,054	3,823
Secured debt	62,111	64,082
Other liabilities	$ 1,998	$ 4,091