Noncontrolling Interests - Variable interest entity (Details) - Accounting Standards Update ("ASU") 2015-02 - Consolidation (Topic 810): Amendments to the Consolidation Analysis - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Variable interest entity
Net real estate	$ 2,985,247	$ 3,040,903
Total assets	3,428,453	3,499,481
Total debt	223,739	251,047
Total liabilities	$ 329,758	$ 364,797