Real Estate Joint Ventures - Summarized Financial Information for Unconsolidated Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Investment In Unconsolidated Affiliates [Line Items]
Cash and cash equivalents	$ 183,483	$ 212,773	$ 337,972	$ 34,515
Other assets	35,867	36,573
Total assets	984,440	982,742
Equity	660,974	665,263
Total liabilities and equity	984,440	982,742
Other affiliates
Investment In Unconsolidated Affiliates [Line Items]
Cash and cash equivalents	12,881	13,760
Other assets	59	58
Total assets	12,940	13,818
Accounts payable and other liabilities	1,424	1,978
Equity	11,516	11,840
Total liabilities and equity	$ 12,940	$ 13,818