Real Estate Fund Investments - Summary of Investment in Unconsolidated Real Estate Fund and Income from Fund Investments (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)
Our Share of Investments:
Investments in unconsolidated real estate funds	$ 25,521	$ 25,521
Loss from unconsolidated real estate funds	(1,254)	(2,540)
Net investment income (loss) [Member]
Our Share of Investments:
Loss from unconsolidated real estate funds	170	(437)
Net unrealized losses [Member]
Our Share of Investments:
Loss from unconsolidated real estate funds	(361)	(2,939)
Carried interest [Member]
Our Share of Investments:
Loss from unconsolidated real estate funds	(1,063)	836
Property Funds [Member]
Our Share of Investments:
Investments in unconsolidated real estate funds	20,813	20,813
Alternative Investment Fund [Member]
Our Share of Investments:
Investments in unconsolidated real estate funds	$ 4,708	$ 4,708