Real Estate Fund Investments - Schedule of Income from Fund Investment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Investment Holdings [Line Items]
Income from real estate fund investments	$ 10,933	$ 30,226
Investment Income [Member]
Investment Holdings [Line Items]
Income from real estate fund investments	3,445	10,793
Investment Expenses [Member]
Investment Holdings [Line Items]
Income from real estate fund investments	239	430
Net Investment Income [Member]
Investment Holdings [Line Items]
Income from real estate fund investments	3,206	10,363
Net Realized Gains
Investment Holdings [Line Items]
Income from real estate fund investments	11,955	11,955
Previously recorded unrealized gains on exited investments
Investment Holdings [Line Items]
Income from real estate fund investments	(6,790)	(6,058)
Net Unrealized Gains [Member]
Investment Holdings [Line Items]
Income from real estate fund investments	$ 2,562	$ 13,966