Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting
Net interest income	$ 21,191	$ 12,928	$ 39,708	$ 23,057
Rental and other income	5,634		10,478
Expenses	15,736	5,798	28,155	11,220
Income (loss) from operations	11,089	7,130	22,031	11,837
Equity in earnings (losses) of unconsolidated ventures	8,961	5,827	18,098	9,042
Realized gain (loss) on investments and other	0	0	(175)	0
Net income (loss)	20,050	12,957	39,954	20,879	61,017
Assets	1,937,811		1,937,811		1,831,104
Real Estate Debt
Segment Reporting
Net interest income	19,737	11,515	36,824	20,750
Rental and other income	0		0
Expenses	227	81	462	150
Income (loss) from operations	19,510	11,434	36,362	20,600
Equity in earnings (losses) of unconsolidated ventures	217	(181)	837	(181)
Realized gain (loss) on investments and other			(175)
Net income (loss)	19,727	11,253	37,024	20,419
Assets	1,453,589		1,453,589		1,347,461
Real Estate Equity
Segment Reporting
Net interest income	0	0	0	0
Rental and other income	5,634		10,478
Expenses	6,483	691	11,422	2,279
Income (loss) from operations	(849)	(691)	(944)	(2,279)
Equity in earnings (losses) of unconsolidated ventures	8,744	6,008	17,261	9,223
Realized gain (loss) on investments and other			0
Net income (loss)	7,895	5,317	16,317	6,944
Assets	327,864		327,864		302,501
Real Estate Securities
Segment Reporting
Net interest income	1,454	1,413	2,884	2,307
Rental and other income	0		0
Expenses	0	7	0	14
Income (loss) from operations	1,454	1,406	2,884	2,293
Equity in earnings (losses) of unconsolidated ventures	0	0	0	0
Realized gain (loss) on investments and other			0
Net income (loss)	1,454	1,406	2,884	2,293
Assets	70,914		70,914		66,837
Corporate
Segment Reporting
Net interest income	0	0	0	0
Rental and other income	0		0
Expenses	9,026	5,019	16,271	8,777
Income (loss) from operations	(9,026)	(5,019)	(16,271)	(8,777)
Equity in earnings (losses) of unconsolidated ventures	0	0	0	0
Realized gain (loss) on investments and other			0
Net income (loss)	(9,026)	(5,019)	(16,271)	(8,777)
Assets	$ 85,444		$ 85,444		$ 114,305