Real Estate Securities (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Minimum [Member]	Dec. 31, 2012 Minimum [Member]	Sep. 30, 2013 Maximum [Member]	Dec. 31, 2012 Maximum [Member]	Sep. 30, 2013 Weighted Average [Member]	Dec. 31, 2012 Weighted Average [Member]
Investment Holdings [Line Items]
Contractual maturities					7 years 10 months 24 days	8 years 7 months 6 days	33 years 3 months 18 days	33 years 8 months 12 days	24 years 8 months 12 days	26 years 1 month 6 days
Proceeds from the sale of real estate securities	$ 228,924,943	$ 36,000,527	$ 282,838,041	$ 64,759,903
Realized (loss)/gain on the sale of real estate securities	(8,044,415)	(849,794)	(8,251,291)	(886,723)
Realized (loss) on other-than-temporary impairments	$ (1,068,845)		$ (1,108,024)	$ (215,345)