Derivative Financial Instruments - Income Statement Effect (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	$ 3,057,651	$ (2,271,875)	$ (4,363,837)	$ 4,095,788
Eurodollar Future [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	2,820,000	(2,272,000)	(3,316,000)	4,096,000
Interest Rate Swaption [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	166,000	0	(1,120,000)	0
Treasury Note Future [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	$ 72,000	$ 0	$ 72,000	$ 0