Mortgage-Backed Securities - By Type (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Mortgage Backed Securities [Line Items]
Fair Value	$ 339,147,913	$ 115,379,574
[MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	317,176,000	109,605,000
[MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	21,972,000	5,775,000
[HybridAdjustableRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	101,255,000	59,485,000
[AdjustableRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	6,210,000	6,531,000
[FixedRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	209,711,000	43,589,000
[InterestOnlySecuritiesMember] | [MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	20,101,000	2,884,000
[InverseInterestOnlyMember] | [MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	$ 1,871,000	$ 2,891,000