Mortgage-Backed Securities - By Type (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Mortgage Backed Securities [Line Items]
Fair Value	$ 360,260,273	$ 115,379,574
[MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	336,778,000	109,605,000
[MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	23,482,000	5,775,000
[HybridAdjustableRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	112,485,000	59,485,000
[AdjustableRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	6,485,000	6,531,000
[FixedRateMortgagesMember] | [MortgageBackedSecuritiesPassThroughCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	217,808,000	43,589,000
[InterestOnlySecuritiesMember] | [MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	21,141,000	2,884,000
[InverseInterestOnlyMember] | [MortgageBackedSecuritiesStructuredCertificatesMember]
Mortgage Backed Securities [Line Items]
Fair Value	$ 2,341,000	$ 2,891,000