AVAILABLE-FOR-SALE SECURITIES - Components of Interest Income on AFS Securities (Details) - USD ($)	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Coupon interest	$ 5,422,834	$ 3,043,152
Net (premium amortization)/ discount accretion	1,399,788	1,855,886
Interest income	6,822,622	4,899,038
Agency
Schedule of Available-for-sale Securities [Line Items]
Coupon interest	5,380,580	2,023,202
Net (premium amortization)/ discount accretion	466,291	23,184
Interest income	5,846,871	2,046,386
Non-Agency
Schedule of Available-for-sale Securities [Line Items]
Coupon interest	42,254	762,081
Net (premium amortization)/ discount accretion	9,946	496,838
Interest income	52,200	1,258,919
Multi-Family
Schedule of Available-for-sale Securities [Line Items]
Coupon interest	0	257,869
Net (premium amortization)/ discount accretion	923,551	1,335,864
Interest income	$ 923,551	$ 1,593,733

Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a),(b))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Amount of accretion (amortization) of purchase discount (premium) on nonoperating securities.

+ References

+ Details

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