Consolidated Statements of Operations - USD ($)	3 Months Ended								6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income:
Available-for-sale securities		$ 5,460,965	$ 6,753,580						$ 13,559,539	$ 19,020,504	$ 24,298,156	$ 16,560,338	$ 16,411,730
Mortgage loans held-for-sale		499,335	585,566						1,291,027	1,790,362	2,097,702	3,634,264	0
Multi-family loans held in securitization trusts		16,794,338	17,249,728						34,885,204	51,679,542	68,016,595	21,158,102	0
Residential loans held in securitization trusts		4,641,887	5,039,380						10,931,159	15,573,046	19,986,204	4,438,634	0
Cash and cash equivalents		4,809	4,236						8,577	13,386	16,351	21,274	11,843
Interest expense:
Repurchase agreements - available-for-sale securities		1,490,698	1,789,532						3,502,300	4,992,998	(6,467,312)	(2,661,329)	(2,243,565)
Repurchase agreements - mortgage loans held-for-sale		300,297	392,394						828,987	1,129,284	(1,323,892)	(2,203,961)	0
Multi-family securitized debt obligations		(15,372,832)	(15,778,322)						(31,913,781)	(47,286,613)	(62,157,176)	(19,400,851)	0
Residential securitized debt obligations		(3,137,247)	(3,102,240)						(6,757,709)	(9,894,956)	(13,156,912)	(3,575,168)	0
Net interest income	$ 6,537,000	7,100,260	8,570,002	$ 9,103,000	$ 6,062,000	$ 4,671,000	$ 3,891,000	$ 3,348,000	17,672,729	24,772,989	31,309,716	17,971,303	14,180,008
Other-than-temporary impairments
Increase in credit reserves		(350,924)	567,205						(1,410,284)	(1,761,208)	(745,492)	0	0
Additional other-than-temporary credit impairment losses		0	0						2,890,939	2,890,939	(2,890,939)	0	0
Total impairment losses recognized in earnings		(350,924)	567,205						(4,301,223)	(4,652,147)	(3,636,431)	0	0
Other income:
Realized gain (loss) on sale of investments, net		1,464,308	524,156						369,843	1,834,151	(533,832)	3,271,592	(31,581,087)
Change in unrealized gain (loss) on fair value option securities		(393,685)	(232,273)						(232,273)	(625,958)	(1,041,649)	0	0
Change in unrealized gain (loss) and net interest income from Linked Transactions			0						0		0	10,605,848	5,838,309
Realized gain (loss) on derivative contracts, net		(8,262,423)	(1,217,392)						(4,047,878)	(12,310,301)	(12,024,730)	(18,214,460)	18,812,854
Change in unrealized gain (loss) on derivative contracts, net		1,631,907	902,032						(849,006)	782,901	4,909,858	(2,931,249)	878,100
Realized gain (loss) on mortgage loans held-for-sale		(13,666)	759,059						1,031,291	1,017,625	1,216,314	(776,971)	0
Change in unrealized gain (loss) on mortgage loans held-for-sale		539,456	(594,542)						(43,159)	496,297	(197,179)	329,728	0
Change in unrealized gain (loss) on mortgage servicing rights		(488,247)	(268,311)						(268,311)	(756,558)	(671,957)	0	0
Change in unrealized gain (loss) on multi-family loans held in securitization trusts		1,804,190	1,803,472						3,840,584	5,644,774	6,097,000	1,473,485	0
Change in unrealized gain (loss) on residential loans held in securitization trusts		(1,323,697)	(2,975,798)						(6,332,205)	(7,655,902)	(8,153,474)	3,059,647	0
Mortgage servicing income		64,962	56,538						56,538	121,500	211,878	0	0
Other income		33,374	26,611						26,611	59,985	85,726	59,590	0
Total other income (loss)		(4,943,521)	(1,216,448)						(6,447,965)	(11,391,486)	(10,102,045)	(3,122,790)	(6,051,824)
Expenses:
Management fee		703,167	698,629						1,416,404	2,119,571	2,774,432	2,627,592	1,287,077
General and administrative expenses		1,419,268	1,717,361						3,401,237	4,820,505	6,660,934	2,901,076	992,115
Operating expenses reimbursable to Manager		1,338,272	1,055,075						2,106,642	3,444,914	4,980,348	3,247,683	2,103,223
Other operating expenses		20,377	(586,298)						(1,205,541)	(1,185,164)	2,448,439	2,504,741	288,416
Compensation expense		64,207	62,348						122,995	187,202	256,608	253,635	230,923
Total expenses		3,504,537	4,119,711						8,252,819	11,757,356	17,120,761	11,534,727	4,901,754
Net income before provision for income taxes		(1,698,722)	3,801,048						(1,329,278)	(3,028,000)	450,479	3,313,786	3,226,430
(Provision for) benefit from income taxes											0	0	0
Net income (loss)	3,478,000	(1,698,722)	3,801,048	(5,130,000)	(3,782,000)	5,213,000	4,425,000	(2,541,000)	(1,329,278)	(3,028,000)	450,479	3,313,786	3,226,430
Dividends to preferred stockholders		(880,509)	(870,726)						(1,751,235)	(2,631,744)	(3,522,036)	(2,887,296)	(44,827)
Net income (loss) attributable to common stockholders	2,588,000	(2,579,231)	2,930,322	(6,011,000)	(4,494,000)	4,154,000	3,789,000	(3,022,000)	(3,080,513)	(5,659,744)	(3,071,557)	426,490	3,181,603
Earnings (loss) per share:
Net income (loss) attributable to common stockholders (basic and diluted)	$ 2,588,000	$ (2,579,231)	$ 2,930,322	$ (6,011,000)	$ (4,494,000)	$ 4,154,000	$ 3,789,000	$ (3,022,000)	$ (3,080,513)	$ (5,659,744)	$ (3,071,557)	$ 426,490	$ 3,181,603
Weighted average number of shares of common stock outstanding (in shares)	14,719,632	14,724,750	14,721,492	14,718,750	14,718,750	14,640,065	11,150,788	8,816,658	14,720,051	14,721,635	14,721,074	12,358,587	6,132,702
Basic and diluted income (loss) per share (in dollars per share)	$ 0.18	$ (0.18)	$ 0.20	$ (0.41)	$ (0.31)	$ 0.28	$ 0.34	$ (0.34)	$ (0.21)	$ (0.38)	$ (0.21)	$ 0.03	$ 0.52
Dividends declared per share of common stock (in dollars per share)		$ 0.30	$ 0.38						$ 0.75	$ 1.05	$ 1.35	$ 1.47	$ 1.64