Condensed Consolidated Statement of Changes in Equity - USD ($)	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Distributions to Stockholders	Accumulated Earnings (Deficit)	Noncontrolling interests
Balance (in shares) at Dec. 31, 2017		1,610,000	22,143,758
Balance at Dec. 31, 2017	$ 145,791,277	$ 37,156,972	$ 221,393	$ 224,048,169	$ (12,617,794)	$ (104,650,235)	$ 1,632,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net (in shares)			1,539,406
Issuance of common stock, net	7,342,967		$ 15,394	7,327,573
Cost of issuing common stock	(32,383)			(32,383)
Restricted stock compensation expense	4,804			4,804
Net income (loss)	11,315,000						11,315,000
Common dividends declared	(2,314,686)					(2,314,686)
Preferred dividends declared	(880,509)					(880,509)
Increase (decrease) in net unrealized gain (loss) on available-for-sale securities, net	(12,154,936)				(12,154,936)
Reclassification adjustment for net gain (loss) included in net income (loss)	1,289,589				1,289,589
Balance (in shares) at Mar. 31, 2018		1,610,000	23,683,164
Balance at Mar. 31, 2018	150,361,123	$ 37,156,972	$ 236,787	231,348,163	(23,483,141)	(107,845,430)	12,947,772
Balance (in shares) at Dec. 31, 2017		1,610,000	22,143,758
Balance at Dec. 31, 2017	145,791,277	$ 37,156,972	$ 221,393	224,048,169	(12,617,794)	(104,650,235)	1,632,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(5,822,037)
Common dividends declared	(5,156,936)
Preferred dividends declared	(2,631,744)
Reclassification adjustment for net gain (loss) included in net income (loss)	12,617,794
Balance (in shares) at Sep. 30, 2018		1,610,000	23,687,664
Balance at Sep. 30, 2018	152,062,266	$ 37,156,972	$ 236,787	231,296,687	0	(112,438,915)	(4,189,265)
Balance (in shares) at Mar. 31, 2018		1,610,000	23,683,164
Balance at Mar. 31, 2018	150,361,123	$ 37,156,972	$ 236,787	231,348,163	(23,483,141)	(107,845,430)	12,947,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cost of issuing common stock	(32,383)			(32,383)
Restricted stock compensation expense	4,858			4,858
Net income (loss)	(21,490,063)						(21,490,063)
Common dividends declared	(1,420,990)					(1,420,990)
Preferred dividends declared	(870,726)					(870,726)
Increase (decrease) in net unrealized gain (loss) on available-for-sale securities, net	12,154,936				12,154,936
Reclassification adjustment for net gain (loss) included in net income (loss)	11,328,205				11,328,205
Balance (in shares) at Jun. 30, 2018		1,610,000	23,683,164
Balance at Jun. 30, 2018	150,034,960	$ 37,156,972	$ 236,787	231,320,638	0	(110,137,146)	(8,542,291)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net (in shares)			4,500
Issuance of common stock, net	0
Cost of issuing common stock	(32,384)			(32,384)
Restricted stock compensation expense	8,433			8,433
Net income (loss)	4,353,026						4,353,026
Common dividends declared	(1,421,260)					(1,421,260)
Preferred dividends declared	(880,509)					(880,509)
Reclassification adjustment for net gain (loss) included in net income (loss)	0
Balance (in shares) at Sep. 30, 2018		1,610,000	23,687,664
Balance at Sep. 30, 2018	152,062,266	$ 37,156,972	$ 236,787	231,296,687	0	(112,438,915)	(4,189,265)
Balance (in shares) at Dec. 31, 2018		1,610,000	23,687,664
Balance at Dec. 31, 2018	150,203,338	$ 37,156,972	$ 236,832	231,305,743	(114,757,019)	(3,838,690)	99,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cost of issuing common stock	(22,383)			(22,383)
Redemption of preferred stock, net (in shares)		(1,610,000)
Redemption of preferred stock, net	(40,250,000)	$ (37,156,972)		(3,093,028)
Restricted stock compensation expense	3,773			3,773
Net income (loss)	1,474,767					1,474,767
Common dividends declared	(1,658,136)				(1,658,136)
Preferred dividends declared	(480,472)				(480,472)
Balance (in shares) at Mar. 31, 2019		0	23,687,664
Balance at Mar. 31, 2019	109,270,887	$ 0	$ 236,832	228,194,105	(116,895,627)	(2,363,923)	99,500
Balance (in shares) at Dec. 31, 2018		1,610,000	23,687,664
Balance at Dec. 31, 2018	150,203,338	$ 37,156,972	$ 236,832	231,305,743	(114,757,019)	(3,838,690)	99,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	5,026,685
Common dividends declared	(5,211,286)
Preferred dividends declared	(488,056)
Reclassification adjustment for net gain (loss) included in net income (loss)	0
Balance (in shares) at Sep. 30, 2019		0	23,687,664
Balance at Sep. 30, 2019	109,221,453	$ 0	$ 236,877	228,153,442	(120,456,361)	1,187,995	99,500
Balance (in shares) at Mar. 31, 2019		0	23,687,664
Balance at Mar. 31, 2019	109,270,887	$ 0	$ 236,832	228,194,105	(116,895,627)	(2,363,923)	99,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cost of issuing common stock	(22,382)			(22,382)
Restricted stock compensation expense	3,814			3,814
Net income (loss)	1,394,170					1,394,170
Common dividends declared	(1,776,575)				(1,776,575)
Preferred dividends declared	(3,792)				(3,792)
Balance (in shares) at Jun. 30, 2019		0	23,687,664
Balance at Jun. 30, 2019	108,866,122	$ 0	$ 236,832	228,175,537	(118,675,994)	(969,753)	99,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net (in shares)			4,500
Issuance of common stock, net	15,300		$ 45	15,255
Cost of issuing common stock	(22,385)			(22,385)
Restricted stock compensation expense (in shares)			(4,500)
Restricted stock compensation expense	(14,965)			(14,965)
Net income (loss)	2,157,748					2,157,748
Common dividends declared	(1,776,575)				(1,776,575)
Preferred dividends declared	(3,792)				(3,792)
Reclassification adjustment for net gain (loss) included in net income (loss)	0
Balance (in shares) at Sep. 30, 2019		0	23,687,664
Balance at Sep. 30, 2019	$ 109,221,453	$ 0	$ 236,877	$ 228,153,442	$ (120,456,361)	$ 1,187,995	$ 99,500