STOCKHOLDERS' EQUITY - Narrative (Details) - USD ($)		1 Months Ended		12 Months Ended					13 Months Ended
	Jun. 16, 2017	Dec. 27, 2016	Jul. 25, 2013	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2016		Dec. 15, 2015
Stockholders' Equity Note [Line Items]
Exercise price of warrants, percentage of IPO price			105.00%
Exercise price of warrants (in dollars per share)		$ 13.11	$ 15.75
Common stock shares into which warrants may be converted (in shares)		3,753,492
Common stock, shares authorized (in shares)				450,000,000		450,000,000			450,000,000
Common stock, par value (in dollars per share)				$ 0.01		$ 0.01			$ 0.01
Common stock, shares issued (in shares)				22,143,758		17,539,258			17,539,258
Dividends		$ 19,384,684		$ 15,426,041		$ 33,420,954		$ 23,396,699
Dividends declared per share of common stock (in dollars per share)		$ 1.33		$ 0.60		$ 2.04		$ 1.35
Dividend payment, percentage in cash		20.00%
Stock dividends		$ 3,878,042
Dividend payment, percentage in stock		80.00%
Stock dividends		$ 15,506,642
Common stock dividends, shares issued (in shares)		2,936,864
Common stock, shares issued (in dollars per share)		$ 5.28
Proceeds from issuance of common stock	$ 19,800,000			$ 19,835,626		$ 15,503,885		$ 0
Stock repurchase program, authorized amount				$ 10,000,000
Preferred stock, liquidation preference (in dollars per share)				$ 25.00		$ 25.00			$ 25.00
Preferred stock, shares authorized (in shares)				50,000,000		50,000,000			50,000,000
Preferred stock, par value (in dollars per share)				$ 0.01		$ 0.01			$ 0.01
Preferred stock, shares issued (in shares)				1,610,000		1,610,000			1,610,000
Preferred stock, dividend rate (percentage)				8.75%		8.75%
Dividends payable				$ 39,132	[1]	$ 39,132	[1]	$ 39,132	$ 39,132	[1]
Series A Preferred Stock
Stockholders' Equity Note [Line Items]
Preferred stock, liquidation preference (in dollars per share)				$ 25
Preferred stock, dividend rate (percentage)				8.75%
IPO
Stockholders' Equity Note [Line Items]
Share price (in dollars per share)			$ 15.00
Common Stock
Stockholders' Equity Note [Line Items]
Common stock, shares issued (in dollars per share)	$ 4.60
Issuance of common stock, net (in shares)	4,600,000			4,604,500		2,952,364		14,000
Dividends payable				$ 11,904,005
Dividends payable, amount per share (in dollars per share)				$ 0.60
Common Stock | IPO
Stockholders' Equity Note [Line Items]
Warrants to purchase common stock			3,125,000
Stock Repurchase Program
Stockholders' Equity Note [Line Items]
Stock repurchase program, authorized amount											$ 10,000,000
Common stock shares repurchased (in shares)				0		126,856			126,856
Weighted average share price of common stock repurchased (in dollars per share)						$ 5.09			$ 5.09
Common stock shares repurchased (in shares)				$ 9,400,000

[1] Our consolidated balance sheets include assets and liabilities of consolidated variable interest entities (“VIE's) as the Company is the primary beneficiary of these VIEs. As of December 31, 2017 and December 31, 2016, assets of consolidated VIEs totaled $1,255,404,335 and $1,369,120,941, respectively, and the liabilities of consolidated VIEs totaled $1,228,295,517 and $1,344,404,080, respectively