CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury stock	Additional Paid-in Capital	Retained Earnings	Accumulated other comprehensive loss	Total Stockholders’ Equity	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2016		18,122,387
Beginning balance at Dec. 31, 2016	$ 282,723	$ 181	$ 0	$ 244,880	$ 27,231	$ 0	$ 272,292	$ 10,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	28,927				28,927		28,927
Net income	30,154							1,227
Sale of shares (in shares)		286,841
Sale of shares	4,052	$ 3		4,049			4,052
Shelf registration fees	(188)			(188)			(188)
Issuance of non-controlling interest in subsidiaries	16,190							16,190
Issuance of shares under dividend reinvestment (in shares)		12,710
Issuance of shares under dividend reinvestment	174			174			174
Stock-based management fee expense (in shares)		122,350
Stock-based management fee expense	2,335	$ 2		2,333			2,335
Stock-based compensation expense (in shares)		43,940
Stock-based compensation expense	912			912			912
Dividends and distributions	(21,368)				(20,602)		(20,602)	(766)
Conversion premium - Convertible senior notes	2,687			2,687			2,687
Other comprehensive loss	(233)					(233)	(233)
Treasury stock	0
Ending balance (in shares) at Dec. 31, 2017		18,588,228
Ending balance at Dec. 31, 2017	317,438	$ 186	0	254,847	35,556	(233)	290,356	27,082
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	28,340				28,340		28,340
Net income	31,337							2,997
Issuance of shares to Great Ajax FS LLC		75,001
Issuance of shares for investment in Great Ajax FS LLC	1,011	$ 1		1,010			1,011
Issuance of non-controlling interest in subsidiaries	6,709							6,709
Issuance of shares under dividend reinvestment (in shares)		14,953
Issuance of shares under dividend reinvestment	199			199			199
Stock-based management fee expense (in shares)		196,503
Stock-based management fee expense	2,786	$ 2		2,784			2,786
Stock-based compensation expense (in shares)		55,466
Stock-based compensation expense	1,203			1,203			1,203
Dividends and distributions	(26,286)				(22,943)		(22,943)	(3,343)
Conversion premium - Convertible senior notes	494			494			494
Other comprehensive loss	(342)					(342)	(342)
Cumulative effect of accounting change	0			(110)	110
Treasury stock	$ (270)		(270)				(270)
Ending balance (in shares) at Dec. 31, 2018	18,909,874	18,909,874
Ending balance at Dec. 31, 2018	$ 334,279	$ 189	(270)	260,427	41,063	(575)	300,834	33,445
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	34,705				34,705		34,705
Net income	37,089							2,384
Sale of shares (in shares)		2,278,518
Sale of shares	34,301	$ 23		34,278			34,301
Stock Issued During Period, Shares, Conversion of Units		624,106
Conversion of Operating Partnership Units	0	$ 6		10,810			10,816	(10,816)
Issuance of non-controlling interest in subsidiaries	22							22
Issuance of shares under dividend reinvestment (in shares)		20,107
Issuance of shares under dividend reinvestment	280			280			280
Stock-based management fee expense (in shares)		237,237
Stock-based management fee expense	2,593	$ 3		2,590			2,593
Stock-based compensation expense (in shares)		85,272
Stock-based compensation expense	1,011	$ 1		1,010			1,011
Dividends and distributions	(27,111)				(26,322)		(26,322)	(789)
Other comprehensive loss	1,852					1,852	1,852
Treasury stock (in shares)		(12,971)
Treasury stock	$ (188)		(188)				(188)
Ending balance (in shares) at Dec. 31, 2019	22,142,143	22,142,143
Ending balance at Dec. 31, 2019	$ 384,084	$ 222	$ (458)	$ 309,395	$ 49,446	$ 1,277	$ 359,882	$ 24,202