Mortgage Loans - Schedule of carrying value of mortgage loans (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Mortgage Loans on Real Estate
Year one	$ 0	$ 4,242
Year two	749	10,946
Year three	9,293	10,300
Year four	9,618	5,133
Year five	5,120	4,386
Year six	4,448	2,970
Prior years, range 1	103,680	99,834
Prior years range 2	677,838	689,731
Prior years range 3	252,730	252,892
Financing receivable, before allowance for credit loss	1,063,476	1,080,434
Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		204
Year four		0
Year five		0
Year six		0
Prior years, range 1		4,267
Prior years range 2		15,893
Prior years range 3		9,208
Financing receivable, before allowance for credit loss		29,572
GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Year one	0
Year two	282
Year three	7,245
Year four	5,991
Year five	1,429
Year six	2,064
Prior years, range 1	28,203
Prior years range 2	173,328
Prior years range 3	66,688
Financing receivable, before allowance for credit loss	285,230
GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Year one	0
Year two	0
Year three	0
Year four	134
Year five	0
Year six	147
Prior years, range 1	4,829
Prior years range 2	44,042
Prior years range 3	14,149
Financing receivable, before allowance for credit loss	63,301
GAOP - 6f6 and below
Mortgage Loans on Real Estate
Year one	0
Year two	467
Year three	1,293
Year four	2,633
Year five	2,863
Year six	1,592
Prior years, range 1	22,945
Prior years range 2	137,594
Prior years range 3	52,365
Financing receivable, before allowance for credit loss	221,752
Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	395,962
Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	57,060
Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	40,171
Great Ajax II REIT
Mortgage Loans on Real Estate
Year one		0
Year two		764
Year three		181
Year four		698
Year five		328
Year six		1,730
Prior years, range 1		46,041
Prior years range 2		339,759
Prior years range 3		125,095
Financing receivable, before allowance for credit loss		514,596
2021-B
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		589
Year four		0
Year five		2,353
Year six		443
Prior years, range 1		28,541
Prior years range 2		159,318
Prior years range 3		50,948
Financing receivable, before allowance for credit loss		242,192
2019-C
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		0
Year four		0
Year five		265
Year six		0
Prior years, range 1		9,020
Prior years range 2		96,995
Prior years range 3		39,801
Financing receivable, before allowance for credit loss		146,081
California
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		1,268
Year four		1,248
Year five		0
Year six		0
Prior years, range 1		1,681
Prior years range 2		6,431
Prior years range 3		1,373
Financing receivable, before allowance for credit loss		12,001
7f7 and better
Mortgage Loans on Real Estate
Year one		471
Year two		0
Year three		2,019
Year four		1,541
Year five		440
Year six		0
Prior years, range 1		3,847
Prior years range 2		17,032
Prior years range 3		6,891
Financing receivable, before allowance for credit loss		32,241
6f6 and below
Mortgage Loans on Real Estate
Year one		0
Year two		1,351
Year three		1,783
Year four		1,470
Year five		209
Year six		368
Prior years, range 1		9,885
Prior years range 2		70,163
Prior years range 3		28,774
Financing receivable, before allowance for credit loss		114,003
18-1 LLC
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		605
Year four		176
Year five		284
Year six		429
Prior years, range 1		819
Prior years range 2		33
Prior years range 3		10
Financing receivable, before allowance for credit loss		2,356
Non-PCD
Mortgage Loans on Real Estate
Year one		3,771
Year two		8,831
Year three		3,855
Year four		0
Year five		507
Year six		0
Prior years, range 1		0
Prior years range 2		0
Prior years range 3		0
Financing receivable, before allowance for credit loss		16,964
Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Year one		0
Year two		0
Year three		204
Year four		0
Year five		0
Year six		0
Prior years, range 1		4,267
Prior years range 2		15,893
Prior years range 3		9,208
Financing receivable, before allowance for credit loss		29,572
Current
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	580,344	588,278
Current | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		13,485
Current | GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	151,909
Current | GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	28,344
Current | GAOP - 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	15,708
Current | Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	336,318
Current | Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	48,027
Current | Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	38
Current | Great Ajax II REIT
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		398,200
Current | 2021-B
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		61,066
Current | 2019-C
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		78,238
Current | California
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		3,938
Current | 7f7 and better
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		13,087
Current | 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		15,169
Current | 18-1 LLC
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,123
Current | Non-PCD
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		16,457
Current | Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		13,485
30
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	95,407	100,458
30 | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		3,927
30 | GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	37,299
30 | GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	9,378
30 | GAOP - 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	3,452
30 | Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	39,754
30 | Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	5,479
30 | Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	45
30 | Great Ajax II REIT
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		52,782
30 | 2021-B
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		24,428
30 | 2019-C
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		13,920
30 | California
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		661
30 | 7f7 and better
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		4,192
30 | 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		4,408
30 | 18-1 LLC
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		67
30 | Non-PCD
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		0
30 | Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		3,927
60
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	62,301	59,968
60 | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,369
60 | GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	25,859
60 | GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	6,091
60 | GAOP - 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	11,844
60 | Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	7,370
60 | Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	1,967
60 | Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	9,170
60 | Great Ajax II REIT
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		19,530
60 | 2021-B
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		24,807
60 | 2019-C
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		11,738
60 | California
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		0
60 | 7f7 and better
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		1,718
60 | 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,064
60 | 18-1 LLC
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		111
60 | Non-PCD
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		0
60 | Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,369
90
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	263,724	271,828
90 | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		7,828
90 | GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	69,020
90 | GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	18,884
90 | GAOP - 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	133,798
90 | Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	12,520
90 | Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	1,587
90 | Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	27,915
90 | Great Ajax II REIT
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		41,931
90 | 2021-B
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		113,459
90 | 2019-C
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		35,727
90 | California
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		5,132
90 | 7f7 and better
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		13,068
90 | 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		62,456
90 | 18-1 LLC
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		55
90 | Non-PCD
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		0
90 | Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		7,828
Foreclosure
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	61,700	59,902
Foreclosure | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		1,963
Foreclosure | GAOP 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	1,143
Foreclosure | GAOP 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	604
Foreclosure | GAOP - 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	56,950
Foreclosure | Great AJAX REIT 7f7 Greater Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	0
Foreclosure | Great AJAX REIT 7f7 Less Than 50
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	0
Foreclosure | Great AJAX REIT 6f6 and Below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss	$ 3,003
Foreclosure | Great Ajax II REIT
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,153
Foreclosure | 2021-B
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		18,432
Foreclosure | 2019-C
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		6,458
Foreclosure | California
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		2,270
Foreclosure | 7f7 and better
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		176
Foreclosure | 6f6 and below
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		29,906
Foreclosure | 18-1 LLC
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		0
Foreclosure | Non-PCD
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		507
Foreclosure | Ajax N | Mortgage Loans Held For Sale
Mortgage Loans on Real Estate
Financing receivable, before allowance for credit loss		$ 1,963