Affiliates - Schedule of Net Income, Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Jan. 31, 2022	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at the Company's share	$ 521	$ (98)
Assets at Company's share	1,244,455		$ 1,336,291
Liabilities at Company's share	988,219		1,025,396
Thetis Asset Management LLC
Schedule of Equity Method Investments [Line Items]
Assets at Company's share	3,815		919
Liabilities at Company's share	103		258
AS Ajax E LLC
Schedule of Equity Method Investments [Line Items]
Assets at Company's share	403		420
Liabilities at Company's share	0		6
Loan pool LLCs
Schedule of Equity Method Investments [Line Items]
Assets at Company's share	480		480
Liabilities at Company's share	99		93
Gaea Real Estate Corp.
Schedule of Equity Method Investments [Line Items]
Assets at Company's share	36,251		37,272
Liabilities at Company's share	15,532		16,346
Great Ajax FS LLC
Schedule of Equity Method Investments [Line Items]
Assets at Company's share	6,249		6,854
Liabilities at Company's share	5,196		$ 5,748
Thetis Asset Management LLC
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at 100%	15,722	11
Net income/(loss) at the Company's share	$ 3,113	2
Ownership percentage (in percent)	19.80%		19.80%
Thetis Asset Management LLC | Assets
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 19,268		$ 4,643
Thetis Asset Management LLC | Liabilities
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	520		$ 1,305
AS Ajax E LLC
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at 100%	63	66
Net income/(loss) at the Company's share	$ 10	11
Ownership percentage (in percent)	16.50%		16.50%
AS Ajax E LLC | Assets
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 2,445		$ 2,553
AS Ajax E LLC | Liabilities
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	1		$ 39
Loan pool LLCs
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at 100%	(16)	(24)
Net income/(loss) at the Company's share	$ (7)	(10)
Ownership percentage (in percent)	40.00%		40.00%		40.40%
Loan pool LLCs | Assets
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 1,200		$ 1,200
Loan pool LLCs | Liabilities
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	248		$ 232
Great Ajax FS LLC
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at 100%	(269)	(763)
Net income/(loss) at the Company's share	$ (26)	(67)
Ownership percentage (in percent)	9.70%		9.70%
Great Ajax FS LLC | Assets
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 65,171		$ 71,477
Great Ajax FS LLC | Liabilities
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	54,185		$ 59,949
Gaea Real Estate Corp.
Schedule of Equity Method Investments [Line Items]
Net income/(loss) at 100%	(113)	(1,105)
Assets and liabilities at 100%				$ 25,500
Net income/(loss) at the Company's share	$ (1)	$ (243)
Ownership percentage (in percent)	22.20%		22.20%
Gaea Real Estate Corp. | Assets
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 163,000		$ 167,591
Gaea Real Estate Corp. | Liabilities
Schedule of Equity Method Investments [Line Items]
Assets and liabilities at 100%	$ 69,839		$ 73,499
Unconsolidated Affiliates
Schedule of Equity Method Investments [Line Items]
Ownership percentage (in percent)	100.00%	100.00%	100.00%