Related Party Transactions - Schedule Statement of Income of Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Related Party Transaction [Line Items]
Related party expense – management fee	$ 2,293	$ 2,273
Related party expense – loan servicing fees	2,091	1,833
Net interest income after the impact of changes in the net present value of expected credit losses
Related Party Transaction [Line Items]
Amount of transaction	7,220	5,952
Thetis Asset Management LLC | Related party expense – management fee
Related Party Transaction [Line Items]
Related party expense – management fee	2,293	2,273
Thetis Asset Management LLC | (Loss)/income from investments in affiliates
Related Party Transaction [Line Items]
Amount of transaction	(41)	168
Servicer | Related party expense – loan servicing fees
Related Party Transaction [Line Items]
Related party expense – loan servicing fees	2,091	1,833
Servicer | Interest income
Related Party Transaction [Line Items]
Amount of transaction	67	0
Gaea | (Loss)/income from investments in affiliates
Related Party Transaction [Line Items]
Amount of transaction	42	18
AS Ajax E LLC | (Loss)/income from investments in affiliates
Related Party Transaction [Line Items]
Amount of transaction	3	9
Loan pool LLCs | (Loss)/income from investments in affiliates
Related Party Transaction [Line Items]
Amount of transaction	(8)	(7)
Great Ajax FS | (Loss)/income from investments in affiliates
Related Party Transaction [Line Items]
Amount of transaction	(93)	(62)
2018-D and -G | Other (loss)/income
Related Party Transaction [Line Items]
Amount of transaction	$ (3,973)	$ 0