Schedule IV Mortgage loans on real estate - Schedule of Mortgage Loan Activity (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	[1],[2]	$ 1,310,873
RPL, NPL and SBC pool portfolio acquisitions, net cost basis		110,146
SBC non-pooled portfolio acquisitions, net cost basis		19,040
Draws on SBC loans		912
Accretion recognized		96,064
Payments received, net		(191,647)
Reclassifications to REO		(12,104)
Provision for loan losses		803	$ 1,164	$ 0
Sale of mortgage loans		180,992
Non-Cash Loan Charges		(20)
Ending balance	[1],[2]	$ 1,151,469	$ 1,310,873

[1] As of December 31, 2019, balances for Mortgage loans, net includes $341.8 million and Secured borrowings, net of deferred costs includes $284.8 million from the 50.0% and 63.0% owned joint ventures, respectively. As of December 31, 2018, balances for Mortgage loans, net include $377.0 million and Secured borrowings, net of deferred costs includes $231.9 million from the 50.0% and 63.0% owned joint ventures, all of which the Company consolidates under U.S. Generally Accepted Accounting Principles ("U.S. GAAP").

[2] Mortgage loans, net include $908.6 million and $897.8 million of loans at December 31, 2019 and December 31, 2018, respectively, transferred to securitization trusts that are variable interest entities (“VIEs”); these loans can only be used to settle obligations of the VIEs. Secured borrowings consist of notes issued by VIEs that can only be settled with the assets and cash flows of the VIEs. The creditors do not have recourse to the primary beneficiary (Great Ajax Corp.). See Note 9 — Debt. Mortgage loans, net include $2.0 million and $1.2 million of allowance for loan losses at December 31, 2019 and December 31, 2018, respectively.