Schedule IV Mortgage loans on real estate - Schedule of Mortgage Loan Activity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	$ 869,091	[1]
Mortgage loan portfolio acquisitions, net cost basis	459,194
Mortgage loan portfolio originations	9,083
Dispositions	0
Accretion recognized	(89,881)
Payments received, net	(153,930)
Reclassifications to REO	(20,294)
Other	516
Ending balance	1,253,541	[1],[2]
Prepaid expenses and other assets
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	$ 1,500

[1] Mortgage loans, net include $996,203 and $598,643 of loans at December 31, 2017 and December 31, 2016, 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 8 — Debt.

[2] Mortgage loans, net include​s $177.1 million, Secured borrowings, net of deferred costs includes $88.4 million, and Non-controlling interests includes $14.0 million from a 50% owned joint venture, which we consolidate under GAAP.