Mortgage notes receivable - Allowance for loan loss (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended			10 Months Ended	12 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2019		Nov. 14, 2019	Dec. 31, 2018
Mortgage notes receivable
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Predecessor	[1]	Predecessor	Predecessor
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance		$ 4,096	$ 1,704		$ 1,704
Provision for loan losses		3,654	(224)
Charge offs		(568)
Financing Receivable, Allowance for Credit Loss, Ending Balance	$ 4,096	$ 7,182	$ 1,480			$ 1,704

[1] Predecessor periods are combined as disclosed in Note 1.