Fair value measurements - Valuation Methodologies and Inputs Used for Assets Measured at Fair Value (Details) $ in Thousands	2 Months Ended	3 Months Ended			10 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019	[1]	Nov. 14, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Predecessor		Predecessor	Predecessor
Assets measured at fair value	$ 832,918	$ 787,343
Warrant Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	5,492	888
Real Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	5,837	$ 3,703
Real Property | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		0
Real Property | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		10
Mortgage notes receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	792,736	$ 637,751
Mortgage notes receivables | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		0
Mortgage notes receivables | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		10
Defaulted and Impaired Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 28,853	$ 145,001
Defaulted and Impaired Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		0
Defaulted and Impaired Loans | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		10
Equity Volatility | Warrant Liability | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		0
Equity Volatility | Warrant Liability | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of inputs		5

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