Fair Value of Financial Instruments - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - Residential loans held in securitization trusts – impaired loans, net $ in Thousands	Dec. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential loans held in securitization trusts – impaired loans, net	$ 5,256
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential loans held in securitization trusts – impaired loans, net	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential loans held in securitization trusts – impaired loans, net	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential loans held in securitization trusts – impaired loans, net	$ 5,256

Fair Value of Financial Instruments - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - Residential loans held in securitization trusts – impaired loans, net
$ in Thousands

Dec. 31, 2019

USD ($)

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Residential loans held in securitization trusts – impaired loans, net

$ 5,256

Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Residential loans held in securitization trusts – impaired loans, net

Level 2

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Residential loans held in securitization trusts – impaired loans, net

Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Residential loans held in securitization trusts – impaired loans, net

$ 5,256