Securitization Transactions (Schedule of Residential Loan Securitizations) (Details) - Non-QM loan securitization $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
February 2021
Securitization Transactions [Line Items]
Total Face Amount of Certificates Issued	$ 251,771
Purchase of certificates	1,600
June 2019 [Member]
Securitization Transactions [Line Items]
Total Face Amount of Certificates Issued	$ 226,913
Economic interest retained	6.10%
Purchase of certificates	$ 1,200
November 2019 [Member]
Securitization Transactions [Line Items]
Total Face Amount of Certificates Issued	$ 267,255
Economic interest retained	6.40%
Purchase of certificates	$ 1,700
June 2020 [Member]
Securitization Transactions [Line Items]
Total Face Amount of Certificates Issued	259,273
Purchase of certificates	1,900
November 2020
Securitization Transactions [Line Items]
Total Face Amount of Certificates Issued	219,732
Purchase of certificates	1,400
The Company [Member] | February 2021
Securitization Transactions [Line Items]
Principal Balance of Loans Transferred to the Depositor	251,771
The Company [Member] | June 2019 [Member]
Securitization Transactions [Line Items]
Principal Balance of Loans Transferred to the Depositor	226,913
The Company [Member] | November 2019 [Member]
Securitization Transactions [Line Items]
Principal Balance of Loans Transferred to the Depositor	267,255
The Company [Member] | June 2020 [Member]
Securitization Transactions [Line Items]
Principal Balance of Loans Transferred to the Depositor	259,273
The Company [Member] | November 2020
Securitization Transactions [Line Items]
Principal Balance of Loans Transferred to the Depositor	$ 219,732
Retained, non-risk retention [Member] | June 2020 [Member]
Securitization Transactions [Line Items]
Economic interest retained	3.50%
Retained, risk retention rules [Member] | February 2021
Securitization Transactions [Line Items]
Economic interest retained	5.80%
Retained, risk retention rules [Member] | June 2020 [Member]
Securitization Transactions [Line Items]
Economic interest retained	8.00%
Retained, risk retention rules [Member] | November 2020
Securitization Transactions [Line Items]
Economic interest retained	7.60%