Expected Loss to be Paid (Recovered) - First Lien Liquidation Rates (Details)	Dec. 31, 2021	Dec. 31, 2020
Current but recently delinquent: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	20.00%	20.00%
Current but recently delinquent: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	20.00%	20.00%
Current but recently delinquent: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	20.00%	20.00%
30 – 59 Days Delinquent: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	35.00%	35.00%
30 – 59 Days Delinquent: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	35.00%	35.00%
30 – 59 Days Delinquent: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	30.00%	30.00%
60 – 89 Days Delinquent: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	40.00%	40.00%
60 – 89 Days Delinquent: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	45.00%	45.00%
60 – 89 Days Delinquent: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	40.00%	40.00%
90+ Days Delinquent: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	55.00%	55.00%
90+ Days Delinquent: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	60.00%	60.00%
90+ Days Delinquent: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	45.00%	45.00%
Bankruptcy: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	45.00%	45.00%
Bankruptcy: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	50.00%	50.00%
Bankruptcy: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	40.00%	40.00%
Foreclosure: | Alt-A and Prime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	60.00%	60.00%
Foreclosure: | Option ARM
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	65.00%	65.00%
Foreclosure: | Subprime
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	55.00%	55.00%
Real Estate Owned
Schedule of Expected Losses to be Paid [Line Items]
Liquidation rate	100.00%	100.00%