Mortgage Servicing Rights - Summary of the Weighted Average Discount Rate and Prepayment Speed Assumptions Used to Determine the Fair Value of MSRs (Details) |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2020 |
Dec. 31, 2019 |
|
| Minimum | ||
| Assumption For Fair Value As Of Balance Sheet Date Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities [Line Items] | ||
| Discount rate | 9.20% | 9.20% |
| Prepayment rate | 9.00% | 8.90% |
| Maximum | ||
| Assumption For Fair Value As Of Balance Sheet Date Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities [Line Items] | ||
| Discount rate | 15.50% | 15.50% |
| Prepayment rate | 34.60% | 30.00% |
| Weighted Average | ||
| Assumption For Fair Value As Of Balance Sheet Date Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities [Line Items] | ||
| Discount rate | 10.10% | 10.20% |
| Prepayment rate | 20.60% | 17.30% |