v3.20.4
Servicing of Financial Assets (Tables)
 12 Months Ended
Dec. 31, 2020
Transfers and Servicing of Financial Assets [Abstract]  
Schedule of Residential Mortgage Servicing Rights Under The Fair Value Measurement Method
The table below presents an analysis of residential MSRs under the fair value measurement method for the years ended December 31: 
 202020192018
 (In millions)
Carrying value, beginning of year$345 $418 $336 
Additions108 42 111 
Increase (decrease) in fair value:
Due to change in valuation inputs or assumptions(89)(62)18 
Economic amortization associated with borrower repayments (1)
(68)(53)(47)
Carrying value, end of year$296 $345 $418 
_________
(1)"Economic amortization associated with borrower repayments" includes both total loan payoffs as well as partial paydowns. In the first quarter of 2020, Regions revised its MSR decay methodology from a passage of time approach to a discounted net cash flow approach. The change in methodology results in shifts between decay and hedge impacts, but does not impact the overall valuation.
Data And Assumptions Used In The Fair Value Calculation As Well As The Valuation's Sensitivity To Rate Fluctuations Related To Mortgage Servicing Rights
Data and assumptions used in the fair value calculation, as well as the valuation’s sensitivity to rate fluctuations, related to residential MSRs (excluding related derivative instruments) as of December 31 are as follows: 
 20202019
 (Dollars in millions)
Unpaid principal balance$34,454 $34,467 
Weighted-average CPR (%)15.6 %12.0 %
Estimated impact on fair value of a 10% increase$(23)$(19)
Estimated impact on fair value of a 20% increase$(42)$(35)
Option-adjusted spread (basis points)560 618 
Estimated impact on fair value of a 10% increase$(7)$(8)
Estimated impact on fair value of a 20% increase$(13)$(16)
Weighted-average coupon interest rate3.9 %4.2 %
Weighted-average remaining maturity (months)287278
Weighted-average servicing fee (basis points)27.5 27.3 
Schedule Of Fees Resulting From The Servicing Of Residential Mortgage Loans
The following table presents servicing related fees, which includes contractually specified servicing fees, late fees and other ancillary income resulting from the servicing of residential mortgage loans for the years ended December 31:
 202020192018
 (In millions)
Servicing related fees and other ancillary income$95 $102 $95