v3.19.3.a.u2
Servicing of Financial Assets (Data And Assumptions Used In The Fair Value Calculation As Well As The Valuation's Sensitivity To Rate Fluctuations Related To Mortgage Servicing Rights) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2019
USD ($)
basis_point
Dec. 31, 2018
USD ($)
basis_point
Servicing Assets at Fair Value [Line Items]    
Unpaid principal balance $ 34,467 $ 36,450
Weighted-average CPR (%) 12.00% 9.00%
Estimated impact on fair value of a 10% increase $ (19) $ (24)
Estimated impact on fair value of a 20% increase $ (35) $ (43)
Option-adjusted spread (basis points) | basis_point 618 755
Estimated impact on fair value of a 10% increase $ (8) $ (13)
Estimated impact on fair value of a 20% increase $ (16) $ (26)
Weighted-Average Coupon Interest Rate 4.20% 4.20%
Weighted-average remaining maturity (months) 278 months 281 months
Weighted-average servicing fee (basis points) | basis_point 27.3 27.1