v3.19.3.a.u2
Fair Value Measurements (Rollforward For Assets And Liabilities Measured At Fair Value On A Recurring Basis With Level 3 Significant Unobservable Inputs) (Details) - Residential Mortgage Servicing Rights [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]      
Opening Balance $ 418 $ 336 $ 324
Gain (Loss) Included in Earnings (115) (29) (52)
Gain (Loss) Included in Other Comprehensive Income (Loss) 0 0 0
Purchases 42 111 64
Sales 0 0 0
Issuances 0 0 0
Settlements 0 0 0
Transfers Into Level 3 0 0 0
Transfers Out Of Level 3 $ 0 0 0
Closing Balance   $ 418 $ 336