XML 188 R156.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value (Fair Value Option for Certain Assets and Liabilities) (Details) - Residential mortgage loans - FVO - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Option, Quantitative Disclosures [Line Items]    
Unpaid principal balance $ 344 $ 650
Difference between estimated fair value and unpaid principal balance (45) (130)
Carrying value at estimated fair value 299 520
Loans in nonaccrual status 89 198
Loans more than 90 days past due 41 94
Loans in nonaccrual status or more than 90 days past due, or both - difference between aggregate estimate fair value and unpaid principal balance $ (36) $ (102)