XML 188 R112.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Share-based Compensation Plans - Restricted Share Units Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average remaining amortization period (in years) 2 years 1 month 6 days    
Restricted share units (RSUs)      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Fair value of RSUs vested during the period $ 187 $ 189 $ 197
Unamortized deferred compensation $ 349    
Restricted share units (RSUs) | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 3 years    
Restricted share units (RSUs) | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 5 years