Share-Based Compensation Plans - Restricted Share Units Narrative (Details) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
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 | $ 190 | $ 187 | $ 189 |
Unamortized deferred compensation | $ 377 | ||
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 |