Share-Based Compensation (Stock Options and Restricted Share Units) (Details) shares in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2019
$ / shares
shares
| |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Stock options granted (in shares) | 42 |
| Weighted-average exercise price of awards granted during the year (in dollars per share) | $ / shares | $ 40.50 |
| Stock options outstanding (in shares) | 192 |
| Weighted-average exercise price of shares outstanding (in dollars per share) | $ / shares | $ 31.84 |
| Restricted share units [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Awards granted (in shares) | 17 |
| Awards nonvested (in shares) | 51 |
| Weighted-average fair value at grant date of nonvested awards (in dollars per share) | $ / shares | $ 36.54 |