Stock-Based Compensation - RSUs and PSUs, Other Disclosures (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Stock-Based Compensation | |||
| Unrecognized compensation cost related to non-vested awards | $ 1,200 | ||
| RSUs and PSUs | |||
| Stock-Based Compensation | |||
| Tax benefits realized in connection with vesting and release of awards | 131 | $ 117 | $ 180 |
| Restricted Stock Units | |||
| Stock-Based Compensation | |||
| Fair value of stock units granted | 674 | 583 | 484 |
| Fair value of stock units vested | 428 | 381 | 463 |
| Unrecognized compensation cost related to non-vested awards | $ 1,100 | ||
| Restricted Stock Units | Weighted-Average | |||
| Stock-Based Compensation | |||
| Vesting period | 2 years 6 months | ||
| Performance Share Units | |||
| Stock-Based Compensation | |||
| Vesting period | 3 years | ||
| Fair value of stock units granted | $ 164 | 118 | 113 |
| Fair value of stock units vested | $ 118 | $ 101 | $ 51 |