Employee Compensation and Benefit Plans - Schedule of Stock-based Compensation Expense and Related Income Tax Benefits (Details) - USD ($) $ / shares in Units, $ 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] | |||
| Stock-based compensation expense | $ 694 | $ 495 | $ 424 |
| Income tax benefit related to stock-based compensation | $ 132 | $ 92 | $ 81 |
| Restricted Stock Units and Performance Stock Units | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Weighted average fair value per stock award granted (in USD per share) | $ 96.27 | $ 73.25 | $ 61.52 |
| Unrecognized compensation expense | $ 592 | $ 515 | $ 547 |
| Weighted average period to be recognized (years) | 1 year 10 months 24 days | 1 year 7 months 6 days | 1 year 9 months 18 days |
| Fair value of stock awards vested | $ 1,315 | $ 512 | $ 471 |