Equity - Share Repurchase Program (Details) - USD ($) shares in Millions, $ in Millions |
12 Months Ended | ||||
|---|---|---|---|---|---|
Dec. 13, 2018 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Feb. 15, 2018 |
|
| Equity, Class of Treasury Stock [Line Items] | |||||
| Payment for shares repurchased | $ 978 | $ 428 | $ 12,215 | ||
| February 2018 Stock Repurchase Program | |||||
| Equity, Class of Treasury Stock [Line Items] | |||||
| Amount authorized under stock repurchase program | $ 10,000 | ||||
| December 2018 Stock Repurchase Authorization | |||||
| Equity, Class of Treasury Stock [Line Items] | |||||
| Shares repurchased (in shares) | 8 | 4 | 109 | ||
| Payment for shares repurchased | $ 757 | $ 300 | $ 10,700 | ||
| Remaining share repurchase authorization amount | $ 3,200 | ||||
| Increase in authorized share repurchase amount | $ 5,000 | ||||
| Open Market Stock Repurchases | |||||
| Equity, Class of Treasury Stock [Line Items] | |||||
| Shares repurchased (in shares) | 11 | ||||
| Payment for shares repurchased | $ 1,300 | ||||