Shareholders' Equity - Summary of Amount of Common Stock Repurchased by the Firm (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
| Equity [Abstract] | ||||
| Common share repurchases | 2.5 | 14.1 | 8.2 | |
| Average cost per share | $ 395.28 | $ 333.61 | $ 236.35 | |
| Total cost of common share repurchases | $ 1,000 | $ 4,700 | $ 1,928 | |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Number of shares that have been repurchased during the period and are being held in treasury. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|