Segment Information - Total Revenue by Geographic Region (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Segment Reporting Information [Line Items] | |||
| Revenue | $ 16,205 | $ 14,539 | $ 14,198 |
| Americas [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Revenue | 10,593 | 9,703 | 9,303 |
| Europe [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Revenue | 4,940 | 4,158 | 4,217 |
| Asia-Pacific [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Revenue | $ 672 | $ 678 | $ 678 |