Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Unrecognized tax benefits at beginning of year | $ 3,513 | $ 2,657 | $ 2,293 |
| Gross increases - current year tax positions | 177 | 814 | 239 |
| Gross increases - prior year tax positions | 42 | 93 | 134 |
| Gross decreases - prior year tax positions | (315) | (51) | (9) |
| Gross decreases - lapse of statute of limitations | (72) | 0 | 0 |
| Unrecognized tax benefits at end of year | $ 3,345 | $ 3,513 | $ 2,657 |