Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Reconciliation of the beginning and ending unrecognized tax benefits | |||
| Unrecognized Tax Benefits, Balance at January 1 | $ 1,081 | $ 882 | $ 381 |
| Additions based on tax positions related to the current year | 9 | 268 | 612 |
| Additions for tax positions of prior years | 120 | 43 | 109 |
| Reductions for tax positions of prior years | (22) | (73) | (129) |
| Settlements | (9) | (35) | (5) |
| Lapse of statute | (2) | (4) | (86) |
| Unrecognized Tax Benefits, Balance at December 31 | $ 1,177 | $ 1,081 | $ 882 |
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|