Commitments and Contingencies - Noncancelable Operating Leases (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Lessee, Lease, Description [Line Items] | |||
| Rent expense | $ 317 | $ 354 | $ 300 |
| Operating lease liabilities | 969 | 1,010 | |
| Operating right-of-use assets obtained in exchange for lease obligations | 222 | $ 497 | |
| 2021 | 251 | ||
| 2022 | 205 | ||
| 2023 | 196 | ||
| 2024 | 151 | ||
| 2025 | 122 | ||
| Thereafter | 437 | ||
| Imputed interest | $ 184 | ||
| Weighted average discount rate | 4.00% | 4.20% | |
| Weighted-average remaining lease term | 7 years 4 months 24 days | 7 years 2 months 12 days | |
| Payments for operating leases | $ 309 | $ 337 | |
| Amount of lease agreements not yet commenced | 150 | ||
| Other assets | |||
| Lessee, Lease, Description [Line Items] | |||
| Operating lease right-of-use assets | 1,000 | 1,100 | |
| Accrued liabilities | |||
| Lessee, Lease, Description [Line Items] | |||
| Operating lease liability | 209 | 239 | |
| Other liabilities | |||
| Lessee, Lease, Description [Line Items] | |||
| Operating lease liabilities | $ 969 | $ 1,000 | |
| X | ||||||||||
- Definition Lessor, Operating Lease, Lease Not yet Commenced, Amount No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Cash payments to lessor's for use of assets under operating leases. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase in right-of-use asset obtained in exchange for operating lease liability. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|