Leases - Maturities of lease liabilities (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Finance Leases | ||
| 2020 | $ 21 | |
| 2021 | 17 | |
| 2022 | 16 | |
| 2023 | 15 | |
| 2024 | 14 | |
| After 2024 | 55 | |
| Total | 138 | |
| Less: Amounts representing interest | 6 | |
| Present value of future minimum lease payments | 132 | |
| Less: Current obligations | 21 | |
| Long-term obligations | 111 | $ 75 |
| Operating Leases | ||
| 2020 | 267 | |
| 2021 | 191 | |
| 2022 | 138 | |
| 2023 | 97 | |
| 2024 | 65 | |
| After 2024 | 173 | |
| Total | 931 | |
| Less: Amounts representing interest | 77 | |
| Present value of future minimum lease payments | 854 | |
| Current operating lease liabilities | 247 | |
| Noncurrent operating lease liabilities | $ 607 | |
| Operating Lease, Liability, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent us-gaap:OperatingLeaseLiabilityNoncurrent |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from finance 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 finance lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due after fifth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due in next fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due in fifth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due in fourth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due in third fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease, due in second fiscal year following latest fiscal year. 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 finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due in next fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fifth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fourth fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's undiscounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year. 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 | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from 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 Indicates line item in statement of financial position that includes operating lease liability. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|