Summary of Significant Accounting Policies - Effect of ASU 2016-02 (Details) - USD ($) $ in Millions |
Jun. 30, 2019 |
Jan. 01, 2019 |
Dec. 31, 2018 |
|---|---|---|---|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
| Operating lease right-of-use assets | $ 442 | $ 347 | |
| Accounts payable and accrued expenses | 1,102 | 735 | $ 736 |
| Operating lease current liabilities | 47 | 30 | |
| Operating lease liabilities | 418 | 339 | |
| Other long-term liabilities | $ 90 | 81 | $ 102 |
| Accounting Standards Update 2016-02 | |||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
| Operating lease right-of-use assets | 347 | ||
| Accounts payable and accrued expenses | (1) | ||
| Operating lease current liabilities | 30 | ||
| Operating lease liabilities | 339 | ||
| Other long-term liabilities | $ (21) |
| X | ||||||||||
- Definition Accounts payable and accrued expenses excluding interest payable current. 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 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 lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|