Recent Accounting Pronouncements - Cash flow changes, reconciliation of components of cash (Details) $ in Millions |
1 Months Ended | ||||
|---|---|---|---|---|---|
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Aug. 31, 2016
item
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Jun. 30, 2018
USD ($)
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Dec. 31, 2017
USD ($)
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Jun. 30, 2017
USD ($)
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Dec. 31, 2016
USD ($)
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| Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] | Ìý | Ìý | Ìý | Ìý | Ìý |
| Cash and cash equivalents | Ìý | $ 485 | $ 1,029 | Ìý | Ìý |
| Restricted cash included in other current assets | Ìý | 55 | 8 | Ìý | Ìý |
| Restricted cash included in other assets | Ìý | 23 | 10 | Ìý | Ìý |
| Total cash and cash equivalents and restricted cash at end of period | Ìý | $ 563 | $ 1,047 | $ 754 | $ 572 |
| Number of cash flow issues the FASB guidance addresses | item | 8 | Ìý | Ìý | Ìý | Ìý |
| X | ||||||||||
- Definition The number of specific cash flow issues the new FASB issued accounting guidance addresses. No definition available.
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| X |
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef |