Share-Based Compensation - Schedule of Unrecognized Compensation Cost (Details) $ in Millions |
12 Months Ended |
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Dec. 31, 2017
USD ($)
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| Restricted Stock Share Awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized compensation cost | $ 7 |
| Recognized over a weighted average period | 1 year 6 months 1 day |
| Restricted Share Unit And Performance Stock Unit Awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized compensation cost | $ 44 |
| Recognized over a weighted average period | 1 year 6 months 1 day |
| Phantom Unit Awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized compensation cost | $ 49 |
| Recognized over a weighted average period | 1 year 1 month 1 day |
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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.
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