Equity - Summary of Equity-based Compensation Expense and Fair Value of Shares Vested on Vesting Date (Detail) - Restricted Incentive [Member] - 2013 Plan [Member] - USD ($) $ in Millions |
12 Months Ended | ||
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Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Equity-based compensation expense | $ 11 | $ 10 | $ 11 |
| Fair value of awards vested on vesting date | $ 5 | $ 14 | $ 6 |
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- Definition Amount of cost (reversal of cost) for employee benefits and share-based payment arrangement. Includes, but is not limited to, pension, other postretirement, postemployment and termination benefits. No definition available.
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- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. 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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