Employee Benefit Plans (Details) - USD ($) $ in Millions  | 
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015  | 
Dec. 31, 2014  | 
Dec. 31, 2013  | 
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| Employee Benefit Plans [Abstract] | |||
| Defined Contribution Plan, Cost Recognized | $ 27 | $ 27 | $ 24 | 
| X | ||||||||||
- References No definition available. 
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- Definition The amount of the cost recognized during the period for defined contribution plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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