Quarterly report pursuant to Section 13 or 15(d)

Assets and Liabilities Measured at Fair Value (Details)

v2.4.1.9
Assets and Liabilities Measured at Fair Value (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable securities $ 118us-gaap_MarketableSecuritiesCurrent $ 108us-gaap_MarketableSecuritiesCurrent
Available-for-sale securities 19us-gaap_AvailableForSaleSecuritiesNoncurrent 31us-gaap_AvailableForSaleSecuritiesNoncurrent
Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 70us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
58us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Marketable securities 118us-gaap_MarketableSecuritiesCurrent
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
108us-gaap_MarketableSecuritiesCurrent
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Available-for-sale securities 19us-gaap_AvailableForSaleSecuritiesNoncurrent
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
31us-gaap_AvailableForSaleSecuritiesNoncurrent
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 70us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
58us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable securities 118us-gaap_MarketableSecuritiesCurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
108us-gaap_MarketableSecuritiesCurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Available-for-sale securities $ 19us-gaap_AvailableForSaleSecuritiesNoncurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
$ 31us-gaap_AvailableForSaleSecuritiesNoncurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember