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) (Recurring, USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Current assets:    
Cash equivalents $ 325us-gaap_CashAndCashEquivalentsFairValueDisclosure $ 245us-gaap_CashAndCashEquivalentsFairValueDisclosure
Long-term liabilities:    
Debt (note 6) 4,601us-gaap_LongTermDebtFairValue 4,626us-gaap_LongTermDebtFairValue
Level 1
   
Current assets:    
Cash equivalents 325us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
245us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Level 2
   
Long-term liabilities:    
Debt (note 6) $ 4,601us-gaap_LongTermDebtFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
$ 4,626us-gaap_LongTermDebtFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember