v2.4.1.9
Debt (Debt) (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations $ 11,282us-gaap_DebtAndCapitalLeaseObligations $ 11,112us-gaap_DebtAndCapitalLeaseObligations
Debt, current portion 199us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent 204us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
Debt, net of current portion 11,083us-gaap_LongTermDebtAndCapitalLeaseObligations 10,908us-gaap_LongTermDebtAndCapitalLeaseObligations
Corporate Debt Securities [Member]    
Debt Instrument [Line Items]    
Long-term Debt 2,075us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_CorporateDebtSecuritiesMember
4,989us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_CorporateDebtSecuritiesMember
Unsecured Debt [Member]    
Debt Instrument [Line Items]    
Long-term Debt 2,800us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
0us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Loans Payable [Member]    
Debt Instrument [Line Items]    
Long-term Debt 2,799us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LoansPayableMember
2,828us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LoansPayableMember
Notes Payable, Other Payables [Member]    
Debt Instrument [Line Items]    
Long-term Debt 1,810us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember
1,901us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember
Secured Debt [Member]    
Debt Instrument [Line Items]    
Long-term Debt 1,596us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SecuredDebtMember
1,191us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SecuredDebtMember
Capital Lease Obligations [Member]    
Debt Instrument [Line Items]    
Long-term Debt $ 202us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_CapitalLeaseObligationsMember
$ 203us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_CapitalLeaseObligationsMember