v3.3.1.900
Debt (Debt) (Details) - USD ($)
$ in Millions
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations $ 12,089 $ 11,282
Debt, current portion 221 199
Debt, net of current portion 11,868 11,083
Unsecured Debt [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 3,450 2,800
Loans Payable [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 3,318 2,799
Corporate Debt Securities [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,809 2,075
Notes Payable, Other Payables [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,745 1,810
Secured Debt [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,580 1,596
Capital Lease Obligations [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations $ 187 $ 202