v3.2.0.727
Debt (Debt) (Details) - USD ($)
$ in Millions
Jun. 30, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations $ 11,691 $ 11,282
Debt, Current 198 199
Long-term Debt, Excluding Current Maturities 11,493 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 2,787 2,799
Corporate Debt Securities [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,928 2,075
Notes Payable, Other Payables [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,737 1,810
Secured Debt [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations 1,588 1,596
Capital Lease Obligations [Member]    
Debt Instrument [Line Items]    
Debt and Capital Lease Obligations $ 201 $ 202