v3.7.0.1
Changes to Debt (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Debt Instrument [Line Items]    
Balance at January 1, 2017 $ 2,645  
Balance at January 1, 2017 105,433  
Balance at January 1, 2017 108,078  
Proceeds from long-term borrowings 13,054  
Proceeds from asset-backed long-term borrowings 1,283  
Repayments of long-term borrowings and capital leases obligations (5,592) $ (376)
Decrease in short-term obligations, excluding current maturities (52) $ (40)
Other (225)  
Balance at March 31, 2017 3,707  
Balance at March 31, 2017 112,839  
Balance at March 31, 2017 116,546  
Debt Maturing within One Year    
Debt Instrument [Line Items]    
Balance at January 1, 2017 2,645  
Proceeds from long-term borrowings 65  
Repayments of long-term borrowings and capital leases obligations (201)  
Decrease in short-term obligations, excluding current maturities (52)  
Reclassifications of long-term debt 1,165  
Other 85  
Balance at March 31, 2017 3,707  
Long-term Debt    
Debt Instrument [Line Items]    
Balance at January 1, 2017 105,433  
Proceeds from long-term borrowings 12,989  
Proceeds from asset-backed long-term borrowings 1,283  
Repayments of long-term borrowings and capital leases obligations (5,391)  
Reclassifications of long-term debt 1,165  
Other (310)  
Balance at March 31, 2017 $ 112,839