v3.7.0.1
Changes to Debt (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2017
Jun. 30, 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 16,009  
Proceeds from asset-backed long-term borrowings 2,878  
Repayments of long-term borrowings and capital leases obligations (10,294) $ (11,300)
Decrease in short-term obligations, excluding current maturities (152) $ 610
Reclassifications of long-term debt 0  
Debt acquired (Note 2) 59  
Other 965  
Balance at June 30, 2017 1,153  
Balance at June 30, 2017 116,390  
Balance at June 30, 2017 117,543  
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 (3,158)  
Decrease in short-term obligations, excluding current maturities (152)  
Reclassifications of long-term debt 1,569  
Debt acquired (Note 2) 7  
Other 177  
Balance at June 30, 2017 1,153  
Long-term Debt    
Debt Instrument [Line Items]    
Balance at January 1, 2017 105,433  
Proceeds from long-term borrowings 15,944  
Proceeds from asset-backed long-term borrowings 2,878  
Repayments of long-term borrowings and capital leases obligations (7,136)  
Reclassifications of long-term debt (1,569)  
Debt acquired (Note 2) 52  
Other 788  
Balance at June 30, 2017 $ 116,390