GM Financial Receivables, Net Allowance for Loan Losses (Details) - GM Financial [Member] - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]    
Loan loss allowance at beginning of period $ 782 $ 695
Provision for loan losses 196 155
Charge-offs (293) (234)
Recoveries 150 124
Effect of foreign currency 8 (12)
Loan loss allowance at end of period $ 843 $ 728