Finance Receivables - Finance Receivables Summary (Details) - Automobile Loan [Member] - Retail Finance Receivables [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable Rollforward [Roll Forward]
Balance at beginning of period	$ 29,124	$ 25,623	$ 23,130
Purchases of retail finance receivables	18,054	17,537	15,085
Principal collections and other	(12,633)	(10,968)	(10,234)
Charge-offs	(1,171)	(996)	(914)
Foreign currency translation	(464)	(2,072)	(1,444)
Balance at end of period	$ 32,910	$ 29,124	$ 25,623