Net Investments in Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Subject to or Available for Operating Lease [Line Items]
Length of lease contract	60 months or less
Vehicles, at cost	$ 32,659	$ 32,823
Accumulated depreciation	(5,927)	(5,550)
Net investment in operating leases before allowance for credit losses	26,732	27,273
Allowance for credit losses	(71)	(64)	$ (49)
Net investment in operating leases	26,661	27,209
Depreciation Expense on Property Subject to or Held for Lease		275	253
Operating Leases, Future Minimum Payments Receivable [Abstract]
2018	4,585
2019	2,797
2020	977
2021	74
2022	6
Net Investment in Operating Leases [Member]
Property Subject to or Available for Operating Lease [Line Items]
Continuing Involvement with Continued to be Recognized Transferred Financial Assets, Amount Outstanding	11,500	11,800
Affiliated Entity [Member]
Property Subject to or Available for Operating Lease [Line Items]
Related Party Transaction, Deferred Interest Supplements and Residual Support Payments on Net Investment in Operating Leases	2,800	2,500
Related Party Transaction, Earned Interest Supplements and Residual Support Costs, Net Investment in Operating Lease	2,100	1,900	1,500
Related Party Transactions, Cash Received and Interest Supplements, Net Investment in Operating Lease	$ 2,400	2,000	1,900
Net investment in leased vehicles-Employee and company vehicles		907
Operating lease revenue on employee leased vehicles		$ 302	$ 284