Net Investments in Operating Leases (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Property Subject to or Available for Operating Lease [Line Items]
Length of lease contract	60 months or less
Vehicles, at cost	$ 33,410		$ 32,659
Accumulated depreciation	(6,024)		(5,927)
Net investment in operating leases before allowance for credit losses	27,386		26,732	$ 26,759
Allowance for credit losses	(72)	$ (71)	(71)	(66)	$ (67)	$ (64)
Net investment in operating leases	27,314		26,661	$ 26,693
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	$ 12,200		$ 11,500