Leasing Leasing (Schedule of Property Subject to or Available for Operating Lease) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Residual value guarantee	15.00%
Vehicles available for operating lease, gross	$ 10,426	$ 9,995
Lessor Operating Lease Accumulated Depreciation	1,562	1,578
Investment in operating leases, net	$ 8,864	$ 8,417
Minimum
Lessor, Lease, Description [Line Items]
Lessor, operating lease, lessee option to purchase underlying asset	P24M
Maximum
Lessor, Lease, Description [Line Items]
Lessor, operating lease, lessee option to purchase underlying asset	P60M
Vehicles
Lessor, Lease, Description [Line Items]
Operating Lease, Residual Value of Leased Asset	$ 352