Segment Information (Narrative) (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets Under Vehicle Programs	$ 12,176	$ 13,815
Americas [Member]
Segment Reporting Information [Line Items]
Segment Assets Exclusive Of Assets Under Vehicle Program	6,700	6,200
Assets Under Vehicle Programs	9,900	10,500
International [Member]
Segment Reporting Information [Line Items]
Segment Assets Exclusive Of Assets Under Vehicle Program	2,800	3,000
Assets Under Vehicle Programs	$ 2,300	$ 3,300