Other Income, Net of Losses (Schedule of Other Income, Net of Losses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Nonoperating Income (Expense) [Abstract]
Late charges and other administrative fees	$ 29	$ 25	$ 83	$ 77
Remarketing fees	19	26	63	82
Servicing fees	5	11	21	41
Income from equity method investments	5	7	18	12
Other income, net	43	22	122	95
Total other income, net of losses	$ 101	$ 91	$ 307	$ 307