Segments - Business Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Segment Information
Number of reportable segments | segment			2
Segments, Income statement information
Revenue	$ 279	$ 410	$ 615	$ 892
Pre-tax income	104	136	232	330
Depreciation of equipment under operating lease	28	43	59	88
Interest expense	72	135	166	285
Provision for/(benefit from) credit losses	27	(8)	45	(4)
Client Financing
Segments, Income statement information
Revenue	244	292	522	614
Pre-tax income	86	96	182	213
Depreciation of equipment under operating lease	28	43	59	88
Interest expense	63	96	145	193
Provision for/(benefit from) credit losses	27	(5)	45	(6)
Commercial Financing
Segments, Income statement information
Revenue	35	118	93	278
Pre-tax income	18	40	50	116
Interest expense	9	39	21	92
Provision for/(benefit from) credit losses	$ (1)	$ (3)	$ 0	$ 2