Condensed Consolidated Statement of Comprehensive Income Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Financing Revenue and Other Income [Abstract]
Interest and fees on finance receivables and loans	$ 1,742	$ 1,807
Interest on loans held-for-sale	2	2
Interest and dividends on investment securities and other earning assets	226	240
Interest on cash and cash equivalents	14	23
Operating leases	367	361
Total financing revenue and other interest income	2,351	2,433
Interest Expense [Abstract]
Interest on deposits	592	592
Interest on short-term borrowings	17	44
Interest on long-term debt	348	419
Total interest expense	957	1,055
Net depreciation expense on operating lease assets	248	246
Net financing revenue and other interest income	1,146	1,132
Other revenue [Abstract]
Insurance premiums and service revenue earned	277	261
Gain on mortgage and automotive loans, net	(12)	10
Other gain on investments, net	(79)	108
Other income, net of losses	80	87
Total other revenue	266	466
Total net revenue	1,412	1,598
Provision for credit losses	903	282
Noninterest Expense [Abstract]
Compensation and benefits expense	360	318
Insurance losses and loss adjustment expenses	74	59
Other operating expenses	486	453
Total noninterest expense	920	830
(Loss) income from continuing operations before income tax (benefit) expense	(411)	486
Statement [Abstract]
Income tax expense from continuing operations	(92)	111
Net income from continuing operations	(319)	375
Loss from discontinued operations, net of tax	0	(1)
Net income	(319)	374
Other comprehensive income (loss), net of tax	583	306
Comprehensive Income	$ 264	$ 680
Earnings Per Share, Basic [Abstract]
Net (loss) income from continuing operations, basic earnings per common share	$ (0.85)	$ 0.93
Net (loss) income, basic earnings per common share	(0.85)	0.93
Earnings Per Share, Diluted [Abstract]
Net (loss) income from continuing operations, diluted earnings per common share	(0.85)	0.92
Net (loss) income, diluted earnings per common share	(0.85)	0.92
Cash dividends declared per common share	$ 0.19	$ 0.17