Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Revenue and Other Interest Income [Abstract]
Interest and fees on finance receivables and loans	$ 1,235	$ 1,074
Interest on loans held-for-sale	0	24
Interest and dividends on investment securities	102	88
Interest on cash and cash equivalents	3	2
Operating leases	769	896
Total financing revenue and other interest income	2,109	2,084
Interest Expense [Abstract]
Interest on deposits	193	172
Interest on short-term borrowings	13	11
Interest on long-term debt	442	429
Total interest expense	648	612
Depreciation expense on operating lease assets	510	622
Net financing revenue (loss)	951	850
Other revenue [Abstract]
Servicing fees	13	10
Insurance premiums and service revenue earned	230	233
Gain (loss) on mortgage and automotive loans, net	1	46
Loss on extinguishment of debt	(4)	(198)
Other gain on investments, net	54	55
Other income, net of losses	82	97
Total other revenue	376	243
Total net revenue (loss)	1,327	1,093
Provision for loan losses	220	116
Noninterest Expense [Abstract]
Compensation and benefits expense	252	255
Insurance losses and loss adjustment expenses	73	56
Other operating expenses	385	384
Total noninterest expense	710	695
Income (loss) from continuing operations before income tax expense	397	282
Income tax expense (benefit) from continuing operations	150	103
Net income (loss) from continuing operations	247	179
Income (loss) from discontinued operations, net of tax	3	397
Net income (loss)	250	576
Other Comprehensive Income (Loss), Net of Tax	146	31
Comprehensive income	$ 396	$ 607
Earnings Per Share, Basic [Abstract]
Net income from continuing operations	$ 0.48	$ 0.23
Income from discontinued operations, net of tax	0.01	0.82
Net income	0.49	1.06
Earnings Per Share, Diluted [Abstract]
Net income from continuing operations	0.48	0.23
Income from discontinued operations, net of tax	0.01	0.82
Net income	$ 0.49	$ 1.06