Consolidated Statement of Income Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Financing Revenue and Other Income [Line Items]
Interest and Fee Income, Loans and Leases	$ 1,368	$ 1,235
Interest and Dividend Income, Securities, Operating, Available-for-sale	134	102
Interest Income, Deposits with Financial Institutions	5	3
Operating Leases, Income Statement, Lease Revenue	543	769
Total financing revenue and other interest income	2,050	2,109
Interest Expense [Abstract]
Interest Expense, Deposits	231	193
Interest Expense, Short-term Borrowings	27	13
Interest Expense, Long-term Debt	424	442
Interest Expense	682	648
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	389	510
Net Financing Revenue	979	951
Other revenue [Abstract]
Insurance Services Revenue	241	230
Gain (Loss) on Sales of Loans, Net	14	1
Gain (Loss) on Extinguishment of Debt	(1)	(4)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	27	54
Noninterest Income, Other Operating Income	115	95
Nonoperating Income (Expense)	396	376
Revenues	1,375	1,327
Provision for Loan Losses Expensed	271	220
Noninterest Expense [Abstract]
Labor and Related Expense	285	252
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	88	73
Other Noninterest Expense	405	385
Noninterest Expense	778	710
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	326	397
Income Tax Expense (Benefit)	113	150
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	213	247
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	1	3
Net Income (Loss) Attributable to Parent	214	250
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	20	146
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 234	$ 396
Earnings Per Share, Basic [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.46	$ 0.48
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0.00	0.01
Earnings Per Share, Basic	0.46	0.49
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share	0.46	0.48
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0.00	0.01
Earnings Per Share, Diluted	0.46	0.49
Common Stock, Dividends, Per Share, Declared	$ 0.08	$ 0.00
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	$ 214	$ 250