Consolidated Statement of Income Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Income (Loss) Attributable to Parent	$ 248	$ 209	$ 360	$ 250	$ 263	$ 268	$ 182	$ 576	$ 1,067	$ 1,289	$ 1,150
Financing Revenue and Other Income [Line Items]
Interest and Fee Income, Loans and Leases									5,162	4,570	4,457
Interest and Fee Income, Loans and Leases Held-for-sale									0	40	1
Interest and Dividend Income, Securities, Operating, Available-for-sale									418	381	367
Interest Income, Deposits with Financial Institutions									14	8	8
Operating Leases, Income Statement, Lease Revenue									2,711	3,398	3,558
Total financing revenue and other interest income									8,305	8,397	8,391
Interest Expense [Abstract]
Interest Expense, Deposits									830	718	664
Interest Expense, Short-term Borrowings									57	49	52
Interest Expense, Long-term Debt									1,742	1,662	2,067
Interest Expense									2,629	2,429	2,783
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease									1,769	2,249	2,233
Net Financing Revenue	976	996	984	951	983	970	916	850	3,907	3,719	3,375
Other revenue [Abstract]
Insurance Services Revenue									945	940	979
Gain (Loss) on Sales of Loans, Net									11	45	7
Gain (Loss) on Extinguishment of Debt									(5)	(357)	(202)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments									185	155	181
Noninterest Income, Other Operating Income									394	359	311
Nonoperating Income (Expense)	392	388	374	376	356	332	211	243	1,530	1,142	1,276
Revenues									5,437	4,861	4,651
Provision for Loan Losses Expensed	267	258	172	220	240	211	140	116	917	707	457
Noninterest Expense [Abstract]
Labor and Related Expense									992	963	947
Policyholder Benefits and Claims Incurred, Net									342	293	410
Other Noninterest Expense									1,605	1,505	1,591
Noninterest Expense	721	735	773	710	668	674	724	695	2,939	2,761	2,948
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	380	391	413	397	431	417	263	282	1,581	1,393	1,246
Income Tax Expense (Benefit)	134	130	56	150	155	144	94	103	470	496	321
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	246	261	357	247	276	273	169	179	1,111	897	925
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ 2	$ (52)	$ 3	$ 3	$ (13)	$ (5)	$ 13	$ 397	$ (44)	$ 392	$ 225
Earnings Per Share, Basic [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.52	$ 0.54	$ 0.70	$ 0.48	$ (1.94)	$ 0.49	$ (2.24)	$ 0.23	$ 2.25	$ (3.47)	$ 1.36
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0.53	0.43	0.71	0.49	(1.97)	0.48	(2.22)	1.06	(0.09)	0.81	0.47
Earnings Per Share, Basic									2.15	(2.66)	1.83
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share	0.52	0.54	0.70	0.48	(1.94)	0.49	(2.24)	0.23	2.24	(3.47)	1.36
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0.52	0.43	0.71	0.49	$ (1.97)	$ 0.47	$ (2.22)	$ 1.06	(0.09)	0.81	0.47
Earnings Per Share, Diluted									2.15	(2.66)	1.83
Common Stock, Dividends, Per Share, Declared	$ 0.08	$ 0.08	$ 0.00	$ 0.00					$ 0.16	$ 0.00	$ 0.00
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent									$ 1,067	$ 1,289	$ 1,150