Parent and Guarantor Consolidating Financial Statements (Schedule of Condensed Consolidating Statement of Income) (Details) - 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
Condensed Income Statements, Captions [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, 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, Related Party									0	0	0
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
Dividends from Bank Subsidiary										0	0
Dividends From Non Bank Subsidiary									0	0	0
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
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
Undistributed income of bank subsidiaries									0	0	0
Undistributed income of nonbank subsidiaries									0	0	0
Net Income (Loss) Attributable to Parent	$ 248	$ 209	$ 360	$ 250	$ 263	$ 268	$ 182	$ 576	1,067	1,289	1,150
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(110)	(165)	210
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									957	1,124	1,360
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									(104)	(83)	(14)
Interest and Fee Income, Loans and Leases Held-for-sale										0	0
Interest and Dividend Income, Securities, Operating, Available-for-sale									0	0	0
Interest Income, Deposits with Financial Institutions									5	1	1
Operating Leases, Income Statement, Lease Revenue									17	9	269
Total financing revenue and other interest income									(71)	(56)	293
Interest Expense, Deposits									8	10	15
Interest Expense, Short-term Borrowings									40	40	43
Interest Expense, Long-term Debt									1,161	1,121	1,492
Interest Expense, Related Party									20	32	88
Interest Expense									1,229	1,203	1,638
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease									14	7	161
Net Financing Revenue									(1,314)	(1,266)	(1,506)
Dividends from Bank Subsidiary										525	1,800
Dividends From Non Bank Subsidiary									965	1,123	651
Insurance Services Revenue									0	0	0
Gain (Loss) on Sales of Loans, Net									(11)	(9)	(5)
Gain (Loss) on Extinguishment of Debt									(3)	(355)	(202)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments									0	0	0
Noninterest Income, Other Operating Income									1,253	1,373	1,279
Nonoperating Income (Expense)									1,239	1,009	1,072
Revenues									890	1,391	2,017
Provision for Loan Losses Expensed									408	157	250
Labor and Related Expense									573	571	586
Policyholder Benefits and Claims Incurred, Net									0	0	0
Other Noninterest Expense									1,261	1,247	1,267
Noninterest Expense									1,834	1,818	1,853
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									(1,352)	(584)	(86)
Income Tax Expense (Benefit)									(279)	(267)	(457)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									(1,073)	(317)	371
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									(39)	356	193
Undistributed income of bank subsidiaries									1,273	581	(680)
Undistributed income of nonbank subsidiaries									906	669	1,266
Net Income (Loss) Attributable to Parent									1,067	1,289	1,150
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(110)	(165)	210
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									957	1,124	1,360
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									0	0	0
Interest and Fee Income, Loans and Leases Held-for-sale										0	0
Interest and Dividend Income, Securities, Operating, Available-for-sale									0	0	0
Interest Income, Deposits with Financial Institutions									0	0	0
Operating Leases, Income Statement, Lease Revenue									0	0	0
Total financing revenue and other interest income									0	0	0
Interest Expense, Deposits									0	0	0
Interest Expense, Short-term Borrowings									0	0	0
Interest Expense, Long-term Debt									0	0	0
Interest Expense, Related Party									0	0	0
Interest Expense									0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease									0	0	0
Net Financing Revenue									0	0	0
Dividends from Bank Subsidiary										525	1,800
Dividends From Non Bank Subsidiary									0	0	0
Insurance Services Revenue									0	0	0
Gain (Loss) on Sales of Loans, Net									0	0	0
Gain (Loss) on Extinguishment of Debt									0	0	0
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments									0	0	0
Noninterest Income, Other Operating Income									0	0	0
Nonoperating Income (Expense)									0	0	0
Revenues									0	525	1,800
Provision for Loan Losses Expensed									0	0	0
Labor and Related Expense									0	0	0
Policyholder Benefits and Claims Incurred, Net									0	0	0
Other Noninterest Expense									0	0	0
Noninterest Expense									0	0	0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									0	525	1,800
Income Tax Expense (Benefit)									(82)	0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									82	525	1,800
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									0	0	0
Undistributed income of bank subsidiaries									1,273	581	(680)
Undistributed income of nonbank subsidiaries									(2)	(1)	(1)
Net Income (Loss) Attributable to Parent									1,353	1,105	1,119
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(63)	(43)	188
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									1,290	1,062	1,307
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									5,266	4,653	4,471
Interest and Fee Income, Loans and Leases Held-for-sale										40	1
Interest and Dividend Income, Securities, Operating, Available-for-sale									421	381	367
Interest Income, Deposits with Financial Institutions									9	7	7
Operating Leases, Income Statement, Lease Revenue									2,694	3,389	3,289
Total financing revenue and other interest income									8,407	8,502	8,223
Interest Expense, Deposits									822	708	649
Interest Expense, Short-term Borrowings									17	9	9
Interest Expense, Long-term Debt									581	541	575
Interest Expense, Related Party									11	17	37
Interest Expense									1,431	1,275	1,270
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease									1,755	2,242	2,072
Net Financing Revenue									5,221	4,985	4,881
Dividends from Bank Subsidiary										0	0
Dividends From Non Bank Subsidiary									0	0	0
Insurance Services Revenue									945	940	979
Gain (Loss) on Sales of Loans, Net									22	54	12
Gain (Loss) on Extinguishment of Debt									(2)	(2)	0
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments									176	155	181
Noninterest Income, Other Operating Income									937	1,373	1,299
Nonoperating Income (Expense)									2,078	2,520	2,471
Revenues									7,299	7,505	7,352
Provision for Loan Losses Expensed									509	550	207
Labor and Related Expense									419	842	793
Policyholder Benefits and Claims Incurred, Net									342	293	410
Other Noninterest Expense									2,130	2,195	2,159
Noninterest Expense									2,891	3,330	3,362
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									3,899	3,625	3,783
Income Tax Expense (Benefit)									831	763	778
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									3,068	2,862	3,005
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									(5)	36	32
Undistributed income of bank subsidiaries									0	0	0
Undistributed income of nonbank subsidiaries									0	0	0
Net Income (Loss) Attributable to Parent									3,063	2,898	3,037
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(106)	(172)	212
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									2,957	2,726	3,249
Affiliated Entity [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									0	0	0
Interest Income, Deposits with Financial Institutions									0	0	0
Affiliated Entity [Member] | Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									11	17	37
Interest Income, Deposits with Financial Institutions									0	0	0
Affiliated Entity [Member] | Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									0	0	0
Interest Income, Deposits with Financial Institutions									0	0	0
Affiliated Entity [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									8	24	82
Interest Income, Deposits with Financial Institutions									9	8	6
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									0	0	0
Interest and Fee Income, Loans and Leases Held-for-sale										0	0
Interest and Dividend Income, Securities, Operating, Available-for-sale									(3)	0	0
Interest Income, Deposits with Financial Institutions									0	0	0
Operating Leases, Income Statement, Lease Revenue									0	0	0
Total financing revenue and other interest income									(31)	(49)	(125)
Interest Expense, Deposits									0	0	0
Interest Expense, Short-term Borrowings									0	0	0
Interest Expense, Long-term Debt									0	0	0
Interest Expense, Related Party									(31)	(49)	(125)
Interest Expense									(31)	(49)	(125)
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease									0	0	0
Net Financing Revenue									0	0	0
Dividends from Bank Subsidiary										(1,050)	(3,600)
Dividends From Non Bank Subsidiary									(965)	(1,123)	(651)
Insurance Services Revenue									0	0	0
Gain (Loss) on Sales of Loans, Net									0	0	0
Gain (Loss) on Extinguishment of Debt									0	0	0
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments									9	0	0
Noninterest Income, Other Operating Income									(1,796)	(2,387)	(2,267)
Nonoperating Income (Expense)									(1,787)	(2,387)	(2,267)
Revenues									(2,752)	(4,560)	(6,518)
Provision for Loan Losses Expensed									0	0	0
Labor and Related Expense									0	(450)	(432)
Policyholder Benefits and Claims Incurred, Net									0	0	0
Other Noninterest Expense									(1,786)	(1,937)	(1,835)
Noninterest Expense									(1,786)	(2,387)	(2,267)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									(966)	(2,173)	(4,251)
Income Tax Expense (Benefit)									0	0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									(966)	(2,173)	(4,251)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									0	0	0
Undistributed income of bank subsidiaries									(2,546)	(1,162)	1,360
Undistributed income of nonbank subsidiaries									(904)	(668)	(1,265)
Net Income (Loss) Attributable to Parent									(4,416)	(4,003)	(4,156)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									169	215	(400)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									(4,247)	(3,788)	(4,556)
Consolidation, Eliminations [Member] | Affiliated Entity [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Fee Income, Loans and Leases									(19)	(41)	(119)
Interest Income, Deposits with Financial Institutions									$ (9)	$ (8)	$ (6)