Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Segment Reporting Information
Total goodwill	$ 4,514	$ 4,259	$ 4,514
Total assets	211,459	206,899
Net interest income	1,195	1,176
Provision for (benefit from) credit losses	45	(173)
Net Interest Income After Provision for (Benefit from) Credit Losses	1,150	1,349
Noninterest Income
Service charges on deposits	152	144
Wealth and asset management revenue	149	143
Commercial banking revenue	135	153
Card and processing revenue	97	94
Leasing business revenue	62	87
Mortgage banking net revenue	52	85
Other noninterest income	52	42
Securities losses, net	(14)	3
Securities losses, net – non-qualifying hedges on MSRs	(1)	(2)
Total noninterest income	684	749
Noninterest Expense
Compensation and benefits	711	706
Technology and communications	101	93
Net occupancy expense	77	79
Equipment expense	36	34
Leasing business expense	32	35
Marketing expense	24	23
Card and processing expense	19	30
Other noninterest expense	222	215
Total noninterest expense	1,222	1,215
Income before income taxes	612	883
Applicable income tax expense (benefit)	118	189
Net Income	494	694
Impairment losses on bank premises		2
Impairment losses of operating lease equipment	2	25
Impairment losses and termination charges	1
Bank premises and equipment held for sale	25		$ 24
Operating Segments | Commercial Banking
Segment Reporting Information
Total goodwill	1,980	1,980
Total assets	77,820	68,645
Net interest income	479	365
Provision for (benefit from) credit losses	(28)	(76)
Net Interest Income After Provision for (Benefit from) Credit Losses	507	441
Noninterest Income
Service charges on deposits	94	90
Wealth and asset management revenue	0	1
Commercial banking revenue	133	151
Card and processing revenue	16	14
Leasing business revenue	62	87
Mortgage banking net revenue	0	0
Other noninterest income	22	12
Securities losses, net	0	6
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	327	361
Noninterest Expense
Compensation and benefits	166	156
Technology and communications	5	4
Net occupancy expense	9	8
Equipment expense	7	6
Leasing business expense	32	35
Marketing expense	1	1
Card and processing expense	2	1
Other noninterest expense	224	209
Total noninterest expense	446	420
Income before income taxes	388	382
Applicable income tax expense (benefit)	70	70
Net Income	318	312
Impairment losses of operating lease equipment	2	25
Operating Segments | Branch Banking
Segment Reporting Information
Total goodwill	2,303	2,047
Total assets	94,552	87,645
Net interest income	430	295
Provision for (benefit from) credit losses	17	41
Net Interest Income After Provision for (Benefit from) Credit Losses	413	254
Noninterest Income
Service charges on deposits	59	54
Wealth and asset management revenue	51	49
Commercial banking revenue	2	2
Card and processing revenue	78	77
Leasing business revenue	0	0
Mortgage banking net revenue	2	2
Other noninterest income	24	20
Securities losses, net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	216	204
Noninterest Expense
Compensation and benefits	177	170
Technology and communications	1	1
Net occupancy expense	47	47
Equipment expense	9	10
Leasing business expense	0	0
Marketing expense	10	8
Card and processing expense	18	30
Other noninterest expense	228	223
Total noninterest expense	490	489
Income before income taxes	139	(31)
Applicable income tax expense (benefit)	30	(7)
Net Income	109	(24)
Impairment losses on bank premises		1
Operating Segments | Consumer Lending
Segment Reporting Information
Total goodwill	0	0
Total assets	32,680	31,873
Net interest income	131	128
Provision for (benefit from) credit losses	6	8
Net Interest Income After Provision for (Benefit from) Credit Losses	125	120
Noninterest Income
Service charges on deposits	0	0
Wealth and asset management revenue	0	0
Commercial banking revenue	0	0
Card and processing revenue	0	0
Leasing business revenue	0	0
Mortgage banking net revenue	50	82
Other noninterest income	3	2
Securities losses, net	0	0
Securities losses, net – non-qualifying hedges on MSRs	(1)	(2)
Total noninterest income	52	82
Noninterest Expense
Compensation and benefits	57	66
Technology and communications	3	2
Net occupancy expense	2	3
Equipment expense	0	0
Leasing business expense	0	0
Marketing expense	1	0
Card and processing expense	0	0
Other noninterest expense	81	90
Total noninterest expense	144	161
Income before income taxes	33	41
Applicable income tax expense (benefit)	7	9
Net Income	26	32
Operating Segments | Wealth and Asset Management
Segment Reporting Information
Total goodwill	231	232
Total assets	13,715	11,654
Net interest income	35	21
Provision for (benefit from) credit losses	0	(1)
Net Interest Income After Provision for (Benefit from) Credit Losses	35	22
Noninterest Income
Service charges on deposits	0	0
Wealth and asset management revenue	142	136
Commercial banking revenue	0	0
Card and processing revenue	1	0
Leasing business revenue	0	0
Mortgage banking net revenue	0	1
Other noninterest income	1	1
Securities losses, net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	144	138
Noninterest Expense
Compensation and benefits	60	53
Technology and communications	0	0
Net occupancy expense	3	4
Equipment expense	0	0
Leasing business expense	0	0
Marketing expense	0	0
Card and processing expense	0	0
Other noninterest expense	79	78
Total noninterest expense	142	135
Income before income taxes	37	25
Applicable income tax expense (benefit)	8	5
Net Income	29	20
General Corporate and Other
Segment Reporting Information
Total goodwill	0	0
Total assets	(7,308)	7,082
Net interest income	120	367
Provision for (benefit from) credit losses	50	(145)
Net Interest Income After Provision for (Benefit from) Credit Losses	70	512
Noninterest Income
Service charges on deposits	(1)	0
Wealth and asset management revenue	0	0
Commercial banking revenue	0	0
Card and processing revenue	2	3
Leasing business revenue	0	0
Mortgage banking net revenue	0	0
Other noninterest income	2	7
Securities losses, net	(14)	(3)
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	(11)	7
Noninterest Expense
Compensation and benefits	251	261
Technology and communications	92	86
Net occupancy expense	16	17
Equipment expense	20	18
Leasing business expense	0	0
Marketing expense	12	14
Card and processing expense	(1)	(1)
Other noninterest expense	(346)	(342)
Total noninterest expense	44	53
Income before income taxes	15	466
Applicable income tax expense (benefit)	3	112
Net Income	12	354
Impairment losses on bank premises		1
Bank premises and equipment held for sale	25	27
Eliminations
Segment Reporting Information
Total goodwill	0	0
Total assets	0	0
Net interest income	0	0
Provision for (benefit from) credit losses	0	0
Net Interest Income After Provision for (Benefit from) Credit Losses	0	0
Noninterest Income
Service charges on deposits	0	0
Wealth and asset management revenue	(44)	(43)
Commercial banking revenue	0	0
Card and processing revenue	0	0
Leasing business revenue	0	0
Mortgage banking net revenue	0	0
Other noninterest income	0	0
Securities losses, net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	(44)	(43)
Noninterest Expense
Compensation and benefits	0	0
Technology and communications	0	0
Net occupancy expense	0	0
Equipment expense	0	0
Leasing business expense	0	0
Marketing expense	0	0
Card and processing expense	0	0
Other noninterest expense	(44)	(43)
Total noninterest expense	(44)	(43)
Income before income taxes	0	0
Applicable income tax expense (benefit)	0	0
Net Income	$ 0	$ 0