Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information
Total goodwill	$ 4,926	$ 4,259	$ 4,926	$ 4,259	$ 4,514	$ 4,258
Total assets	206,782	205,390	206,782	205,390
Net interest income	1,339	1,208	2,534	2,385
Provision for (benefit from) credit losses	179	(115)	224	(288)
Net Interest Income After Provision for (Benefit from) Credit Losses	1,160	1,323	2,310	2,673
Noninterest Income
Service charges on deposits	154	149	306	292
Wealth and asset management revenue	140	145	289	288
Commercial banking revenue	137	160	272	313
Card and processing revenue	105	102	201	196
Leasing business revenue	56	61	118	148
Mortgage banking net revenue	31	64	83	149
Other noninterest income	85	49	138	92
Securities losses, net	(32)	10	(47)	13
Securities losses, net – non-qualifying hedges on MSRs	0	1	(1)	(1)
Total noninterest income	676	741	1,359	1,490
Noninterest Expense
Compensation and benefits	584	638	1,295	1,343
Technology and communications	98	94	199	187
Net occupancy expense	75	77	152	156
Equipment expense	36	34	72	68
Leasing business expense	31	33	63	68
Marketing expense	28	20	52	43
Card and processing expense	20	20	38	50
Other noninterest expense	240	237	463	454
Total noninterest expense	1,112	1,153	2,334	2,369
Income (loss) before income taxes	724	911	1,335	1,794
Applicable income tax expense (benefit)	162	202	279	391
Net Income	562	709	1,056	1,403
Impairment losses on bank premises	1	2	1	4
Impairment losses of operating lease equipment	0	0	2	25
Impairment losses and termination charges	1	2	2	2
Bank premises and equipment held for sale	24		24		24
Operating Segments | Commercial Banking
Segment Reporting Information
Total goodwill	1,946	1,981	1,946	1,981	1,980	1,980
Total assets	80,424	68,851	80,424	68,851
Net interest income	516	376	1,006	741
Provision for (benefit from) credit losses	85	(151)	56	(227)
Net Interest Income After Provision for (Benefit from) Credit Losses	431	527	950	968
Noninterest Income
Service charges on deposits	92	92	188	181
Wealth and asset management revenue	1	1	1	1
Commercial banking revenue	136	156	269	307
Card and processing revenue	18	15	33	29
Leasing business revenue	56	61	118	148
Mortgage banking net revenue	0	0	0	0
Other noninterest income	42	30	64	42
Securities losses, net	0	0	0	7
Securities losses, net – non-qualifying hedges on MSRs	0	0	0	0
Total noninterest income	345	355	673	715
Noninterest Expense
Compensation and benefits	142	136	310	292
Technology and communications	2	4	7	7
Net occupancy expense	9	8	18	17
Equipment expense	7	7	14	13
Leasing business expense	31	33	63	68
Marketing expense	1	2	2	3
Card and processing expense	2	2	4	3
Other noninterest expense	224	207	448	416
Total noninterest expense	418	399	866	819
Income (loss) before income taxes	358	483	757	864
Applicable income tax expense (benefit)	64	90	137	160
Net Income	294	393	620	704
Impairment losses of operating lease equipment			2	25
Operating Segments | Branch Banking
Segment Reporting Information
Total goodwill	2,302	2,047	2,302	2,047	2,303	2,047
Total assets	90,520	87,646	90,520	87,646
Net interest income	554	301	972	596
Provision for (benefit from) credit losses	20	25	39	66
Net Interest Income After Provision for (Benefit from) Credit Losses	534	276	933	530
Noninterest Income
Service charges on deposits	62	57	119	111
Wealth and asset management revenue	51	52	102	102
Commercial banking revenue	2	3	4	5
Card and processing revenue	83	84	162	161
Leasing business revenue	0	0	0	0
Mortgage banking net revenue	1	3	3	5
Other noninterest income	20	25	44	45
Securities losses, net	0	0	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0	0	0
Total noninterest income	219	224	434	429
Noninterest Expense
Compensation and benefits	158	158	334	328
Technology and communications	1	1	2	2
Net occupancy expense	49	49	95	96
Equipment expense	10	9	18	19
Leasing business expense	0	0	0	0
Marketing expense	12	7	22	15
Card and processing expense	19	19	36	49
Other noninterest expense	209	207	438	430
Total noninterest expense	458	450	945	939
Income (loss) before income taxes	295	50	422	20
Applicable income tax expense (benefit)	62	10	89	4
Net Income	233	40	333	16
Impairment losses on bank premises	1	2	1	3
Operating Segments | Consumer Lending
Segment Reporting Information
Total goodwill	0	0	0	0	0	0
Total assets	32,802	33,215	32,802	33,215
Net interest income	114	142	246	269
Provision for (benefit from) credit losses	4	0	10	8
Net Interest Income After Provision for (Benefit from) Credit Losses	110	142	236	261
Noninterest Income
Service charges on deposits	0	0	0	0
Wealth and asset management revenue	0	0	0	0
Commercial banking revenue	0	0	0	0
Card and processing revenue	0	0	0	0
Leasing business revenue	0	0	0	0
Mortgage banking net revenue	30	60	79	142
Other noninterest income	3	2	6	4
Securities losses, net	0	0	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	1	(1)	(1)
Total noninterest income	33	63	84	145
Noninterest Expense
Compensation and benefits	60	61	116	127
Technology and communications	4	3	6	5
Net occupancy expense	2	3	5	5
Equipment expense	0	0	0	0
Leasing business expense	0	0	0	0
Marketing expense	1	1	2	1
Card and processing expense	0	0	0	0
Other noninterest expense	79	95	160	186
Total noninterest expense	146	163	289	324
Income (loss) before income taxes	(3)	42	31	82
Applicable income tax expense (benefit)	(1)	9	6	17
Net Income	(2)	33	25	65
Operating Segments | Wealth and Asset Management
Segment Reporting Information
Total goodwill	226	231	226	231	$ 231	$ 231
Total assets	13,062	10,881	13,062	10,881
Net interest income	53	21	88	42
Provision for (benefit from) credit losses	0	0	0	(1)
Net Interest Income After Provision for (Benefit from) Credit Losses	53	21	88	43
Noninterest Income
Service charges on deposits	0	0	0	0
Wealth and asset management revenue	132	138	274	274
Commercial banking revenue	0	1	0	1
Card and processing revenue	1	1	1	1
Leasing business revenue	0	0	0	0
Mortgage banking net revenue	0	1	1	2
Other noninterest income	(1)	2	0	3
Securities losses, net	0	0	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0	0	0
Total noninterest income	132	143	276	281
Noninterest Expense
Compensation and benefits	56	49	116	103
Technology and communications	0	0	0	0
Net occupancy expense	3	4	6	7
Equipment expense	0	0	0	0
Leasing business expense	0	0	0	0
Marketing expense	0	0	1	1
Card and processing expense	0	0	0	0
Other noninterest expense	78	78	157	156
Total noninterest expense	137	131	280	267
Income (loss) before income taxes	48	33	84	57
Applicable income tax expense (benefit)	10	7	18	12
Net Income	38	26	66	45
General Corporate and Other
Segment Reporting Information
Total goodwill	452	0	452	0
Total assets	(10,026)	4,797	(10,026)	4,797
Net interest income	102	368	222	737
Provision for (benefit from) credit losses	70	11	119	(134)
Net Interest Income After Provision for (Benefit from) Credit Losses	32	357	103	871
Noninterest Income
Service charges on deposits	0	0	(1)	0
Wealth and asset management revenue	0	0	0	0
Commercial banking revenue	(1)	0	(1)	0
Card and processing revenue	3	2	5	5
Leasing business revenue	0	0	0	0
Mortgage banking net revenue	0	0	0	0
Other noninterest income	21	(10)	24	(2)
Securities losses, net	(32)	10	(47)	6
Securities losses, net – non-qualifying hedges on MSRs	0	0	0	0
Total noninterest income	(9)	2	(20)	9
Noninterest Expense
Compensation and benefits	168	234	419	493
Technology and communications	91	86	184	173
Net occupancy expense	12	13	28	31
Equipment expense	19	18	40	36
Leasing business expense	0	0	0	0
Marketing expense	14	10	25	23
Card and processing expense	(1)	(1)	(2)	(2)
Other noninterest expense	(306)	(304)	(652)	(645)
Total noninterest expense	(3)	56	42	109
Income (loss) before income taxes	26	303	41	771
Applicable income tax expense (benefit)	27	86	29	198
Net Income	(1)	217	12	573
Impairment losses on bank premises				1
Bank premises and equipment held for sale	24	25	24	25
Eliminations
Segment Reporting Information
Total goodwill	0	0	0	0
Total assets	0	0	0	0
Net interest income	0	0	0	0
Provision for (benefit from) credit losses	0	0	0	0
Net Interest Income After Provision for (Benefit from) Credit Losses	0	0	0	0
Noninterest Income
Service charges on deposits	0	0	0	0
Wealth and asset management revenue	(44)	(46)	(88)	(89)
Commercial banking revenue	0	0	0	0
Card and processing revenue	0	0	0	0
Leasing business revenue	0	0	0	0
Mortgage banking net revenue	0	0	0	0
Other noninterest income	0	0	0	0
Securities losses, net	0	0	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0	0	0
Total noninterest income	(44)	(46)	(88)	(89)
Noninterest Expense
Compensation and benefits	0	0	0	0
Technology and communications	0	0	0	0
Net occupancy expense	0	0	0	0
Equipment expense	0	0	0	0
Leasing business expense	0	0	0	0
Marketing expense	0	0	0	0
Card and processing expense	0	0	0	0
Other noninterest expense	(44)	(46)	(88)	(89)
Total noninterest expense	(44)	(46)	(88)	(89)
Income (loss) before income taxes	0	0	0	0
Applicable income tax expense (benefit)	0	0	0	0
Net Income	$ 0	$ 0	$ 0	$ 0