Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information
Net interest income	$ 1,517	$ 1,195
Provision for credit losses	164	45
Net Interest Income After Provision for Credit Losses	1,353	1,150
Noninterest Income
Commercial banking revenue	161	135
Wealth and asset management revenue	146	149
Service charges on deposits	137	152
Card and processing revenue	100	97
Mortgage banking net revenue	69	52
Leasing business revenue	57	62
Other noninterest income	22	52
Securities gains (losses), net	4	(14)
Securities losses, net – non-qualifying hedges on MSRs	0	(1)
Total noninterest income	696	684
Noninterest Expense
Compensation and benefits	757	711
Technology and communications	118	101
Net occupancy expense	81	77
Equipment expense	37	36
Leasing business expense	34	32
Marketing expense	29	24
Card and processing expense	22	19
Other noninterest expense	253	222
Total noninterest expense	1,331	1,222
Income (loss) before income taxes	718	612
Applicable income tax expense (benefit)	160	118
Net Income	558	494
Total goodwill	4,915	4,514	$ 4,915
Total assets	208,657	211,459
Impairment losses on bank premises	1	0
Bank premises and equipment held for sale	22		$ 24
Impairment losses and termination charges	1	1
Operating Segments | Commercial Banking
Segment Reporting Information
Net interest income	977	523
Provision for credit losses	46	(34)
Net Interest Income After Provision for Credit Losses	931	557
Noninterest Income
Commercial banking revenue	160	135
Wealth and asset management revenue	1	0
Service charges on deposits	87	100
Card and processing revenue	22	20
Mortgage banking net revenue	0	0
Leasing business revenue	57	62
Other noninterest income	16	22
Securities gains (losses), net	(7)	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	336	339
Noninterest Expense
Compensation and benefits	190	182
Technology and communications	2	5
Net occupancy expense	11	10
Equipment expense	7	7
Leasing business expense	34	32
Marketing expense	0	1
Card and processing expense	3	2
Other noninterest expense	304	240
Total noninterest expense	551	479
Income (loss) before income taxes	716	417
Applicable income tax expense (benefit)	136	76
Net Income	580	341
Total goodwill	2,324	1,980
Total assets	83,545	79,970
Impairment losses of operating lease equipment		2
Operating Segments | Consumer and Small Business Banking
Segment Reporting Information
Net interest income	1,257	517
Provision for credit losses	51	29
Net Interest Income After Provision for Credit Losses	1,206	488
Noninterest Income
Commercial banking revenue	1	0
Wealth and asset management revenue	53	51
Service charges on deposits	51	53
Card and processing revenue	74	74
Mortgage banking net revenue	69	52
Leasing business revenue	0	0
Other noninterest income	25	27
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	(1)
Total noninterest income	273	256
Noninterest Expense
Compensation and benefits	224	218
Technology and communications	7	4
Net occupancy expense	51	48
Equipment expense	11	9
Leasing business expense	0	0
Marketing expense	17	11
Card and processing expense	20	18
Other noninterest expense	315	293
Total noninterest expense	645	601
Income (loss) before income taxes	834	143
Applicable income tax expense (benefit)	175	31
Net Income	659	112
Total goodwill	2,365	2,303
Total assets	85,296	86,626
Impairment losses on bank premises	1	0
Operating Segments | Wealth and Asset Management
Segment Reporting Information
Net interest income	101	35
Provision for credit losses	0	0
Net Interest Income After Provision for Credit Losses	101	35
Noninterest Income
Commercial banking revenue	0	0
Wealth and asset management revenue	138	142
Service charges on deposits	0	0
Card and processing revenue	1	1
Mortgage banking net revenue	0	0
Leasing business revenue	0	0
Other noninterest income	(1)	1
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	138	144
Noninterest Expense
Compensation and benefits	61	60
Technology and communications	0	0
Net occupancy expense	3	3
Equipment expense	0	0
Leasing business expense	0	0
Marketing expense	0	0
Card and processing expense	0	0
Other noninterest expense	82	79
Total noninterest expense	146	142
Income (loss) before income taxes	93	37
Applicable income tax expense (benefit)	19	8
Net Income	74	29
Total goodwill	226	231
Total assets	11,707	13,715
General Corporate and Other
Segment Reporting Information
Net interest income	(818)	120
Provision for credit losses	67	50
Net Interest Income After Provision for Credit Losses	(885)	70
Noninterest Income
Commercial banking revenue	0	0
Wealth and asset management revenue	0	0
Service charges on deposits	(1)	(1)
Card and processing revenue	3	2
Mortgage banking net revenue	0	0
Leasing business revenue	0	0
Other noninterest income	(18)	2
Securities gains (losses), net	11	(14)
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	(5)	(11)
Noninterest Expense
Compensation and benefits	282	251
Technology and communications	109	92
Net occupancy expense	16	16
Equipment expense	19	20
Leasing business expense	0	0
Marketing expense	12	12
Card and processing expense	(1)	(1)
Other noninterest expense	(402)	(346)
Total noninterest expense	35	44
Income (loss) before income taxes	(925)	15
Applicable income tax expense (benefit)	(170)	3
Net Income	(755)	12
Total goodwill	0	0
Total assets	28,109	31,148
Impairment losses on bank premises	0
Bank premises and equipment held for sale	22	25
Eliminations
Segment Reporting Information
Net interest income	0	0
Provision for credit losses	0	0
Net Interest Income After Provision for Credit Losses	0	0
Noninterest Income
Commercial banking revenue	0	0
Wealth and asset management revenue	(46)	(44)
Service charges on deposits	0	0
Card and processing revenue	0	0
Mortgage banking net revenue	0	0
Leasing business revenue	0	0
Other noninterest income	0	0
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	(46)	(44)
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	(46)	(44)
Total noninterest expense	(46)	(44)
Income (loss) before income taxes	0	0
Applicable income tax expense (benefit)	0	0
Net Income	0	0
Total goodwill	0	0
Total assets	$ 0	$ 0