Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting Information
Total goodwill	$ 4,259	$ 4,261	$ 4,258
Total assets	206,899	185,391
Net interest income	1,176	1,229
(Benefit from) provision for credit losses	(173)	640
Net Interest Income After (Benefit from) Provision for Credit Losses	1,349	589
Noninterest Income
Commercial banking revenue	153	124
Service charges on deposits	144	148
Wealth and asset management revenue	143	134
Card and processing revenue	94	86
Leasing business revenue	87	73
Mortgage banking net revenue	85	120
Other noninterest income	42	7
Securities gains (losses), net	3	(24)
Securities losses, net – non-qualifying hedges on MSRs	(2)	3
Total noninterest income	749	671
Noninterest Expense
Compensation and benefits	706	647
Technology and communications	93	93
Net occupancy expense	79	82
Leasing business expense	35	35
Equipment expense	34	32
Card and processing expense	30	31
Marketing expense	23	31
Other noninterest expense	215	249
Total noninterest expense	1,215	1,200
Income Before Income Taxes	883	60
Applicable income tax expense (benefit)	189	14
Net Income	694	46
Impairment losses on bank premises	2	3
Impairment charges of operating lease equipment	25	3
Bank premises and equipment held for sale	27	36	$ 35
Impairment losses and termination charges		2
General Corporate and Other
Segment Reporting Information
Total goodwill	0	0
Total assets	7,082	(8,253)
Net interest income	367	91
(Benefit from) provision for credit losses	(145)	519
Net Interest Income After (Benefit from) Provision for Credit Losses	512	(428)
Noninterest Income
Commercial banking revenue	0	(1)
Service charges on deposits	0	(1)
Wealth and asset management revenue	0	0
Card and processing revenue	3	3
Leasing business revenue	0	0
Mortgage banking net revenue	0	0
Other noninterest income	7	(10)
Securities gains (losses), net	(3)	(24)
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	7	(33)
Noninterest Expense
Compensation and benefits	261	217
Technology and communications	86	87
Net occupancy expense	17	26
Leasing business expense	0	0
Equipment expense	18	14
Card and processing expense	(1)	(1)
Marketing expense	14	14
Other noninterest expense	(342)	(350)
Total noninterest expense	53	7
Income Before Income Taxes	466	(468)
Applicable income tax expense (benefit)	112	(86)
Net Income	354	(382)
Bank premises and equipment held for sale	27
Eliminations
Segment Reporting Information
Total goodwill	0	0
Total assets	0	0
Net interest income	0	0
(Benefit from) provision for credit losses	0	0
Net Interest Income After (Benefit from) Provision for Credit Losses	0	0
Noninterest Income
Commercial banking revenue	0	0
Service charges on deposits	0	0
Wealth and asset management revenue	(43)	(40)
Card and processing revenue	0	0
Leasing business revenue	0	0
Mortgage banking net 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	(43)	(40)
Noninterest Expense
Compensation and benefits	0	0
Technology and communications	0	0
Net occupancy expense	0	0
Leasing business expense	0	0
Equipment expense	0	0
Card and processing expense	0	0
Marketing expense	0	0
Other noninterest expense	(43)	(40)
Total noninterest expense	(43)	(40)
Income Before Income Taxes	0	0
Applicable income tax expense (benefit)	0	0
Net Income	0	0
Commercial Banking
Noninterest Expense
Impairment charges of operating lease equipment	25	3
Commercial Banking | Operating Segments
Segment Reporting Information
Total goodwill	1,980	1,961
Total assets	68,645	84,576
Net interest income	365	507
(Benefit from) provision for credit losses	(76)	45
Net Interest Income After (Benefit from) Provision for Credit Losses	441	462
Noninterest Income
Commercial banking revenue	151	124
Service charges on deposits	90	84
Wealth and asset management revenue	1	1
Card and processing revenue	14	16
Leasing business revenue	87	73
Mortgage banking net revenue	0	0
Other noninterest income	12	(11)
Securities gains (losses), net	6	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	361	287
Noninterest Expense
Compensation and benefits	156	150
Technology and communications	4	3
Net occupancy expense	8	7
Leasing business expense	35	35
Equipment expense	6	7
Card and processing expense	1	2
Marketing expense	1	2
Other noninterest expense	209	274
Total noninterest expense	420	480
Income Before Income Taxes	382	269
Applicable income tax expense (benefit)	70	45
Net Income	312	224
Branch Banking | Operating Segments
Segment Reporting Information
Total goodwill	2,047	2,047
Total assets	87,645	70,283
Net interest income	295	505
(Benefit from) provision for credit losses	41	62
Net Interest Income After (Benefit from) Provision for Credit Losses	254	443
Noninterest Income
Commercial banking revenue	2	1
Service charges on deposits	54	65
Wealth and asset management revenue	49	44
Card and processing revenue	77	67
Leasing business revenue	0	0
Mortgage banking net revenue	2	2
Other noninterest income	20	19
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	204	198
Noninterest Expense
Compensation and benefits	170	168
Technology and communications	1	1
Net occupancy expense	47	44
Leasing business expense	0	0
Equipment expense	10	11
Card and processing expense	30	30
Marketing expense	8	13
Other noninterest expense	223	221
Total noninterest expense	489	488
Income Before Income Taxes	(31)	153
Applicable income tax expense (benefit)	(7)	32
Net Income	(24)	121
Consumer Lending | Operating Segments
Segment Reporting Information
Total goodwill	0	0
Total assets	31,873	27,132
Net interest income	128	89
(Benefit from) provision for credit losses	8	13
Net Interest Income After (Benefit from) Provision for Credit Losses	120	76
Noninterest Income
Commercial banking revenue	0	0
Service charges on deposits	0	0
Wealth and asset management revenue	0	0
Card and processing revenue	0	0
Leasing business revenue	0	0
Mortgage banking net revenue	82	117
Other noninterest income	2	4
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	(2)	3
Total noninterest income	82	124
Noninterest Expense
Compensation and benefits	66	51
Technology and communications	2	2
Net occupancy expense	3	2
Leasing business expense	0	0
Equipment expense	0	0
Card and processing expense	0	0
Marketing expense	0	1
Other noninterest expense	90	66
Total noninterest expense	161	122
Income Before Income Taxes	41	78
Applicable income tax expense (benefit)	9	17
Net Income	32	61
Wealth and Asset Management | Operating Segments
Segment Reporting Information
Total goodwill	232	253
Total assets	11,654	11,653
Net interest income	21	37
(Benefit from) provision for credit losses	(1)	1
Net Interest Income After (Benefit from) Provision for Credit Losses	22	36
Noninterest Income
Commercial banking revenue	0	0
Service charges on deposits	0	0
Wealth and asset management revenue	136	129
Card and processing revenue	0	0
Leasing business revenue	0	0
Mortgage banking net revenue	1	1
Other noninterest income	1	5
Securities gains (losses), net	0	0
Securities losses, net – non-qualifying hedges on MSRs	0	0
Total noninterest income	138	135
Noninterest Expense
Compensation and benefits	53	61
Technology and communications	0	0
Net occupancy expense	4	3
Leasing business expense	0	0
Equipment expense	0	0
Card and processing expense	0	0
Marketing expense	0	1
Other noninterest expense	78	78
Total noninterest expense	135	143
Income Before Income Taxes	25	28
Applicable income tax expense (benefit)	5	6
Net Income	$ 20	$ 22