Results of Operations and Average Assets by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net interest income	$ 898	$ 879
Provision for loan and lease losses	91	168
Net interest income (loss) after provision for loan and lease losses	807	711
Noninterest income:
Mortgage banking net revenue	204	102
Service charges on deposits	129	124
Investment advisory revenue	96	98
Corporate banking revenue	97	86
Card and processing revenue	59	80
Other noninterest income	175	81
Securities gains, net	9	8
Securities gains, net - non-qualifying hedges on mortgage servicing rights		5
Total noninterest income	769	584
Noninterest expense:
Salaries, wages and incentives	399	351
Employee benefits	112	97
Net occupancy expense	77	77
Technology and communications	47	45
Card and processing expense	30	29
Equipment expense	27	29
Other noninterest expense	281	290
Total noninterest expense	973	918
Income (loss) before income taxes	603	377
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	173	112
Net income (loss)	430	265
Net income (loss)	430	265
Dividends on preferred stock	9	177
Net income available to common shareholders	421	88
Total goodwill	2,417	2,417	2,417
Total Assets	116,747	110,485	116,967
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	348	329
Provision for loan and lease losses	76	152
Net interest income (loss) after provision for loan and lease losses	272	177
Noninterest income:
Service charges on deposits	54	50
Investment advisory revenue	2	3
Corporate banking revenue	93	81
Card and processing revenue	12	9
Other noninterest income	16	32
Total noninterest income	177	175
Noninterest expense:
Salaries, wages and incentives	58	45
Employee benefits	16	13
Net occupancy expense	5	5
Technology and communications	2	3
Card and processing expense	1	1
Equipment expense	1
Other noninterest expense	205	201
Total noninterest expense	288	268
Income (loss) before income taxes	161	84
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	19	(5)
Net income (loss)	142	89
Net income (loss)	142	89
Net income available to common shareholders	142	89
Total goodwill	613	613
Total Assets	46,388	43,461
Branch Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	335	339
Provision for loan and lease losses	86	116
Net interest income (loss) after provision for loan and lease losses	249	223
Noninterest income:
Mortgage banking net revenue	3	3
Service charges on deposits	74	73
Investment advisory revenue	31	28
Corporate banking revenue	3	3
Card and processing revenue	60	77
Other noninterest income	19	20
Total noninterest income	190	204
Noninterest expense:
Salaries, wages and incentives	112	114
Employee benefits	37	34
Net occupancy expense	47	46
Technology and communications	1	1
Card and processing expense	28	28
Equipment expense	13	13
Other noninterest expense	156	164
Total noninterest expense	394	400
Income (loss) before income taxes	45	27
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	16	9
Net income (loss)	29	18
Net income (loss)	29	18
Net income available to common shareholders	29	18
Total goodwill	1,656	1,656
Total Assets	48,544	47,205
Consumer Lending [Member]
Segment Reporting Information [Line Items]
Net interest income	80	90
Provision for loan and lease losses	54	94
Net interest income (loss) after provision for loan and lease losses	26	(4)
Noninterest income:
Mortgage banking net revenue	201	99
Other noninterest income	10	10
Securities gains, net - non-qualifying hedges on mortgage servicing rights		5
Total noninterest income	211	114
Noninterest expense:
Salaries, wages and incentives	44	33
Employee benefits	12	11
Net occupancy expense	2	2
Other noninterest expense	104	104
Total noninterest expense	162	150
Income (loss) before income taxes	75	(40)
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	27	(14)
Net income (loss)	48	(26)
Net income (loss)	48	(26)
Net income available to common shareholders	48	(26)
Total Assets	23,155	21,982
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Net interest income	27	28
Provision for loan and lease losses	3	5
Net interest income (loss) after provision for loan and lease losses	24	23
Noninterest income:
Service charges on deposits	1	1
Investment advisory revenue	94	95
Corporate banking revenue	1	1
Card and processing revenue	1	1
Total noninterest income	97	98
Noninterest expense:
Salaries, wages and incentives	35	34
Employee benefits	9	9
Net occupancy expense	3	2
Other noninterest expense	63	62
Total noninterest expense	110	107
Income (loss) before income taxes	11	14
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	4	5
Net income (loss)	7	9
Net income (loss)	7	9
Net income available to common shareholders	7	9
Total goodwill	148	148
Total Assets	7,684	6,794
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net interest income	108	93
Provision for loan and lease losses	(128)	(199)
Net interest income (loss) after provision for loan and lease losses	236	292
Noninterest income:
Corporate banking revenue		1
Card and processing revenue	(14)	(7)
Other noninterest income	130	19
Securities gains, net	9	8
Total noninterest income	125	21
Noninterest expense:
Salaries, wages and incentives	150	125
Employee benefits	38	30
Net occupancy expense	20	22
Technology and communications	44	41
Card and processing expense	1
Equipment expense	13	16
Other noninterest expense	(216)	(213)
Total noninterest expense	50	21
Income (loss) before income taxes	311	292
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	107	117
Net income (loss)	204	175
Net income (loss)	204	175
Dividends on preferred stock	9	177
Net income available to common shareholders	195	(2)
Total Assets	(9,024)	(8,957)
Business Intersegment, Eliminations
Noninterest income:
Investment advisory revenue	(31)	(28)
Total noninterest income	(31)	(28)
Noninterest expense:
Equipment expense		(28)
Other noninterest expense	(31)
Total noninterest expense	$ (31)	$ (28)