Business Segment Information (Market Segment Financial Results) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011		Jun. 30, 2010
Net interest income (expense) (FTE)			$ 788		$ 840
Provision for loan losses	47	126	96		301
Noninterest income	202	194	409		388
Noninterest expenses	409	397	824		801
Provision (benefit) for income taxes (FTE)			78		21
Income from discontinued operations, net of tax					17
Net income (loss)	96	70	199		122
Net credit-related charge-offs	191	319	191		319
Assets, average	54,148	56,885	54,148		56,885
Loans, average			39,361		40,990
Deposits, average			41,041		39,125
Return on average assets, ratio			0.73%	[1]	0.43%	[1]
Net interest margin, ratio			3.19%	[2]	3.23%	[2]
Efficiency ratio			69.19%		65.45%
Midwest [Member]
Net interest income (expense) (FTE)			407		415
Provision for loan losses			49		114
Noninterest income			200		198
Noninterest expenses			371		366
Provision (benefit) for income taxes (FTE)			72		47
Net income (loss)			115		86
Net credit-related charge-offs	81	98	81		98
Assets, average	14,287	14,915	14,287		14,915
Loans, average			14,077		14,777
Deposits, average			18,273		17,526
Return on average assets, ratio			1.18%	[1]	0.92%	[1]
Net interest margin, ratio			4.48%	[2]	4.75%	[2]
Efficiency ratio			61.14%		59.37%
Western [Member]
Net interest income (expense) (FTE)			330		325
Provision for loan losses			31		86
Noninterest income			74		69
Noninterest expenses			217		215
Provision (benefit) for income taxes (FTE)			55		32
Net income (loss)			101		61
Net credit-related charge-offs	52	112	52		112
Assets, average	12,459	13,090	12,459		13,090
Loans, average			12,250		12,886
Deposits, average			12,347		11,939
Return on average assets, ratio			1.51%	[1]	0.90%	[1]
Net interest margin, ratio			5.39%	[2]	5.08%	[2]
Efficiency ratio			53.77%		54.74%
Texas [Member]
Net interest income (expense) (FTE)			176		160
Provision for loan losses			2		16
Noninterest income			48		43
Noninterest expenses			124		125
Provision (benefit) for income taxes (FTE)			36		22
Net income (loss)			62		40
Net credit-related charge-offs	12	33	12		33
Assets, average	7,056	6,771	7,056		6,771
Loans, average			6,848		6,565
Deposits, average			5,982		5,137
Return on average assets, ratio			1.75%	[1]	1.18%	[1]
Net interest margin, ratio			5.18%	[2]	4.92%	[2]
Efficiency ratio			55.27%		61.44%
Florida [Member]
Net interest income (expense) (FTE)			23		21
Provision for loan losses			19		19
Noninterest income			7		7
Noninterest expenses			24		21
Provision (benefit) for income taxes (FTE)			(4)		(4)
Net income (loss)			(9)		(8)
Net credit-related charge-offs	23	17	23		17
Assets, average	1,543	1,576	1,543		1,576
Loans, average			1,573		1,575
Deposits, average			382		382
Return on average assets, ratio			(1.11%)	[1]	(1.00%)	[1]
Net interest margin, ratio			2.98%	[2]	2.74%	[2]
Efficiency ratio			78.79%		74.63%
Other Markets [Member]
Net interest income (expense) (FTE)			82		86
Provision for loan losses			(2)		75
Noninterest income			24		25
Noninterest expenses			41		43
Provision (benefit) for income taxes (FTE)			(1)		(26)
Net income (loss)			68		19
Net credit-related charge-offs	21	54	21		54
Assets, average	3,171	3,859	3,171		3,859
Loans, average			2,891		3,578
Deposits, average			2,375		2,099
Return on average assets, ratio			4.31%	[1]	1.03%	[1]
Net interest margin, ratio			5.81%	[2]	4.88%	[2]
Efficiency ratio			41.42%		40.96%
International [Member]
Net interest income (expense) (FTE)			38		37
Provision for loan losses			(5)		(8)
Noninterest income			18		18
Noninterest expenses			19		16
Provision (benefit) for income taxes (FTE)			15		16
Net income (loss)			27		31
Net credit-related charge-offs	2	5	2		5
Assets, average	1,749	1,642	1,749		1,642
Loans, average			1,681		1,589
Deposits, average			1,320		1,013
Return on average assets, ratio			3.06%	[1]	3.70%	[1]
Net interest margin, ratio			4.37%	[2]	4.63%	[2]
Efficiency ratio			33.87%		29.81%
Finance & Other Businesses [Member]
Net interest income (expense) (FTE)			(268)		(204)
Provision for loan losses			2		(1)
Noninterest income			38		28
Noninterest expenses			28		15
Provision (benefit) for income taxes (FTE)			(95)		(66)
Income from discontinued operations, net of tax					17
Net income (loss)			(165)		(107)
Assets, average	13,883	15,032	13,883		15,032
Loans, average			41		20
Deposits, average			$ 362		$ 1,029

[1] Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.

[2] Net interest margin is calculated based on the greater of average earning assets or average deposits and purchased funds.