Financial Derivatives (Derivatives Total Notional or Contractual Amounts and Fair Values) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	$ 9,833	$ 9,463
Derivative Liability, Fair Value	7,696	7,606
Derivative, Collateral, Obligation to Return Cash	967	843
Derivative, Collateral, Right to Reclaim Cash	987	1,051
Legally Enforceable Master Netting Agreement Asset	6,071	6,052
Legally Enforceable Master Netting Agreement Liability	6,071	6,052
Derivative Asset, Fair Value, Net	2,775	2,360
Derivative Liability, Fair Value, Net	658	711
Derivative Notional Amount	393,254	391,329
One month LIBOR [Member]
Derivatives, Fair Value [Line Items]
Floating rate portion of interest rate contracts	54.00%	57.00%
Three month LIBOR [Member]
Derivatives, Fair Value [Line Items]
Floating rate portion of interest rate contracts	46.00%	43.00%
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	2,023	1,888
Derivative Liability, Fair Value	172	116
Derivative Notional Amount	28,829	29,234
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	7,810	7,575
Derivative Liability, Fair Value	7,524	7,490
Derivative Notional Amount	364,425	362,095
Not Designated as Hedging Instrument [Member] | Residential Mortgages [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	3,288	3,458
Derivative Liability, Fair Value	2,645	2,893
Derivative Notional Amount	195,676	196,991
Not Designated as Hedging Instrument [Member] | Residential Mortgages [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	3,125	3,390
Derivative Liability, Fair Value	2,546	2,854
Derivative Notional Amount	180,381	185,621
Not Designated as Hedging Instrument [Member] | Residential Mortgages [Member] | Loan Sales Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	163	68
Derivative Liability, Fair Value	99	39
Derivative Notional Amount	15,295	11,370
Not Designated as Hedging Instrument [Member] | Commercial Mortgage Banking [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	78	59
Derivative Liability, Fair Value	105	80
Derivative Notional Amount	4,607	2,720
Not Designated as Hedging Instrument [Member] | Commercial Mortgage Banking [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	76	54
Derivative Liability, Fair Value	105	80
Derivative Notional Amount	4,512	2,625
Not Designated as Hedging Instrument [Member] | Commercial Mortgage Banking [Member] | Credit Default Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	2	5
Derivative Notional Amount	95	95
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	4,437	4,046
Derivative Liability, Fair Value	4,459	4,178
Derivative Notional Amount	162,480	158,095
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	4,272	3,804
Derivative Liability, Fair Value	4,287	3,943
Derivative Notional Amount	146,243	142,732
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member] | Equity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	1	5
Derivative Liability, Fair Value	4	8
Derivative Notional Amount	146	184
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	157	231
Derivative Liability, Fair Value	162	222
Derivative Notional Amount	12,732	11,920
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member] | Risk Participation Agreement [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	7	6
Derivative Liability, Fair Value	6	5
Derivative Notional Amount	3,359	3,259
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	7	12
Derivative Liability, Fair Value	315	339
Derivative Notional Amount	1,662	4,289
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member] | Other Risk Management Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	4	6
Derivative Liability, Fair Value		39
Derivative Notional Amount	974	3,669
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member] | Credit Default Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		6
Derivative Notional Amount	15	209
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member] | Equity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	3
Derivative Liability, Fair Value	3
Derivative Notional Amount	11
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	4	4
Derivative Notional Amount	38	25
Not Designated as Hedging Instrument [Member] | Other Risk Management Activity [Member] | Other Derivative Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	308	296
Derivative Notional Amount	624	386
Not Designated as Hedging Instrument [Member] | Swaps [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	2,855	3,127
Derivative Liability, Fair Value	2,404	2,673
Derivative Notional Amount	83,142	98,406
Not Designated as Hedging Instrument [Member] | Swaps [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	61	43
Derivative Liability, Fair Value	92	77
Derivative Notional Amount	1,222	1,180
Not Designated as Hedging Instrument [Member] | Swaps [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	4,146	3,649
Derivative Liability, Fair Value	4,233	3,863
Derivative Notional Amount	124,095	122,088
Not Designated as Hedging Instrument [Member] | Swaps [Member] | Other Risk Management Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	4	5
Derivative Liability, Fair Value		39
Derivative Notional Amount	623	1,704
Not Designated as Hedging Instrument [Member] | Swaptions [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	220	216
Derivative Liability, Fair Value	131	167
Derivative Notional Amount	6,309	10,312
Not Designated as Hedging Instrument [Member] | Swaptions [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		3
Derivative Notional Amount		450
Not Designated as Hedging Instrument [Member] | Swaptions [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	97	136
Derivative Liability, Fair Value	41	73
Derivative Notional Amount	2,161	1,713
Not Designated as Hedging Instrument [Member] | Swaptions [Member] | Other Risk Management Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		1
Derivative Notional Amount		225
Not Designated as Hedging Instrument [Member] | Futures [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	46,281	63,616
Not Designated as Hedging Instrument [Member] | Futures [Member] | Loan Sales Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	820	634
Not Designated as Hedging Instrument [Member] | Futures [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	2,000
Not Designated as Hedging Instrument [Member] | Futures [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	9,229	6,982
Not Designated as Hedging Instrument [Member] | Futures [Member] | Other Risk Management Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	351	1,740
Not Designated as Hedging Instrument [Member] | Future Options [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	17
Derivative Liability, Fair Value	6
Derivative Notional Amount	40,900	8,000
Not Designated as Hedging Instrument [Member] | Future Options [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	2
Derivative Notional Amount	200
Not Designated as Hedging Instrument [Member] | Residential Mortgage Loan Commitments [Member] | Residential Mortgage Servicing Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	33	47
Derivative Liability, Fair Value	5	14
Derivative Notional Amount	3,749	5,287
Not Designated as Hedging Instrument [Member] | Residential Mortgage Loan Commitments [Member] | Loan Sales Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	161	65
Derivative Liability, Fair Value	99	39
Derivative Notional Amount	13,075	9,486
Not Designated as Hedging Instrument [Member] | Residential Mortgage Loan Commitments [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	9
Derivative Liability, Fair Value	11	1
Derivative Notional Amount	2,366	487
Not Designated as Hedging Instrument [Member] | Commercial Mortgage Loan Commitments [Member] | Commercial Mortgage Banking Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	13	8
Derivative Liability, Fair Value	13	3
Derivative Notional Amount	1,090	995
Not Designated as Hedging Instrument [Member] | Bond Options [Member] | Loan Sales Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	2	3
Derivative Notional Amount	1,400	1,250
Not Designated as Hedging Instrument [Member] | Caps Floors Sold [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	2	6
Derivative Notional Amount	4,241	5,861
Not Designated as Hedging Instrument [Member] | Caps Floors Purchased [Member] | Customer-related Activities Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	20	19
Derivative Notional Amount	4,151	5,601
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	1,429	1,316
Derivative Liability, Fair Value	154	116
Derivative Notional Amount	13,233	12,273
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Receive Fixed Swaps [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	1,428	1,316
Derivative Notional Amount	11,000	10,476
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Pay Fixed Swaps [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	1
Derivative Liability, Fair Value	154	116
Derivative Notional Amount	2,233	1,797
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	594	572
Derivative Notional Amount	14,999	16,635
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Receive Fixed Swaps [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	562	529
Derivative Notional Amount	13,770	13,902
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Forward Purchase Commitments [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value	32	43
Derivative Notional Amount	1,229	2,733
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	18
Derivative Notional Amount	$ 597	$ 326