Notional Amounts and Fair Values for All Derivative Instruments Included in the Consolidated Balance Sheets (Detail) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	$ 2,600	$ 2,074	$ 2,542
Fair value - Derivative Liabilities	1,505	1,314	1,448
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	851	607	880
Fair value - Derivative Liabilities	7	31	38
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	679	442	683
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Fair Value Hedging | Interest Rate Swap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Notional amount	4,080	4,355	4,355
Fair value - Derivative Assets	679	442	683
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Fair Value Hedging | Interest Rate Swap | Bank Time Deposits
Derivatives, Fair Value [Line Items]
Notional amount			230
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	172	165	197
Fair value - Derivative Liabilities	7	31	38
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging | Interest Rate Swap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Notional amount	250	1,190	804
Fair value - Derivative Liabilities	7	31	22
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging | Interest Rate Swap | Commercial And Industrial Loans [Member]
Derivatives, Fair Value [Line Items]
Notional amount	1,500	3,000	3,500
Fair value - Derivative Assets	60	8	19
Fair value - Derivative Liabilities			16
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging | Interest Rate Floor | Commercial And Industrial Loans [Member]
Derivatives, Fair Value [Line Items]
Notional amount	1,500	1,500	1,500
Fair value - Derivative Assets	112	153	176
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging | Interest Rate Cap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Notional amount	500	1,500	2,500
Fair value - Derivative Assets		4	2
Nondesignated
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	1,749	1,467	1,662
Fair value - Derivative Liabilities	1,498	1,283	1,410
Nondesignated | Risk Management and Other Business Purposes
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	311	317	344
Fair value - Derivative Liabilities	104	126	114
Nondesignated | Risk Management and Other Business Purposes | Interest Rate Swap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Notional amount	360	173	247
Fair value - Derivative Assets	1	3	4
Fair value - Derivative Liabilities	3	1	1
Nondesignated | Risk Management and Other Business Purposes | Interest Rate Contract | Mortgage Servicing Rights
Derivatives, Fair Value [Line Items]
Notional amount	3,577	12,477	6,717
Fair value - Derivative Assets	193	141	248
Fair value - Derivative Liabilities	2	81	11
Nondesignated | Risk Management and Other Business Purposes | Forward Contracts | Assets Held-for-sale
Derivatives, Fair Value [Line Items]
Notional amount	5,062	6,389	7,037
Fair value - Derivative Assets	4	90	2
Fair value - Derivative Liabilities	59	14	32
Nondesignated | Risk Management and Other Business Purposes | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Notional amount	1,696	2,494	2,671
Fair value - Derivative Assets	12	4	14
Fair value - Derivative Liabilities	12	4	14
Nondesignated | Risk Management and Other Business Purposes | Put Option
Derivatives, Fair Value [Line Items]
Notional amount	901	769	759
Fair value - Derivative Liabilities	1	8	8
Nondesignated | Risk Management and Other Business Purposes | Warrant
Derivatives, Fair Value [Line Items]
Notional amount	205	175	173
Fair value - Derivative Assets	101	79	76
Nondesignated | Risk Management and Other Business Purposes | Swap
Derivatives, Fair Value [Line Items]
Notional amount	423	363	384
Fair value - Derivative Liabilities	27	18	48
Nondesignated | Customer Accommodation [Member]
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	1,438	1,150	1,318
Fair value - Derivative Liabilities	1,394	1,157	1,296
Nondesignated | Customer Accommodation [Member] | Interest Rate Contract
Derivatives, Fair Value [Line Items]
Notional amount	29,433	26,817	27,376
Fair value - Derivative Assets	827	701	918
Fair value - Derivative Liabilities	851	735	963
Nondesignated | Customer Accommodation [Member] | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Notional amount	19,243	17,998	15,643
Fair value - Derivative Assets	459	339	259
Fair value - Derivative Liabilities	435	319	235
Nondesignated | Customer Accommodation [Member] | Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Notional amount	4,772	1,772	4,264
Fair value - Derivative Assets	38	9	35
Fair value - Derivative Liabilities	1	9	0
Nondesignated | Customer Accommodation [Member] | Commodity Contract
Derivatives, Fair Value [Line Items]
Notional amount	2,102	1,878	1,561
Fair value - Derivative Assets	112	99	105
Fair value - Derivative Liabilities	105	92	97
Nondesignated | Customer Accommodation [Member] | Derivative | Certificates of Deposit
Derivatives, Fair Value [Line Items]
Notional amount	34	70	106
Fair value - Derivative Assets	2	2	1
Fair value - Derivative Liabilities	$ 2	$ 2	$ 1