Notional Amounts and Fair Values for All Derivative Instruments Included in the Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	$ 1,553	$ 1,972
Fair value - Derivative Liabilities	754	915
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	332	640
Fair value - Derivative Liabilities	34	1
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	292	558
Fair value - Derivative Liabilities	13
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Fair Value Hedging | Interest Rate Swap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	292	558
Fair value - Derivative Liabilities	13
Notional amount	3,205	2,880
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	40	82
Fair value - Derivative Liabilities	21	1
Accumulated Net Gain (Loss) from Designated or Qualifying Hedges | Cash Flow Hedging | Interest Rate Swap | Long-Term Debt
Derivatives, Fair Value [Line Items]
Fair value - Derivative Liabilities		1
Notional amount		250
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]
Fair value - Derivative Assets	40	60
Fair value - Derivative Liabilities	21
Notional amount	2,200	1,000
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]
Fair value - Derivative Assets		22
Notional amount		1,500
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
Nondesignated
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	1,221	1,332
Fair value - Derivative Liabilities	720	914
Nondesignated | Risk Management and Other Business Purposes
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	538	398
Fair value - Derivative Liabilities	63	47
Nondesignated | Risk Management and Other Business Purposes | Interest Rate Contract | Mortgage Servicing Rights
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	141	219
Fair value - Derivative Liabilities	14
Notional amount	4,092	10,177
Nondesignated | Risk Management and Other Business Purposes | Forward Contracts | Assets Held-for-sale
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	13	2
Fair value - Derivative Liabilities	1	14
Notional amount	1,448	5,322
Nondesignated | Risk Management and Other Business Purposes | Warrant [Member]
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	384	177
Notional amount	664	416
Nondesignated | Risk Management and Other Business Purposes | Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value - Derivative Liabilities	48	33
Notional amount	947	644
Nondesignated | Customer Accommodation [Member]
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	683	934
Fair value - Derivative Liabilities	657	867
Nondesignated | Customer Accommodation [Member] | Interest Rate Contract
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	329	586
Fair value - Derivative Liabilities	339	602
Notional amount	28,112	27,354
Nondesignated | Customer Accommodation [Member] | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	276	201
Fair value - Derivative Liabilities	252	183
Notional amount	19,688	17,297
Nondesignated | Customer Accommodation [Member] | Interest Rate Lock Commitments [Member]
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	12	60
Fair value - Derivative Liabilities	1
Notional amount	924	4,894
Nondesignated | Customer Accommodation [Member] | Commodity Contract
Derivatives, Fair Value [Line Items]
Fair value - Derivative Assets	66	87
Fair value - Derivative Liabilities	65	82
Notional amount	3,300	3,084
Nondesignated | Customer Accommodation [Member] | Derivative | Certificates of Deposit
Derivatives, Fair Value [Line Items]
Notional amount		$ 5