Summary of Significant Commitments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	$ 62,050	$ 53,403
Commitments to Extend Credit [Member]
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	62,050	53,403
Financial Standby Letter of Credit
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	4,129	4,281
Forward Contracts
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	1,448	5,322
Noncancelable Lease Obligations [Member]
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	746	769
Private Equity Funds
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	90	121
Purchase Commitment
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	84	87
Capital Additions
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	33	29
Capital Lease Obligations
Long-term Purchase Commitment [Line Items]
Commitments to Extend Credit	$ 19	$ 24