Commitments, Contingencies, Guarantees, and Others - Guarantees, LOC and Loss Sharing, U.K Cross Sell (Detail) (USD $)	3 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Payment Protection Insurance
Loss Contingencies [Line Items]
Loss contingency accrual	$ 167,000,000	$ 169,000,000
Loss accrual increase (decrease)	23,000,000
Letter of Credit
Loss Contingencies [Line Items]
Contractual amounts of standby letters of credit and commercial letters of credit	2,100,000,000	2,000,000,000
Other Liabilities | Letter of Credit
Loss Contingencies [Line Items]
Letters of credit outstanding	3,000,000	4,000,000
Financial Standby Letter of Credit
Loss Contingencies [Line Items]
Guarantees, maximum exposure	14,000,000	16,000,000
Financial Standby Letter of Credit | Other Liabilities
Loss Contingencies [Line Items]
Guarantee obligation	14,000,000	15,000,000
Loss Sharing Agreement
Loss Contingencies [Line Items]
Guarantee obligation	$ 34,000,000	$ 14,000,000