Net Gains (Losses) Recorded in the Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used For Customer Accommodation (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Interest Rate Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 5	$ 9	$ 9	$ 14
Interest Rate Contract | Customer Contracts | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(1)	(2)	(1)	(3)
Interest Rate Contract | Fair Value Adjustments on Hedges and Derivative Contracts 1 [Member] | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings		3	1	4
Interest Rate Contract | Interest Rate Lock Commitments | Mortgage Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	38	(58)	74	(2)
Commodity Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	2	2	3	4
Commodity Contract | Fair Value Adjustments on Hedges and Derivative Contracts 1 [Member] | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings		(1)		(1)
Foreign Exchange Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	17	20	32	38
Foreign Exchange Contract | Fair Value Adjustments on Hedges and Derivative Contracts 1 [Member] | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings		$ (1)	$ 2	$ (1)