Activity in the Allowance for Credit Losses (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		Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Components:
Balance at beginning of period	$ 2,086		$ 2,205		$ 2,094		$ 2,219
Provision for loan losses	76		152		182		356
Provision(Benefit) for unfunded commitments	(3)		(6)		(7)		2
Loan charge-offs	(158)		(233)		(309)		(506)
Loan recoveries	45		54		86		101
Balance at end of period	2,046		2,172		2,046		2,172
Loans and Leases Receivable, Allowance	2,003		2,125		2,003		2,125		2,040	2,044	2,152	2,174
Unfunded commitments reserve	43	[1]	47	[1]	43	[1]	47	[1]
Allowance for credit losses	$ 2,046		$ 2,172		$ 2,046		$ 2,172

[1] The unfunded commitments reserve is recorded in other liabilities in the Consolidated Balance Sheets.