Summary of Subsequent Defaults (Detail) (Quarter to date, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Financing Receivable, Modifications
Number of contracts	568	[1]	574	[1]
Recorded Investment in Loans Modified in a TDR During the Period	$ 26	[1]	$ 12	[1]
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Number of contracts	6	[1]
Recorded Investment in Loans Modified in a TDR During the Period	14	[1]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner Occupied
Financing Receivable, Modifications
Number of contracts	2	[1]
Recorded Investment in Loans Modified in a TDR During the Period	3	[1]
Consumer Portfolio Segment | Home Equity
Financing Receivable, Modifications
Number of contracts	10	[1]	14	[1]
Recorded Investment in Loans Modified in a TDR During the Period			1	[1]
Consumer Portfolio Segment | Automobile Loans
Financing Receivable, Modifications
Number of contracts	2	[1]	3	[1]
Consumer Portfolio Segment | Credit Card
Financing Receivable, Modifications
Number of contracts	507	[1]	515	[1]
Recorded Investment in Loans Modified in a TDR During the Period	3	[1]	3	[1]
Residential Mortgage Loans
Financing Receivable, Modifications
Number of contracts	41	[1]	42	[1]
Recorded Investment in Loans Modified in a TDR During the Period	$ 6	[1]	$ 8	[1]

[1]  Excludes all loans and leases held for sale and loans acquired with deteriorated credit quality.