Deposits Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deposits [Abstract]
Time deposit accounts individually equal to or greater than $100,000	$ 197	$ 133
Interest expense paid on time deposit accounts individually equal to or greater than $100,000	0.6	0.5	0.9
Time deposit accounts individually equal to or greater than $100,000 scheduled to mature within one year	$ 197