Summary Information on Allowance for Loan and Lease Loss Activity (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	$ 42,957	$ 49,426	$ 62,135
Provision (credit) for loan and lease losses	(1,084)	3,649	1,428
Loan and lease charge-offs	(11,165)	(12,804)	(16,505)
Loan and lease recoveries	8,058	2,686	2,368
Net charge-offs	(3,107)	(10,118)	(14,137)
Balance at period end	$ 38,766	$ 42,957	$ 49,426