Allowance for Loan and Lease Losses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	$ 18,805	$ 14,448
Loans and leases charged off	(203)	(906)
Recoveries of loans and leases previously charged off	435	305
Transfer of loans to held-for-sale	(963)
Provision for loan and lease losses	1,929	2,168
Balance at end of year	$ 20,003	$ 16,015