Accounting for Certain Loans Acquired in a Transfer - Accretable Yield or Income Expected to be Collected (Detail) (Loans Purchased With Evidence Of Credit Deterioration [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Loans Purchased With Evidence Of Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	$ 3,185	$ 6,111
Additions
Accretion	(138)	(451)
Reclassification from nonaccreatable difference
Disposals	(18)	(696)
Balance at March 31	$ 3,029	$ 4,964