Short-term Borrowings - Interest Expense on Short-Term Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	$ 1,262	$ 1,070	$ 728
Federal funds purchased [Member]
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	43	128	41
Borrowings from FHLB [Member]
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	893	545	16
Securities sold under agreements to repurchase [Member]
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	$ 326	$ 397	$ 671