Securities - Securities with Unrealized Losses not Recognized in Income (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
12 Months or less, Fair Value	$ 82,360	$ 92,234
12 Months or less, Unrealized Loss	(1,737)	(2,905)
More than 12 months, Fair Value	5,939	1,247
More than 12 months, Unrealized Loss	(204)	(125)
Total Fair Value	88,299	93,481
Total Unrealized Loss	(1,941)	(3,030)
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or less, Fair Value	34,017	30,800
12 Months or less, Unrealized Loss	(534)	(764)
More than 12 months, Fair Value
More than 12 months, Unrealized Loss
Total Fair Value	34,017	30,800
Total Unrealized Loss	(534)	(764)
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or less, Fair Value	18,620	28,428
12 Months or less, Unrealized Loss	(824)	(1,556)
More than 12 months, Fair Value	2,890	968
More than 12 months, Unrealized Loss	(186)	(121)
Total Fair Value	21,510	29,396
Total Unrealized Loss	(1,010)	(1,677)
Mortgage-backed Securities in Government Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or less, Fair Value	29,723	32,557
12 Months or less, Unrealized Loss	(379)	(553)
More than 12 months, Fair Value	3,049	279
More than 12 months, Unrealized Loss	(18)	(4)
Total Fair Value	32,772	32,836
Total Unrealized Loss	(397)	(557)
Equity Securities in Financial Institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or less, Fair Value		449
12 Months or less, Unrealized Loss		(32)
More than 12 months, Fair Value
More than 12 months, Unrealized Loss
Total Fair Value		449
Total Unrealized Loss		$ (32)