Securities - Available for Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 201,486	$ 199,094
Gross Unrealized Gains	4,452	3,549
Gross Unrealized Losses	(1,941)	(3,030)
Total securities available for sale, Fair Value	203,997	199,613
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	52,816	52,229
Gross Unrealized Gains	124	95
Gross Unrealized Losses	(534)	(764)
Total securities available for sale, Fair Value	52,406	51,560
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	81,073	79,975
Gross Unrealized Gains	3,247	2,327
Gross Unrealized Losses	(1,010)	(1,677)
Total securities available for sale, Fair Value	83,310	80,625
Mortgage-backed Securities in Government Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	67,116	66,409
Gross Unrealized Gains	1,081	1,127
Gross Unrealized Losses	(397)	(557)
Total securities available for sale, Fair Value	67,800	66,979
Total Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	201,005	198,613
Gross Unrealized Gains	4,452	3,549
Gross Unrealized Losses	(1,941)	(2,998)
Total securities available for sale, Fair Value	203,516	199,164
Equity Securities in Financial Institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	481	481
Gross Unrealized Gains
Gross Unrealized Losses		(32)
Total securities available for sale, Fair Value	$ 481	$ 449