Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Values of Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 222,019	$ 198,771
Unrealized gains	2,754	5,330
Unrealized losses	(8,651)	(338)
Fair Value	216,122	203,763
U.S. Government agencies and corporations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	71,851	36,868
Unrealized gains	0	102
Unrealized losses	(6,463)	0
Fair Value	65,388	36,970
Mortgage backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	94,313	109,440
Unrealized gains	1,362	2,589
Unrealized losses	(1,245)	(328)
Fair Value	94,430	111,701
Collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,650	22,483
Unrealized gains	255	398
Unrealized losses	(250)	0
Fair Value	18,655	22,881
State and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,521	29,980
Unrealized gains	1,137	2,241
Unrealized losses	(693)	(10)
Fair Value	32,965	32,211
Preferred Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,684
Unrealized gains	0
Unrealized losses	0
Fair Value	$ 4,684