Securities - Amortized Cost of Securities and their Estimated Fair Values (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 326,662	$ 320,323
Gross Unrealized Gains	7,921	5,665
Gross Unrealized Losses	(2,944)	(7,078)
Estimated Fair Value	331,639	318,910
FHLB Stock [Member] | Restricted [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,428	4,428
Gross Unrealized Gains
Gross Unrealized Losses
Estimated Fair Value	4,428	4,428
U.S. Treasury Securities [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,973
Gross Unrealized Gains	5
Gross Unrealized Losses
Estimated Fair Value	3,978
U.S. Agency Securities [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	118,130	120,608
Gross Unrealized Gains	2,126	1,856
Gross Unrealized Losses	(1,210)	(2,441)
Estimated Fair Value	119,046	120,023
Corporate Bonds [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,000	2,000
Gross Unrealized Gains	5
Gross Unrealized Losses		(16)
Estimated Fair Value	2,005	1,984
Taxable Municipals Bonds [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	14,119	18,337
Gross Unrealized Gains	333	458
Gross Unrealized Losses	(226)	(738)
Estimated Fair Value	14,226	18,057
Tax Free Municipals Bonds [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	61,918	64,291
Gross Unrealized Gains	3,643	2,066
Gross Unrealized Losses	(227)	(898)
Estimated Fair Value	65,334	65,459
Trust Preferred Securities [Member] | Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,600	1,600
Gross Unrealized Gains
Gross Unrealized Losses	(111)	(111)
Estimated Fair Value	1,489	1,489
GNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,450	17,327
Gross Unrealized Gains	695	590
Gross Unrealized Losses	(101)	(142)
Estimated Fair Value	28,044	17,775
FNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	65,479	70,104
Gross Unrealized Gains	866	526
Gross Unrealized Losses	(749)	(1,938)
Estimated Fair Value	65,596	68,692
FHLMC [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,142	1,301
Gross Unrealized Gains	38	35
Gross Unrealized Losses
Estimated Fair Value	1,180	1,336
Non-Agency CMOs [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,811	8,459
Gross Unrealized Gains	4
Gross Unrealized Losses	(194)	(374)
Estimated Fair Value	10,621	8,085
Agency CMOs [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,040	16,296
Gross Unrealized Gains	206	134
Gross Unrealized Losses	(126)	(420)
Estimated Fair Value	$ 20,120	$ 16,010