Securities - Amortized Cost of Securities and their Estimated Fair Values (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	$ 4,428	$ 4,428
Amortized Cost	243,151	297,848
Gross Unrealized Gains	5,728	7,762
Gross Unrealized Losses	(1,206)	(1,982)
Estimated Fair Value	247,673	303,628
Estimated Fair Value, Less than 12 months	47,474	38,057
Unrealized Losses, Less than 12 months	(355)	(233)
Estimated Fair Value, 12 months or longer	43,491	79,304
Unrealized Losses, 12 months or longer	(851)	(1,749)
Estimated Fair Value	90,965	117,361
Unrealized Losses	(1,206)	(1,982)
Restricted [Member]
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	4,428	4,428
FHLB stock	4,428	4,428
U.S. Treasury Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,001	3,977
Gross Unrealized Gains	10	3
Estimated Fair Value	2,011	3,980
Agency CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25,316	28,024
Gross Unrealized Gains	186	176
Gross Unrealized Losses	(94)	(205)
Estimated Fair Value	25,408	27,995
Agency CMO [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	8,245	9,545
Unrealized Losses, Less than 12 months	(29)	(91)
Estimated Fair Value, 12 months or longer	1,970	7,685
Unrealized Losses, 12 months or longer	(65)	(114)
Estimated Fair Value	10,215	17,230
Unrealized Losses	(94)	(205)
Tax Free Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,143	57,399
Gross Unrealized Gains	2,511	3,814
Gross Unrealized Losses	(202)	(166)
Estimated Fair Value	51,452	61,047
Tax Free Municipals Bonds [Member] | U.S. Agency Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	1,475
Unrealized Losses, Less than 12 months	(3)
Estimated Fair Value, 12 months or longer	6,209	6,647
Unrealized Losses, 12 months or longer	(199)	(166)
Estimated Fair Value	7,684	6,647
Unrealized Losses	(202)	(166)
Taxable Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,428	11,871
Gross Unrealized Gains	150	235
Gross Unrealized Losses	(78)	(63)
Estimated Fair Value	8,500	12,043
Taxable Municipals Bonds [Member] | U.S. Agency Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	2,043
Unrealized Losses, Less than 12 months	(15)
Estimated Fair Value, 12 months or longer	2,994	4,785
Unrealized Losses, 12 months or longer	(63)	(63)
Estimated Fair Value	5,037	4,785
Unrealized Losses	(78)	(63)
Trust Preferred Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,608	1,600
Gross Unrealized Gains	195
Gross Unrealized Losses		(111)
Estimated Fair Value	1,803	1,489
Trust Preferred Securities [Member] | U.S. Agency Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, 12 months or longer		1,489
Unrealized Losses, 12 months or longer		(111)
Estimated Fair Value		1,489
Unrealized Losses		(111)
GNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,874	27,535
Gross Unrealized Gains	252	670
Gross Unrealized Losses	(124)	(122)
Estimated Fair Value	22,002	28,083
GNMA [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	4,954	12,568
Unrealized Losses, Less than 12 months	(38)	(108)
Estimated Fair Value, 12 months or longer	11,177	2,895
Unrealized Losses, 12 months or longer	(86)	(14)
Estimated Fair Value	16,131	15,463
Unrealized Losses	(124)	(122)
FNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,733	50,617
Gross Unrealized Gains	423	694
Gross Unrealized Losses	(112)	(536)
Estimated Fair Value	33,044	50,775
FNMA [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	7,338
Unrealized Losses, Less than 12 months	(62)
Estimated Fair Value, 12 months or longer	3,068	18,927
Unrealized Losses, 12 months or longer	(50)	(536)
Estimated Fair Value	10,406	18,927
Unrealized Losses	(112)	(536)
FHLMC [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,657	3,276
Gross Unrealized Gains	30	38
Gross Unrealized Losses	(34)
Estimated Fair Value	5,653	3,314
FHLMC [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	2,663
Unrealized Losses, Less than 12 months	(34)
Estimated Fair Value	2,663
Unrealized Losses	(34)
SLMA CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,806	9,895
Gross Unrealized Losses	(23)	(252)
Estimated Fair Value	3,783	9,643
SLMA CMO [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	183	1,923
Unrealized Losses, Less than 12 months	(2)	(14)
Estimated Fair Value, 12 months or longer	3,600	7,720
Unrealized Losses, 12 months or longer	(21)	(238)
Estimated Fair Value	3,783	9,643
Unrealized Losses	(23)	(252)
Agency Debt Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	92,585	101,654
Gross Unrealized Gains	1,971	2,125
Gross Unrealized Losses	(539)	(527)
Estimated Fair Value	94,017	103,252
Agency Debt Securities [Member] | U.S. Agency Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	20,573	14,021
Unrealized Losses, Less than 12 months	(172)	(20)
Estimated Fair Value, 12 months or longer	14,473	29,156
Unrealized Losses, 12 months or longer	(367)	(507)
Estimated Fair Value	35,046	43,177
Unrealized Losses	$ (539)	(527)
Commercial Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,000
Gross Unrealized Gains		7
Estimated Fair Value		$ 2,007