Securities - Amortized Cost of Securities and their Estimated Fair Values (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	$ 4,428	$ 4,428
Amortized Cost	234,126	297,848
Gross Unrealized Gains	6,417	7,762
Gross Unrealized Losses	(621)	(1,982)
Estimated Fair Value	239,922	303,628
Estimated Fair Value, Less than 12 months	16,417	38,057
Unrealized Losses, Less than 12 months	(90)	(233)
Estimated Fair Value, 12 months or longer	37,734	79,304
Unrealized Losses, 12 months or longer	(531)	(1,749)
Estimated Fair Value	54,151	117,361
Unrealized Losses	(621)	(1,982)
Restricted [Member]
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	0	4,428
FHLB stock	0	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	9	3
Estimated Fair Value	2,010	3,980
Agency Debt Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	91,190	101,654
Gross Unrealized Gains	2,352	2,125
Gross Unrealized Losses	(159)	(527)
Estimated Fair Value	93,383	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	5,009	14,021
Unrealized Losses, Less than 12 months	(13)	(20)
Estimated Fair Value, 12 months or longer	9,997	29,156
Unrealized Losses, 12 months or longer	(146)	(507)
Estimated Fair Value	15,006	43,177
Unrealized Losses	(159)	(527)
Taxable Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,173	11,871
Gross Unrealized Gains	217	235
Gross Unrealized Losses	(16)	(63)
Estimated Fair Value	7,374	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, 12 months or longer	1,926	4,785
Unrealized Losses, 12 months or longer	(16)	(63)
Estimated Fair Value	1,926	4,785
Unrealized Losses	(16)	(63)
Tax Free Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	47,209	57,399
Gross Unrealized Gains	2,525	3,814
Gross Unrealized Losses	(96)	(166)
Estimated Fair Value	49,638	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, 12 months or longer	6,308	6,647
Unrealized Losses, 12 months or longer	(96)	(166)
Estimated Fair Value	6,308	6,647
Unrealized Losses	(96)	(166)
Trust Preferred Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,613	1,600
Gross Unrealized Gains	177
Gross Unrealized Losses		(111)
Estimated Fair Value	1,790	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	20,214	27,535
Gross Unrealized Gains	249	670
Gross Unrealized Losses	(89)	(122)
Estimated Fair Value	20,374	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	4,180	12,568
Unrealized Losses, Less than 12 months	(22)	(108)
Estimated Fair Value, 12 months or longer	10,694	2,895
Unrealized Losses, 12 months or longer	(67)	(14)
Estimated Fair Value	14,874	15,463
Unrealized Losses	(89)	(122)
FNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	31,596	50,617
Gross Unrealized Gains	583	694
Gross Unrealized Losses	(20)	(536)
Estimated Fair Value	32,159	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	2,267
Unrealized Losses, Less than 12 months	(12)
Estimated Fair Value, 12 months or longer	3,101	18,927
Unrealized Losses, 12 months or longer	(8)	(536)
Estimated Fair Value	5,368	18,927
Unrealized Losses	(20)	(536)
FHLMC [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,353	3,276
Gross Unrealized Gains	46	38
Gross Unrealized Losses	(16)
Estimated Fair Value	5,383	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	2,539
Unrealized Losses, Less than 12 months	(16)
Estimated Fair Value	2,539
Unrealized Losses	(16)
SLMA CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,819	9,895
Gross Unrealized Losses	(183)	(252)
Estimated Fair Value	3,636	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		1,923
Unrealized Losses, Less than 12 months		(14)
Estimated Fair Value, 12 months or longer	3,636	7,720
Unrealized Losses, 12 months or longer	(183)	(238)
Estimated Fair Value	3,636	9,643
Unrealized Losses	(183)	(252)
Agency CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	23,958	28,024
Gross Unrealized Gains	259	176
Gross Unrealized Losses	(42)	(205)
Estimated Fair Value	24,175	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	2,422	9,545
Unrealized Losses, Less than 12 months	(27)	(91)
Estimated Fair Value, 12 months or longer	2,072	7,685
Unrealized Losses, 12 months or longer	(15)	(114)
Estimated Fair Value	4,494	17,230
Unrealized Losses	$ (42)	(205)
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