Securities - Amortized Cost of Securities and their Estimated Fair Values (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	$ 4,428	$ 4,428
FHLB stock	4,428	4,428
Amortized Cost	231,618	233,429
Gross Unrealized Gains	6,669	5,108
Gross Unrealized Losses	(458)	(1,360)
Estimated Fair Value	237,829	237,177
Estimated Fair Value, Less than 12 months	18,395	70,099
Unrealized Losses, Less than 12 months	(72)	(569)
Estimated Fair Value, 12 months or longer	16,639	42,178
Unrealized Losses, 12 months or longer	(386)	(791)
Estimated Fair Value	35,034	112,277
Unrealized Losses	(458)	(1,360)
U.S. Agency Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 months	6,091
Unrealized Losses, Less than 12 months	(10)
Estimated Fair Value, 12 months or longer	2,956
Unrealized Losses, 12 months or longer	(36)
Estimated Fair Value	9,047
Unrealized Losses	(46)
U.S. Treasury Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,001	2,001
Gross Unrealized Gains	4
Gross Unrealized Losses		(1)
Estimated Fair Value	2,005	2,000
U.S. Treasury 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		2,000
Unrealized Losses, Less than 12 months		(1)
Estimated Fair Value		2,000
Unrealized Losses		(1)
U.S. Agency Debt Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	89,094	91,694
Gross Unrealized Gains	2,714	1,727
Gross Unrealized Losses	(46)	(488)
Estimated Fair Value	91,762	92,933
Taxable Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,174	6,190
Gross Unrealized Gains	99	52
Gross Unrealized Losses	(7)	(65)
Estimated Fair Value	6,266	6,177
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	561	2,159
Unrealized Losses, Less than 12 months	(7)	(32)
Estimated Fair Value, 12 months or longer		1,887
Unrealized Losses, 12 months or longer		(33)
Estimated Fair Value	561	4,046
Unrealized Losses	(7)	(65)
Tax Free Municipals Bonds [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	38,573	42,237
Gross Unrealized Gains	2,271	2,481
Gross Unrealized Losses	(15)	(59)
Estimated Fair Value	40,829	44,659
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	1,326
Unrealized Losses, Less than 12 months	(3)
Estimated Fair Value, 12 months or longer	1,313	3,878
Unrealized Losses, 12 months or longer	(12)	(59)
Estimated Fair Value	2,639	3,878
Unrealized Losses	(15)	(59)
Trust Preferred Securities [Member] | Available for Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,621	1,617
Gross Unrealized Gains	353	248
Estimated Fair Value	1,974	1,865
GNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	28,305	29,990
Gross Unrealized Gains	318	239
Gross Unrealized Losses	(111)	(239)
Estimated Fair Value	28,512	29,990
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	1,688	10,840
Unrealized Losses, Less than 12 months	(24)	(105)
Estimated Fair Value, 12 months or longer	5,771	11,508
Unrealized Losses, 12 months or longer	(87)	(134)
Estimated Fair Value	7,459	22,348
Unrealized Losses	(111)	(239)
FNMA [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,510	28,189
Gross Unrealized Gains	571	266
Gross Unrealized Losses	(35)	(152)
Estimated Fair Value	33,046	28,303
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	5,763	11,484
Unrealized Losses, Less than 12 months	(21)	(87)
Estimated Fair Value, 12 months or longer	3,079	3,036
Unrealized Losses, 12 months or longer	(14)	(65)
Estimated Fair Value	8,842	14,520
Unrealized Losses	(35)	(152)
FHLMC [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,711	8,113
Gross Unrealized Gains	74	24
Gross Unrealized Losses	(7)	(51)
Estimated Fair Value	10,778	8,086
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	2,966	7,336
Unrealized Losses, Less than 12 months	(7)	(51)
Estimated Fair Value	2,966	7,336
Unrealized Losses	(7)	(51)
Non-Agency CMO [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,757
Gross Unrealized Losses	(237)
Estimated Fair Value	3,520
Non-Agency CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		3,828
Gross Unrealized Losses		(174)
Estimated Fair Value		3,654
Non-Agency CMO [Member] | Mortgage-Backed Securities [Member] | Temporarily Impaired Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, 12 months or longer	3,520	3,654
Unrealized Losses, 12 months or longer	(237)	(174)
Estimated Fair Value	3,520	3,654
Unrealized Losses	(237)	(174)
Agency CMO [Member] | Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,872	19,570
Gross Unrealized Gains	265	71
Gross Unrealized Losses		(131)
Estimated Fair Value	$ 19,137	19,510
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		9,781
Unrealized Losses, Less than 12 months		(90)
Estimated Fair Value, 12 months or longer		1,991
Unrealized Losses, 12 months or longer		(41)
Estimated Fair Value		11,772
Unrealized Losses		(131)
U.S. Agency 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		26,499
Unrealized Losses, Less than 12 months		(203)
Estimated Fair Value, 12 months or longer		16,224
Unrealized Losses, 12 months or longer		(285)
Estimated Fair Value		42,723
Unrealized Losses		$ (488)