Allowance for Loan Losses - Allowance by Impairment Methodology and Loans by Impairment Methodology (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for loan losses:
Balance at beginning of year	$ 13,075	$ 12,937	$ 16,036
Charge-offs	(4,492)	(3,793)	(15,789)
Recoveries	2,486	376	310
Provision for (recovery of) loan losses	(425)	3,555	12,380
Balance at end of year	10,644	13,075	12,937
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	1,379	1,838	2,438
Allowance for loan losses, Collectively evaluated for impairment	9,265	11,237	10,499
Loans:
Ending Balance	357,093	383,594	392,440
Loans, Individually evaluated for impairment	21,694	16,980	25,920
Loans, Collectively evaluated for impairment	335,399	366,614	366,520
Construction and Land Development [Member]
Allowance for loan losses:
Balance at beginning of year	2,481	2,843	4,050
Charge-offs	(2,962)	(431)	(2,983)
Recoveries		1	50
Provision for (recovery of) loan losses	3,191	68	1,726
Balance at end of year	2,710	2,481	2,843
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	882	567	930
Allowance for loan losses, Collectively evaluated for impairment	1,828	1,914	1,913
Loans:
Ending Balance	34,060	43,524	48,363
Loans, Individually evaluated for impairment	6,862	2,516	7,640
Loans, Collectively evaluated for impairment	27,198	41,008	40,723
Secured by 1-4 Family Residential [Member]
Allowance for loan losses:
Balance at beginning of year	3,712	3,766	1,681
Charge-offs	(260)	(761)	(4,369)
Recoveries	823	68	6
Provision for (recovery of) loan losses	(1,300)	639	6,718
Balance at end of year	2,975	3,712	3,766
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	190	306	848
Allowance for loan losses, Collectively evaluated for impairment	2,785	3,406	2,918
Loans:
Ending Balance	141,961	134,964	122,339
Loans, Individually evaluated for impairment	3,431	3,776	6,860
Loans, Collectively evaluated for impairment	138,530	131,188	115,479
Other Real Estate [Member]
Allowance for loan losses:
Balance at beginning of year	6,163	5,192	9,187
Charge-offs	(1,070)	(2,154)	(7,551)
Recoveries	1,304	64
Provision for (recovery of) loan losses	(1,979)	3,061	3,556
Balance at end of year	4,418	6,163	5,192
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	263	930	351
Allowance for loan losses, Collectively evaluated for impairment	4,155	5,233	4,841
Loans:
Ending Balance	145,968	176,573	181,141
Loans, Individually evaluated for impairment	11,143	10,528	10,940
Loans, Collectively evaluated for impairment	134,825	163,692	170,201
Commercial and Industrial [Member]
Allowance for loan losses:
Balance at beginning of year	608	963	858
Charge-offs	(37)	(261)	(348)
Recoveries	179	35	3
Provision for (recovery of) loan losses	(308)	(129)	450
Balance at end of year	442	608	963
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	44	35	309
Allowance for loan losses, Collectively evaluated for impairment	398	573	654
Loans:
Ending Balance	22,803	20,718	29,446
Loans, Individually evaluated for impairment	258	160	480
Loans, Collectively evaluated for impairment	22,545	20,558	28,966
Consumer and Other Loans [Member]
Allowance for loan losses:
Balance at beginning of year	111	173	260
Charge-offs	(163)	(186)	(268)
Recoveries	180	208	251
Provision for (recovery of) loan losses	(29)	(84)	(70)
Balance at end of year	99	111	173
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment
Allowance for loan losses, Collectively evaluated for impairment	99	111	173
Loans:
Ending Balance	12,301	7,815	11,151
Loans, Individually evaluated for impairment
Loans, Collectively evaluated for impairment	$ 12,301	$ 7,815	$ 11,151