Loans - Past Due and Non-Accrual Balances by Loan Classification (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	$ 474,839	$ 453,205
30-89 Days Past Due	2,706	2,491
Non-accrual Loans	12,128	7,663	9,824
Special Mention	6,518	13,511
Impaired Loans Currently Performing Substandard	45,269	58,617
Impaired Loans Currently Performing Doubtful
Total loans, gross	541,460	535,487
One-to-Four Family Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	148,481	155,936
30-89 Days Past Due	1,682	1,339
Non-accrual Loans	865	2,243	2,795
Special Mention	1,423	779
Impaired Loans Currently Performing Substandard	5,406	2,038
Impaired Loans Currently Performing Doubtful
Total loans, gross	157,857	162,335
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	33,672	34,732
30-89 Days Past Due	248	5
Non-accrual Loans	275	66	24
Special Mention		1,109
Impaired Loans Currently Performing Substandard	877	1,171
Impaired Loans Currently Performing Doubtful
Total loans, gross	35,072	37,083
Junior Liens [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	3,128	3,584
30-89 Days Past Due	33	237
Non-accrual Loans	2	4
Special Mention	44	47
Impaired Loans Currently Performing Substandard	369	464
Impaired Loans Currently Performing Doubtful
Total loans, gross	3,576	4,336
Multi-Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	28,433	27,463
Non-accrual Loans		38	190
Special Mention		1,478
Impaired Loans Currently Performing Substandard		4,077
Impaired Loans Currently Performing Doubtful
Total loans, gross	28,433	33,056
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	9,007	13,876
30-89 Days Past Due	175	176
Non-accrual Loans
Special Mention	176
Impaired Loans Currently Performing Substandard		4,848
Impaired Loans Currently Performing Doubtful
Total loans, gross	9,358	18,900
Land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	17,259	14,237
30-89 Days Past Due	133	137
Non-accrual Loans	2,257	2,768	3,279
Special Mention	1,789	7,683
Impaired Loans Currently Performing Substandard	16,209	21,081
Impaired Loans Currently Performing Doubtful
Total loans, gross	37,647	45,906
Non-Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	127,731	101,894
30-89 Days Past Due	90	293
Non-accrual Loans	7,187	1,134	1,268
Special Mention	2,183	1,230
Impaired Loans Currently Performing Substandard	14,304	18,647
Impaired Loans Currently Performing Doubtful
Total loans, gross	151,495	122,637
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	11,376	13,266
30-89 Days Past Due	151	74
Non-accrual Loans	316	145
Impaired Loans Currently Performing Substandard	536	401
Impaired Loans Currently Performing Doubtful
Total loans, gross	12,379	13,886
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	51,324	43,961
30-89 Days Past Due	91	230
Non-accrual Loans	482	617	2,160
Special Mention	96	516
Impaired Loans Currently Performing Substandard	2,742	5,225
Impaired Loans Currently Performing Doubtful
Total loans, gross	54,735	50,549
Farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Currently Performing	44,428	44,256
30-89 Days Past Due	103
Non-accrual Loans	744	648	49
Special Mention	807	669
Impaired Loans Currently Performing Substandard	4,826	665
Impaired Loans Currently Performing Doubtful
Total loans, gross	$ 50,908	$ 46,799