Loans - Summary of Company's Impaired Loans, Including Respective Regulatory Classification and Respective Specific Reserve (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	$ 567,667	$ 562,494
Specific Allowance for Impairment	463	630	$ 746
Allowance for Performing Loans	6,061	5,070
Multi-Family [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	31,289	24,725
Specific Allowance for Impairment		138
Allowance for Performing Loans	153	89
One-to-Four Family Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	145,859	145,999
Specific Allowance for Impairment	206	60
Allowance for Performing Loans	1,119	970
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	33,063	33,644
Allowance for Performing Loans	306	201
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	36,923	34,878
Allowance for Performing Loans	746	377
Land [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	21,881	22,453
Specific Allowance for Impairment		69
Allowance for Performing Loans	1,096	1,310
Non-Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	154,658	149,711
Specific Allowance for Impairment	108	134
Allowance for Performing Loans	1,056	1,005
Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	45,593	42,246
Allowance for Performing Loans	577	358
Junior Liens [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	1,661	1,771
Allowance for Performing Loans	10	8
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	8,482	20,324
Specific Allowance for Impairment	50	49
Allowance for Performing Loans	113	309
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	88,258	86,743
Specific Allowance for Impairment	99	180
Allowance for Performing Loans	885	443
Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	528,574	531,462
Pass [Member] | Multi-Family [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	26,460	21,644
Pass [Member] | One-to-Four Family Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	142,893	142,729
Pass [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	32,767	33,475
Pass [Member] | Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	36,923	34,878
Pass [Member] | Land [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	10,324	11,794
Pass [Member] | Non-Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	144,076	138,865
Pass [Member] | Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	44,509	41,917
Pass [Member] | Junior Liens [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	1,616	1,720
Pass [Member] | Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	8,229	20,123
Pass [Member] | Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	80,777	84,317
Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	1,451	2,958
Special Mention [Member] | One-to-Four Family Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	753	41
Special Mention [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	21
Special Mention [Member] | Land [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	38	41
Special Mention [Member] | Non-Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	282	2,489
Special Mention [Member] | Junior Liens [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	33	35
Special Mention [Member] | Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	324	352
Impaired Loans Substandard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	37,642	28,074
Impaired Loans Substandard [Member] | Multi-Family [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	4,829	3,081
Impaired Loans Substandard [Member] | One-to-Four Family Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	2,213	3,229
Impaired Loans Substandard [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	275	169
Impaired Loans Substandard [Member] | Land [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	11,519	10,618
Impaired Loans Substandard [Member] | Non-Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	10,300	8,357
Impaired Loans Substandard [Member] | Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	1,084	329
Impaired Loans Substandard [Member] | Junior Liens [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	12	16
Impaired Loans Substandard [Member] | Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	253	201
Impaired Loans Substandard [Member] | Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	$ 7,157	$ 2,074