Loans - Risk Category of Loans by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	$ 1,137,191	$ 1,049,165
Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,082,044	979,700
Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	16,069	15,956
Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	39,078	53,509
Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	39,078	53,509
Permanent Real Estate Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	858,462	780,444
Permanent Real Estate Loans [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	815,211	724,005
Permanent Real Estate Loans [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	15,138	15,715
Permanent Real Estate Loans [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	28,113	40,724
Permanent Real Estate Loans [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	28,113	40,724
Permanent Real Estate Loans [Member] | Land [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	9,487	9,683
Permanent Real Estate Loans [Member] | Land [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	8,955	9,069
Permanent Real Estate Loans [Member] | Land [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans		127
Permanent Real Estate Loans [Member] | Land [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	532	487
Permanent Real Estate Loans [Member] | Land [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Land [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Land [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	532	487
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	669,270	585,025
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	661,994	575,903
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,492	404
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5,784	8,718
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5,784	8,718
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	56,445	54,485
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	49,294	48,918
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	4,167	2,962
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,984	2,605
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Multi-Family Residential [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,984	2,605
Permanent Real Estate Loans [Member] | Nonresidential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	123,260	131,251
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	94,968	90,115
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	9,479	12,222
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	18,813	28,914
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Permanent Real Estate Loans [Member] | Nonresidential [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	18,813	28,914
Permanent Real Estate Loans [Member] | One-to Four-Family Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	669,270	585,025
Construction Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	57,402	53,349
Construction Loans [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	54,952	50,257
Construction Loans [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,450	3,092
Construction Loans [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Construction Loans [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Construction Loans [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,450	3,092
Construction Loans [Member] | One-to Four-Family Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	52,735	53,349
Construction Loans [Member] | One-to Four-Family Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	52,735	53,349
Construction Loans [Member] | One-to Four-Family Residential [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	50,285	50,257
Construction Loans [Member] | One-to Four-Family Residential [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,450	3,092
Construction Loans [Member] | One-to Four-Family Residential [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Construction Loans [Member] | One-to Four-Family Residential [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Construction Loans [Member] | One-to Four-Family Residential [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,450	3,092
Construction Loans [Member] | Multi-Family and Nonresidential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	4,667
Construction Loans [Member] | Multi-Family and Nonresidential [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	4,667
Construction Loans [Member] | Multi-Family and Nonresidential [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Construction Loans [Member] | Multi-Family and Nonresidential [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	181,474	189,231
Consumer Loans [Member] | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5,300	5,669
Consumer Loans [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	179,156	185,656
Consumer Loans [Member] | Unclassified | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5,217	5,548
Consumer Loans [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	11	51
Consumer Loans [Member] | Special Mention | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans		5
Consumer Loans [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,307	3,524
Consumer Loans [Member] | Substandard | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	83	116
Consumer Loans [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Doubtful | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Classified Loss | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	2,307	3,524
Consumer Loans [Member] | Classified | Auto [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	83	116
Consumer Loans [Member] | Home Equity [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	154,936	159,795
Consumer Loans [Member] | Home Equity [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	153,068	156,795
Consumer Loans [Member] | Home Equity [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans		46
Consumer Loans [Member] | Home Equity [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,868	2,954
Consumer Loans [Member] | Home Equity [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Home Equity [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Home Equity [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,868	2,954
Consumer Loans [Member] | Marine [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	4,003	4,308
Consumer Loans [Member] | Marine [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	3,839	4,148
Consumer Loans [Member] | Marine [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	11
Consumer Loans [Member] | Marine [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	153	160
Consumer Loans [Member] | Marine [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Marine [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Marine [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	153	160
Consumer Loans [Member] | Recreational Vehicles [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	15,249	17,347
Consumer Loans [Member] | Recreational Vehicles [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	15,051	17,066
Consumer Loans [Member] | Recreational Vehicles [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	198	281
Consumer Loans [Member] | Recreational Vehicles [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Recreational Vehicles [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Recreational Vehicles [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	198	281
Consumer Loans [Member] | Other [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,986	2,112
Consumer Loans [Member] | Other [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	1,981	2,099
Consumer Loans [Member] | Other [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5	13
Consumer Loans [Member] | Other [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Other [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Consumer Loans [Member] | Other [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	5	13
Commercial Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	39,853	26,141
Commercial Loans [Member] | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	39,685	25,714
Commercial Loans [Member] | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	168	427
Commercial Loans [Member] | Unclassified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	32,725	19,782
Commercial Loans [Member] | Unclassified | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	32,671	19,714
Commercial Loans [Member] | Unclassified | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	54	68
Commercial Loans [Member] | Special Mention
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	920	190
Commercial Loans [Member] | Special Mention | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	920	190
Commercial Loans [Member] | Substandard
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	6,208	6,169
Commercial Loans [Member] | Substandard | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	6,094	5,810
Commercial Loans [Member] | Substandard | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	114	359
Commercial Loans [Member] | Doubtful
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Doubtful | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Doubtful | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Classified Loss
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Classified Loss | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Classified Loss | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	0	0
Commercial Loans [Member] | Classified
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	6,208	6,169
Commercial Loans [Member] | Classified | Secured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	6,094	5,810
Commercial Loans [Member] | Classified | Unsecured [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Total loans	$ 114	$ 359