Loans - Presentation of Recorded Investment in Nonaccrual Loans and Loans Past Due Over 90 Days and Still on Accrual by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	$ 20,096	$ 20,451
Commercial Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	11,383	11,472
Commercial Loans [Member] | Multifamily [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	85	93
Commercial Loans [Member] | Nonresidential [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	5,700	5,781
Commercial Loans [Member] | Land [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	531	531
Commercial Loans [Member] | Construction [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	1,051	1,051
Commercial Loans [Member] | Secured [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	4,016	4,016
Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	6,652	6,816
Residential Mortgage Loans [Member] | One-to Four-Family [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	6,652	6,816
Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	2,061	2,163
Consumer Loans [Member] | Home Equity [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	1,653	1,792
Consumer Loans [Member] | Auto [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	47	66
Consumer Loans [Member] | Marine [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	259	119
Consumer Loans [Member] | Recreational Vehicle [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	101	184
Consumer Loans [Member] | Other [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	$ 1	$ 2