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	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	$ 20,706	$ 23,543
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	45
Permanent Real Estate Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	12,149	13,053
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Construction Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	2,453	3,084
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	1,960	3,248
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	45
Commercial Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	4,144	4,158
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Land [Member] | Permanent Real Estate Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	531	496
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Auto [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	84	110
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Home Equity [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	1,574	2,726
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	45
One-to Four-Family Residential [Member] | Permanent Real Estate Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	4,700	6,356
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Multi-Family Residential [Member] | Permanent Real Estate Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	114	641
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Nonresidential [Member] | Permanent Real Estate Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	6,804	5,560
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
One-to Four-Family Residential [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	2,453	3,084
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Multi-Family and Nonresidential [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Marine [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	123	136
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Recreational Vehicles [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	175	263
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Other [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	4	13
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Secured [Member] | Commercial Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	4,019	4,028
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	0	0
Unsecured [Member] | Commercial Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Financing receivable, recorded investment, Nonaccrual	125	130
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	$ 0	$ 0