Loans - Non-accrual Loans (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	$ 11,812	$ 7,663	$ 12,119
One-to-four Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	1,131	2,243	2,577
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	22	66	91
Junior liens [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	37	4	107
Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans		38	190
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans
Land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	2,255	2,768	4,290
Non-Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	7,055	1,134	4,000
Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	781	648	727
Consumer loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	11	145	16
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	$ 520	$ 617	$ 121