Schedule of Trouble Debt Restructurings by Accrual Status (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	$ 1,404
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	90
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	1,314
Accrual Status [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	90
Accrual Status [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	90
Non Accrual Status [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	1,314
Non Accrual Status [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring	$ 1,314