Loans Receivable, Net Due Within One Year (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal payments due within one year	$ 90	[1]	$ 620	[1]
Loans receivable, net due within one year	1,733	[1]	620	[1]
Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal payments due within one year		[1]	527	[1]
Unpaid principal balance			44,904
Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal payments due within one year	90	[1]	93	[1]
Commercial loans | Revolving lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 1,643	[1]

[1] Excludes loans ninety or more days past due.