Loans Receivable, Net Due Within One Year (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal payments due within one year	$ 620	[1]	$ 136	[1]
Loans receivable, net due within one year	620	[1]	1,172	[1]
Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal payments due within one year	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	93	[1]	136	[1]
Commercial loans | Revolving lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance			$ 1,036	[1]

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