Delinquency Information for Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
30-59 Days Past Due	$ 2,457
60-89 Days Past Due	569
90 Days or More Past Due	2,816	879
Total Past Due	5,842	879
Current	18,580	2,921
Total	24,422	3,800
Residential real estate loans
Financing Receivable, Recorded Investment [Line Items]
30-59 Days Past Due	2,457
60-89 Days Past Due	569
90 Days or More Past Due	2,816
Total Past Due	5,842
Current	16,367
Total	22,209
Commercial real estate loans
Financing Receivable, Recorded Investment [Line Items]
90 Days or More Past Due		38
Total Past Due		38
Current	1,722	1,885
Total	1,722	1,923
Commercial loans
Financing Receivable, Recorded Investment [Line Items]
90 Days or More Past Due		841
Total Past Due		841
Current	491	1,036
Total	491	1,877
Commercial loans | Revolving lines of credit
Financing Receivable, Recorded Investment [Line Items]
Current		1,036
Total		1,036
Commercial loans | Term note
Financing Receivable, Recorded Investment [Line Items]
Current	491
Total	491
Commercial loans | Purchased credit-impaired term loan
Financing Receivable, Recorded Investment [Line Items]
90 Days or More Past Due		841
Total Past Due		841
Total		$ 841