Other Borrowings - Summary of Other Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Other borrowings	$ 20,000
ConvertibleAdvanceTwo [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Advances from Federal Home Loan Bank	7,953
FixedRateAdvanceOne [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Advances from Federal Home Loan Bank	3,301
FixedRateAdvanceTwo [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Advances from Federal Home Loan Bank	$ 8,746