Loans and Allowance for Loan Losses - Summary of Carrying Balances of TDR's (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Total TDRS	$ 7,261	$ 8,040
Performing Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Total TDRS	4,226	4,443
Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Total TDRS	$ 3,035	$ 3,597