Loans Receivable, Credit Quality for Loans and the Allowance for Loan Losses - Summary of Changes in Accretable Discount Related to Purchased Credit Impaired Loans (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Receivables [Abstract]        
Balance - beginning of period $ 326 $ 332 $ 310 $ 378
Accretion recognized during the period (48) (58) (104) (719)
Net reclassification from non-accretable to accretable 38 48 110 663
Balance - end of period $ 316 $ 322 $ 316 $ 322