Foreclosed Assets - Summary of Activity in Balance of Foreclosed Assets (Detail)
$ in Thousands
12 Months Ended
Dec. 31, 2015
USD ($)
Assets
Dec. 31, 2014
USD ($)
Assets
Dec. 31, 2013
USD ($)
Schedule Of Foreclosed Assets Activity [Line Items]      
Beginning balance, net $ 4,894 $ 6,262  
Acquisitions   695  
Additions/transfers from loans 5,435 5,753  
Dispositions/sales (4,458) (7,608)  
Valuation adjustments (502) (208)  
Ending balance, net 5,369 4,894 $ 6,262
Ending valuation allowance $ (572) $ (208)  
Ending number of foreclosed assets | Assets 26 29  
Proceeds from sale of foreclosed assets $ 5,449 $ 9,762  
Gain on sale of foreclosed assets 991 2,153 1,640
Noncovered [Member]      
Schedule Of Foreclosed Assets Activity [Line Items]      
Beginning balance, net 4,449 5,588  
Acquisitions   695  
Additions/transfers from loans 5,880 5,753  
Dispositions/sales (4,458) (7,391)  
Valuation adjustments (502) (196)  
Ending balance, net 5,369 4,449 5,588
Ending valuation allowance $ (572) $ (208)  
Ending number of foreclosed assets | Assets 26 28  
Proceeds from sale of foreclosed assets $ 5,449 $ 9,517  
Gain on sale of foreclosed assets 991 2,125  
Covered [Member]      
Schedule Of Foreclosed Assets Activity [Line Items]      
Beginning balance, net 445 674  
Additions/transfers from loans $ (445)    
Dispositions/sales   (217)  
Valuation adjustments   (12)  
Ending balance, net   $ 445 $ 674
Ending number of foreclosed assets | Assets   1  
Proceeds from sale of foreclosed assets   $ 245  
Gain on sale of foreclosed assets   $ 28