Employee Benefit Plans - Non-vested Restricted Stock Activity (Detail) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2011
Dec. 31, 2010
Compensation Related Costs [Abstract]      
Non-vested restricted stock at beginning of year, Number of shares 119,055 177,520 212,840
Granted, Number of shares 48,700    
Vested, Number of shares (63,895)    
Forfeited, Number of shares (50)    
Non-vested restricted stock at end of year, Number of shares 103,810 177,520 212,840
Non-vested restricted stock at beginning of year, Weighted average grant date fair value $ 10.25    
Granted, Weighted average grant date fair value $ 18.96    
Vested, Weighted average grant date fair value $ 9.71    
Forfeited, Weighted average grant date fair value $ 9.50    
Non-vested restricted stock at end of year, Weighted average grant date fair value $ 14.68