Securities - Summary of Gross Unrealized Losses and Fair Value of Securities (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Held-to-maturity, Gross unrealized losses, Total $ 785 $ 1,707
Gross unrealized losses, Less than 12 months 1,452 3,065
Fair value, Less than 12 months 76,746 85,737
Gross unrealized losses, 12 months or more 240 196
Fair value, 12 months or more 7,391 4,416
Gross unrealized losses, Total 1,692 3,261
Fair value, Total 84,137 90,153
Equity securities [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Gross unrealized losses, Less than 12 months     
Fair value, Less than 12 months     
Gross unrealized losses, 12 months or more   1
Fair value, 12 months or more   1
Gross unrealized losses, Total   1
Fair value, Total   1
U.S. Treasury Security [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Gross unrealized losses, Less than 12 months 9 8
Fair value, Less than 12 months 996 997
Gross unrealized losses, 12 months or more      
Fair value, 12 months or more      
Gross unrealized losses, Total 9 8
Fair value, Total 996 997
U.S. Government agencies [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Held-to-maturity, Gross unrealized losses, Less than 12 months 301 771
Held-to-maturity, Fair value, Less than 12 months 13,179 14,559
Held-to-maturity, Gross unrealized losses, 12 months or more 10 57
Held-to-maturity, Fair value, 12 months or more 2,792 1,799
Held-to-maturity, Gross unrealized losses, Total 311 828
Held-to-maturity, Fair value, Total 15,971 16,358
Gross unrealized losses, Less than 12 months 306 590
Fair value, Less than 12 months 16,693 15,409
Gross unrealized losses, 12 months or more 188 116
Fair value, 12 months or more 3,812 1,884
Gross unrealized losses, Total 494 706
Fair value, Total 20,505 17,293
Mortgage-backed securities of government agencies [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Held-to-maturity, Gross unrealized losses, Less than 12 months 474 879
Held-to-maturity, Fair value, Less than 12 months 19,775 20,149
Held-to-maturity, Gross unrealized losses, 12 months or more      
Held-to-maturity, Fair value, 12 months or more      
Held-to-maturity, Gross unrealized losses, Total 474 879
Held-to-maturity, Fair value, Total 19,775 20,149
Gross unrealized losses, Less than 12 months 291 691
Fair value, Less than 12 months 21,627 29,938
Gross unrealized losses, 12 months or more      
Fair value, 12 months or more      
Gross unrealized losses, Total 291 691
Fair value, Total 21,627 29,938
State and political subdivisions [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Gross unrealized losses, Less than 12 months 62 122
Fair value, Less than 12 months 2,197 3,522
Gross unrealized losses, 12 months or more 42 21
Fair value, 12 months or more 787 233
Gross unrealized losses, Total 104 143
Fair value, Total 2,984 3,755
Corporate bonds [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Gross unrealized losses, Less than 12 months 2 4
Fair value, Less than 12 months 573 1,163
Gross unrealized losses, 12 months or more    1
Fair value, 12 months or more    499
Gross unrealized losses, Total 2 5
Fair value, Total 573 1,662
Asset-backed securities of government agencies [Member]
    
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]    
Gross unrealized losses, Less than 12 months 7  
Fair value, Less than 12 months 1,706  
Gross unrealized losses, 12 months or more     
Fair value, 12 months or more     
Gross unrealized losses, Total 7  
Fair value, Total $ 1,706