XML 74 R53.htm IDEA: XBRL DOCUMENT v3.6.0.2
Investment Securities - Additional Information (Detail)
12 Months Ended
Dec. 31, 2016
USD ($)
Security
Dec. 31, 2015
USD ($)
Security
Dec. 31, 2014
USD ($)
Schedule of Available-for-sale Securities [Line Items]      
Federal Reserve stock owned by Company | $ $ 507,000 $ 507,000  
Federal Home Loan Bank stock | $ 545,000 533,000  
Securities available for sale pledged as collateral on public deposits | $ $ 96,800,000 $ 68,800,000 $ 84,700,000
Corporate Bonds [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Number of available for sale securities related to unrealized losses less than twelve months 1    
Number of available for sale securities related to unrealized losses more than twelve months 1    
Number of securities related to unrealized losses 8 2  
Number of available for sale securities related to unrealized losses   3  
U.S. Treasury [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Number of available for sale securities related to unrealized losses less than twelve months 1    
Number of available for sale securities related to unrealized losses   1  
U.S. Government Agencies [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Number of available for sale securities related to unrealized losses less than twelve months 17    
Number of available for sale securities related to unrealized losses more than twelve months 6    
Number of securities related to unrealized losses 1 1  
Number of available for sale securities related to unrealized losses   11  
GSE - Mortgage-backed Securities and CMO's [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Number of available for sale securities related to unrealized losses less than twelve months 10    
Number of available for sale securities related to unrealized losses more than twelve months 4    
Number of available for sale securities related to unrealized losses   12  
Available for sale securities | $ $ 0    
State and Political Subdivisions [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Number of available for sale securities related to unrealized losses less than twelve months 7    
Number of securities related to unrealized losses 8 2  
Number of available for sale securities related to unrealized losses   1