XML 63 R46.htm IDEA: XBRL DOCUMENT v3.10.0.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 1 Months Ended 12 Months Ended
Jan. 01, 2018
USD ($)
Sep. 20, 2017
Mar. 31, 2017
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Period for federal funds purchased and sold       1 day  
Average aggregate reserve       $ 12,600,000 $ 11,400,000
Loan non-accrual classification period       90 days  
Days to charged consumer loans to the value of the collateral       90 days  
Maximum time for re-evaluation (in months)       12 months  
Re-evaluation period for real estate       2 years  
Amount of fair value of capital over carrying value       $ 58,500,000  
Percentage of fair value of capital over carrying value       51.10%  
Number of times fair value of capital in excess of carrying value of goowill description       over fourteen times  
Other real estate owned       $ 600,000 $ 674,000
Percentage of likelihood of realization of recognized tax benefit, minimum       50.00%  
Share stock split ratio   2      
Amount of reclassification effect       $ 0  
Corporate income tax rate       21.00%  
ASU 2018-02 [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Net effect on total stockholder's equity due to reclassification of tax effects $ 0        
Reclassification of tax effects from AOCI due to adoption of new Tax Cuts and Job Acts $ 359,000        
ASU 2016-02 [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Expected right of use assets       $ 500,000  
Expected liability related to lease       $ 500,000  
Accounting Standards Update 2017-08 [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Accelerated amortization expense adjustment     $ 30,000    
Maximum [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Maturity period of cash equivalents       3 months