Annual report pursuant to Section 13 and 15(d)

Note 1 - Summary of Significant Accounting Policies (Details Textual)

v3.19.3.a.u2
Note 1 - Summary of Significant Accounting Policies (Details Textual)
12 Months Ended
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Jan. 01, 2019
USD ($)
Number of Reporting Units 1      
Unrecognized Tax Benefits Threshold Percentage 50.00%      
Advertising Expense $ 581,000 $ 557,000 $ 716,000  
Accounting Standards Update 2016-02 [Member]        
Operating Lease, Right-of-Use Asset       $ 15,300,000
Operating Lease, Liability, Total       $ 15,300,000
Metro Bancshares, Inc [Member]        
Finite-Lived Intangible Assets, Remaining Amortization Period 7 years      
Goodwill, Ending Balance $ 13,600,000      
Minimum [Member]        
Property, Plant and Equipment, Useful Life 3 years      
Lessee, Operating Lease, Renewal Term 1 year      
Decrease in Allowance for Loan Losses, Percent 1.00%      
Maximum [Member]        
Property, Plant and Equipment, Useful Life 39 years 6 months      
Lessee, Operating Lease, Renewal Term 5 years      
Decrease in Allowance for Loan Losses, Percent 5.00%      
Federal Reserve Bank [Member]        
Cash Reserve Deposit Required and Made $ 33,900,000 $ 51,000,000.0