Note 2 - Business Combinations (Details Textual)
$ in Thousands
 3 Months Ended 9 Months Ended 11 Months Ended 12 Months Ended
Apr. 01, 2015
USD ($)
Jan. 01, 2015
USD ($)
shares
Oct. 01, 2014
USD ($)
Dec. 31, 2016
USD ($)
Jun. 30, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2016
USD ($)
Dec. 13, 2016
USD ($)
Dec. 13, 2015
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Noninterest Income, Other Operating Income               $ 4,868 $ 4,849 $ 4,868 $ 4,849 $ 3,083
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group       $ 9,621   $ 8,987 $ 9,621     9,621 8,987  
Robert J. McAllister Agency, Inc. ("RJM") [Member]                        
Business Combination, Consideration Transferred $ 1,000                      
Payments to Acquire Businesses, Gross $ 500                      
Business Combination, Payment of Contingent Consideration Installment         $ 85              
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High, Each Installment         $ 100              
Business Combination, Number of Remaining Contingent Consideration Installments             4          
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High, Each Remaining Installment       100     $ 100     100    
Noninterest Income, Other Operating Income       15                
Continental Bank Holdings, Inc. ("CBH") [Member]                        
Business Combination, Consideration Transferred   $ 125,059                    
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares including Fractional Shares | shares   3,878,383                    
Business Combination Stock Consideration Conversion Ratio of Shares in Acquirer   0.45                    
Business Combination, Consideration Transferred, Equity Interest Cash Out of Certain Warrants   $ 1,323                    
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group   $ 507                    
Conversion of Stock, Shares Converted | shares   8,618,629                    
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares   3,878,383                    
Business Acquisition, Equity Interest, Number of Fractional Shares Paid in Cash | shares   79                    
Powers Craft Parker and Beard (PCPB) [Member]                        
Business Combination, Consideration Transferred     $ 7,024                  
Payments to Acquire Businesses, Gross     5,399                  
Business Combination, Payment of Contingent Consideration Installment       $ 542   $ 542            
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High, Each Installment     $ 542                  
Business Combination, Number of Remaining Contingent Consideration Installments       1   2            
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High, Each Remaining Installment       $ 542   $ 542 542     542 542  
Business Combination, Number of Consideration Installments     3                  
Business Combination, Remaining Contingent Consideration Installment       $ 542   $ 1,100 $ 542     $ 542 $ 1,100