Note 2 - Business Combinations - Consideration Paid and Fair Value of Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($)
$ in Thousands
Apr. 01, 2015
Jan. 01, 2015
Oct. 01, 2014
Dec. 31, 2016
Jun. 30, 2016
Dec. 31, 2015
Dec. 31, 2014
Goodwill       $ 104,765   $ 104,765 $ 35,781
Continental Bank Holdings, Inc. ("CBH") [Member]              
Value of consideration   $ 125,059          
Cash accounts   17,934          
Other assets   17,974          
Total assets   676,173          
Other liabilities   6,573          
Total liabilities   619,466          
Net assets acquired   56,707          
Goodwill   68,352          
Common shares issued (3,878,304)   121,391          
Cash in lieu of fractional shares   2          
Cash-out of certain warrants   1,323          
Fair value of options assumed   2,343          
Investment securities available for sale   181,838          
Loans*   424,737          
Premises and equipment   9,037          
Deferred income taxes   7,684          
Bank-owned life insurance   12,054          
Deposits   481,674          
FHLB and other long-term borrowings   19,726          
Short-term borrowings   108,609          
Unfavorable lease liability   2,884          
Continental Bank Holdings, Inc. ("CBH") [Member] | Core Deposits [Member]              
Intangible assets   4,191          
Continental Bank Holdings, Inc. ("CBH") [Member] | Off-Market Favorable Lease [Member]              
Intangible assets   724          
Powers Craft Parker and Beard (PCPB) [Member]              
Cash paid at closing     $ 5,399        
Contingent payment liability     1,083        
Value of consideration     7,024        
Cash accounts     1,274        
Other assets     850        
Total assets     8,341        
Deferred tax liability     2,437        
Other liabilities     1,818        
Total liabilities     4,255        
Net assets acquired     4,086        
Goodwill     2,938        
Investment securities available for sale     302        
Premises and equipment     100        
Label 2     542        
Powers Craft Parker and Beard (PCPB) [Member] | Trade Names [Member]              
Intangible assets     955        
Powers Craft Parker and Beard (PCPB) [Member] | Customer Relationships [Member]              
Intangible assets     3,280        
Powers Craft Parker and Beard (PCPB) [Member] | Noncompete Agreements [Member]              
Intangible assets     $ 1,580        
Robert J. McAllister Agency, Inc. ("RJM") [Member]              
Cash paid at closing $ 500            
Contingent payment liability 500            
Value of consideration 1,000            
Cash accounts 20            
Other assets 4            
Total assets 705            
Deferred tax liability 291            
Other liabilities 46            
Total liabilities 337            
Net assets acquired 368            
Goodwill 632            
Label 2         $ 100    
Robert J. McAllister Agency, Inc. ("RJM") [Member] | Trade Names [Member]              
Intangible assets            
Robert J. McAllister Agency, Inc. ("RJM") [Member] | Customer Relationships [Member]              
Intangible assets 424            
Robert J. McAllister Agency, Inc. ("RJM") [Member] | Noncompete Agreements [Member]              
Intangible assets 257            
Scenario, Previously Reported [Member] | Continental Bank Holdings, Inc. ("CBH") [Member]              
Value of consideration   125,059          
Cash accounts   17,934          
Other assets   18,085          
Total assets   676,820          
Other liabilities   4,706          
Total liabilities   617,599          
Net assets acquired   59,221          
Goodwill   65,838          
Common shares issued (3,878,304)   121,391          
Cash in lieu of fractional shares   2          
Cash-out of certain warrants   1,323          
Fair value of options assumed   2,343          
Investment securities available for sale   181,838          
Loans* [1]   426,601          
Premises and equipment   9,037          
Deferred income taxes   6,288          
Bank-owned life insurance   12,054          
Deposits   481,674          
FHLB and other long-term borrowings   19,726          
Short-term borrowings   108,609          
Unfavorable lease liability   2,884          
Scenario, Previously Reported [Member] | Continental Bank Holdings, Inc. ("CBH") [Member] | Core Deposits [Member]              
Intangible assets   4,191          
Scenario, Previously Reported [Member] | Continental Bank Holdings, Inc. ("CBH") [Member] | Off-Market Favorable Lease [Member]              
Intangible assets   792          
Scenario, Previously Reported [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member]              
Cash paid at closing 500            
Contingent payment liability 500            
Value of consideration 1,000            
Cash accounts 20            
Other assets 4            
Total assets 834            
Deferred tax liability 336            
Other liabilities 46            
Total liabilities 382            
Net assets acquired 452            
Goodwill 548            
Scenario, Previously Reported [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Trade Names [Member]              
Intangible assets 129            
Scenario, Previously Reported [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Customer Relationships [Member]              
Intangible assets 424            
Scenario, Previously Reported [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Noncompete Agreements [Member]              
Intangible assets 257            
Restatement Adjustment [Member] | Continental Bank Holdings, Inc. ("CBH") [Member]              
Value of consideration            
Cash accounts            
Other assets   (111)          
Total assets   (647)          
Other liabilities   1,867          
Total liabilities   1,867          
Net assets acquired   (2,514)          
Goodwill   2,514          
Common shares issued (3,878,304)            
Cash in lieu of fractional shares            
Cash-out of certain warrants            
Fair value of options assumed            
Investment securities available for sale            
Loans* [1]   (1,864)          
Premises and equipment            
Deferred income taxes   1,396          
Bank-owned life insurance            
Deposits            
FHLB and other long-term borrowings            
Short-term borrowings            
Unfavorable lease liability            
Restatement Adjustment [Member] | Continental Bank Holdings, Inc. ("CBH") [Member] | Core Deposits [Member]              
Intangible assets            
Restatement Adjustment [Member] | Continental Bank Holdings, Inc. ("CBH") [Member] | Off-Market Favorable Lease [Member]              
Intangible assets   $ (68)          
Restatement Adjustment [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member]              
Cash paid at closing            
Contingent payment liability            
Value of consideration            
Cash accounts            
Other assets            
Total assets (129)            
Deferred tax liability (45)            
Other liabilities            
Total liabilities (45)            
Net assets acquired (84)            
Goodwill 84            
Restatement Adjustment [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Trade Names [Member]              
Intangible assets (129)            
Restatement Adjustment [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Customer Relationships [Member]              
Intangible assets            
Restatement Adjustment [Member] | Robert J. McAllister Agency, Inc. ("RJM") [Member] | Noncompete Agreements [Member]              
Intangible assets            
[1] includes $507 thousand of loans held for sale