Business Combinations (Details Textual) - USD ($)
 3 Months Ended 12 Months Ended
Sep. 30, 2015
Jun. 19, 2015
Jul. 01, 2013
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Business Acquisition [Line Items]                    
Goodwill       $ 35,090,000       $ 35,090,000 $ 5,591,000  
Gross contractual amount receivable       429,700,000       429,700,000    
Business acquisition transaction expenses       1,736,000 $ 2,499,000 $ 1,912,000 $ 245,000 6,392,000 0 $ 330,000
Intangible assets at carrying value       7,821,000       7,821,000 3,222,000  
Core Deposits                    
Business Acquisition [Line Items]                    
Intangible assets at carrying value       5,600,000       $ 5,600,000    
Tri-State 1st Banc Incorporation                    
Business Acquisition [Line Items]                    
Shares of stock issued for acquisition 1,296,517                  
Fair value of total consideration transferred $ 14,340,000                  
Shares shareholders are entitled to elect to receive per shares 174.70%                  
Cash shareholders are entitled to elect to receive per share $ 14.20       $ 14.20          
Business Acquisition Shares Being Exchanged for Stock 75.00%                  
Business Acquisition Shares Being Exchanged for Cash 25.00%                  
Business Acquisition, Effective Date of Acquisition               Oct. 01, 2015    
Goodwill $ 2,818,000       $ 2,818,000          
Fair value of other intangible assets 1,173,000       1,173,000          
Tri-State 1st Banc Incorporation | Core Deposits                    
Business Acquisition [Line Items]                    
Fair value of other intangible assets $ 1,200,000       $ 1,200,000          
Tri-State 1st Banc Incorporation | Series A Preferred Stock                    
Business Acquisition [Line Items]                    
Cash shareholders are entitled to elect to receive per share $ 13.60       $ 13.60          
National Bancshares Corporation                    
Business Acquisition [Line Items]                    
Shares of stock issued for acquisition   7,262,955                
Fair value of total consideration transferred   $ 74,780,000                
Shares shareholders are entitled to elect to receive per shares   403.40%                
Cash shareholders are entitled to elect to receive per share   $ 32.15                
Business Acquisition, Effective Date of Acquisition               Jun. 19, 2015    
Goodwill   $ 26,681,000                
Fair value of other intangible assets   $ 4,409,000                
Maximum shares exchanged for stock   80.00%                
Maximum shares exchanged for cash   20.00%                
National Bancshares Corporation | Core Deposits                    
Business Acquisition [Line Items]                    
Fair value of other intangible assets   $ 4,400,000                
National Associates Incorporated                    
Business Acquisition [Line Items]                    
Fair value of total consideration transferred     $ 4,400,000              
Business Acquisition, Effective Date of Acquisition               Jul. 01, 2013    
Goodwill     2,600,000              
Fair value of other intangible assets       2,300,000       $ 2,300,000    
Contingent future payments       1,500,000       1,500,000    
Contingent consideration initial fair value     $ 920,000           156,000  
Business acquisition transaction expenses               1,300,000    
Business acquisition final payment               1,500,000    
After impairment of goodwill               1,900,000 $ 1,900,000  
Intangible assets at carrying value       $ 1,300,000       $ 1,300,000