| 
           STOCK-BASED COMPENSATION (Tables)
  
         | 
        9 Months Ended | 
      
      
        | 
           Sep. 30, 2014 
         | 
      
      
        | STOCK-BASED COMPENSATION [Abstract] | 
         
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        | Summary of Shares Available in Each Plan | 
        
 
		
			The following table summarizes the shares available in the 2011 Plan as of September 30, 2014:  
		 
		
			 
		 
		
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						2011 Plan 
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						Beginning Authorization 
				 | 
				
1,000,000 
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						Granted 
				 | 
				
(516,727)
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						Expired, forfeited, or cancelled 
				 | 
				
50,260 
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						Remaining available for grant 
				 | 
				
533,533 
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
		  
		
			 
		 
		  
	   
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        | Summary of Stock Option Activity | 
        
 
		
			The following table summarizes the stock option activity for the nine months ended September 30, 2014:
		 
		
			 
		 
		
			 
		 
		
			 
		 
		
			 
		 
		
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						Number of Stock Options 
				 | 
				
					 
						  
				 | 
				
					 
						Weighted Average Exercise Price 
				 | 
			 
			
				| 
					 
						Options outstanding, December 31, 2013 
				 | 
				
402,946 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
16.48 
				 | 
			 
			
				| 
					 
						Options converted upon StellarOne acquisition 
				 | 
				
124,217 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
20.88 
				 | 
			 
			
				| 
					 
						Exercised 
				 | 
				
(67,057)
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
16.89 
				 | 
			 
			
				| 
					 
						Expired 
				 | 
				
(60,579)
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
22.91 
				 | 
			 
			
				| 
					 
						Options outstanding, September 30, 2014 
				 | 
				
399,527 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
16.81 
				 | 
			 
			
				| 
					 
						Options exercisable, September 30, 2014 
				 | 
				
273,971 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
18.16 
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
		  
		
			 
		 
		  
	   
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        | Summary of Information Concerning Stock Options | 
        
 
		
			The following table summarizes information concerning stock options issued to the Company’s employees that are vested or are expected to vest and stock options exercisable as of September 30, 2014:
		 
		
			 
		 
		
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						Stock Options Vested or Expected to Vest 
				 | 
				
					 
						  
				 | 
				
					 
						Exercisable 
				 | 
			 
			
				| 
					 
						Stock options (number of shares) 
				 | 
				
					 
						  
				 | 
				
398,809 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
273,971 
				 | 
			 
			
				| 
					 
						Weighted average remaining contractual life in years 
				 | 
				
					 
						  
				 | 
				
5.22 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
4.48 
				 | 
			 
			
				| 
					 
						Weighted average exercise price on shares above water 
				 | 
				
					 
						$ 
				 | 
				
14.38 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
14.68 
				 | 
			 
			
				| 
					 
						Aggregate intrinsic value 
				 | 
				
					 
						$ 
				 | 
				
2,815,845 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
1,670,373 
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
		  
		
			 
		 
		  
	   
 | 
      
      
        | Summary of Nonvested Stock Activity | 
        
 
		
			The following table summarizes the restricted stock activity for the nine months ended September 30, 2014:
		 
		
			 
		 
		
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						Number of Shares of Restricted Stock 
				 | 
				
					 
						  
				 | 
				
					 
						Weighted Average Grant-Date Fair Value 
				 | 
			 
			
				| 
					 
						Balance, December 31, 2013 
				 | 
				
260,763 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
16.47 
				 | 
			 
			
				| 
					 
						Granted 
				 | 
				
134,431 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
24.29 
				 | 
			 
			
				| 
					 
						Net settle for taxes  
				 | 
				
(63,916)
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
24.83 
				 | 
			 
			
				| 
					 
						Vested 
				 | 
				
(14,707)
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
14.64 
				 | 
			 
			
				| 
					 
						Forfeited 
				 | 
				
(25,377)
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
20.94 
				 | 
			 
			
				| 
					 
						Balance, September 30, 2014 
				 | 
				
291,194 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
20.04 
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
		  
		
			 
		 
		  
	   
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        | Estimated Unamortized Compensation Expense Recognized in Future | 
        
 
		
			The estimated unamortized compensation expense, net of estimated forfeitures, related to nonvested stock and stock options issued and outstanding as of September 30, 2014 that will be recognized in future periods is as follows (dollars in thousands): 
		 
		
			 
		 
		
			 
		 
		
			 
		 
		
			 
		 
		
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						Stock Options 
				 | 
				
					 
						  
				 | 
				
					 
						Restricted Stock 
				 | 
				
					 
						  
				 | 
				
					 
						Total 
				 | 
			 
			
				| 
					 
						For the remaining three months of 2014 
				 | 
				
					 
						$ 
				 | 
				
79 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
480 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
559 
				 | 
			 
			
				| 
					 
						For year ending December 31, 2015 
				 | 
				
					 
						  
				 | 
				
233 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
1,469 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
1,702 
				 | 
			 
			
				| 
					 
						For year ending December 31, 2016 
				 | 
				
					 
						  
				 | 
				
130 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
1,155 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
1,285 
				 | 
			 
			
				| 
					 
						For year ending December 31, 2017 
				 | 
				
					 
						  
				 | 
				
15 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
443 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
458 
				 | 
			 
			
				| 
					 
						For year ending December 31, 2018 
				 | 
				
					 
						  
				 | 
				
					 
						  - 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
56 
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
56 
				 | 
			 
			
				| 
					 
						Total 
				 | 
				
					 
						$ 
				 | 
				
457 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
3,603 
				 | 
				
					 
						  
				 | 
				
					 
						$ 
				 | 
				
4,060 
				 | 
			 
			
				| 
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
				 | 
				
					 
						  
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