Annual report pursuant to Section 13 and 15(d)

INTANGIBLE ASSETS (Narrative) (Details)

v3.6.0.2
INTANGIBLE ASSETS (Narrative) (Details) - USD ($)
 3 Months Ended 12 Months Ended
Jun. 30, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
May 31, 2016
Jan. 01, 2014
Finite-Lived Intangible Assets [Line Items]            
Goodwill   $ 298,191,000 $ 293,522,000      
Impairment charges $ 0          
Intangible assets, amortization expense   7,210,000 8,445,000 $ 9,795,000    
Core Deposits            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization expense   $ 6,900,000 8,400,000 9,800,000    
Core Deposits | Minimum            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period   4 years        
Core Deposits | Maximum            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period   14 years        
Other Intangible Assets            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization expense   $ 280,000 $ 0 $ 0    
StellarOne Bank            
Finite-Lived Intangible Assets [Line Items]            
Acquired intangible assets           $ 29,600,000
Goodwill           $ 234,100,000
ODCM            
Finite-Lived Intangible Assets [Line Items]            
Goodwill         $ 4,700,000  
Business combination, finite-lived intangibles         $ 4,500,000  
ODCM | Minimum            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period   5 years        
ODCM | Maximum            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period   10 years