Quarterly report pursuant to Section 13 or 15(d)

INTANGIBLE ASSETS (Narrative) (Details)

v3.5.0.2
INTANGIBLE ASSETS (Narrative) (Details) - USD ($)
 3 Months Ended 9 Months Ended
May 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Jan. 01, 2014
Finite-Lived Intangible Assets [Line Items]                
Goodwill   $ 298,191,000     $ 298,191,000   $ 293,522,000  
Impairment charges     $ 0          
Intangible assets, amortization expense   1,843,000   $ 2,074,000 5,468,000 $ 6,435,000    
StellarOne                
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              
Amortizable intangible assets $ 4,500,000              
Minimum | ODCM                
Finite-Lived Intangible Assets [Line Items]                
Intangible assets, amortization period 5 years              
Maximum | ODCM                
Finite-Lived Intangible Assets [Line Items]                
Intangible assets, amortization period 10 years              
Core Deposits                
Finite-Lived Intangible Assets [Line Items]                
Intangible assets, amortization expense   1,700,000   $ 2,100,000 $ 5,300,000 $ 6,400,000    
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   $ 160,000     $ 160,000