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 6 Months Ended
May 31, 2016
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Jan. 01, 2014
Finite-Lived Intangible Assets [Line Items]              
Goodwill   $ 297,659,000   $ 297,659,000   $ 293,522,000  
Impairment charges   0          
Intangible assets, amortization expense   $ 1,745,000 $ 2,138,000 $ 3,625,000 $ 4,361,000    
StellarOne [Member]              
Finite-Lived Intangible Assets [Line Items]              
Acquired intangible assets             $ 29,600,000
Goodwill             $ 234,100,000
ODCM [Member]              
Finite-Lived Intangible Assets [Line Items]              
Goodwill $ 4,100,000            
Amortizable intangible assets $ 3,800,000            
Acquired amortizable assets, useful life 10 years            
Core Deposits [Member] | Minimum [Member]              
Finite-Lived Intangible Assets [Line Items]              
Intangible assets, amortization period       4 years      
Core Deposits [Member] | Maximum [Member]              
Finite-Lived Intangible Assets [Line Items]              
Intangible assets, amortization period       14 years