Quarterly report pursuant to Section 13 or 15(d)

BORROWINGS (Narrative) (Details)

v3.8.0.1
BORROWINGS (Narrative) (Details)
$ in Thousands
 3 Months Ended 9 Months Ended
Jan. 01, 2014
USD ($)
Aug. 23, 2012
USD ($)
Sep. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2017
USD ($)
acquisition
Sep. 30, 2016
USD ($)
Subordinated Borrowing [Line Items]              
Remaining available balance for the federal funds lines     $ 185,000 $ 175,000   $ 185,000  
Remaining available balance of alternate line of credit     25,000 25,000   25,000  
Maximum collateral dependent line of credit with the FHLB     2,700,000 2,400,000   2,700,000  
Subordinated debt     150,000 150,000   150,000  
Prepayment penalty   $ 19,600          
Prepayment penalty amortization expense     486   $ 474 1,433 $ 1,404
Trust Preferred Capital Notes              
Subordinated Borrowing [Line Items]              
Trust preferred capital notes principal balance           90,500  
Subordinated Debt              
Subordinated Borrowing [Line Items]              
Remaining fair value discount on acquired notes     1,900 $ 1,800   $ 1,900  
Spread on LIBOR       5.00%      
Maturity Date           Dec. 15, 2026  
Subordinated Debt | LIBOR              
Subordinated Borrowing [Line Items]              
Spread on LIBOR           3.175%  
Acquisitions, Prior To 2006              
Subordinated Borrowing [Line Items]              
Number of bank acquisitions | acquisition           2  
Trust preferred capital notes principal balance           $ 58,500  
StellarOne              
Subordinated Borrowing [Line Items]              
Long-term FHLB borrowings $ 70,000   20,000     20,000  
Remaining fair value premium on acquired FHLB advances     223     223  
StellarOne | Trust Preferred Capital Notes              
Subordinated Borrowing [Line Items]              
Trust preferred capital notes principal balance $ 32,000            
Remaining fair value discount on acquired notes     $ 6,500     $ 6,500