Quarterly report pursuant to Section 13 or 15(d)

BORROWINGS (Narrative) (Details)

v3.7.0.1
BORROWINGS (Narrative) (Details)
$ in Thousands
 3 Months Ended 12 Months Ended
Jan. 01, 2014
USD ($)
Aug. 23, 2012
USD ($)
Mar. 31, 2017
USD ($)
acquisition
Mar. 31, 2016
USD ($)
Dec. 31, 2016
USD ($)
Subordinated Borrowing [Line Items]          
Remaining available balance for the federal funds lines     $ 175,000   $ 175,000
Remaining available balance of alternate line of credit     25,000   25,000
Maximum collateral dependent line of credit with the FHLB     2,500,000   2,400,000
Subordinated debt     150,000   150,000
Prepayment penalty   $ 19,600      
Prepayment penalty amortization expense     470 $ 463  
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     $ 2,000   $ 2,000
Spread on LIBOR     5.00%    
Maturity Date         Dec. 15, 2026
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    
Remaining fair value premium on acquired FHLB advances     448    
StellarOne | Trust Preferred Capital Notes          
Subordinated Borrowing [Line Items]          
Trust preferred capital notes principal balance $ 32,000        
Remaining fair value discount on acquired notes     $ 6,700    
LIBOR | Subordinated Debt          
Subordinated Borrowing [Line Items]          
Spread on LIBOR     3.175%