Annual report pursuant to Section 13 and 15(d)

SECURITIES (Narrative) (Details)

v3.10.0.1
SECURITIES (Narrative) (Details)
 3 Months Ended 12 Months Ended
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
security
Dec. 31, 2017
USD ($)
security
Schedule of Investments [Line Items]      
Available for sale securities that had been in a continuous loss position for more than 12 months, amount   $ 385,433,000 $ 197,640,000
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss   10,184,000 4,188,000
Held to maturity securities unrealized gains before tax   $ 119,000 3,600,000
Held-to-maturity securities in a continuous loss position for longer than 12 months, fair value     $ 1,084,000
Held-to-maturity securities in a continuous loss position for longer than 12 months, number of securities | security   0 2
Held to maturity securities in a continuous loss position, more than 12 months, accumulated loss     $ 31,000
Federal Home Loan Bank requires Bank to maintain percentage of stock equal to outstanding borrowings   4.25% 4.25%
Percentage of Federal Reserve Bank of Richmond reserve   6.00% 6.00%
Restricted equity securities consist of Federal Reserve Bank stock   $ 52,600,000 $ 27,600,000
Federal Home Loan Bank Stock   72,000,000 $ 47,700,000
Credit-related OTTI   $ 0  
Available-for-sale Securities      
Schedule of Investments [Line Items]      
Available for sale securities that had been in a continuous loss position | security   138 71
Accounting Standards Update 2017-12      
Schedule of Investments [Line Items]      
Available for sale debt securities, transfer, amount $ 187,400,000 $ 187,400,000