Quarterly report pursuant to Section 13 or 15(d)

SECURITIES (Narrative) (Details)

v3.19.1
SECURITIES (Narrative) (Details)
 3 Months Ended 12 Months Ended
Mar. 31, 2019
USD ($)
security
Dec. 31, 2018
USD ($)
security
Schedule of Investments [Line Items]    
Available-for-sale securities that had been in a continuous loss position for more than 12 months, fair value $ 503,030,000 $ 385,433,000
Available-for-sale securities that had been in a continuous loss position for more than 12 months, unrealized loss $ 6,599,000 $ 10,184,000
Federal Home Loan Bank requires Bank to maintain percentage of stock equal to outstanding borrowings 4.25% 4.25%
Held-to-maturity, securities in unrealized loss positions, qualitative disclosure, number of positions (security) | security 0 0
Percentage of Federal Reserve Bank of Richmond reserve 6.00% 6.00%
Restricted equity securities consist of Federal Reserve Bank stock $ 61,800,000 $ 52,600,000
Federal Home Loan Bank stock 74,100,000 $ 72,000,000
Credit-related OTTI $ 0  
Available-for-sale Securities    
Schedule of Investments [Line Items]    
Number of available-for-sale securities that had been in a continuous loss position | security 187 138