Quarterly report pursuant to Section 13 or 15(d)

SECURITIES (Narrative) (Details)

v3.20.2
SECURITIES (Narrative) (Details)
9 Months Ended 12 Months Ended
Sep. 30, 2020
USD ($)
security
Dec. 31, 2019
USD ($)
security
Schedule of Investments [Line Items]    
Available for sale securities that had been in a continuous loss position for more than 12 months $ 27,800,000 $ 75,000,000.0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss 314,000 696,000
AFS securities in an unrealized loss, credit related impairment 0 $ 0
Available for sale securities, allowance for credit losses 0  
Available for sale securities past due or non-accrual 0  
HTM securities, additional reserve for allowance for credit losses 0  
Held to maturity securities, past due $ 0  
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 $ 67,000,000.0 $ 67,000,000.0
Federal Home Loan Bank Stock $ 45,200,000 $ 63,900,000
Available-for-sale Securities    
Schedule of Investments [Line Items]    
Available for sale securities that had been in a continuous loss position for more than 12 months, Number of issues | security 18 47
Non-agency collateralized mortgage obligations    
Schedule of Investments [Line Items]    
SSFA rating percentage 20.00%