SECURITIES, Securities Transferred and Securities Pledged (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($) Security	Dec. 31, 2020 USD ($) Security
SECURITIES [Abstract]
Holdings of securities of any one issuer, other than the U.S. government and its agencies, in an amount greater than 10% of stockholders' equity | Security	0	0
Carrying value of securities pledged to collateralize public deposits and for other purposes | $	$ 321.5	$ 292.2