FAIR VALUE - Securities Available for Sale Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
States and Political Subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		$ 64
Purchases		0
Total gains or (losses):
Included in other comprehensive income (loss)		0
Settlements		(64)
Transfers into Level 3		0
Transfers out of Level 3		0
Ending Balance	$ 0	0
Corporate Notes and Bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9,826	0
Purchases	0	8,250
Total gains or (losses):
Included in other comprehensive income (loss)	(76)	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(9,750)	(8,250)
Ending Balance	$ 0	$ 0