OTHER INTANGIBLE ASSETS - Carrying Amount and Accumulated Amortization of Intangible Assets, Amortizable and Arose from Merger (Details) - USD ($) $ in Thousands	Feb. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Acquired intangible assets:
Gross carrying value		$ 10,984
Accumulated amortization		(1,907)
Net carrying amount		9,077	$ 0
Core deposits
Acquired intangible assets:
Gross Carrying Amount	$ 10,200
Gross carrying value		10,204
Accumulated amortization		(1,427)
Net carrying amount		8,777
Noncompete Agreements
Acquired intangible assets:
Gross Carrying Amount	$ 780
Gross carrying value		780
Accumulated amortization		(480)
Net carrying amount		$ 300