GOODWILL AND INTANGIBLE ASSETS - Estimated annual amortization expense of core deposit intangibles (Details) (Estimated annual amortization expense of core deposit intangibles, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Estimated annual amortization expense of core deposit intangibles
Core deposit intangibles amortization	$ 24	$ 78	$ 130	$ 180	$ 234	$ 288	$ 342	$ 461	$ 601	$ 652