SECURITIES - Amortized cost and Fair values of held-to-maturity securities transferred from available-for-sale securities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Held-to-maturity
Fair Value	$ 481,925	$ 478,801
U.S. government agency
Held-to-maturity
Fair Value	80,173	78,696
Mortgage-backed: Agency residential
Held-to-maturity
Fair Value	95,225	96,258
Mortgage-backed: Agency commercial
Held-to-maturity
Fair Value	$ 265,108	$ 261,799
Debt Securities Transferred
Held-to-maturity
Debt securities held-to-maturity			$ 114,850
Fair Value			104,131
Debt Securities Transferred | U.S. government agency
Held-to-maturity
Debt securities held-to-maturity			78,841
Fair Value			71,048
Debt Securities Transferred | Mortgage-backed: Agency residential
Held-to-maturity
Debt securities held-to-maturity			8,175
Fair Value			7,651
Debt Securities Transferred | Mortgage-backed: Agency commercial
Held-to-maturity
Debt securities held-to-maturity			27,834
Fair Value			$ 25,432