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LOANS AND ALLOWANCE FOR CREDIT LOSSES - Summary of Impaired Loans, Excluding Purchased Impaired (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Impaired loans
Average carrying balance of individually assessed loans	$ 20,400	$ 30,800	$ 43,100	$ 31,100
Commercial Portfolio Segment
Impaired loans
Loans with allowance allocation, Carrying Balance	4,411		4,411		$ 22,143
Loans with allowance allocation, Contractual Balance	4,544		4,544		22,338
Loans with allowance allocation, Specifically Allocated Allowance	2,192		2,192		3,628
Loans without allowance allocation, Carrying Balance	14,966		14,966		16,818
Loans without allowance allocation, Contractual Balance	18,607		18,607		18,638
Loans without allowance allocation, Specifically Allocated Allowance	0		0		0
CRE - multifamily | Commercial Portfolio Segment
Impaired loans
Loans with allowance allocation, Carrying Balance	0		0		12,068
Loans with allowance allocation, Contractual Balance	0		0		12,068
Loans with allowance allocation, Specifically Allocated Allowance	0		0		2,764
CRE - owner occupied | Commercial Portfolio Segment
Impaired loans
Loans without allowance allocation, Carrying Balance	6,090		6,090		7,554
Loans without allowance allocation, Contractual Balance	6,771		6,771		8,360
Loans without allowance allocation, Specifically Allocated Allowance	0		0		0
CRE - non-owner occupied | Commercial Portfolio Segment
Impaired loans
Loans with allowance allocation, Carrying Balance	0		0		10,075
Loans with allowance allocation, Contractual Balance	0		0		10,270
Loans with allowance allocation, Specifically Allocated Allowance	0		0		864
Loans without allowance allocation, Carrying Balance	1,335		1,335		1,592
Loans without allowance allocation, Contractual Balance	2,389		2,389		2,606
Loans without allowance allocation, Specifically Allocated Allowance	0		0		0
Commercial & industrial and other business loans | Commercial Portfolio Segment
Impaired loans
Loans with allowance allocation, Carrying Balance	4,411		4,411		0
Loans with allowance allocation, Contractual Balance	4,544		4,544		0
Loans with allowance allocation, Specifically Allocated Allowance	2,192		2,192		0
Loans without allowance allocation, Carrying Balance	7,541		7,541		7,672
Loans without allowance allocation, Contractual Balance	9,447		9,447		7,672
Loans without allowance allocation, Specifically Allocated Allowance	$ 0		$ 0		$ 0

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