LOANS AND CREDIT QUALITY - Activity in Allowance for Credit Losses by Loan Portfolio (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Allowance for credit losses by loan portfolio
Beginning balance	$ 41,500	$ 47,123
Charge-offs	(683)	(44)
Recoveries	94	88
Provision	589	(9,223)
Ending balance	41,500	37,944
Commercial loans \| Real Estate Sector
Allowance for credit losses by loan portfolio
Beginning balance	27,859	21,486
Charge-offs	0	0
Recoveries	0	0
Provision	(179)	(1,400)
Ending balance	27,680	20,086
Commercial loans \| Commercial and Industrial Sector
Allowance for credit losses by loan portfolio
Beginning balance	4,277	17,279
Charge-offs	(633)	(11)
Recoveries	24	24
Provision	658	(6,846)
Ending balance	4,326	10,446
Commercial loans \| Non-owner occupied CRE
Allowance for credit losses by loan portfolio
Beginning balance	2,102	7,509
Charge-offs	0	0
Recoveries	0	0
Provision	506	(5,215)
Ending balance	2,608	2,294
Commercial loans \| Multifamily
Allowance for credit losses by loan portfolio
Beginning balance	10,974	5,854
Charge-offs	0	0
Recoveries	0	0
Provision	(1,187)	2,573
Ending balance	9,787	8,427
Commercial loans \| Multifamily construction
Allowance for credit losses by loan portfolio
Beginning balance	998	507
Charge-offs	0	0
Recoveries	0	0
Provision	347	(51)
Ending balance	1,345	456
Commercial loans \| CRE construction
Allowance for credit losses by loan portfolio
Beginning balance	196	150
Charge-offs	0	0
Recoveries	0	0
Provision	8	34
Ending balance	204	184
Commercial loans \| Single family construction
Allowance for credit losses by loan portfolio
Beginning balance	12,418	6,411
Charge-offs	0	0
Recoveries	0	0
Provision	107	1,324
Ending balance	12,525	7,735
Commercial loans \| Single family construction to permanent
Allowance for credit losses by loan portfolio
Beginning balance	1,171	1,055
Charge-offs	0	0
Recoveries	0	0
Provision	40	(65)
Ending balance	1,211	990
Commercial loans \| Owner occupied CRE
Allowance for credit losses by loan portfolio
Beginning balance	1,030	5,006
Charge-offs	0	0
Recoveries	0	0
Provision	(120)	(1,470)
Ending balance	910	3,536
Commercial loans \| Commercial business
Allowance for credit losses by loan portfolio
Beginning balance	3,247	12,273
Charge-offs	(633)	(11)
Recoveries	24	24
Provision	778	(5,376)
Ending balance	3,416	6,910
Consumer loans
Allowance for credit losses by loan portfolio
Beginning balance	9,364	8,358
Charge-offs	(50)	(33)
Recoveries	70	64
Provision	110	(977)
Ending balance	9,494	7,412
Consumer loans \| Single family
Allowance for credit losses by loan portfolio
Beginning balance	5,610	4,394
Charge-offs	0	0
Recoveries	15	4
Provision	179	(636)
Ending balance	5,804	3,762
Consumer loans \| Home equity and other
Allowance for credit losses by loan portfolio
Beginning balance	3,754	3,964
Charge-offs	(50)	(33)
Recoveries	55	60
Provision	(69)	(341)
Ending balance	$ 3,690	$ 3,650

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

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