LOANS AND RELATED ALLOWANCE FOR CREDIT LOSSES - Schedule of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Allowance for loan losses
Total loans	$ 9,039,686	$ 8,335,309
Allowance for credit losses on unfunded commitments	105,357	96,270	$ 106,094	$ 127,302
Net loans	8,934,329	8,239,039
Construction and commercial multifamily \| Construction
Allowance for loan losses
Total loans	640,371	319,452
Allowance for credit losses on unfunded commitments	2,885	1,227	3,206	5,111
Construction and commercial multifamily \| Commercial multifamily
Allowance for loan losses
Total loans	599,145	620,088
Allowance for credit losses on unfunded commitments	2,475	1,810	6,120	5,916
Commercial real estate loans \| Commercial real estate owner occupied
Allowance for loan losses
Total loans	628,646	640,489
Allowance for credit losses on unfunded commitments	9,443	10,739	12,752	12,380
Commercial real estate loans \| Commercial real estate non-owner occupied
Allowance for loan losses
Total loans	2,606,409	2,496,237
Allowance for credit losses on unfunded commitments	38,221	30,724	32,106	35,850
Commercial and industrial loans
Allowance for loan losses
Total loans	1,359,249	1,445,236
Allowance for credit losses on unfunded commitments	18,602	18,743	22,584	25,013
Residential real estate \| Residential real estate
Allowance for loan losses
Total loans	2,760,312	2,312,447
Allowance for credit losses on unfunded commitments	19,622	18,666	22,406	28,491
Consumer loans \| Home equity
Allowance for loan losses
Total loans	224,223	227,450
Allowance for credit losses on unfunded commitments	2,015	2,173	4,006	6,482
Consumer loans \| Consumer other
Allowance for loan losses
Total loans	221,331	273,910
Allowance for credit losses on unfunded commitments	$ 12,094	$ 12,188	$ 2,914	$ 8,059

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

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

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-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

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