OTHER BORROWINGS (Textuals) (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Funds Borrowed Against Current Borrowing Capacity	$ 125,257,000	$ 182,877,000
Debt Securities Pledged as Collateral for Repurchase Transaction Accounts, Amortized Costs	215,600,000
Repurchase Agreements [Member] \| Retail repurchase agreements [Member]
Debt Instrument [Line Items]
Funds Borrowed Against Current Borrowing Capacity	$ 125,257,000	182,877,000
Repurchase Agreements [Member] \| Retail repurchase agreements [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Repurchase agreements, interest rate	0.05%
Repurchase Agreements [Member] \| Retail repurchase agreements [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Repurchase agreements, interest rate	3.94%
Federal Reserve Bank Advances [Member] \| Federal Reserve Bank of San Francisco [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 1,520,000,000
Funds Borrowed Against Current Borrowing Capacity	0	0
Subsidiary, Banner Bank [Member] \| Repurchase Agreements [Member]
Debt Instrument [Line Items]
Line of credit, current	0
Subsidiary, Banner Bank [Member] \| Federal Funds Purchased [Member]
Debt Instrument [Line Items]
Line of credit, current	$ 0	$ 0

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