Subsequent Events	3 Months Ended
Mar. 31, 2026
Subsequent Events [Abstract]
Subsequent Events	Note 14: SUBSEQUENT EVENT On April 30,2026, the Company entered into a definitive merger agreement to acquire Pacific Financial Corporation, the holding company for Bank of the Pacific, in an all stock transaction. Under the terms of the agreement, at the effective time of the merger, shareholders of Pacific Financial Corporation will receive 0.2633 shares of Banner Corporation common stock for each Pacific Financial Corporation common share they own. The transaction is expected to close in the third quarter of 2026 and is subject to closing conditions, including Pacific Financial shareholder and regulatory approvals. As the transaction has not closed as of the date these unaudited condensed consolidated financial statements were issued, the acquisition has not been reflected in the accompanying unaudited condensed consolidated financial statements.

Subsequent Events

3 Months Ended

Mar. 31, 2026

Note 14: SUBSEQUENT EVENT

On April 30,2026, the Company entered into a definitive merger agreement to acquire Pacific Financial Corporation, the holding company for Bank of the Pacific, in an all stock transaction. Under the terms of the agreement, at the effective time of the merger, shareholders of Pacific Financial Corporation will receive 0.2633 shares of Banner Corporation common stock for each Pacific Financial Corporation common share they own. The transaction is expected to close in the third quarter of 2026 and is subject to closing conditions, including Pacific Financial shareholder and regulatory approvals. As the transaction has not closed as of the date these unaudited condensed consolidated financial statements were issued, the acquisition has not been reflected in the accompanying unaudited condensed consolidated financial statements.