Note 11 - Merger	6 Months Ended
Jun. 30, 2021
Notes to Financial Statements
Business Combination Disclosure [Text Block]	*NOTE 11.* MERGER Pending Merger with Columbia Banking System, Inc.** As announced by the Company on June 23, 2021 and reported in the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on June 24, 2021 (the “Current Report”), the Company has entered into an Agreement and Plan of Merger dated June 23, 2021 (the “Merger Agreement”), pursuant to which, subject to the satisfaction or waiver of certain conditions set forth in the Merger Agreement, the Company will merge with and into Columbia (the “Merger”), with Columbia as the surviving entity. Subject to the terms and conditions of the Merger Agreement, at the date and time when the Merger becomes effective (the “Effective Time”), the Bank of Commerce shareholders will have the right to receive, in respect of each share of common stock of Bank of Commerce (“Bank of Commerce Common Stock”), a number of common shares of Columbia (“Columbia Common Stock”) equal to the Exchange Ratio (as defined below), subject to adjustments as set forth in the Merger Agreement (the “Merger Consideration”). “Exchange Ratio” means 0.40 of a share of Columbia Common Stock per each share of Bank of Commerce Common Stock subject to certain potential adjustments. Based on Columbia’s closing stock price on June 23, 2021, the aggregate merger consideration is valued at $266.0 million, which includes $265.6 million of Columbia common stock to be issued to Bank of Commerce shareholders and $400 thousand of cash to be paid to option holders. The value of the merger consideration will fluctuate until closing based on the value of Columbia’s stock. The transaction is expected to close in the fourth quarter of 2021, and its completion is contingent upon approval from BOCH’s shareholders, the receipt of other customary regulatory approvals, and other customary closing conditions.

Note 11 - Merger

6 Months Ended

Jun. 30, 2021

Business Combination Disclosure [Text Block]

NOTE 11. MERGER

Pending Merger with Columbia Banking System, Inc.

As announced by the Company on June 23, 2021 and reported in the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on June 24, 2021 (the “Current Report”), the Company has entered into an Agreement and Plan of Merger dated June 23, 2021 (the “Merger Agreement”), pursuant to which, subject to the satisfaction or waiver of certain conditions set forth in the Merger Agreement, the Company will merge with and into Columbia (the “Merger”), with Columbia as the surviving entity.

Subject to the terms and conditions of the Merger Agreement, at the date and time when the Merger becomes effective (the “Effective Time”), the Bank of Commerce shareholders will have the right to receive, in respect of each share of common stock of Bank of Commerce (“Bank of Commerce Common Stock”), a number of common shares of Columbia (“Columbia Common Stock”) equal to the Exchange Ratio (as defined below), subject to adjustments as set forth in the Merger Agreement (the “Merger Consideration”). “Exchange Ratio” means 0.40 of a share of Columbia Common Stock per each share of Bank of Commerce Common Stock subject to certain potential adjustments. Based on Columbia’s closing stock price on June 23, 2021, the aggregate merger consideration is valued at $266.0 million, which includes $265.6 million of Columbia common stock to be issued to Bank of Commerce shareholders and $400 thousand of cash to be paid to option holders. The value of the merger consideration will fluctuate until closing based on the value of Columbia’s stock.

The transaction is expected to close in the fourth quarter of 2021, and its completion is contingent upon approval from BOCH’s shareholders, the receipt of other customary regulatory approvals, and other customary closing conditions.