Acquisitions	9 Months Ended
Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisitions	Acquisitions Freehold Bank On December 1, 2021, the Company completed its acquisition of Freehold Bancorp, MHC, Freehold Bancorp, Inc. and Freehold Bank (collectively, the "Freehold Entities" or "Freehold"). Pursuant to the terms of the merger agreement, Freehold Bancorp, MHC merged with and into the MHC, with the MHC as the surviving entity; and Freehold Bancorp, Inc. merged with and into Columbia Financial, with Columbia Financial as the surviving entity. In connection with the merger, Freehold Bank converted to a federal savings bank and operated as a wholly-owned subsidiary of Columbia Financial, until October 5, 2024, when the Company merged Freehold Bank into Columbia Bank. Under the terms of the merger agreement, upon the merger of the two banks, depositors of Freehold Bank became depositors of Columbia Bank and have the same rights and privileges in the MHC as if their accounts had been established at Columbia Bank on the date established at Freehold Bank. The Company issued 2,591,007 shares of its common stock to the MHC, representing an amount equal to the fair value of the Freehold Entities as determined by an independent appraiser, at the effective time of the holding company mergers. Merger-related expenses are recorded in the Consolidated Statements of Income and are expensed as incurred. Direct acquisition and other charges incurred in connection with the acquisition of the Freehold Entities totaled $23,000 and $737,000 during the three and nine months ended September 30, 2024, and $14,000 and $88,000 recorded during the three and nine months ended September 30, 2023.

Acquisitions

9 Months Ended

Sep. 30, 2024

Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]

Freehold Bank

On December 1, 2021, the Company completed its acquisition of Freehold Bancorp, MHC, Freehold Bancorp, Inc. and Freehold Bank (collectively, the "Freehold Entities" or "Freehold"). Pursuant to the terms of the merger agreement, Freehold Bancorp, MHC merged with and into the MHC, with the MHC as the surviving entity; and Freehold Bancorp, Inc. merged with and into Columbia Financial, with Columbia Financial as the surviving entity. In connection with the merger, Freehold Bank converted to a federal savings bank and operated as a wholly-owned subsidiary of Columbia Financial, until October 5, 2024, when the Company merged Freehold Bank into Columbia Bank. Under the terms of the merger agreement, upon the merger of the two banks, depositors of Freehold Bank became depositors of Columbia Bank and have the same rights and privileges in the MHC as if their accounts had been established at Columbia Bank on the date established at Freehold Bank. The Company issued 2,591,007 shares of its common stock to the MHC, representing an amount equal to the fair value of the Freehold Entities as determined by an independent appraiser, at the effective time of the holding company mergers.

Merger-related expenses are recorded in the Consolidated Statements of Income and are expensed as incurred. Direct acquisition and other charges incurred in connection with the acquisition of the Freehold Entities totaled $23,000 and $737,000 during the three and nine months ended September 30, 2024, and $14,000 and $88,000 recorded during the three and nine months ended September 30, 2023.