Acquisitions	3 Months Ended
Mar. 31, 2024
Business Combination and Asset Acquisition [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 operates as a wholly-owned subsidiary of Columbia Financial. The Company intends to merge Freehold Bank into Columbia Bank at a future date that has not yet been determined. Under the terms of the merger agreement, upon the subsequent merger of the two banks, depositors of Freehold Bank will become depositors of Columbia Bank and will 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 $22,000 during the three months ended March 31, 2024. There were no merger expenses recorded during the three months ended March 31, 2023.

Acquisitions

3 Months Ended

Mar. 31, 2024

Business Combination and Asset Acquisition [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 operates as a wholly-owned subsidiary of Columbia Financial. The Company intends to merge Freehold Bank into Columbia Bank at a future date that has not yet been determined. Under the terms of the merger agreement, upon the subsequent merger of the two banks, depositors of Freehold Bank will become depositors of Columbia Bank and will 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 $22,000 during the three months ended March 31, 2024. There were no merger expenses recorded during the three months ended March 31, 2023.