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Business Combinations and Asset Acquisitions - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023 | Feb. 28, 2023
Asset Acquisition [Line Items] |  |  |  |  |  |
Goodwill | $ 1,029,234 |  | $ 1,029,234 |  | $ 1,029,234 |
Business Combination, Acquisition Related Costs | 2,364 | $ 18,938 | 21,483 | $ 164,485 |  |
Umpqua Bank and Columbia Banking System Merger |  |  |  |  |  |
Asset Acquisition [Line Items] |  |  |  |  |  |
Goodwill |  |  |  |  |  | $ 1,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  |  |  |  | $ 710,200
Business Combination, Acquisition Related Costs | $ 1,600 | $ 18,900 | $ 8,800 | $ 164,500 |  |

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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479405/805-10-25-23 + Details
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