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Business Combinations - Schedule if purchase price (Details) - Columbia Banking Systems and Pacific Premier Bancorp Merger $ / shares in Units, $ in Millions | Aug. 31, 2025 USD ($) $ / shares shares
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Business Combination [Line Items] |
Shares of Columbia common stock issued to Pacific Premier Stockholders | shares | 87,632,000
Columbia's market price per common share (in dollars) as of August 31, 2025 | $ / shares | $ 26.77
Fair value of purchase price consideration transferred | $ 2,346
Fair value of restricted stock exchanged | 9
Total purchase price consideration | $ 2,355

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