Business Combinations and Asset Acquisitions - PCD Loans (Details) - USD ($) $ in Thousands		3 Months Ended
	Feb. 28, 2023	Mar. 31, 2023
Asset Acquisition [Line Items]
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date		$ 26,492
Umpqua Bank and Columbia Banking System Merger
Asset Acquisition [Line Items]
Financing Receivable, Purchased with Credit Deterioration, Amount at Par Value	$ 478,648
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	26,492
Financing Receivable, Purchased with Credit Deterioration, Discount (Premium)	(49,337)
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price	$ 402,819