Business Combinations and Asset Acquisitions - PCD Loans (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 28, 2023	Dec. 31, 2023
Asset Acquisition [Line Items]
Initial ACL on PCD loans acquired during the period		$ 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
Initial ACL on PCD loans acquired during the period	26,492
Financing Receivable, Purchased with Credit Deterioration, Discount (Premium)	(49,337)
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price	$ 402,819