Subsequent Events	12 Months Ended
Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn October 12, 2021, Umpqua and Columbia announced that their boards of directors unanimously approved a Merger Agreement under which the two companies will combine in an all-stock transaction. On January 26, 2022, Umpqua and Columbia held special meetings of shareholders to vote to approve the merger agreement and received all required shareholder approvals related to the proposed combination. Completion of the transaction is subject to remaining regulatory approvals and the satisfaction of other customary closing conditions set forth in the merger agreement. The transaction is expected to close in mid-2022.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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