Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-34624
Entity Registrant Name	Umpqua Holdings Corporation
Entity Incorporation, State or Country Code	OR
Entity Tax Identification Number	93-1261319
Entity Address, Address Line One	One SW Columbia Street
Entity Address, Address Line Two	Suite 1200
Entity Address, City or Town	Portland
Entity Address, State or Province	OR
Entity Address, Postal Zip Code	97258
City Area Code	503
Local Phone Number	727-4100
Title of 12(b) Security	Common Stock
Trading Symbol	UMPQ
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		220,228,968
Documents Incorporated by Reference	Portions of the Proxy Statement for the 2021 Annual Meeting of Shareholders of Umpqua Holdings Corporation ("Proxy Statement") are incorporated by reference in this Form 10-K in response to Part III, Items 10, 11, 12, 13 and 14.
Entity Public Float			$ 1,475,075,623
Entity Central Index Key	0001077771
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false