Other Real Estate Owned, Net (Schedule Of Changes In Other Real Estate Owned) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Real Estate Owned Valuation Allowance [Roll Forward]
Balance, beginning of period	$ 23,935	$ 27,512	$ 53,666
Additions to OREO due to acquisition	8,666umpq_RealEstateOwnedAcquisitions	0umpq_RealEstateOwnedAcquisitions	1,602umpq_RealEstateOwnedAcquisitions
Additions to OREO	24,873us-gaap_TransferToOtherRealEstate	24,193us-gaap_TransferToOtherRealEstate	24,686us-gaap_TransferToOtherRealEstate
Dispositions of OREO	(15,804)umpq_RealEstateOwnedPeriodDecrease	(25,610)umpq_RealEstateOwnedPeriodDecrease	(40,900)umpq_RealEstateOwnedPeriodDecrease
Valuation adjustments in the period	(3,728)	(2,160)	(11,542)
Balance, end of period	$ 37,942	$ 23,935	$ 27,512

Real Estate Owned, Acquisitions

No definition available.

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- Definition

Real Estate Owned Period Decrease

+ References

No definition available.

+ Details

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4437-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

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- Definition

Amount of the valuation allowance for real estate owned that was applied in the period against the carrying amount of real estate owned that was sold, written down or written off.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(4))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Subparagraph 4

-Article 9

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- Definition

Value transferred from mortgage loans to real estate owned (REO) in noncash transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

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