The change in the fair value of the stock price represented as a percentage.

No definition available.

Name:	umpq_ChangeInFairValueStock
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Discounted rate of carrying value of other real estate owned.

+ References

No definition available.

+ Details

Name:	umpq_DiscountedRateOfCarryingValueOfOtherRealEstateOwned
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Estimated fair value of trade name.

+ References

No definition available.

+ Details

Name:	umpq_EstimatedFairValueOfTradeName
Namespace Prefix:	umpq_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value adjustments in goodwill impairment analysis as a percentage of core deposits.

+ References

No definition available.

+ Details

Name:	umpq_FairValueAdjustmentsInGoodwillImpairmentAnalysisAsPercentageOfCoreDeposits
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of the overall loan portfolio at a discount relative to its book value.

+ References

No definition available.

+ Details

Name:	umpq_FairValueOfOverallLoanPortfolioAtDiscountRelativeToItsBookValue
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of the overall loan portfolio at a discount relative to its carrying value.

+ References

No definition available.

+ Details

Name:	umpq_FairValueOfOverallLoanPortfolioAtDiscountRelativeToItsCarryingValue
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Liquidity premiums for construction and non-performing loans as a percentage.

+ References

No definition available.

+ Details

Name:	umpq_LiquidityPremiumsForConstructionAndNonPerformingLoansAsPercentage
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Liquidity premiums for individual performing loans as a percentage.

+ References

No definition available.

+ Details

Name:	umpq_LiquidityPremiumsForIndividualPerformingLoansAsPercentage
Namespace Prefix:	umpq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Loan Pools With Common Characteristics

+ References

No definition available.

+ Details

Name:	umpq_NumberOfLoanPoolsWithCommonCharacteristics
Namespace Prefix:	umpq_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-Clause 5

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 72

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 47

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6905597&loc=d3e13816-109267

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 43

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6905597&loc=d3e13854-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The change during the reporting period in the carrying value of goodwill. The change could be the result of new goodwill acquired, goodwill impairment during the period, goodwill written off related to the sale of a business or other adjustments to goodwill.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6905597&loc=d3e13816-109267

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 72

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_GoodwillPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 46

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16373-109275

+ Details

Name:	us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Goodwill And Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jun. 30, 2009	Dec. 31, 2008
Reductions to goodwill	$ 44,000	$ 96,000	$ 81,000
Number of loan pools with common characteristics					68
Liquidity premiums for individual performing loans as a percentage					4.60%
Liquidity premiums for construction and non-performing loans as a percentage					30.00%
Fair value of the overall loan portfolio at a discount relative to its book value					9.00%
Fair value of the overall loan portfolio at a discount relative to its carrying value				12.00%
Fair value adjustments in goodwill impairment analysis as a percentage of core deposits	0.53%
Discounted rate of carrying value of other real estate owned	25.00%
Estimated fair value of trade name	19,300,000
Percentage change in fair value of stock	60.00%
Goodwill, Impairment Loss			111,952,000
Merchant Servicing Portfolio [Member]
Impairment of intangible assets (excluding goodwill)			804,000
Community Banking [Member]
Goodwill, Impairment Loss			$ 111,952,000