Regulatory Capital (Summary of Company's Capital Amounts And Ratios) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Consolidated [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 2,553,161	$ 2,391,267
Capital to Risk Weighted Assets	14.34%	15.20%
Capital Required for Capital Adequacy	$ 1,424,127	$ 1,258,198
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 1,780,159	$ 1,572,747
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Risk Based Capital	$ 2,073,402	$ 2,271,563
Tier One Risk Based Capital to Risk Weighted Assets	11.65%	14.44%
Tier One Risk Based Capital Required for Capital Adequacy	$ 1,068,096	$ 629,099
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,424,127	$ 943,648
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	6.00%
Tier One Common Equity	$ 2,020,814
Tier One Common Equity to Risk Weighted Assets	11.35%
Tier One Common Equity Required for Capital Adequacy	$ 801,072
Tier One Common Equity Required for Capital Adequacy to Risk Weighted Assets	4.50%
Tier One Common Equity Required to be Well Capitalized	$ 1,157,104
Tier One Common Equity Required to be Well Capitalized to Risk Weighted Assets	6.50%
Tier One Leverage Capital	$ 2,073,402	$ 2,271,563
Tier One Leverage Capital to Average Assets	9.73%	10.99%
Tier One Leverage Capital Required for Capital Adequacy	$ 852,091	$ 827,128
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 1,065,114	$ 1,033,910
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Umpqua Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 2,368,213	$ 2,181,776
Capital to Risk Weighted Assets	13.32%	13.90%
Capital Required for Capital Adequacy	$ 1,422,495	$ 1,255,819
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 1,778,118	$ 1,569,774
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Risk Based Capital	$ 2,234,458	$ 2,062,151
Tier One Risk Based Capital to Risk Weighted Assets	12.57%	13.14%
Tier One Risk Based Capital Required for Capital Adequacy	$ 1,066,871	$ 627,910
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,422,495	$ 941,864
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	6.00%
Tier One Common Equity	$ 2,234,458
Tier One Common Equity to Risk Weighted Assets	12.57%
Tier One Common Equity Required for Capital Adequacy	$ 800,153
Tier One Common Equity Required for Capital Adequacy to Risk Weighted Assets	4.50%
Tier One Common Equity Required to be Well Capitalized	$ 1,155,777
Tier One Common Equity Required to be Well Capitalized to Risk Weighted Assets	6.50%
Tier One Leverage Capital	$ 2,234,458	$ 2,062,151
Tier One Leverage Capital to Average Assets	10.50%	9.96%
Tier One Leverage Capital Required for Capital Adequacy	$ 851,554	$ 828,061
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 1,064,443	$ 1,035,076
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%

Tier One Common Equity

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Tier One Common Equity Required for Capital Adequacy

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Tier One Common Equity Required for Capital Adequacy to Risk Weighted Assets

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Tier One Common Equity Required to be Well Capitalized

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Tier One Common Equity Required to be Well Capitalized to Risk Weighted Assets

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Tier One Common Equity to Risk Weighted Assets

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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