Regulatory Capital (Summary of Company's Capital Amounts And Ratios) (Details) $ in Thousands	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Consolidated
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 5,082,012	$ 4,770,335
Capital to Risk Weighted Assets	0.1275	0.1186
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Capital Required to be Well Capitalized to Risk Weighted Assets	0.1000	0.1000
Tier One Risk Based Capital	$ 4,200,595	$ 3,876,985
Tier One Risk Based Capital to Risk Weighted Assets	0.1054	0.0964
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	0.0800	0.0800
Common Equity Tier One Capital	$ 4,200,595	$ 3,876,985
Common Equity Tier One Capital Ratio	0.1054	0.0964
Tier One Common Equity Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Common Equity Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier One Leverage Capital	$ 4,200,595	$ 3,876,985
Tier One Leverage Capital to Average Assets	0.0831	0.0760
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400	0.0400
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	0.0500	0.0500
Umpqua Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 4,951,381	$ 4,653,920
Capital to Risk Weighted Assets	0.1242	0.1157
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Capital Required to be Well Capitalized to Risk Weighted Assets	0.1000	0.1000
Tier One Risk Based Capital	$ 4,530,964	$ 4,231,569
Tier One Risk Based Capital to Risk Weighted Assets	0.1137	0.1052
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	0.0800	0.0800
Common Equity Tier One Capital	$ 4,530,964	$ 4,231,569
Common Equity Tier One Capital Ratio	0.1137	0.1052
Tier One Common Equity Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Common Equity Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier One Leverage Capital	$ 4,530,964	$ 4,231,569
Tier One Leverage Capital to Average Assets	0.0897	0.0830
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400	0.0400
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	0.0500	0.0500

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

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Amount of total capital as defined by regulatory framework.

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Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
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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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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
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