Other Assets (Schedule of Other Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Accrued interest receivable	$ 48,343us-gaap_InterestReceivable	$ 23,720us-gaap_InterestReceivable
Prepaid expenses	44,031	8,301
Derivative assets	29,210us-gaap_DerivativeAssets	17,921us-gaap_DerivativeAssets
Income taxes receivable	18,663us-gaap_IncomeTaxesReceivable	15,665us-gaap_IncomeTaxesReceivable
Equity method investments	16,604us-gaap_EquityMethodInvestments	13,783us-gaap_EquityMethodInvestments
Investment in unconsolidated Trusts	14,296umpq_InvestmentInUnconsolidatedTrusts	6,933umpq_InvestmentInUnconsolidatedTrusts
Commercial servicing asset	9,329us-gaap_ServicingAsset	575us-gaap_ServicingAsset
Other	51,935us-gaap_OtherAssetsMiscellaneous	25,060us-gaap_OtherAssetsMiscellaneous
Total	$ 232,411us-gaap_OtherAssets	$ 111,958us-gaap_OtherAssets

Investment in unconsolidated trusts.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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The aggregate carrying amounts, as of the balance sheet date, of assets not separately disclosed in the balance sheet.

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Amount of other miscellaneous assets.

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Carrying amount as of the balance sheet date of expenditures made in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs.

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Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

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