Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations-Umpqua Holdings Corporation (the "Company") is a financial holding company with headquarters in Portland, Oregon, that is engaged primarily in the business of commercial and retail banking and the delivery of retail brokerage services. The Company provides a wide range of banking, wealth management, mortgage and other financial services to corporate, institutional and individual customers through its wholly-owned banking subsidiary Umpqua Bank (the "Bank"). The Company engages in the retail brokerage business through its wholly-owned subsidiary Umpqua Investments, Inc. ("Umpqua Investments"). The Bank also has a wholly-owned subsidiary, Financial Pacific Leasing Inc., a commercial equipment leasing company. Pivotus Ventures, Inc., a wholly-owned subsidiary of Umpqua Holdings Corporation, uses a startup dynamic and collaboration with other institutions to validate, develop, and test new bank platforms that could have a significant impact on the experience and economics of banking. The Company and its subsidiaries are subject to regulation by certain federal and state agencies and undergo periodic examination by these regulatory agencies.
Basis of Financial Statement Presentation	Basis of Financial Statement Presentation-The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States and with prevailing practices within the banking and securities industries. In preparing such financial statements, management is required to make certain estimates and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the balance sheet and the reported amounts of revenues and expenses for the reporting period. Actual results could differ significantly from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan and lease losses, the valuation of mortgage servicing rights, the fair value of junior subordinated debentures, and the valuation of goodwill and other intangible assets.
Consolidation	Consolidation-The accompanying consolidated financial statements include the accounts of the Company, the Bank and its subsidiary, Umpqua Investments, and Pivotus. All significant intercompany balances and transactions have been eliminated in consolidation. As of December 31, 2017, the Company had 25 wholly-owned trusts ("Trusts") that were formed to issue trust preferred securities and related common securities of the Trusts. The Company has not consolidated the accounts of the Trusts in its consolidated financial statements. As a result, the junior subordinated debentures issued by the Company to the Trusts are reflected on the Company's consolidated balance sheet as junior subordinated debentures.
Subsequent events	Subsequent events-The Company has evaluated events and transactions through the date the consolidated financial statements were issued for potential recognition or disclosure.
Cash and Cash Equivalents	Cash and Cash Equivalents-Cash and cash equivalents include cash and due from banks and temporary investments which are federal funds sold and interest bearing balances due from other banks. Cash and cash equivalents generally have a maturity of 90 days or less at the time of purchase.
Trading Account Securities	Trading Account Securities-Debt and equity securities held for resale are classified as trading account securities and reported at fair value. Realized and unrealized gains or losses are recorded in non-interest income.
Investment Securities	Investment Securities-Debt securities are classified as held to maturity if the Company has both the intent and ability to hold those securities to maturity regardless of changes in market conditions, liquidity needs or changes in general economic conditions. These securities are carried at cost adjusted for amortization of purchase premiums and accretion of purchase discounts, computed by the effective interest method over their contractual lives. Securities are classified as available for sale if the Company intends and has the ability to hold those securities for an indefinite period of time, but not necessarily to maturity. Any decision to sell a security classified as available for sale would be based on various factors, including significant movements in interest rates, changes in the maturity mix of assets and liabilities, liquidity needs, regulatory capital considerations and other similar factors. Securities available for sale are carried at fair value. Unrealized holding gains or losses are included in other comprehensive income ("OCI") as a separate component of shareholders' equity, net of tax. Realized gains or losses, determined on the basis of the cost of specific securities sold, are included in earnings. Premiums and discounts are amortized or accreted over the life of the related investment security as an adjustment to yield using the effective interest method. Dividend and interest income are recognized when earned. Transfers of securities from available for sale to held to maturity are accounted for at fair value as of the date of the transfer. The difference between the fair value and the par value at the date of transfer is considered a premium or discount and is accounted for accordingly. Any unrealized gain or loss at the date of the transfer is reported in OCI, and is amortized over the remaining life of the security as an adjustment of yield in a manner consistent with the amortization of any premium or discount, and will offset or mitigate the effect on interest income of the amortization of the premium or discount for that held to maturity security. We review investment securities on an ongoing basis for the presence of other-than-temporary impairment ("OTTI") or permanent impairment, taking into consideration current market conditions, fair value in relationship to cost, extent and nature of the change in fair value, issuer rating changes and trends, whether we intend to sell a security or if it is more likely than not that we will be required to sell the security before recovery of our amortized cost basis of the investment, which may be maturity, and other factors. For debt securities, if we intend to sell the security or it is more likely than not that we will be required to sell the security before recovering its cost basis, the entire impairment loss would be recognized in earnings as an OTTI. If we do not intend to sell the security and it is not more likely than not that we will be required to sell the security but we do not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings.
Loans Held for Sale	Loans Held for Sale-The Company has elected to account for loans held for sale, which is comprised of residential mortgage loans, at fair value. Fair value is determined based on quoted secondary market prices for similar loans, including the implicit fair value of embedded servicing rights. The change in fair value of loans held for sale is primarily driven by changes in interest rates subsequent to loan funding and changes in the fair value of the related servicing asset, resulting in revaluation adjustments to the recorded fair value. The inputs used in the fair value measurements are considered Level 2 inputs. The use of the fair value option allows the change in the fair value of loans to more effectively offset the change in the fair value of derivative instruments that are used as economic hedges to loans held for sale. Loan origination fees and direct origination costs are recognized immediately in net income. Interest income on loans held for sale is included in interest income in the Consolidated Statements of Income and recognized when earned. Loans held for sale are placed on nonaccrual in a manner consistent with loans held for investment. The Company recognizes the gain or loss on the sale of loans when the sales criteria for derecognition are met.
Acquired Loans and Leases	Acquired Loans and Leases-Purchased loans and leases are recorded at their fair value at the acquisition date. Credit discounts are included in the determination of fair value; therefore, an allowance for loan and lease losses is not recorded at the acquisition date. Acquired loans are evaluated upon acquisition and classified as either purchased impaired or purchased non-impaired. Purchased impaired loans reflect credit deterioration since origination such that it is probable at acquisition that the Company will be unable to collect all contractually required payments. Purchased impaired loans are aggregated into pools based on individually evaluated common risk characteristics and aggregate expected cash flows are estimated for each pool. A pool is accounted for as a single asset with a single interest rate, cumulative loss rate and cash flow expectation. The risk characteristics used to aggregate the purchased impaired loans into different pools include risk rating, underlying collateral, type of interest rate (fixed or adjustable), types of amortization, loan purpose, and other similar factors. A loan will be removed from a pool of loans only if the loan is sold, foreclosed, or assets are received in full satisfaction of the loan, and will be removed from the pool at its carrying value. If an individual loan is removed from a pool of loans, the difference between its relative carrying amount and the cash, fair value of the collateral, or other assets received will be recognized in income immediately as interest income on loans and would not affect the effective yield used to recognize the accretable yield on the remaining pool. If, at acquisition, the loans are collateral dependent and acquired primarily for the rewards of ownership of the underlying collateral, or if cash flows expected to be collected cannot be reasonably estimated, no accrual of income occurs. The cash flows expected to be received over the life of the pool are estimated by management. These cash flows are input into a loan accounting system which calculates the carrying values of the pools and underlying loans, book yields, effective interest income and impairment, if any, based on actual and projected events. Default rates, loss severity, and prepayment speed assumptions will be periodically reassessed and updated within the accounting system to update our expectation of future cash flows. The excess of the cash flows expected to be collected over a pool's carrying value is considered to be the accretable yield and is recognized as interest income over the estimated life of the pool using the effective yield method. The accretable yield may change due to changes in the timing and amounts of expected cash flows. Changes in the accretable yield are disclosed quarterly. The excess of the undiscounted contractual amounts due over the cash flows expected to be collected is considered to be the nonaccretable difference. The nonaccretable difference represents our estimate of the credit losses expected to occur and was considered in determining the fair value of the loans as of the acquisition date. Subsequent to the acquisition date, any increases in expected cash flows over those expected at the purchase date in excess of fair value are adjusted through a change to the accretable yield on a prospective basis. Any subsequent decreases in expected cash flows attributable to credit deterioration are recognized by recording a provision for loan losses. The purchased impaired loans acquired are and will continue to be subject to the Company's credit review and monitoring. The purchased impaired loan portfolio also includes revolving lines of credit with funded and unfunded commitments. The funded portion of these loans, representing the balances outstanding at the time of acquisition, are accounted for as purchased impaired. The unfunded portion of these loans as of the acquisition date as well as any additional advances on these loans subsequent to the acquisition date are not classified as purchased impaired, and are accounted for similar to newly originated loans. For purchased non-impaired loans, the difference between the fair value and unpaid principal balance of the loan at the acquisition date is amortized or accreted to interest income using the effective interest method over the remaining period to contractual maturity or until repayment in full or sale of the loan. For purchased leases and equipment finance loans, the difference in the cash flows expected to be collected over the initial allocation of fair value to the acquired leases and loans is accreted into interest income over their related term based on the effective interest method.
Originated Loans and Leases	Originated Loans and Leases-Loans are stated at the amount of unpaid principal, net of unearned income and any deferred fees or costs. All discounts and premiums are recognized over the contractual life of the loan as yield adjustments. Leases are recorded at the amount of minimum future lease payments receivable and estimated residual value of the leased equipment, net of unearned income and any deferred fees. Initial direct costs related to lease originations are deferred as part of the investment in direct financing leases and amortized over their term using the effective interest method. Unearned lease income is amortized over the term using the effective interest method. Loans are classified as impaired when, based on current information and events, it is probable that the Bank will be unable to collect the scheduled payments of principal and interest when due, in accordance with the terms of the original loan agreement. The carrying value of impaired loans is based on the present value of expected future cash flows (discounted at each loan's effective interest rate), estimated note sale price, or, for collateral dependent loans, at fair value of the collateral, less selling costs. If the measurement of each impaired loan's value is less than the recorded investment in the loan, we recognize this impairment and adjust the carrying value of the loan to fair value through the allowance for loan and lease losses. This can be accomplished by charging off the impaired portion of the loan or establishing a specific component to be provided for in the allowance for loan and lease losses.
Income Recognition on Non-Accrual and Impaired Loans	Income Recognition on Non-Accrual and Impaired Loans- Loans, including impaired loans, are classified as non-accrual if the collection of principal and interest is doubtful. Generally, this occurs when a loan is past due as to maturity or payment of principal or interest by 90 days or more, unless such loans are well-secured and in the process of collection. Generally, if a loan or portion thereof is partially charged-off, the loan is considered impaired and classified as non-accrual. Loans that are less than 90 days past due may also be classified as non-accrual if repayment in full of principal and/or interest is in doubt. Generally, when a loan is classified as non-accrual, all uncollected accrued interest is reversed to interest income and the accrual of interest income is terminated. Generally, any cash payments subsequently received are applied as a reduction of principal outstanding. In cases where the future collectability of the principal balance in full is expected, interest income may be recognized on a cash basis. A loan may be restored to accrual status when the borrower's financial condition improves so that full collection of future contractual payments is considered likely. For those loans placed on non-accrual status due to payment delinquency, return to accrual status will generally not occur until the borrower demonstrates repayment ability over a period of not less than six months. Loans and leases are reported as past due when installment payments, interest payments, or maturity payments are past due based on contractual terms. All loans and leases determined to be impaired are individually assessed for impairment except for homogeneous loans which are collectively evaluated for impairment. The specific factors considered in determining that a loan or lease is impaired include borrower financial capacity, current economic, business and market conditions, collection efforts, collateral position and other factors deemed relevant. Generally, impaired loans and leases are placed on non-accrual status and all cash receipts are applied to the principal balance. Continuation of accrual status and recognition of interest income on impaired loans and leases is generally limited to performing restructured loans. Loans are reported as troubled debt restructurings when the Bank grants a more than insignificant concession(s) to a borrower experiencing financial difficulties that it would not otherwise consider. Examples of such concessions include forgiveness of principal or accrued interest, extending the maturity date or providing a lower interest rate than would be normally available for a transaction of similar risk. As a result of these concessions, restructured loans are impaired as the Bank will not collect all amounts due, both principal and interest, in accordance with the terms of the original loan agreement. Impairment reserves on non-collateral dependent restructured loans are measured by comparing the present value of expected future cash flows on the restructured loans discounted at the interest rate of the original loan agreement to the loan's carrying value. These impairment reserves are recognized as a specific component to be provided for in the allowance for loan and lease losses. The decision to classify a loan as impaired is made by the Bank's Allowance for Loan and Lease Losses ("ALLL") Committee. The ALLL Committee meets regularly to review the status of all problem and potential problem loans. If the ALLL Committee concludes a loan is impaired but recovery of principal and interest is expected, an impaired loan may remain on accrual status.
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses- The Bank performs regular credit reviews of the loan and lease portfolio to determine the credit quality of the portfolio and the adherence to underwriting standards. When loans and leases are originated, they are assigned a risk rating that is reassessed periodically during the term of the loan. The Company's risk rating methodology assigns risk ratings ranging from 1 to 10, where a higher rating represents higher risk. The 10 risk rating categories are a primary factor in determining an appropriate amount for the allowance for loan and lease losses. The Bank has a management ALLL Committee, which is responsible for, among other things, regularly reviewing the ALLL methodology, including loss factors, and ensuring that it is designed and applied in accordance with generally accepted accounting principles. The ALLL Committee reviews and approves loans and leases recommended for impaired status. The ALLL Committee also approves removing loans and leases from impaired status. The Company's Audit and Compliance Committee provides board oversight of the ALLL process and reviews and approves the ALLL methodology on a quarterly basis. Each risk rating is assessed an inherent credit loss factor that determines the amount of the allowance for loan and lease losses provided for that group of loans and leases with similar risk rating and loan type. Credit loss factors may vary by region based on management's belief that there may ultimately be different credit loss rates experienced in each region. Regular credit reviews of the portfolio also identify loans that are considered potentially impaired. Potentially impaired loans are referred to the ALLL Committee which reviews and approves designated loans as impaired. When we identify a loan as impaired, we measure the impairment using discounted cash flows or estimated note sale price, except when the sole remaining source of the repayment for the loan is the liquidation of the collateral. In these cases, we use the current fair value of the collateral, less selling costs, instead of discounted cash flows. If we determine that the value of the impaired loan is less than the recorded investment in the loan, we either recognize an impairment reserve as a specific component to be provided for in the allowance for loan and lease losses or charge-off the impaired balance on collateral dependent loans if it is determined that such amount represents a confirmed loss. The combination of the risk rating-based allowance component and the impairment reserve allowance component lead to an allocated allowance for loan and lease losses. The Bank may also maintain an unallocated allowance amount to provide for other credit losses inherent in a loan and lease portfolio that may not have been contemplated in the credit loss factors. This unallocated amount generally comprises less than 5% of the allowance, but may be maintained at higher levels during times of economic conditions characterized by falling real estate values. The unallocated amount is reviewed periodically based on trends in credit losses, the results of credit reviews and overall economic trends. As adjustments become necessary, they are reported in earnings in the periods in which they become known as a change in the provision for loan and lease losses and a corresponding charge to the allowance. Loans, or portions thereof, deemed uncollectible are charged to the allowance. Provisions for losses, and recoveries on loans previously charged-off, are added to the allowance. The adequacy of the ALLL is monitored on a regular basis and is based on management's evaluation of numerous factors. These factors include the quality of the current loan portfolio; the trend in the loan portfolio's risk ratings; current economic conditions; loan concentrations; loan growth rates; past-due and non-performing trends; evaluation of specific loss estimates for all significant problem loans; historical charge-off and recovery experience; and other pertinent information. Management believes that the ALLL was adequate as of December 31, 2017. There is, however, no assurance that future loan losses will not exceed the levels provided for in the ALLL and could possibly result in additional charges to the provision for loan and lease losses. In addition, bank regulatory authorities, as part of their periodic examination of the Bank, may require additional charges to the provision for loan and lease losses in future periods if warranted as a result of their review. The Bank's methodology for assessing the appropriateness of the Allowance for Loan and Lease Loss ("ALLL") consists of three key elements: 1) the formula allowance; 2) the specific allowance; and 3) the unallocated allowance. By incorporating these factors into a single allowance requirement analysis, we believe all risk-based activities within the loan and lease portfolios are simultaneously considered. Formula Allowance When loans and leases are originated or acquired, they are assigned a risk rating that is reassessed periodically during the term of the loan or lease through the credit review process. The Bank's risk rating methodology assigns risk ratings ranging from 1 to 10, where a higher rating represents higher risk. The 10 risk rating categories are a primary factor in determining an appropriate amount for the formula allowance. The formula allowance is calculated by applying risk factors to various segments of pools of outstanding loans and leases. Risk factors are assigned to each portfolio segment based on management's evaluation of the losses inherent within each segment. Segments with greater risk of loss will therefore be assigned a higher risk factor. Base risk – The portfolio is segmented into loan categories, and these categories are assigned a Base risk factor based on an evaluation of the loss inherent within each segment. Extra risk – Additional risk factors provide for an additional allocation of ALLL based on the loan and lease risk rating system and loan delinquency, and reflect the increased level of inherent losses associated with more adversely classified loans and leases. Risk factors may be changed periodically based on management's evaluation of the following factors: loss experience; changes in the level of non-performing loans and leases; regulatory exam results; changes in the level of adversely classified loans and leases; improvement or deterioration in economic conditions; and any other factors deemed relevant. Additionally, Financial Pacific Leasing Inc. considers additional quantitative and qualitative factors: migration analysis; a static pool analysis of historic recoveries; and forecasting uncertainties. A migration analysis is a technique used to estimate the likelihood that an account will progress through the various delinquency states and ultimately be charged off. Specific Allowance Regular credit reviews of the portfolio identify loans that are considered potentially impaired. Potentially impaired loans are referred to the ALLL Committee which reviews and approves designated loans as impaired. A loan is considered impaired when, based on current information and events, we determine that we will probably not be able to collect all amounts due according to the loan contract, including scheduled interest payments. When we identify a loan as impaired, we measure the impairment using discounted cash flows or estimated note sale price, except when the sole remaining source of the repayment for the loan is the liquidation of the collateral. In these cases, we use the current fair value of the collateral, less selling costs, instead of discounted cash flows. If we determine that the value of the impaired loan is less than the recorded investment in the loan, we either recognize an impairment reserve as a specific allowance to be provided for in the allowance for loan and lease losses or charge-off the impaired balance on collateral-dependent loans if it is determined that such amount represents a confirmed loss. Loans determined to be impaired are excluded from the formula allowance so as not to double-count the loss exposure. The combination of the formula allowance component and the specific allowance component represents the allocated allowance for loan and lease losses. There was no unallocated allowance as of December 31, 2017 and December 31, 2016. Management believes that the ALLL was adequate as of December 31, 2017. There is, however, no assurance that future loan and lease losses will not exceed the levels provided for in the ALLL and could possibly result in additional charges to the provision for loan and lease losses. The RUC is established to absorb inherent losses associated with our commitment to lend funds, such as with a letter or line of credit. The adequacy of the ALLL and RUC are monitored on a regular basis and are based on management's evaluation of numerous factors. These factors include the quality of the current loan portfolio; the trend in the loan portfolio's risk ratings; current economic conditions; loan concentrations; loan growth rates; past-due and non-performing trends; evaluation of specific loss estimates for all significant problem loans; historical charge-off and recovery experience; and other pertinent information. There have been no significant changes to the Bank's ALLL methodology or policies in the periods presented.
Reserve for Unfunded Commitments	Reserve for Unfunded Commitments-A reserve for unfunded commitments ("RUC") is maintained at a level that, in the opinion of management, is adequate to absorb probable losses associated with the Bank's commitment to lend funds under existing agreements, such as letters or lines of credit. Management determines the adequacy of the reserve for unfunded commitments based upon reviews of individual credit facilities, current economic conditions, the risk characteristics of the various categories of commitments and other relevant factors. The reserve is based on estimates, and ultimate losses may vary from the current estimates. These estimates are evaluated on a regular basis and, as adjustments become necessary, they are reported in earnings in the periods in which they become known. Draws on unfunded commitments that are considered uncollectible at the time funds are advanced are charged to the allowance for loan and lease losses. Provisions for unfunded commitment losses are added to the reserve for unfunded commitments, which is included in the Other Liabilities section of the consolidated balance sheets.
Loan Fees and Direct Loan Origination Costs	Loan and Lease Fees and Direct Loan Origination Costs-Origination and commitment fees and direct loan origination costs for loans and leases held for investment are deferred and recognized as an adjustment to the yield over the life of the portfolio loans and leases.
Restricted Equity Securities	Restricted Equity Securities-Restricted equity securities were $43.5 million and $45.5 million at December 31, 2017 and 2016, respectively. Federal Home Loan Bank stock amounted to $42.0 million and $44.1 million of the total restricted securities as of December 31, 2017 and 2016, respectively. Federal Home Loan Bank stock represents the Bank's investment in the Federal Home Loan Banks of Des Moines and San Francisco ("FHLB") stock and is carried at par value, which reasonably approximates its fair value. Management periodically evaluates FHLB stock for other-than-temporary or permanent impairment. Management's determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. As a member of the FHLB system, the Bank is required to maintain a minimum level of investment in FHLB stock based on specific percentages of its outstanding mortgages, total assets, or FHLB advances. At December 31, 2017, the Bank's minimum required investment in FHLB stock was $42.0 million. The Bank may request redemption at par value of any stock in excess of the minimum required investment. Stock redemptions are at the discretion of the FHLB. The remaining restricted equity securities balance primarily represents an investment in Pacific Coast Bankers' Bancshares stock.
Premises and Equipment	Premises and Equipment-Premises and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is provided over the estimated useful life of equipment, generally three to ten years, on a straight-line or accelerated basis. Depreciation is provided over the estimated useful life of premises, up to 39 years, on a straight-line or accelerated basis. Generally, leasehold improvements are amortized or accreted over the life of the related lease, or the life of the related asset, whichever is shorter. Expenditures for major renovations and betterments of the Company's premises and equipment are capitalized. The Company purchases, as well as internally develops and customizes, certain software to enhance or perform internal business functions. Software development costs incurred in the preliminary project stages, as well as costs incurred for software that is part of a hosting arrangement, are charged to non-interest expense. Costs associated with designing software configuration, installation, coding programs and testing systems are capitalized and amortized using the straight-line method over three to seven years. Management reviews long-lived assets any time that a change in circumstance indicates that the carrying amount of these assets may not be recoverable. Recoverability of these assets is determined by comparing the carrying value of the asset to the forecasted undiscounted cash flows of the operation associated with the asset. If the evaluation of the forecasted cash flows indicates that the carrying value of the asset is not recoverable, the asset is written down to fair value.
Goodwill and Other Intangibles	Goodwill and Other Intangibles-Intangible assets are comprised of goodwill and other intangibles acquired in business combinations. Goodwill is not amortized but instead is periodically tested for impairment. Intangible assets with definite useful lives are amortized to their estimated residual values over their respective estimated useful lives, and also reviewed for impairment. Amortization of intangible assets is included in non-interest expense in the Consolidated Statements of Income. The Company performs a goodwill impairment analysis on an annual basis as of December 31. On at least an annual basis, we assess qualitative factors to determine whether it is necessary to perform a quantitative impairment test. Additionally, the Company performs a goodwill impairment evaluation on an interim basis when events or circumstances indicate impairment potentially exists. A significant amount of judgment is involved in determining if an indicator of impairment has occurred. Such indicators may include, among others, a significant decline in our expected future cash flows; a sustained, significant decline in our stock price and market capitalization; a significant adverse change in legal factors or in the business climate; adverse action or assessment by a regulator; and unanticipated competition.
Residential Mortgage Servicing Rights (MSR)	Residential Mortgage Servicing Rights ("MSR")- The Company determines its classes of servicing assets based on the asset type being serviced along with the methods used to manage the risk inherent in the servicing assets, which includes the market inputs used to value the servicing assets. The Company measures its residential mortgage servicing assets at fair value and reports changes in fair value through earnings. Fair value adjustments encompass market-driven valuation changes and the runoff in value that occurs from the passage of time, which are separately disclosed. Under the fair value method, the MSR is carried in the balance sheet at fair value and the changes in fair value are reported in earnings under the caption residential mortgage banking revenue, net in the period in which the change occurs. Retained MSR are measured at fair value as of the date of the related loan sale. We use quoted market prices when available. Subsequent fair value measurements are determined using a discounted cash flow model. In order to determine the fair value of the MSR, the present value of expected net future cash flows is estimated. Assumptions used include market discount rates, anticipated prepayment speeds, delinquency and foreclosure rates, and ancillary fee income net of servicing costs. This model is periodically validated by an independent model validation group. The model assumptions and the MSR fair value estimates are also compared to observable trades of similar portfolios as well as to MSR broker valuations and industry surveys, as available. The expected life of the loans underlying the MSR can vary from management's estimates due to prepayments by borrowers, especially when rates change significantly. Prepayments outside of management's estimates would impact the recorded value of the residential mortgage servicing rights. The value of the residential mortgage servicing rights is also dependent upon the discount rate used in the model, which management reviews on an ongoing basis. A significant increase in the discount rate would reduce the value of residential mortgage servicing rights.
GNMA Loan Sales	GNMA Loan Sales-The Company originates government guaranteed loans which are sold to Ginnie Mae ("GNMA"). Pursuant to GNMA servicing guidelines, the Company has the unilateral right to repurchase certain delinquent loans (loans past due 90 days or more) sold to GNMA, if the loans meet defined delinquent loan criteria. As a result of this unilateral right, once the delinquency criteria have been met, and regardless of whether the repurchase option has been exercised, the Company accounts for the loans as if they had been repurchased. The Company recognizes these loans within loans and leases, net and also recognizes a corresponding liability that is recorded in other liabilities. If the loan is repurchased, the liability is settled and the loan remains.
SBA/USDA Loans Sales, Servicing, and Commercial Servicing Asset	SBA/USDA Loans Sales, Servicing, and Commercial Servicing Asset-The Bank, on a limited basis, sells or transfers loans, including the guaranteed portion of Small Business Administration ("SBA") and Department of Agriculture ("USDA") loans (with servicing retained) for cash proceeds. The Bank records a servicing asset when it sells a loan and retains the servicing rights. The servicing asset is recorded at fair value upon sale, and the fair value is estimated by discounting estimated net future cash flows from servicing using discount rates that approximate current market rates and using estimated prepayment rates. Subsequent to initial recognition, the servicing rights are carried at the lower of amortized cost or fair value, and are amortized in proportion to, and over the period of, the estimated net servicing income. For purposes of evaluating and measuring impairment, the fair value of Commercial and SBA servicing rights are measured using a discounted estimated net future cash flow model as described above. Any impairment is measured as the amount by which the carrying value of servicing rights for an interest rate-stratum exceeds its fair value. No impairment charges were recorded for the years ended December 31, 2017, 2016 and 2015, related to these servicing assets. A premium over the adjusted carrying value is received upon the sale of the guaranteed portion of an SBA or USDA loan. The Bank's investment in an SBA or USDA loan is allocated among the sold and retained portions of the loan based on the relative fair value of each portion at the time of loan origination, adjusted for payments and other activities. Because the portion retained does not carry an SBA or USDA guarantee, part of the gain recognized on the sold portion of the loan is deferred and amortized as a yield enhancement on the retained portion in order to obtain a market equivalent yield.
Other Real Estate Owned	Other Real Estate Owned- Other real estate owned ("OREO") represents real estate which the Bank has taken control of in partial or full satisfaction of loans. At the time of foreclosure, OREO is recorded at fair value less costs to sell the property, which becomes the property's new basis. Any write-downs at the date of acquisition are charged to the allowance for loan and lease losses. After foreclosure, management periodically performs valuations such that the real estate is carried at the lower of its new cost basis or fair value, net of estimated costs to sell. Subsequent valuation adjustments are recognized within net loss on OREO. Revenue and expenses from operations are included in other non-interest expense in the Consolidated Statements of Income. In some instances, the Bank may make loans to facilitate the sales of other real estate owned. Management reviews all sales for which it is the lending institution to determine if it meets the criteria to recognize the sale for accounting purposes. Any gains related to sales of other real estate owned may be deferred until the buyer has a sufficient initial and continuing investment in the property.
Income Taxes	Income Taxes-Income taxes are accounted for using the asset and liability method. Under this method a deferred tax asset or liability is determined based on the enacted tax rates which will be in effect when the differences between the financial statement carrying amounts and tax basis of existing assets and liabilities are expected to be reported in the Company's income tax returns. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established to reduce the net carrying amount of deferred tax assets ("DTA") if it is determined to be more likely than not, that all or some portion of the potential deferred tax asset will not be realized. Deferred tax assets are recognized subject to management's judgment that realization is "more likely than not." Uncertain tax positions that meet the more likely than not recognition threshold are measured to determine the amount of benefit to recognize. An uncertain tax position is measured at the amount of benefit that management believes has a greater than 50% likelihood of realization upon settlement. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the DTA will or will not be realized. The Company's ultimate realization of the DTA is dependent upon the generation of future taxable income during the periods in which temporary differences become deductible. Management considers the nature and amount of historical and projected future taxable income, the scheduled reversal of deferred tax assets and liabilities, and available tax planning strategies in making this assessment. The amount of deferred taxes recognized could be impacted by changes to any of these variables.
Derivatives	Derivatives-The Bank enters into forward delivery contracts to sell residential mortgage loans or mortgage-backed securities to broker/dealers at specific prices and dates in order to hedge the interest rate risk in its portfolio of mortgage loans held for sale and its residential mortgage loan commitments. The commitments to originate mortgage loans held for sale and the related forward delivery contracts are considered derivatives. The Bank also executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are hedged by simultaneously entering into an offsetting interest rate swap that the Bank executes with a third party, such that the Bank minimizes its net risk exposure. The Company considers all free-standing derivatives as economic hedges and recognizes these derivatives as either assets or liabilities in the balance sheet, and requires measurement of those instruments at fair value through adjustments to current earnings. None of the Company's derivatives are designated as hedging instruments. The fair value of the derivative residential mortgage loan commitments is estimated using the net present value of expected future cash flows. Assumptions used include pull-through rate assumption based on historical information, current mortgage interest rates, the stage of completion of the underlying application and underwriting process, direct origination costs yet to be incurred, the time remaining until the expiration of the derivative loan commitment, and the expected net future cash flows related to the associated servicing of the loan. The Bank may use derivatives to hedge the risk of changes in the fair values of interest rate lock commitments and residential mortgage loans held for sale. None of the Company's derivatives are designated as hedging instruments. Rather, they are accounted for as free-standing derivatives, or economic hedges, with changes in the fair value of the derivatives reported in income. The Company primarily utilizes forward interest rate contracts in its derivative risk management strategy.
Operating Segments	Operating Segments- Public enterprises are required to report certain information about their operating segments in its financial statements. They are also required to report certain enterprise-wide information about the Company's products and services, its activities in different geographic areas, and its reliance on major customers. The basis for determining the Company's operating segments is the manner in which management operates the business. In the first quarter of 2017, the Company realigned its operating segments based on changes in its internal reporting structure to align with the changes in the Company's Chief Operating Decision Maker. The Company now reports four primary segments, which are also the Company's reporting units: Commercial Bank, Wealth Management, Retail Bank, and Home Lending with the remainder as Corporate and other.
Share-Based Payment	Share-Based Payment- We recognize expense in the income statement for the grant-date fair value of restricted share awards, stock options and other equity-based forms of compensation issued to employees over the employees' requisite service period (generally the vesting period). The requisite service period may be subject to performance conditions. The fair value of the restricted share awards is based on the Company's share price on the grant date. Stock options and restricted stock awards generally vest ratably over three to five years and are recognized as expense over that same period of time. The exercise price of each option equals the market price of the Company's common stock on the date of the grant, and the maximum term is ten years. Certain restricted stock awards are subject to performance-based and market-based vesting as well as other approved vesting conditions and cliff vest based on those conditions. Compensation expense is recognized over the service period to the extent restricted stock awards are expected to vest. The fair value of the restricted stock award grants is estimated as of the grant date using a Monte Carlo simulation pricing model.
Earnings per Share (EPS)	Earnings per Share ("EPS")- Nonvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are participating securities and are included in the computation of EPS pursuant to the two-class method. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. Certain of the Company's nonvested restricted stock awards qualify as participating securities. Net income is allocated between the common stock and participating securities pursuant to the two-class method, based on their rights to receive dividends, participate in earnings or absorb losses. Basic earnings per common share is computed by dividing net earnings available to common shareholders by the weighted average number of common shares outstanding during the period, excluding participating nonvested restricted shares. Diluted earnings per common share is computed in a similar manner, except that first the denominator is increased to include the number of additional common shares that would have been outstanding if potentially dilutive common shares, excluding the participating securities, were issued using the treasury stock method. For all periods presented, stock options, certain restricted stock awards and restricted stock units are potentially dilutive non-participating instruments issued by the Company. Next, we determine and include in diluted earnings per common share calculation the more dilutive effect of the participating securities using the treasury stock method or the two-class method. Undistributed losses are not allocated to the nonvested share-based payment awards (the participating securities) under the two-class method as the holders are not contractually obligated to share in the losses of the Company.
Fair Value Measurements	Fair Value Measurements- Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy for disclosure of assets and liabilities measured or disclosed at fair value. The classification of assets and liabilities within the hierarchy is based on whether the inputs to the valuation methodology used for measurement are observable or unobservable. Observable inputs reflect market-derived or market-based information obtained from independent sources, while unobservable inputs reflect our estimates about market data. In general, fair values determined by Level 1 inputs utilize quoted prices for identical assets or liabilities traded in active markets that the Company has the ability to access. Fair values determined by Level 2 inputs utilize inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets and liabilities in active markets, and inputs other than quoted prices that are observable for the asset or liability, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements- In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606), which creates Topic 606 and supersedes Topic 605, Revenue Recognition. In August 2015, FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606), which postponed the effective date of 2014-09. Multiple ASUs and interpretative guidance have been issued in connection with ASU 2014-09. The core principle of Topic 606 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In general, the new guidance requires companies to use more judgment and make more estimates than under current guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. The standard is effective for public entities for interim and annual periods beginning after December 15, 2017; early adoption is not permitted. For financial reporting purposes, the standard allows for either full retrospective adoption, meaning the standard is applied to all of the periods presented, or modified retrospective adoption, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company has reviewed all revenue sources to determine the sources that are in scope for this guidance. As a bank, key revenue sources, such as interest income, have been identified as out of scope of this new guidance. The Company's overall assessment of key in-scope revenue sources include service charges on deposits, credit card and payment processing fees, and brokerage revenues. The Company adopted the guidance on January 1, 2018, utilizing the modified retrospective approach. The guidance will not have a material or significant impact on the Company's consolidated financial statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The new guidance is intended to improve the recognition and measurement of financial instruments. This ASU requires equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. In addition, the amendment requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes and requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (i.e., securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements. This ASU also eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The amendment also requires a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument specific credit risk (also referred to as "own credit") when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. ASU No. 2016-01 is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted the guidance on January 1, 2018 and will not have a material impact on the Company's consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The amendments in this update require lessees, among other things, to recognize lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under previous authoritative guidance. This update also introduces new disclosure requirements for leasing arrangements. ASU 2016-02 is effective for financial statements issued for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company has established a project team for the implementation of this new standard. The team has completed implementation of a new leasing software that will support the current leasing process, as well as aid in the transition to the new leasing guidance. Although an estimate of the impact of the new leasing standard has not yet been determined, the Company expects a significant new lease asset and related lease liability on the balance sheet due to the number of leased properties the Bank currently has that are accounted for under current operating lease guidance. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments —Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU is intended to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The ASU requires the measurement of all expected credit losses for certain financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates, but will continue to use judgment to determine which loss estimation method is appropriate for their circumstances. The ASU requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization's portfolio. These disclosures include qualitative and quantitative requirements that provide additional information about the amounts recorded in the financial statements. In addition, the ASU amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early application will be permitted for specified periods. The Company has an established cross-functional team and project management governance process in place to manage implementation of this new guidance. The team has been working on the process by vetting the data elements and implementing modeling options that are expected to be critical to the new process. An estimate of the impact of this standard has not yet been determined, however, the impact is expected to be significant. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The ASU was issued to simplify the subsequent measurement of goodwill and the amendment eliminates Step 2 from the goodwill impairment test. The annual, or interim, goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The amendment is effective for annual reporting periods beginning after December 31, 2019. Early adoption of the update is permitted. The Company does not expect this ASU to have a material impact on the Company's consolidated financial statements. In February 2017, the FASB issued ASU No. 2017-05, Other Income —Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. The amendment clarifies that a financial asset is within the scope of Subtopic 610-20 if it meets the definition of an in substance nonfinancial asset. The amendments also define the term in substance nonfinancial asset. The amendments clarify that nonfinancial assets within the scope of Subtopic 610-20 may include nonfinancial assets transferred within a legal entity to a counterparty. A contract that includes the transfer of ownership interests in one or more consolidated subsidiaries is within the scope of Subtopic 610-20 if substantially all of the fair value of the assets that are promised to the counterparty in a contract is concentrated in nonfinancial assets. The amendments clarify that an entity should identify each distinct nonfinancial asset or in substance nonfinancial asset promised to a counterparty and derecognize each asset when a counterparty obtains control of it. The amendment is effective at the same time as the Topic 606, Revenue from Contracts with Customers. For public entities, the amendments are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. The Company adopted the guidance on January 1, 2018 and does not expect this ASU to have a material impact on the Company's consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The ASU is intended to improve and simplify accounting rules for hedge accounting by better aligning a company's financial reporting for hedging activities with the economic objectives of those activities. The standard refines and expands hedge accounting for both financial (e.g., interest rate) and commodity risks. Its provisions create more transparency around how economic results are presented, both on the face of the financial statements and in the footnotes. The ASU takes effect for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, early adoption is permitted in any interim period or fiscal years before the effective date of the standard. The Company is currently evaluating the impact of this ASU on the Company's consolidated financial statements. In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842) - Land Easement Practical Expedient for Transition to Topic 842. The ASU clarifies the application of the new lease guidance to land easements and eases adoption efforts for some land easements. The amendment provides an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under Topic 840, Leases. An entity that elects this practical expedient should evaluate new or modified land easements under Topic 842 beginning at the date that the entity adopts Topic 842. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. The ASU has the same effective date and transition requirements as ASU 2016-02, which is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early application will be permitted for specified periods. The Company is currently evaluating the impact of this ASU on the Company's consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The ASU was issued to address certain stranded tax effects in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act of 2017. The ASU provides companies the option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change from the newly enacted corporate tax rate is recorded. The amount of the reclassification would be calculated on the basis of the difference between the historical and newly enacted tax rates for deferred tax liabilities and assets related to items within accumulated other comprehensive income. The ASU requires companies to disclose its accounting policy related to releasing income tax effects from AOCI, whether it has elected to reclassify the stranded tax effects, and information about the other income tax effects that are reclassified. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods, therein, and early adoption is permitted for public business entities for which financial statements have not yet been issued. As of December 31, 2017, Umpqua adopted the ASU and made a reclassification adjustment from accumulated other comprehensive income to retained earnings on the Consolidated Statements of Changes in Shareholders' Equity, related to the stranded tax effects due to the change in the federal corporate tax rate applied on the unrealized gains (losses) on investments on a portfolio basis, to reflect the provisions of this ASU.
Reclassifications	Reclassifications- Certain amounts reported in prior years' consolidated financial statements have been reclassified to conform to the current presentation. In the first quarter of 2017, the Company realigned its operating segments based on changes in its internal reporting structure to align with the changes in the Company's Chief Operating Decision Maker. The Company now reports four primary segments: Commercial Bank, Wealth Management, Retail Bank, and Home Lending with the remainder as Corporate and other. As a result of this realignment, segment reporting was updated. The prior periods have been updated to be comparable to the current period presentation in Note 24 - Segment Information.
Loans and Leases, Troubled Debt Restructurings	In order for a newly restructured loan to be considered for accrual status, the loan's collateral coverage generally will be greater than or equal to 100% of the loan balance, the loan is current on payments, and the borrower must either prefund an interest reserve or demonstrate the ability to make payments from a verified source of cash flow. Impaired restructured loans carry a specific allowance and the allowance on impaired restructured loans is calculated consistently across the portfolios.
Income Tax Uncertainties	The Company periodically reviews its income tax positions based on tax laws and regulations and financial reporting considerations, and records adjustments as appropriate. This review takes into consideration the status of current taxing authorities' examinations of the Company's tax returns, recent positions taken by the taxing authorities on similar transactions, if any, and the overall tax environment.