Summary of Significant Accounting Policies

Organization

Columbia Banking System, Inc. (the “Corporation”, “we”, “our”, “Columbia” or the “Company”) is the holding company for Columbia State Bank (“Columbia Bank” or the “Bank”) and Columbia Trust Company (“Columbia Trust”). The Bank provides a full range of financial services through 143 branch locations, including 73 in the State of Washington, 56 in Oregon and 14 in Idaho. Columbia Trust provides fiduciary, agency, trust and related services, and life insurance products. Because the Bank comprises substantially all of the business of the Corporation, references to the “Company” mean the Corporation, the Bank and Columbia Trust together. The Corporation is approved as a bank holding company pursuant to the Gramm-Leach-Bliley Act of 1999.

The Company’s accounting and reporting policies conform to accounting principles generally accepted in the United States of America (“GAAP”) and practices in the financial services industry. To prepare the financial statements in conformity with GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, and income and expenses during the reporting period. Circumstances and events that differ significantly from those underlying our estimates and assumptions could cause actual financial results to differ from our estimates. The most significant estimates included in the financial statements relate to the allowance for loan and lease losses, business combinations, purchased credit impaired loans, Federal Deposit Insurance Corporation (“FDIC”) loss-sharing asset and goodwill impairment.

The Company has applied its accounting policies and estimation methods consistently in all periods presented in these financial statements (to the periods in which they applied).

Consolidation

The Consolidated Financial Statements of the Company include the accounts of the Corporation and its subsidiaries, including the Bank and Columbia Trust. Intercompany balances and transactions have been eliminated in consolidation.

Cash and cash equivalents

Cash and cash equivalents include cash and due from banks, and interest bearing balances due from correspondent banks and the Federal Reserve Bank. Cash equivalents have a maturity of 90 days or less at the time of purchase.

Securities

Securities are classified based on management’s intention on the date of purchase. All securities are classified as available for sale and are presented at fair value. Unrealized gains or losses on securities available for sale are excluded from net income but are included as separate components of other comprehensive income, net of taxes. Purchase premiums or discounts on securities available for sale are amortized or accreted into income using the interest method over the terms of the individual securities. The Company performs a quarterly assessment to determine whether a decline in fair value below amortized cost is other-than-temporary. Amortized cost includes adjustments made to the cost of an investment for accretion, amortization, collection of cash and previous other-than temporary impairment recognized in earnings. Other-than-temporary impairment exists when it is probable that the Company will be unable to recover the entire amortized cost basis of the security.

In performing the quarterly assessment for debt securities, management considers whether or not the Company expects to recover the entire amortized cost basis of the security. In addition, management also considers whether it is more likely than not that it will not have to sell the security before recovery of its cost basis. If the Company intends to sell a security or it is more likely than not it will be required to sell a security prior to recovery of its cost basis, the entire amount of impairment is recognized in earnings. If the Company does not intend to sell the security or it is not more likely than not it will be required to sell the security prior to recovery of its cost basis, the credit loss component of impairment is recognized in earnings and impairment associated with non-credit factors, such as market liquidity, is recognized in “Other comprehensive income (loss), net of tax”. A credit loss is the difference between the cost basis of the security and the present value of cash flows expected to be collected, discounted at the security’s effective interest rate at the date of acquisition. The cost basis of an other-than-temporarily impaired security is written down by the amount of impairment recognized in earnings. The new cost basis is not adjusted for subsequent recoveries in fair value. However, the difference between the new amortized cost basis and the cash flows expected to be collected is accreted as interest income. The total other-than-temporary impairment, if any, is presented in the Consolidated Statements of Income with a reduction for the amount of other-than-temporary impairment that is recognized in “Other Comprehensive Income”, if any.

Realized gains or losses on sales of securities available for sale are recorded using the specific identification method.

Federal Home Loan Bank Stock

FHLB stock is composed of two sub-classes: membership stock and activity based stock. Membership stock is stock we are required to purchase and hold as a condition of membership in the FHLB. The Company’s membership stock purchase requirement is measured as a percentage of our year-end assets, subject to a $10 million cap. Activity based stock is stock we are required to purchase and hold in order to obtain an advance or participate in FHLB mortgage programs. Class B stock may be redeemed, subject to certain limitations, on five years’ written notice to the FHLB. Our FHLB stock is carried at par value because the shares are issued, transferred, redeemed, and repurchased by the FHLB at a par value of $100. The FHLB stock is subject to recoverability testing per the Financial Services-Depository and Lending topic of the FASB Accounting Standards Codification (“ASC”).

Loans

Loans, excluding purchased credit impaired loans are generally carried at the unpaid principal balance, net of premiums, discounts and net deferred loan fees. Net deferred loan fees include nonrefundable loan origination fees less direct loan origination costs. Net deferred loan fees, premiums and discounts are amortized into interest income using either the interest method or straight-line method over the terms of the loans, adjusted for actual prepayments. The amortization is calculated using the interest method for all loans except revolving loans, for which the straight-line method is used. Interest income is accrued as earned. Fees related to lending activities other than the origination or purchase of loans are recognized as noninterest income during the period the related services are performed.

Nonaccrual loans—Loans are placed on nonaccrual status when a loan becomes contractually past due 90 days with respect to interest or principal unless the loan is both well secured and in the process of collection, or if full collection of interest or principal becomes uncertain. When a loan is placed on nonaccrual status, any accrued and unpaid interest receivable is reversed and the amortization of net deferred loan fees, premiums and discounts ceases. The interest payments received on nonaccrual loans are generally accounted for on the cost-recovery method whereby the interest payment is applied to the principal balances. Loans may be returned to accrual status when improvements in credit quality eliminate the doubt as to the full collectability of both interest and principal and a period of sustained performance has occurred.

Impaired loans—Loans are considered impaired when based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement or when a loan has been modified in a troubled debt restructuring. The assessment for impairment occurs when and while such loans are designated as classified per the Company’s internal risk rating system or when and while such loans are on nonaccrual. All nonaccrual loans greater than $500,000 and all troubled debt restructured loans are considered impaired and analyzed individually on a quarterly basis. Classified loans with an outstanding balance greater than $500,000 are evaluated for potential impairment on a quarterly basis.

Restructured Loans—A loan is classified as a troubled debt restructuring when a borrower is experiencing financial difficulties that lead to a restructuring of the loan, and the Company grants concessions to the borrower in the restructuring that it would not otherwise consider. These concessions may include interest rate reductions, principal forgiveness, extension of maturity date and other actions intended to minimize potential losses. Generally, a nonaccrual loan that is restructured remains on nonaccrual status for a period of six months to demonstrate that the borrower can meet the restructured terms. If the borrower’s performance under the new terms is not reasonably assured, the loan remains classified as a nonaccrual loan.

Purchased Credit Impaired Loans (“PCI Loans”)—Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are accounted for under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. In addition, because of the significant discounts associated with certain of the acquired loan portfolios, the Company elected to account for those certain acquired loans under ASC 310-30.

In situations where such loans have similar risk characteristics, loans are aggregated into pools to estimate cash flows. A pool is accounted for as a single asset with a single interest rate, cumulative loss rate and cash flow expectation. Expected cash flows at the acquisition date in excess of the fair value of loans are considered to be accretable yield, which is recognized as interest income over the life of the loan pool using a level yield method if the timing and amount of the future cash flows of the pool is reasonably estimable. Subsequent to the acquisition date, any increases in cash flow over those expected at purchase date in excess of fair value are recorded as interest income prospectively. Any subsequent decreases in cash flow over those expected at purchase date due to credit deterioration are recognized by recording an allowance for losses on purchased credit impaired loans. Any disposals of loans, including sales of loans, payments in full or foreclosures result in the removal of the loan from the loan pool at the carrying amount.

Unfunded loan commitments—Unfunded commitments are generally related to providing credit facilities to clients of the Bank and are not actively traded financial instruments. These unfunded commitments are disclosed as financial instruments with off-balance sheet risk in Note 17 in the Notes to Consolidated Financial Statements.

Allowance for Loan and Lease Losses

The allowance for loan and lease losses (the “allowance”) is an accounting estimate of incurred credit losses in our loan portfolio at the balance sheet date. The provision for loan and lease losses is the expense recognized in the Consolidated Statements of Income to adjust the allowance to the levels deemed appropriate by management, as measured by the Company’s credit loss estimation methodologies.

Loans Collectively Evaluated for Impairment—This measure of estimated credit losses is based upon the loss experience over a historical base period adjusted for a loss emergence period. The loss emergence period is an estimate of the period that it takes, on average, for us to identify the amount of loss incurred for a loan that has suffered a loss-causing event. We then consider the effects of certain qualitative factors such as economic and business conditions, concentration of credit, nature and volume of portfolio, and problem loan trends to ensure our allowance reflects the inherent losses in the loan portfolio.

Loan and lease losses are charged against the allowance when management believes the collectability of a loan balance is unlikely. Subsequent recoveries, if any, are credited to the allowance.

Loans Individually Evaluated for Impairment—This measure of estimated credit losses begins if, based upon current information and events, we believe it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement or when a loan has been modified in a troubled debt restructuring. When a loan has been identified as impaired, the amount of impairment will be measured using discounted cash flows, except when it is determined that the remaining source of repayment for the loan is the operation or liquidation of the underlying collateral. In these cases, the current fair value of the collateral, reduced by costs to sell, will be used in place of discounted cash flows. As a final alternative, the observable market price of the debt may be used to assess impairment. Predominantly, the Company uses the fair value of collateral approach based upon a reliable valuation. When the measurement of the impaired loan is less than the recorded amount of the loan, an impairment is recognized by recording a charge-off to the allowance or by designating a specific reserve.

Purchased Credit Impaired Loans—The Company updates its cash flow projections for purchased credit impaired loans accounted for under ASC 310-30 on a quarterly basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis. The loan migration analysis is a matrix of probability that is used to estimate the probability of a loan pool transitioning into a particular delinquency state given its delinquency state at the remeasurement date. Loss severity factors are based upon either actual charge-off data within the loan pools or industry averages, and recovery lags are based upon the collateral within the loan pools.

Any decreases in expected cash flows after the acquisition date and subsequent measurement periods are recognized by recording a provision for loan losses. See “Purchased Credit Impaired Loans” for further discussion.

Unfunded Commitments and Letters of Credit—The allowance for unfunded commitments is maintained at a level believed by management to be sufficient to absorb estimated probable losses related to these unfunded credit facilities. The determination of the adequacy of the allowance is based on periodic evaluations of the unfunded credit facilities including an assessment of the probability of commitment usage, credit risk factors for loans outstanding to these same customers, and the terms and expiration dates of the unfunded credit facilities. The allowance for unfunded commitments is included in “Other liabilities” on the Consolidated Balance Sheets, with changes to the balance charged against noninterest expense.

Premises and Equipment

Land, buildings, leasehold improvements and equipment are stated at cost less accumulated depreciation and amortization. Gains or losses on dispositions are reflected in current operations. Expenditures for improvements and major renewals are capitalized, and ordinary maintenance, repairs and small purchases are charged to “Occupancy” in the Consolidated Statements of Income. Depreciation and amortization are computed based on the straight-line method over the estimated useful lives of the various classes of assets. The ranges of useful lives for the principal classes of assets are as follows:



Buildings and building improvements	5 to 39 years
Leasehold improvements	Term of lease or useful life, whichever is shorter
Furniture, fixtures and equipment	3 to 7 years
Vehicles	5 years
Computer software	3 to 5 years

Software

Capitalized software is stated at cost, less accumulated amortization. Amortization is computed on a straight-line basis and charged to expense over the estimated useful life of the software, which is generally three years. Capitalized software is included in “Premises and equipment, net” in the Consolidated Balance Sheets.

Other Real Estate Owned

Other real estate owned (“OREO”) is composed of real estate acquired by the Company through either foreclosure or deed in lieu of foreclosure in satisfaction of debt. At acquisition, OREO is recorded at fair value less estimated costs to sell. Any fair value adjustments at acquisition are charged to the allowance, or in the event of a write-up without previous losses charged to the allowance, a credit to earnings is recorded. The fair value of the OREO is based upon current appraisal. Losses that result from the ongoing periodic valuation of these properties are charged to the net cost of operation of OREO in the period in which they are identified. Improvements to the OREO are capitalized and holding costs are charged to the net cost of operation of OREO as incurred.

FDIC Loss-sharing Asset

The acquisition date fair value of the reimbursement the Company expected to receive from the FDIC under loss-sharing agreements was recorded in the FDIC loss-sharing asset on the Consolidated Balance Sheets. Subsequent to initial recognition, the FDIC loss-sharing asset is reviewed quarterly and adjusted for any changes in expected cash flows. These adjustments are measured on the same basis as the related covered assets. Any decrease in expected cash flows for the covered assets due to an increase in expected credit losses will increase the FDIC loss-sharing asset and any increase in expected future cash flows for the covered assets due to a decrease in expected credit losses will decrease the FDIC loss-sharing asset. Changes in the estimated cash flows on covered assets that are immediately recognized in income generally result in a similar immediate adjustment to the loss-sharing asset while changes in expected cash flows on covered assets that are accounted for as an adjustment to yield generally result in adjustments to the amortization or accretion rate for the loss-sharing asset. Increases and decreases to the FDIC loss-sharing asset are recorded as adjustments to noninterest income.

Goodwill and Intangibles

Net assets of companies acquired in purchase transactions are recorded at fair value at the date of acquisition. Identified intangibles are amortized on an accelerated basis over the period benefited. Goodwill is not amortized but is reviewed for potential impairment during the third quarter on an annual basis or, more frequently, if events or circumstances indicate a potential impairment, at the reporting unit level. A reporting unit is an operating segment or one level below an operating segment for which discrete financial information is available and regularly reviewed by management. The Company consists of a single reporting unit. If the fair value of the reporting unit, including goodwill, is determined to be less than the carrying amount of the reporting unit, a further test is required to measure the amount of impairment. If an impairment loss exists, the carrying amount of goodwill is adjusted to a new cost basis. Subsequent reversal of a previously recognized goodwill impairment loss is prohibited.

Intangible assets are evaluated for impairment if events and circumstances indicate a possible impairment. Such evaluation of other intangible assets is based on undiscounted cash flow projections. At December 31, 2016, intangible assets included on the Consolidated Balance Sheets principally consists of a core deposit intangible amortized using an accelerated method with an original estimated life of 10 years.

Income Taxes

The provision for income taxes includes current and deferred income tax expense on net income adjusted for temporary and permanent differences such as interest income on state and municipal securities and investments in affordable housing credits. Deferred tax assets and liabilities are recognized for the expected future tax consequences of existing temporary differences between the financial reporting and tax reporting basis of assets and liabilities using enacted tax laws and rates. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. On a quarterly basis, management evaluates deferred tax assets to determine if these tax benefits are expected to be realized in future periods. This determination is based on facts and circumstances, including the Company’s current and future tax outlook. To the extent a deferred tax asset is no longer considered “more likely than not” to be realized, a valuation allowance is established.

We recognize the tax benefit from uncertain tax positions only if it is more likely than not that the tax positions will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. We recognize interest and penalties related to unrecognized tax benefits in “Provision for income taxes” in the Consolidated Statements of Income.

Advertising

Advertising costs are generally expensed as incurred.

Earnings per Common Share

The Company’s capital structure includes convertible preferred shares, common shares, restricted common shares, common share options, and during portions of 2014 and 2013, warrants to purchase common shares. Restricted common shares participate in dividends declared on common shares at the same rate as common shares. Convertible preferred shares participate in dividends declared on common shares on an “as if converted” basis. Accordingly, the Company calculates earnings per common share (“EPS”) using the two-class method under the Earnings per Share topic of the FASB ASC. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common shareholders but does not require the presentation of basic and diluted EPS for securities other than common shares.

Under the two-class method, basic EPS is computed by dividing earnings allocated to common shareholders by the weighted average number of common shares outstanding for the period. Earnings allocated to common shareholders represents net income reduced by earnings allocated to participating securities. Participating securities include nonvested restricted stock awards and preferred stock. Diluted EPS is computed in the same manner as basic earnings per share except that the denominator is increased to include the number of additional common shares that would have been outstanding if certain shares issuable upon exercise of options and warrants were included unless those additional shares would have been anti-dilutive. For the diluted EPS computation, the treasury stock method is applied and compared to the two-class method and whichever method results in a more dilutive impact is utilized to calculate diluted EPS.

Share-Based Payment

The Company accounts for stock options and stock awards in accordance with the Compensation—Stock Compensation topic of the FASB ASC. Authoritative guidance requires the Company to measure the cost of employee services received in exchange for an award of equity instruments, such as stock options or stock awards, based on the fair value of the award on the grant date. This cost must be recognized in the Consolidated Statements of Income over the vesting period of the award.

The Company issues restricted stock awards which generally vest over a four or five-year period during which time the holder receives dividends and has full voting rights. Restricted stock is valued at the closing price of the Company’s stock on the date of an award.

Derivatives and Hedging Activities

In accordance with the Derivatives and Hedging topic of the FASB ASC, the Company recognizes derivatives as assets or liabilities on the Consolidated Balance Sheets at their fair value. The Company periodically enters into interest rate contracts with customers and offsetting contracts with third parties. As these interest rate contracts are not designated as hedges under the Derivatives and Hedging topic of the FASB ASC, the changes in fair value of these instruments are recognized immediately in earnings.

Accounting Pronouncements

During the year ended December 31, 2016, the following Accounting Standards Updates were issued or became effective:

In August 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-15, Classification of Certain Cash Receipts and Cash Payments. The amendments in this ASU provide specific guidance on several statement of cash flow classification issues to reduce diversity in practice. The amendments in ASU 2016-15 are effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption is permitted. The Company is assessing the impact that this guidance will have on its Consolidated Financial Statements.

In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments. The amendments included in this ASU require an entity to reflect its current estimate of all expected credit losses for assets held at an amortized cost basis. For available for sale debt securities, credit losses will be measured in a manner similar to current GAAP, however, this ASU will require that credit losses be presented as an allowance rather than as a write-down. The amendments in ASU 2016-13 are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and are required to be adopted through a modified retrospective approach, with a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the ASU is effective.

Currently, the Company cannot reasonably estimate the impact that adoption of ASU 2016-13 will have on its Consolidated Financial Statements; however, the impact may be significant. That assessment is based upon the fact that, unlike the incurred loss models in existing GAAP, the current expected credit loss (“CECL”) model in ASU 2016-13 does not specify a threshold for the recognition of an impairment allowance. Rather, the Company will recognize an impairment allowance equal to its estimate of lifetime expected credit losses, adjusted for prepayments, for in-scope financial instruments as of the end of the reporting period. Accordingly, the impairment allowance measured under the CECL model could increase significantly from the impairment allowance measured under the Company’s existing incurred loss model. Significant CECL implementation matters to be addressed by the Company include selecting loss estimation methodologies, identifying, sourcing and storing data, addressing data gaps, defining a reasonable and supportable forecast period, selecting historical loss information which will be reverted to, documenting the CECL estimation process, assessing the impact to internal controls over financial reporting, capital planning, and seeking process approval from audit and regulatory stakeholders.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. The amendments included in this ASU simplify several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The amendments in ASU 2016-09 are effective for the first interim or annual period beginning after December 15, 2016. Early adoption is permitted. The Company has determined the impact of this guidance will not be material to its Consolidated Financial Statements.

In February 2016, the FASB issued ASU 2016-02, Leases. The amendments included in this ASU create a new accounting model for both lessees and lessors. The new guidance requires lessees to recognize lease liabilities, initially measured as the present value of future lease payments, and corresponding right-of-use assets for all leases with lease terms greater than 12 months. This model differs from the current lease accounting model, which does not require such lease liabilities and corresponding right-of-use assets to be recorded for operating leases. The amendments in ASU 2016-02 must be adopted using the modified retrospective approach and will be effective for the first interim or annual period beginning after December 15, 2018. Early adoption is permitted. During 2016, the Company implemented a new lease administration application that allows the Company to readily measure future lease payment streams, which is an important component of the new lease accounting model. The Company is assessing the impact that this guidance will have on its Consolidated Financial Statements. See Note 17, “Commitments and Contingent Liabilities”, for more information regarding the minimum future payments related to our operating leases.

In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities. The amendments in ASU 2016-01 require all equity investments to be measured at fair value with changes in the fair value recognized through net income. The amendments in ASU 2016-01 also require an entity 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 when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. In addition, the amendments in this update eliminate the requirement 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 for public business entities. The amendments in ASU 2016-01 are effective for the first interim or annual period beginning after December 15, 2017. The Company is assessing the impact that this guidance will have on its Consolidated Financial Statements but does not expect the impact to be material.