Significant Accounting Policies	9 Months Ended
Sep. 30, 2011
Significant Accounting Policies [Abstract]
Significant Accounting Policies	Note 1: Significant Accounting Policies *Nature of Operations* Chemical Financial Corporation (Chemical or the Corporation) operates in a single operating segment — commercial banking. The Corporation is a financial holding company, headquartered in Midland, Michigan, that operates through one commercial bank, Chemical Bank. Chemical Bank operates within the State of Michigan as a state-chartered commercial bank. Chemical Bank operates through an internal organizational structure of four regional banking units and offers a full range of traditional banking and fiduciary products and services to the residents and business customers in the bank’s geographical market areas. The products and services offered by the regional banking units, through branch banking offices, are generally consistent throughout the Corporation, as is the pricing of those products and services. The marketing of products and services throughout the Corporation’s regional banking units is generally uniform, as many of the markets served by the regional banking units overlap. The distribution of products and services is uniform throughout the Corporation’s regional banking units and is achieved primarily through retail branch banking offices, automated teller machines and electronically accessed banking products. *Basis of Presentation* The accompanying unaudited consolidated financial statements of the Corporation and its subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Corporation’s consolidated financial statements and footnotes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2010. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments believed necessary to present fairly the financial condition and results of operations of the Corporation for the periods presented. Operating results for the three and nine months ended September 30, 2011 are not necessarily indicative of the results that may be expected for the year ending December 31, 2011. *Use of Estimates* Management makes estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying footnotes. Estimates that are particularly susceptible to significant change include the determination of the allowance for loan losses, expected cash flows from acquired loans, fair value amounts related to business combinations, pension expense, income taxes, goodwill impairment and those assets that require fair value measurement. Actual results could differ from these estimates. *Business Combinations* On April 30, 2010, the Corporation acquired 100% of O.A.K. Financial Corporation (OAK) for total consideration of $83.7 million. Pursuant to the guidance of Accounting Standards Codification (ASC) Topic 805, Business Combinations (ASC 805) effective for all acquisitions with closing dates after January 1, 2009, the Corporation recognized the assets acquired and the liabilities assumed in the OAK acquisition at their fair values as of the acquisition date with the related acquisition and restructuring costs expensed in the period incurred. The Corporation recorded $43.5 million of goodwill in conjunction with the acquisition, which represented the purchase price over the fair values of the identifiable net assets acquired. Additionally, the Corporation recorded $9.8 million of other intangible assets as a result of the OAK acquisition attributable to core deposits, mortgage servicing rights and non-compete agreements acquired. See Note 2 for further information regarding the OAK acquisition. *Originated Loans* Originated loans include all of the Corporation’s portfolio loans, excluding loans acquired in the OAK acquisition. Originated loans are stated at their principal amount outstanding, net of unearned income, charge-offs and unamortized deferred fees and costs. Interest income on loans is reported based on the level-yield method and includes amortization of deferred loan fees and costs over the loan term. Net loan commitment fees for commitment periods greater than one year are deferred and amortized into fee income on a straight-line basis over the commitment period. Loan interest income is recognized on the accrual basis. The past due status of a loan is based on the loan’s contractual terms. A loan is placed in the nonaccrual category when principal or interest is past due 90 days or more (except for real estate residential loans that are transferred at 120 days past due), unless the loan is both well-secured and in the process of collection, or earlier when, in the opinion of management, there is sufficient reason to doubt the collectibility of principal or interest. Interest previously accrued, but not collected, is reversed and charged against interest income at the time the loan is placed in nonaccrual status. The subsequent recognition of interest income on a nonaccrual loan is then recognized only to the extent cash is received and where future collection of principal is probable. Loans are returned to accrual status when principal and interest payments are brought current, payments have been received consistently for a period of time (generally six months) and collectibility is no longer in doubt. *Loans Acquired in a Business Combination* Loans acquired in a business combination (acquired loans) consist of loans acquired in the acquisition of OAK. Acquired loans were recorded at fair value, without a carryover of OAK’s associated allowance for loan losses related to these loans, through a fair value discount that was, in part, attributable to deterioration in credit quality. The fair value discount was recorded as a reduction of the acquired loans’ outstanding principal balances in the consolidated statement of financial position at the acquisition date. Those loans that qualify under ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (ASC 310-30), are recorded at fair value at acquisition. The calculation of the fair value of the acquired loans entailed estimating the amount and timing of both principal and interest cash flows expected to be collected on such loans and then discounting those cash flows at market interest rates. The excess of a loan’s expected cash flows at the acquisition date over its estimated fair value is referred to as the “accretable yield,” which is recognized into interest income over the remaining life of the loan on a level-yield basis. The difference between a loan’s contractually required principal and interest payments at the acquisition date and the cash flows expected to be collected at the acquisition date is referred to as the “nonaccretable difference,” which includes an estimate of future credit losses expected to be incurred over the life of the loan and interest payments that are not expected to be collected. The estimate of expected credit losses was determined based on due diligence performed by executive and senior officers of the Corporation, with assistance from third-party consultants. Decreases to the expected cash flows in subsequent periods will require the Corporation to record a provision for loan losses. Improvements in expected cash flows in subsequent periods will result in reversing a portion of the nonaccretable difference, which is then classified as part of the accretable yield and subsequently recognized into interest income over the remaining life of the loan. The Corporation must make numerous assumptions, interpretations and judgments using internal and third-party credit quality information to determine whether it is probable that the Corporation will be able to collect all contractually required payments. This is a point in time assessment and inherently subjective due to the nature of the available information and judgment involved. Evidence of credit quality deterioration as of the purchase date may include credit metrics such as past due and nonaccrual status, deterioration in borrower credit scores and negative changes to loan-to-value percentages. Acquired loans with an outstanding principal balance of $105 million at the acquisition date were determined to be loans with deteriorated credit quality and, therefore, met the scope criteria set forth in ASC 310-30. Further, the Corporation understands, as outlined in the American Institute of Certified Public Accountants’ open letter to the Office of the Chief Accountant of the Securities and Exchange Commission (SEC) dated December 18, 2009 and pending further standard setting, that for acquired loans that do not meet the scope criteria of ASC 310-30, a company may elect to account for such acquired loans pursuant to the provisions of either ASC 310-20, Nonrefundable Fees and Other Costs, or ASC 310-30. The Corporation elected to apply ASC 310-30 by analogy to acquired loans that were determined not to have deteriorated credit quality with an outstanding principal balance of $578 million at the acquisition date and thus follows the accounting and disclosure guidance of ASC 310-30 for these loans. Accordingly, the Corporation applied ASC 310-30 to the entire loan portfolio acquired in the acquisition of OAK with an outstanding principal balance of $683 million at the acquisition date. None of the acquired loans were classified as debt securities. ASC 310-30 allows investors to aggregate loans acquired into loan pools that have common risk characteristics and thereby use a composite interest rate and expectation of cash flows expected to be collected for the loan pools. Under the provisions of ASC 310-30, the Corporation aggregated acquired loans into 14 pools based upon common risk characteristics, including types of loans, commercial type loans with similar risk grades and whether loans were performing or nonperforming. A pool is considered a single unit of accounting for the purposes of applying the guidance as described above. A loan will be removed from a pool of acquired loans only if the loan is sold, foreclosed, paid off or written off, and will be removed from the pool at the 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 would not affect the effective yield used to recognize the accretable difference on the remaining pool. The Corporation estimated the cash flows expected to be collected over the life of the pools of loans at acquisition and estimates expected cash flows quarterly thereafter, based on a set of assumptions including expectations as to default rates, prepayment rates and loss severities. In the event that the updated expected cash flows increase in a pool from those originally projected at acquisition date, the Corporation will adjust the accretable yield amount with a resulting change in the amount recognized in interest income in subsequent periods. In the event that the updated expected cash flows in a pool decrease from those originally projected at the acquisition date, the Corporation will consider that loan pool impaired, which results in the Corporation recording a charge to the provision for loan losses. *Loans Modified Under Troubled Debt Restructurings* Loans modified under troubled debt restructurings (TDRs) involve granting a concession to a borrower who is experiencing financial difficulty. Concessions generally include modifications to original loan terms, including changes to a loan’s payment schedule or interest rate, which generally would not otherwise be considered. The Corporation’s loans reported as TDRs continue to accrue interest at the loan’s effective interest rate as the Corporation expects to collect the full amount of principal and interest accrued at the loan’s original contractual rate at the time of modification. TDRs are reported as nonperforming TDRs until a six-month payment history of principal and interest payments, in accordance with the loan modification, is sustained, at which time the Corporation moves them to a performing TDR status. All TDRs are accounted for as impaired loans and are considered accordingly as part of the analysis of the allowance for loan losses. The Corporation’s commercial and real estate commercial TDRs generally consist of allowing borrowers to defer scheduled principal payments and make interest only payments for a specified period of time at the stated interest rate of the original loan agreement or lower payments due to a modification of the loan’s contractual term. The Corporation does not expect to incur a loss on these loans based on its assessment of the borrowers’ expected cash flows, and accordingly, no additional provision for loan losses has been recognized related to these loans. Since no loss is incurred on these loans, they accrue interest at the loan’s contractual interest rate. These loans are individually evaluated for impairment and transferred to nonaccrual status if it is probable that any remaining principal and interest payments due on the loan will not be collected in accordance with the modified terms of the loan. The Corporation’s real estate residential TDRs generally consist of reducing a borrower’s monthly payments by decreasing the interest rate charged on the loan for a specified period of time (generally 24 months). The Corporation recognizes additional provision for loan losses related to impairment on these loans based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. These loans accrue interest at the loan’s effective interest rate, which consists of contractual interest in addition to an adjustment for the accretion of computed impairment. These loans are moved to nonaccrual status if they become 90 days past due as to principal or interest, or sooner if conditions warrant. *Impaired Loans* A loan is defined to be impaired when it is probable that payment of principal and interest will not be made in accordance with the original contractual terms of the loan agreement. Impaired loans include all classes of nonaccrual loans, all TDRs (nonperforming and performing) and acquired loans that were not performing in accordance with original contractual terms. Impaired loans are carried at the lower of the present value of expected cash flows discounted at the loan’s effective interest rate or the estimated fair value of the collateral if the loan is collateral dependent. *Nonperforming Loans* Nonperforming loans are comprised of originated loans for which the accrual of interest has been discontinued (nonaccrual loans), accruing loans contractually past due 90 days or more as to interest or principal payments and nonperforming TDRs. *Allowance for Loan Losses* The allowance for loan losses (allowance) is presented as a reserve against loans. The allowance represents management’s assessment of probable loan losses inherent in the Corporation’s loan portfolio. Management’s evaluation of the adequacy of the allowance is based on a continuing review of the loan portfolio, actual loan loss experience, the underlying value of the collateral, risk characteristics of the loan portfolio, the level and composition of nonperforming loans, the financial condition of the borrowers, the balance of the loan portfolio, loan growth, economic conditions, employment levels in the Corporation’s local markets, and special factors affecting specific business sectors. The Corporation maintains formal policies and procedures to monitor and control credit risk. Management evaluates the allowance on a quarterly basis in an effort to ensure the level is adequate to absorb probable losses inherent in the loan portfolio. The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be incurred in the remainder of the originated loan portfolio, but that have not been specifically identified. The Corporation utilizes its own loss experience to estimate inherent losses on loans. Internal risk ratings are assigned to each commercial, real estate commercial, real estate construction and land development loan at the time of approval and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review quarterly on all loans greater than $0.25 million that have deteriorated below certain levels of credit risk, and may allocate a specific portion of the allowance to such loans based upon this review. A portion of the allowance is allocated to the remaining loans by applying projected loss ratios, based on numerous factors. Projected loss ratios incorporate factors such as recent charge-off experience, trends with respect to adversely risk-rated commercial, real estate commercial, real estate construction and land development loans, trends with respect to past due and nonaccrual loans, changes in economic conditions and trends, changes in the value of underlying collateral and other credit risk factors. This evaluation involves a high degree of uncertainty. In determining the allowance and the related provision for loan losses, the Corporation considers four principal elements: (i) valuation allowances based upon probable losses identified during the review of impaired commercial, real estate commercial, real estate construction and land development loans, (ii) allocations established for adversely-rated commercial, real estate commercial, real estate construction and land development loans and nonaccrual real estate residential, consumer installment and home equity loans, (iii) allocations, by loan classes, on all other loans based principally on multi-year historical loan loss experience and loan loss trends and (iv) an unallocated allowance based on the imprecision in the overall allowance methodology. The first element reflects the Corporation’s estimate of probable losses based upon the systematic review of individually impaired commercial, real estate commercial, real estate construction and land development loans in the originated loan portfolio. These estimates are based upon a number of objective factors, such as payment history, financial condition of the borrower and discounted collateral exposure. The Corporation measures the investment in an impaired loan based on one of three methods: the loan’s observable market price; the fair value of the collateral; or, the present value of expected future cash flows discounted at the loan’s effective interest rate. At September 30, 2011, loans in the commercial loan portfolio that were in nonaccrual status were valued based on the fair value of the collateral securing the loan, while TDRs in the commercial loan portfolio were valued based on the present value of expected future cash flows discounted at the loan’s effective interest rate. It is the Corporation’s general policy to, at least annually, obtain new appraisals on impaired loans that are primarily secured by real estate. When the Corporation determines that the fair value of the collateral is less than the carrying value of an impaired loan on nonaccrual status and a portion is deemed not collectible, the portion of the impairment that is deemed not collectible is charged off (confirmed loss) and deducted from the allowance. The remaining carrying value of the impaired loan is classified as a nonperforming loan. When the Corporation determines that the fair value of the collateral is less than the carrying value of an impaired loan but believes it is probable it will recover this impairment, the Corporation establishes a valuation allowance for such impairment. The second element reflects the application of the Corporation’s loan grade risk rating system. This risk rating system is similar to those employed by state and federal banking regulators. Loans in the commercial loan portfolio that are risk rated below a certain predetermined risk grade and nonaccrual real estate residential and nonaccrual consumer installment and home equity loans are assigned a loss allocation factor that is based upon a historical analysis of actual loan losses incurred and a valuation of the type of collateral securing the loans. The third element is determined by assigning allocations based principally upon a multi-year average of loss experience for each class of loan. Average losses may be adjusted based on current loan loss experience and delinquency trends. This component considers the lagging impact of historical charge-off ratios in periods where future loan charge-offs are expected to increase or decrease, trends in delinquencies and nonaccrual loans, the changing portfolio mix in terms of collateral, average loan balance, loan growth and the degree of seasoning in the various loan portfolios. Loan loss analyses are performed quarterly. During the quarter ended September 30, 2011, the Corporation revised its historical loan loss experience from three years to five years to better capture and reflect the loss experience inherent in the various classes of the loan portfolio. In addition, the Corporation judgmentally applied a percentage weighting to each of the years in the five-year period with higher weighting placed on the most recent years. The change did not have a significant impact on the overall allowance for loan losses. The fourth element is based on factors that cannot be associated with a specific credit or loan class and reflects an attempt to ensure that the overall allowance appropriately reflects a margin for the imprecision necessarily inherent in the estimates of loan losses. Management maintains an unallocated allowance to recognize the uncertainty and imprecision underlying the process of estimating inherent loan losses in the loan portfolio. Determination of the probable losses inherent in the portfolio, which are not necessarily captured by the allocation methodology discussed above, involves the exercise of judgment. The unallocated allowance associated with the imprecision in the risk rating system is based on a historical evaluation of the accuracy of the risk ratings associated with loans. This unallocated portion of the allowance is judgmentally determined and generally serves to compensate for the uncertainty in estimating inherent losses, particularly in times of changing economic conditions, and also considers the possibility of improper risk ratings. The unallocated portion of the allowance also takes into consideration economic conditions within the State of Michigan and nationwide, including unemployment levels, industry-wide loan delinquency rates, and declining commercial and residential real estate values and historically high inventory levels of residential lots, condominiums and single family houses held for sale. Although the Corporation allocates portions of the allowance to specific loans and loan types, the entire allowance is available for any loan losses that occur. Loans that are deemed not collectible are charged off and deducted from the allowance. The provision for loan losses and recoveries on loans previously charged off are added to the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off against the allowance. Acquired loans are aggregated into pools based upon common risk characteristics. An allowance may be recorded related to acquired loans, if an acquired loan pool experiences a decrease in expected cash flows as compared to those projected at the acquisition date. On a quarterly basis, the expected future cash flow of each pool is estimated based on various factors including changes in property values of collateral dependent loans, default rates, loss severities and prepayment speeds. Decreases in estimates of expected cash flows within a pool generally result in a charge to the provision for loan losses and a corresponding increase in the allowance allocated to acquired loans for the particular pool. Increases in estimates of expected cash flows within a pool generally result first in a reduction in the allowance allocated to acquired loans for the particular pool, and second in an adjustment to the accretable yield for the pool, which will increase amounts recognized in interest income in subsequent periods. Various regulatory agencies, as an integral part of their examination process, periodically review the allowance. Such agencies may require additions to the allowance based on their judgment reflecting information available to them at the time of their examinations. *Fair Value Measurements* Fair value for assets and liabilities measured at fair value on a recurring or nonrecurring basis refers to the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants in the market in which the reporting entity transacts such sales or transfers based on the assumptions market participants would use when pricing an asset or liability. Assumptions are developed based on prioritizing information within a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data, such as the reporting entity’s own data. The Corporation may choose to measure eligible items at fair value at specified election dates. Unrealized gains and losses on items for which the fair value measurement option has been elected are reported in earnings at each subsequent reporting date. The fair value option (i) may be applied instrument by instrument, with certain exceptions, allowing the Corporation to record identical financial assets and liabilities at fair value or by another measurement basis permitted under GAAP, (ii) is irrevocable (unless a new election date occurs) and (iii) is applied only to entire instruments and not to portions of instruments. At September 30, 2011, December 31, 2010 and September 30, 2010, the Corporation had not elected the fair value option for any financial assets or liabilities. *Share-Based Compensation* The Corporation has granted stock options, stock awards and restricted stock performance units to certain executive and senior management employees. The Corporation accounts for share-based compensation expense using the modified-prospective transition method. Under that method, compensation expense is recognized for share-based awards granted after December 31, 2005, based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance for performance-based awards. The fair value of stock options is recognized as compensation expense on a straight-line basis over the requisite service period. The fair value of restricted stock performance units is recognized as compensation expense over the requisite performance period. Cash flows realized from the tax benefits of exercised stock option awards that result from actual tax deductions that are in excess of the recorded tax benefits related to the compensation expense recognized for those options (excess tax benefits) are classified as financing activities on the consolidated statements of cash flows. *Income and Other Taxes* The Corporation is subject to the income and other tax laws of the United States and the State of Michigan. These laws are complex and are subject to different interpretations by the taxpayer and the various taxing authorities. In determining the provision for income and other taxes, management must make judgments and estimates about the application of these inherently complex laws, related regulations and case law. In the process of preparing the Corporation’s tax returns, management attempts to make reasonable interpretations of enacted tax laws. These interpretations are subject to challenge by the tax authorities upon audit or to reinterpretation based on management’s ongoing assessment of facts and evolving case law. The Corporation and its subsidiaries file a consolidated federal income tax return. The provision for federal income taxes is based on income and expenses, as reported in the consolidated financial statements, rather than amounts reported on the Corporation’s federal income tax return. The difference between the federal statutory income tax rate and the Corporation’s effective federal income tax rate is primarily a function of the proportion of the Corporation’s interest income exempt from federal taxation, nondeductible interest expense and other nondeductible expenses relative to pretax income and tax credits. When income and expenses are recognized in different periods for tax purposes than for book purposes, deferred tax assets and liabilities are recognized for the future tax consequences attributable to the temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income or expense in the period that includes the enactment date of the change. On a quarterly basis, management assesses the reasonableness of its effective federal tax rate based upon its current best estimate of taxable income and the applicable taxes expected for the full year. Deferred tax assets and liabilities are reassessed on an annual basis, or sooner, if business events or circumstances warrant. Management also assesses the need for a valuation allowance for deferred tax assets on a quarterly basis using information about the Corporation’s current and historical financial position and results of operations. Income tax positions are evaluated to determine whether it is more-likely-than-not that a tax position will be sustained upon examination based on the technical merits of the tax position. If a tax position is more-likely-than-not to be sustained, a tax benefit is recognized for the amount that is greater than 50% likely to be realized. Reserves for contingent tax liabilities attributable to unrecognized tax benefits associated with uncertain tax positions are reviewed quarterly for adequacy based upon developments in tax law and the status of audits or examinations. The Corporation had no reserve for contingent income tax liabilities recorded at September 30, 2011, December 31, 2010 or September 30, 2010. The tax periods open to examination by the Internal Revenue Service include the calendar years ended December 31, 2010, 2009 and 2008. The calendar years ended December 31, 2010, 2009 and 2008 are open to examination for the Corporation’s Michigan Business Tax and the calendar years ended December 31, 2007 and 2006 are open to examination for the Michigan Single Business Tax of the Corporation and certain subsidiaries of the Corporation. *Shareholders’ Equity* Common Stock Repurchase Programs From time to time, the board of directors approves common stock repurchase programs allowing management to repurchase shares of the Corporation’s common stock in the open market. The repurchased shares are available for later reissuance in connection with potential future stock dividends, the Corporation’s dividend reinvestment plan, employee benefit plans and other general corporate purposes. Under these programs, the timing and actual number of shares subject to repurchase are at the discretion of management and are contingent on a number of factors, including the projected parent company cash flow requirements and the Corporation’s market price per share. In January 2008, the board of directors of the Corporation authorized management to repurchase up to 500,000 shares of the Corporation’s common stock under a stock repurchase program. Since the January 2008 authorization, no shares have been repurchased. At September 30, 2011, there were 500,000 remaining shares available for repurchase under the Corporation’s stock repurchase programs. Preferred Stock On April 20, 2009, the shareholders of the Corporation authorized the board of directors of the Corporation to issue up to 200,000 shares of preferred stock in connection with either an acquisition by the Corporation of an entity that has shares of preferred stock issued and outstanding pursuant to any program established by the United States government or participation by the Corporation in any program established by the United States government. At September 30, 2011, no shares of preferred stock were issued and outstanding. Common Stock On April 18, 2011, the shareholders of the Corporation approved an amendment to the restated articles of incorporation to increase the number of authorized shares of common stock from 30,000,000 to 45,000,000. *Legal Matters* The Corporation and Chemical Bank are subject to certain legal actions arising in the ordinary course of business. In the opinion of management, after consultation with legal counsel, the ultimate disposition of these matters is not expected to have a material adverse effect on the consolidated financial condition or results of operations of the Corporation. *Adopted Accounting Pronouncements* Determination of Troubled Debt Restructurings and Related Disclosures: In April 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-02, Receivables (Topic 310): A Creditor’s Determination of Whether a Restructuring is a Troubled Debt Restructuring (ASU 2011-02). ASU 2011-02 provides additional clarifying guidance for creditors in determining whether modifications to a loan constitute a concession granted by the creditor; evaluating whether a restructuring results in a delay in payment that is insignificant; and determining whether a debtor is experiencing financial difficulties. ASU 2011-02 also establishes the effective date for certain disclosures about loans modified under troubled debt restructurings that had been delayed by the FASB’s issuance of ASU No. 2011-01, Receivables (Topic 310): Deferral of the Effective Date of Disclosures about Troubled Debt Restructurings in Update No. 2010-20. For public entities, ASU 2011-02 (including related disclosures) is effective for the first interim or annual period beginning on or after June 15, 2011, with early adoption permitted. The adoption of ASU 2011-02 as of July 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations. As a result of adopting the amendments of ASU 2011-02, the Corporation reassessed all loan restructurings that occurred on or after January 1, 2011 for identification as a TDR. No new TDRs resulted from this assessment. See Note 4, Loans, to the consolidated financial statements for disclosures related to TDRs. Testing Goodwill for Impairment: In September 2011, the FASB issued ASU No. 2011-08, Intangibles – Goodwill and Other (Topic 350): Testing for Goodwill Impairment (ASU 2011-08). Prior to ASU 2011-08, a two-step test was required to assess goodwill for impairment. In Step 1, the fair value of a reporting unit was computed and compared to the carrying value, and if the fair value was lower, then Step 2 was used to measure the amount of goodwill impairment, if any. ASU 2011-08 permits an entity to make a qualitative assessment as to whether it is more-likely-than-not that a reporting unit’s fair value is less than its carrying value before applying the two-step goodwill impairment test. If an entity concludes that it is not more-likely-than-not that the fair value of a reporting unit is less than its carrying value, it would not be required to perform the two-step impairment test for the reporting unit. ASU 2011-08 applies to both an entity’s annual and, if necessary, interim goodwill impairment test. ASU 2011-08 is effective for fiscal years beginning after December 15, 2011, with early adoption permitted. The Corporation elected to adopt ASU 2011-08 as of September 30, 2011 and applied the qualitative assessment approach to its annual goodwill impairment test as of that same date. The adoption of ASU 2011-08 did not have a material impact on the Corporation’s consolidated financial condition or results of operations. See Note 5, Intangible Assets, to the consolidated financial statements for further discussion of the Corporation’s annual goodwill impairment test. *Pending Accounting Pronouncements* Transfers and Servicing of Financial Assets: In April 2011, the FASB issued ASU No. 2011-03, Transfers and Servicing (Topic 860): Reconsideration of Effective Control for Repurchase Agreements (ASU 2011-03). ASU 2011-03 modifies current guidance by eliminating (i) from the assessment of effective control over transferred financial assets in connection with a repurchase agreement the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets on substantially the agreed terms, even in the event of the transferee’s default, and (ii) the condition requiring the transferor to have obtained sufficient collateral to demonstrate that ability. ASU 2011-03 is effective for interim and annual periods beginning on or after December 15, 2011, with early adoption prohibited. The adoption of ASU 2011-03 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations. Fair Value Measurement and Disclosure Requirements: In May 2011, the FASB issued ASU No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs (ASU 2011-04). The amended guidance of ASU 2011-04 (i) clarifies how a principal market is determined, (ii) establishes the valuation premise for the highest and best use of nonfinancial assets, (iii) addresses the fair value measurement of instruments with offsetting market or counterparty credit risks, (iv) extends the prohibition on blockage factors to all three levels of the fair value hierarchy, and (v) requires additional disclosures including transfers between Level 1 and Level 2 of the fair value hierarchy, quantitative and qualitative information and a description of an entity’s valuation process for Level 3 fair value measurements, and fair value hierarchy disclosures for financial instruments not measured at fair value. ASU 2011-04 is effective for interim and annual periods beginning on or after December 15, 2011, with early adoption prohibited. The adoption of ASU 2011-04 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations. Presentation of Comprehensive Income: In June 2011, the FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income (ASU 2011-05). ASU 2011-05 amends current guidance by (i) eliminating the option to present components of other comprehensive income (OCI) as part of the statement of changes in shareholders’ equity, (ii) requiring the presentation of each component of net income and each component of OCI either in a single continuous statement or in two separate but consecutive statements, and (iii) requiring the presentation of reclassification adjustments on the face of the statement. The amendments of ASU 2011-05 do not change the option to present components of OCI either before or after related income tax effects, the items that must be reported in OCI, when an item of OCI should be reclassified to net income, or the computation of earnings per share (which continues to be based on net income). ASU 2011-05 is effective for interim and annual periods beginning on or after December 15, 2011 for public companies, with early adoption permitted and retrospective application required. The adoption of ASU 2011-05 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations.

Significant Accounting Policies

9 Months Ended

Sep. 30, 2011

Significant Accounting Policies [Abstract]

Note 1: Significant Accounting Policies

Nature of Operations

Chemical Financial Corporation (Chemical or the Corporation) operates in a single operating segment — commercial banking. The Corporation is a financial holding company, headquartered in Midland, Michigan, that operates through one commercial bank, Chemical Bank. Chemical Bank operates within the State of Michigan as a state-chartered commercial bank. Chemical Bank operates through an internal organizational structure of four regional banking units and offers a full range of traditional banking and fiduciary products and services to the residents and business customers in the bank’s geographical market areas. The products and services offered by the regional banking units, through branch banking offices, are generally consistent throughout the Corporation, as is the pricing of those products and services. The marketing of products and services throughout the Corporation’s regional banking units is generally uniform, as many of the markets served by the regional banking units overlap. The distribution of products and services is uniform throughout the Corporation’s regional banking units and is achieved primarily through retail branch banking offices, automated teller machines and electronically accessed banking products.

Basis of Presentation

The accompanying unaudited consolidated financial statements of the Corporation and its subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Corporation’s consolidated financial statements and footnotes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2010. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments believed necessary to present fairly the financial condition and results of operations of the Corporation for the periods presented. Operating results for the three and nine months ended September 30, 2011 are not necessarily indicative of the results that may be expected for the year ending December 31, 2011.

Use of Estimates

Management makes estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying footnotes. Estimates that are particularly susceptible to significant change include the determination of the allowance for loan losses, expected cash flows from acquired loans, fair value amounts related to business combinations, pension expense, income taxes, goodwill impairment and those assets that require fair value measurement. Actual results could differ from these estimates.

Business Combinations

On April 30, 2010, the Corporation acquired 100% of O.A.K. Financial Corporation (OAK) for total consideration of $83.7 million. Pursuant to the guidance of Accounting Standards Codification (ASC) Topic 805, Business Combinations (ASC 805) effective for all acquisitions with closing dates after January 1, 2009, the Corporation recognized the assets acquired and the liabilities assumed in the OAK acquisition at their fair values as of the acquisition date with the related acquisition and restructuring costs expensed in the period incurred. The Corporation recorded $43.5 million of goodwill in conjunction with the acquisition, which represented the purchase price over the fair values of the identifiable net assets acquired. Additionally, the Corporation recorded $9.8 million of other intangible assets as a result of the OAK acquisition attributable to core deposits, mortgage servicing rights and non-compete agreements acquired.

See Note 2 for further information regarding the OAK acquisition.

Originated Loans

Originated loans include all of the Corporation’s portfolio loans, excluding loans acquired in the OAK acquisition.

Originated loans are stated at their principal amount outstanding, net of unearned income, charge-offs and unamortized deferred fees and costs. Interest income on loans is reported based on the level-yield method and includes amortization of deferred loan fees and costs over the loan term. Net loan commitment fees for commitment periods greater than one year are deferred and amortized into fee income on a straight-line basis over the commitment period.

Loan interest income is recognized on the accrual basis. The past due status of a loan is based on the loan’s contractual terms. A loan is placed in the nonaccrual category when principal or interest is past due 90 days or more (except for real estate residential loans that are transferred at 120 days past due), unless the loan is both well-secured and in the process of collection, or earlier when, in the opinion of management, there is sufficient reason to doubt the collectibility of principal or interest. Interest previously accrued, but not collected, is reversed and charged against interest income at the time the loan is placed in nonaccrual status. The subsequent recognition of interest income on a nonaccrual loan is then recognized only to the extent cash is received and where future collection of principal is probable. Loans are returned to accrual status when principal and interest payments are brought current, payments have been received consistently for a period of time (generally six months) and collectibility is no longer in doubt.

Loans Acquired in a Business Combination

Loans acquired in a business combination (acquired loans) consist of loans acquired in the acquisition of OAK. Acquired loans were recorded at fair value, without a carryover of OAK’s associated allowance for loan losses related to these loans, through a fair value discount that was, in part, attributable to deterioration in credit quality. The fair value discount was recorded as a reduction of the acquired loans’ outstanding principal balances in the consolidated statement of financial position at the acquisition date.

Those loans that qualify under ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (ASC 310-30), are recorded at fair value at acquisition. The calculation of the fair value of the acquired loans entailed estimating the amount and timing of both principal and interest cash flows expected to be collected on such loans and then discounting those cash flows at market interest rates. The excess of a loan’s expected cash flows at the acquisition date over its estimated fair value is referred to as the “accretable yield,” which is recognized into interest income over the remaining life of the loan on a level-yield basis. The difference between a loan’s contractually required principal and interest payments at the acquisition date and the cash flows expected to be collected at the acquisition date is referred to as the “nonaccretable difference,” which includes an estimate of future credit losses expected to be incurred over the life of the loan and interest payments that are not expected to be collected. The estimate of expected credit losses was determined based on due diligence performed by executive and senior officers of the Corporation, with assistance from third-party consultants. Decreases to the expected cash flows in subsequent periods will require the Corporation to record a provision for loan losses. Improvements in expected cash flows in subsequent periods will result in reversing a portion of the nonaccretable difference, which is then classified as part of the accretable yield and subsequently recognized into interest income over the remaining life of the loan.

The Corporation must make numerous assumptions, interpretations and judgments using internal and third-party credit quality information to determine whether it is probable that the Corporation will be able to collect all contractually required payments. This is a point in time assessment and inherently subjective due to the nature of the available information and judgment involved. Evidence of credit quality deterioration as of the purchase date may include credit metrics such as past due and nonaccrual status, deterioration in borrower credit scores and negative changes to loan-to-value percentages.

Acquired loans with an outstanding principal balance of $105 million at the acquisition date were determined to be loans with deteriorated credit quality and, therefore, met the scope criteria set forth in ASC 310-30. Further, the Corporation understands, as outlined in the American Institute of Certified Public Accountants’ open letter to the Office of the Chief Accountant of the Securities and Exchange Commission (SEC) dated December 18, 2009 and pending further standard setting, that for acquired loans that do not meet the scope criteria of ASC 310-30, a company may elect to account for such acquired loans pursuant to the provisions of either ASC 310-20, Nonrefundable Fees and Other Costs, or ASC 310-30. The Corporation elected to apply ASC 310-30 by analogy to acquired loans that were determined not to have deteriorated credit quality with an outstanding principal balance of $578 million at the acquisition date and thus follows the accounting and disclosure guidance of ASC 310-30 for these loans. Accordingly, the Corporation applied ASC 310-30 to the entire loan portfolio acquired in the acquisition of OAK with an outstanding principal balance of $683 million at the acquisition date. None of the acquired loans were classified as debt securities.

ASC 310-30 allows investors to aggregate loans acquired into loan pools that have common risk characteristics and thereby use a composite interest rate and expectation of cash flows expected to be collected for the loan pools. Under the provisions of ASC 310-30, the Corporation aggregated acquired loans into 14 pools based upon common risk characteristics, including types of loans, commercial type loans with similar risk grades and whether loans were performing or nonperforming. A pool is considered a single unit of accounting for the purposes of applying the guidance as described above. A loan will be removed from a pool of acquired loans only if the loan is sold, foreclosed, paid off or written off, and will be removed from the pool at the 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 would not affect the effective yield used to recognize the accretable difference on the remaining pool. The Corporation estimated the cash flows expected to be collected over the life of the pools of loans at acquisition and estimates expected cash flows quarterly thereafter, based on a set of assumptions including expectations as to default rates, prepayment rates and loss severities. In the event that the updated expected cash flows increase in a pool from those originally projected at acquisition date, the Corporation will adjust the accretable yield amount with a resulting change in the amount recognized in interest income in subsequent periods. In the event that the updated expected cash flows in a pool decrease from those originally projected at the acquisition date, the Corporation will consider that loan pool impaired, which results in the Corporation recording a charge to the provision for loan losses.

Loans Modified Under Troubled Debt Restructurings

Loans modified under troubled debt restructurings (TDRs) involve granting a concession to a borrower who is experiencing financial difficulty. Concessions generally include modifications to original loan terms, including changes to a loan’s payment schedule or interest rate, which generally would not otherwise be considered. The Corporation’s loans reported as TDRs continue to accrue interest at the loan’s effective interest rate as the Corporation expects to collect the full amount of principal and interest accrued at the loan’s original contractual rate at the time of modification. TDRs are reported as nonperforming TDRs until a six-month payment history of principal and interest payments, in accordance with the loan modification, is sustained, at which time the Corporation moves them to a performing TDR status. All TDRs are accounted for as impaired loans and are considered accordingly as part of the analysis of the allowance for loan losses.

The Corporation’s commercial and real estate commercial TDRs generally consist of allowing borrowers to defer scheduled principal payments and make interest only payments for a specified period of time at the stated interest rate of the original loan agreement or lower payments due to a modification of the loan’s contractual term. The Corporation does not expect to incur a loss on these loans based on its assessment of the borrowers’ expected cash flows, and accordingly, no additional provision for loan losses has been recognized related to these loans. Since no loss is incurred on these loans, they accrue interest at the loan’s contractual interest rate. These loans are individually evaluated for impairment and transferred to nonaccrual status if it is probable that any remaining principal and interest payments due on the loan will not be collected in accordance with the modified terms of the loan.

The Corporation’s real estate residential TDRs generally consist of reducing a borrower’s monthly payments by decreasing the interest rate charged on the loan for a specified period of time (generally 24 months). The Corporation recognizes additional provision for loan losses related to impairment on these loans based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. These loans accrue interest at the loan’s effective interest rate, which consists of contractual interest in addition to an adjustment for the accretion of computed impairment. These loans are moved to nonaccrual status if they become 90 days past due as to principal or interest, or sooner if conditions warrant.

Impaired Loans

A loan is defined to be impaired when it is probable that payment of principal and interest will not be made in accordance with the original contractual terms of the loan agreement. Impaired loans include all classes of nonaccrual loans, all TDRs (nonperforming and performing) and acquired loans that were not performing in accordance with original contractual terms. Impaired loans are carried at the lower of the present value of expected cash flows discounted at the loan’s effective interest rate or the estimated fair value of the collateral if the loan is collateral dependent.

Nonperforming Loans

Nonperforming loans are comprised of originated loans for which the accrual of interest has been discontinued (nonaccrual loans), accruing loans contractually past due 90 days or more as to interest or principal payments and nonperforming TDRs.

Allowance for Loan Losses

The allowance for loan losses (allowance) is presented as a reserve against loans. The allowance represents management’s assessment of probable loan losses inherent in the Corporation’s loan portfolio.

Management’s evaluation of the adequacy of the allowance is based on a continuing review of the loan portfolio, actual loan loss experience, the underlying value of the collateral, risk characteristics of the loan portfolio, the level and composition of nonperforming loans, the financial condition of the borrowers, the balance of the loan portfolio, loan growth, economic conditions, employment levels in the Corporation’s local markets, and special factors affecting specific business sectors. The Corporation maintains formal policies and procedures to monitor and control credit risk. Management evaluates the allowance on a quarterly basis in an effort to ensure the level is adequate to absorb probable losses inherent in the loan portfolio.

The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be incurred in the remainder of the originated loan portfolio, but that have not been specifically identified. The Corporation utilizes its own loss experience to estimate inherent losses on loans. Internal risk ratings are assigned to each commercial, real estate commercial, real estate construction and land development loan at the time of approval and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review quarterly on all loans greater than $0.25 million that have deteriorated below certain levels of credit risk, and may allocate a specific portion of the allowance to such loans based upon this review. A portion of the allowance is allocated to the remaining loans by applying projected loss ratios, based on numerous factors. Projected loss ratios incorporate factors such as recent charge-off experience, trends with respect to adversely risk-rated commercial, real estate commercial, real estate construction and land development loans, trends with respect to past due and nonaccrual loans, changes in economic conditions and trends, changes in the value of underlying collateral and other credit risk factors. This evaluation involves a high degree of uncertainty.

In determining the allowance and the related provision for loan losses, the Corporation considers four principal elements: (i) valuation allowances based upon probable losses identified during the review of impaired commercial, real estate commercial, real estate construction and land development loans, (ii) allocations established for adversely-rated commercial, real estate commercial, real estate construction and land development loans and nonaccrual real estate residential, consumer installment and home equity loans, (iii) allocations, by loan classes, on all other loans based principally on multi-year historical loan loss experience and loan loss trends and (iv) an unallocated allowance based on the imprecision in the overall allowance methodology.

The first element reflects the Corporation’s estimate of probable losses based upon the systematic review of individually impaired commercial, real estate commercial, real estate construction and land development loans in the originated loan portfolio. These estimates are based upon a number of objective factors, such as payment history, financial condition of the borrower and discounted collateral exposure. The Corporation measures the investment in an impaired loan based on one of three methods: the loan’s observable market price; the fair value of the collateral; or, the present value of expected future cash flows discounted at the loan’s effective interest rate. At September 30, 2011, loans in the commercial loan portfolio that were in nonaccrual status were valued based on the fair value of the collateral securing the loan, while TDRs in the commercial loan portfolio were valued based on the present value of expected future cash flows discounted at the loan’s effective interest rate. It is the Corporation’s general policy to, at least annually, obtain new appraisals on impaired loans that are primarily secured by real estate. When the Corporation determines that the fair value of the collateral is less than the carrying value of an impaired loan on nonaccrual status and a portion is deemed not collectible, the portion of the impairment that is deemed not collectible is charged off (confirmed loss) and deducted from the allowance. The remaining carrying value of the impaired loan is classified as a nonperforming loan. When the Corporation determines that the fair value of the collateral is less than the carrying value of an impaired loan but believes it is probable it will recover this impairment, the Corporation establishes a valuation allowance for such impairment.

The second element reflects the application of the Corporation’s loan grade risk rating system. This risk rating system is similar to those employed by state and federal banking regulators. Loans in the commercial loan portfolio that are risk rated below a certain predetermined risk grade and nonaccrual real estate residential and nonaccrual consumer installment and home equity loans are assigned a loss allocation factor that is based upon a historical analysis of actual loan losses incurred and a valuation of the type of collateral securing the loans.

The third element is determined by assigning allocations based principally upon a multi-year average of loss experience for each class of loan. Average losses may be adjusted based on current loan loss experience and delinquency trends. This component considers the lagging impact of historical charge-off ratios in periods where future loan charge-offs are expected to increase or decrease, trends in delinquencies and nonaccrual loans, the changing portfolio mix in terms of collateral, average loan balance, loan growth and the degree of seasoning in the various loan portfolios. Loan loss analyses are performed quarterly. During the quarter ended September 30, 2011, the Corporation revised its historical loan loss experience from three years to five years to better capture and reflect the loss experience inherent in the various classes of the loan portfolio. In addition, the Corporation judgmentally applied a percentage weighting to each of the years in the five-year period with higher weighting placed on the most recent years. The change did not have a significant impact on the overall allowance for loan losses.

The fourth element is based on factors that cannot be associated with a specific credit or loan class and reflects an attempt to ensure that the overall allowance appropriately reflects a margin for the imprecision necessarily inherent in the estimates of loan losses. Management maintains an unallocated allowance to recognize the uncertainty and imprecision underlying the process of estimating inherent loan losses in the loan portfolio. Determination of the probable losses inherent in the portfolio, which are not necessarily captured by the allocation methodology discussed above, involves the exercise of judgment. The unallocated allowance associated with the imprecision in the risk rating system is based on a historical evaluation of the accuracy of the risk ratings associated with loans. This unallocated portion of the allowance is judgmentally determined and generally serves to compensate for the uncertainty in estimating inherent losses, particularly in times of changing economic conditions, and also considers the possibility of improper risk ratings. The unallocated portion of the allowance also takes into consideration economic conditions within the State of Michigan and nationwide, including unemployment levels, industry-wide loan delinquency rates, and declining commercial and residential real estate values and historically high inventory levels of residential lots, condominiums and single family houses held for sale.

Although the Corporation allocates portions of the allowance to specific loans and loan types, the entire allowance is available for any loan losses that occur. Loans that are deemed not collectible are charged off and deducted from the allowance. The provision for loan losses and recoveries on loans previously charged off are added to the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off against the allowance.

Acquired loans are aggregated into pools based upon common risk characteristics. An allowance may be recorded related to acquired loans, if an acquired loan pool experiences a decrease in expected cash flows as compared to those projected at the acquisition date. On a quarterly basis, the expected future cash flow of each pool is estimated based on various factors including changes in property values of collateral dependent loans, default rates, loss severities and prepayment speeds. Decreases in estimates of expected cash flows within a pool generally result in a charge to the provision for loan losses and a corresponding increase in the allowance allocated to acquired loans for the particular pool. Increases in estimates of expected cash flows within a pool generally result first in a reduction in the allowance allocated to acquired loans for the particular pool, and second in an adjustment to the accretable yield for the pool, which will increase amounts recognized in interest income in subsequent periods.

Various regulatory agencies, as an integral part of their examination process, periodically review the allowance. Such agencies may require additions to the allowance based on their judgment reflecting information available to them at the time of their examinations.

Fair Value Measurements

Fair value for assets and liabilities measured at fair value on a recurring or nonrecurring basis refers to the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants in the market in which the reporting entity transacts such sales or transfers based on the assumptions market participants would use when pricing an asset or liability. Assumptions are developed based on prioritizing information within a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data, such as the reporting entity’s own data.

The Corporation may choose to measure eligible items at fair value at specified election dates. Unrealized gains and losses on items for which the fair value measurement option has been elected are reported in earnings at each subsequent reporting date. The fair value option (i) may be applied instrument by instrument, with certain exceptions, allowing the Corporation to record identical financial assets and liabilities at fair value or by another measurement basis permitted under GAAP, (ii) is irrevocable (unless a new election date occurs) and (iii) is applied only to entire instruments and not to portions of instruments. At September 30, 2011, December 31, 2010 and September 30, 2010, the Corporation had not elected the fair value option for any financial assets or liabilities.

Share-Based Compensation

The Corporation has granted stock options, stock awards and restricted stock performance units to certain executive and senior management employees. The Corporation accounts for share-based compensation expense using the modified-prospective transition method. Under that method, compensation expense is recognized for share-based awards granted after December 31, 2005, based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance for performance-based awards. The fair value of stock options is recognized as compensation expense on a straight-line basis over the requisite service period. The fair value of restricted stock performance units is recognized as compensation expense over the requisite performance period.

Cash flows realized from the tax benefits of exercised stock option awards that result from actual tax deductions that are in excess of the recorded tax benefits related to the compensation expense recognized for those options (excess tax benefits) are classified as financing activities on the consolidated statements of cash flows.

Income and Other Taxes

The Corporation is subject to the income and other tax laws of the United States and the State of Michigan. These laws are complex and are subject to different interpretations by the taxpayer and the various taxing authorities. In determining the provision for income and other taxes, management must make judgments and estimates about the application of these inherently complex laws, related regulations and case law. In the process of preparing the Corporation’s tax returns, management attempts to make reasonable interpretations of enacted tax laws. These interpretations are subject to challenge by the tax authorities upon audit or to reinterpretation based on management’s ongoing assessment of facts and evolving case law.

The Corporation and its subsidiaries file a consolidated federal income tax return. The provision for federal income taxes is based on income and expenses, as reported in the consolidated financial statements, rather than amounts reported on the Corporation’s federal income tax return. The difference between the federal statutory income tax rate and the Corporation’s effective federal income tax rate is primarily a function of the proportion of the Corporation’s interest income exempt from federal taxation, nondeductible interest expense and other nondeductible expenses relative to pretax income and tax credits. When income and expenses are recognized in different periods for tax purposes than for book purposes, deferred tax assets and liabilities are recognized for the future tax consequences attributable to the temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income or expense in the period that includes the enactment date of the change.

On a quarterly basis, management assesses the reasonableness of its effective federal tax rate based upon its current best estimate of taxable income and the applicable taxes expected for the full year. Deferred tax assets and liabilities are reassessed on an annual basis, or sooner, if business events or circumstances warrant. Management also assesses the need for a valuation allowance for deferred tax assets on a quarterly basis using information about the Corporation’s current and historical financial position and results of operations.

Income tax positions are evaluated to determine whether it is more-likely-than-not that a tax position will be sustained upon examination based on the technical merits of the tax position. If a tax position is more-likely-than-not to be sustained, a tax benefit is recognized for the amount that is greater than 50% likely to be realized. Reserves for contingent tax liabilities attributable to unrecognized tax benefits associated with uncertain tax positions are reviewed quarterly for adequacy based upon developments in tax law and the status of audits or examinations. The Corporation had no reserve for contingent income tax liabilities recorded at September 30, 2011, December 31, 2010 or September 30, 2010.

The tax periods open to examination by the Internal Revenue Service include the calendar years ended December 31, 2010, 2009 and 2008. The calendar years ended December 31, 2010, 2009 and 2008 are open to examination for the Corporation’s Michigan Business Tax and the calendar years ended December 31, 2007 and 2006 are open to examination for the Michigan Single Business Tax of the Corporation and certain subsidiaries of the Corporation.

Shareholders’ Equity

Common Stock Repurchase Programs

From time to time, the board of directors approves common stock repurchase programs allowing management to repurchase shares of the Corporation’s common stock in the open market. The repurchased shares are available for later reissuance in connection with potential future stock dividends, the Corporation’s dividend reinvestment plan, employee benefit plans and other general corporate purposes. Under these programs, the timing and actual number of shares subject to repurchase are at the discretion of management and are contingent on a number of factors, including the projected parent company cash flow requirements and the Corporation’s market price per share.

In January 2008, the board of directors of the Corporation authorized management to repurchase up to 500,000 shares of the Corporation’s common stock under a stock repurchase program. Since the January 2008 authorization, no shares have been repurchased. At September 30, 2011, there were 500,000 remaining shares available for repurchase under the Corporation’s stock repurchase programs.

Preferred Stock

On April 20, 2009, the shareholders of the Corporation authorized the board of directors of the Corporation to issue up to 200,000 shares of preferred stock in connection with either an acquisition by the Corporation of an entity that has shares of preferred stock issued and outstanding pursuant to any program established by the United States government or participation by the Corporation in any program established by the United States government. At September 30, 2011, no shares of preferred stock were issued and outstanding.

Common Stock

On April 18, 2011, the shareholders of the Corporation approved an amendment to the restated articles of incorporation to increase the number of authorized shares of common stock from 30,000,000 to 45,000,000.

Legal Matters

The Corporation and Chemical Bank are subject to certain legal actions arising in the ordinary course of business. In the opinion of management, after consultation with legal counsel, the ultimate disposition of these matters is not expected to have a material adverse effect on the consolidated financial condition or results of operations of the Corporation.

Adopted Accounting Pronouncements

Determination of Troubled Debt Restructurings and Related Disclosures: In April 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-02, Receivables (Topic 310): A Creditor’s Determination of Whether a Restructuring is a Troubled Debt Restructuring (ASU 2011-02). ASU 2011-02 provides additional clarifying guidance for creditors in determining whether modifications to a loan constitute a concession granted by the creditor; evaluating whether a restructuring results in a delay in payment that is insignificant; and determining whether a debtor is experiencing financial difficulties. ASU 2011-02 also establishes the effective date for certain disclosures about loans modified under troubled debt restructurings that had been delayed by the FASB’s issuance of ASU No. 2011-01, Receivables (Topic 310): Deferral of the Effective Date of Disclosures about Troubled Debt Restructurings in Update No. 2010-20. For public entities, ASU 2011-02 (including related disclosures) is effective for the first interim or annual period beginning on or after June 15, 2011, with early adoption permitted. The adoption of ASU 2011-02 as of July 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations.

As a result of adopting the amendments of ASU 2011-02, the Corporation reassessed all loan restructurings that occurred on or after January 1, 2011 for identification as a TDR. No new TDRs resulted from this assessment. See Note 4, Loans, to the consolidated financial statements for disclosures related to TDRs.

Testing Goodwill for Impairment: In September 2011, the FASB issued ASU No. 2011-08, Intangibles – Goodwill and Other (Topic 350): Testing for Goodwill Impairment (ASU 2011-08). Prior to ASU 2011-08, a two-step test was required to assess goodwill for impairment. In Step 1, the fair value of a reporting unit was computed and compared to the carrying value, and if the fair value was lower, then Step 2 was used to measure the amount of goodwill impairment, if any. ASU 2011-08 permits an entity to make a qualitative assessment as to whether it is more-likely-than-not that a reporting unit’s fair value is less than its carrying value before applying the two-step goodwill impairment test. If an entity concludes that it is not more-likely-than-not that the fair value of a reporting unit is less than its carrying value, it would not be required to perform the two-step impairment test for the reporting unit. ASU 2011-08 applies to both an entity’s annual and, if necessary, interim goodwill impairment test. ASU 2011-08 is effective for fiscal years beginning after December 15, 2011, with early adoption permitted. The Corporation elected to adopt ASU 2011-08 as of September 30, 2011 and applied the qualitative assessment approach to its annual goodwill impairment test as of that same date. The adoption of ASU 2011-08 did not have a material impact on the Corporation’s consolidated financial condition or results of operations. See Note 5, Intangible Assets, to the consolidated financial statements for further discussion of the Corporation’s annual goodwill impairment test.

Pending Accounting Pronouncements

Transfers and Servicing of Financial Assets: In April 2011, the FASB issued ASU No. 2011-03, Transfers and Servicing (Topic 860): Reconsideration of Effective Control for Repurchase Agreements (ASU 2011-03). ASU 2011-03 modifies current guidance by eliminating (i) from the assessment of effective control over transferred financial assets in connection with a repurchase agreement the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets on substantially the agreed terms, even in the event of the transferee’s default, and (ii) the condition requiring the transferor to have obtained sufficient collateral to demonstrate that ability. ASU 2011-03 is effective for interim and annual periods beginning on or after December 15, 2011, with early adoption prohibited. The adoption of ASU 2011-03 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations.

Fair Value Measurement and Disclosure Requirements: In May 2011, the FASB issued ASU No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs (ASU 2011-04). The amended guidance of ASU 2011-04 (i) clarifies how a principal market is determined, (ii) establishes the valuation premise for the highest and best use of nonfinancial assets, (iii) addresses the fair value measurement of instruments with offsetting market or counterparty credit risks, (iv) extends the prohibition on blockage factors to all three levels of the fair value hierarchy, and (v) requires additional disclosures including transfers between Level 1 and Level 2 of the fair value hierarchy, quantitative and qualitative information and a description of an entity’s valuation process for Level 3 fair value measurements, and fair value hierarchy disclosures for financial instruments not measured at fair value. ASU 2011-04 is effective for interim and annual periods beginning on or after December 15, 2011, with early adoption prohibited. The adoption of ASU 2011-04 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations.

Presentation of Comprehensive Income: In June 2011, the FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income (ASU 2011-05). ASU 2011-05 amends current guidance by (i) eliminating the option to present components of other comprehensive income (OCI) as part of the statement of changes in shareholders’ equity, (ii) requiring the presentation of each component of net income and each component of OCI either in a single continuous statement or in two separate but consecutive statements, and (iii) requiring the presentation of reclassification adjustments on the face of the statement. The amendments of ASU 2011-05 do not change the option to present components of OCI either before or after related income tax effects, the items that must be reported in OCI, when an item of OCI should be reclassified to net income, or the computation of earnings per share (which continues to be based on net income). ASU 2011-05 is effective for interim and annual periods beginning on or after December 15, 2011 for public companies, with early adoption permitted and retrospective application required. The adoption of ASU 2011-05 is not expected to have a material impact on the Corporation’s consolidated financial condition or results of operations.