Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2011
Summary of Significant Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 1 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Chemical Financial Corporation (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. The Corporation’s primary sources of revenue are from its loan products and investment securities. Accounting Standards Codification The Financial Accounting Standards Board’s (FASB) Accounting Standards Codification (ASC) became effective on July 1, 2009. At that date, the ASC became FASB’s officially recognized source of authoritative U.S. generally accepted accounting principles (GAAP) applicable to all public and non-public non-governmental entities, superseding existing FASB, American Institute of Certified Public Accountants (AICPA), Emerging Issues Task Force (EITF) and related literature. Rules and interpretive releases of the Securities and Exchange Commission (SEC) under the authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. All other accounting literature is considered non-authoritative. The switch to the ASC affects the way companies refer to GAAP in financial statements and accounting policies. Reclassifications The Corporation’s investments in Federal Home Loan Bank of Indianapolis (FHLB) and Federal Reserve Bank (FRB) stock have been reclassified from other securities to interest receivable and other assets on the Corporation’s consolidated statements of financial position and cash flows for all periods presented. Certain other amounts in the 2010 and 2009 consolidated financial statements and notes thereto have been reclassified to conform with the 2011 presentation. Such reclassifications had no effect on the Corporation’s shareholders’ equity or net income. Basis of Presentation and Principles of Consolidation The accounting and reporting policies of the Corporation and its subsidiaries conform to GAAP, SEC rules and interpretive releases and prevailing practices within the banking industry. The consolidated financial statements of the Corporation include the accounts of the Corporation and its wholly owned subsidiaries. All significant income and expenses are recorded on the accrual basis. Intercompany accounts and transactions have been eliminated in preparing the consolidated financial statements. The Corporation consolidates variable interest entities (VIEs) in which it is the primary beneficiary. In general, a VIE is an entity that either (i) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (ii) has a group of equity owners that are unable to make significant decisions about its activities or (iii) has a group of equity owners that do not have the obligation to absorb losses or the right to receive return as generated by its operations. If any of these characteristics are present, the entity is subject to a variable interests consolidation model, and consolidation is based on variable interests, not on ownership of the entity’s outstanding voting stock. Variable interests are defined as contractual, ownership, or other monetary interests in an entity that change with fluctuations in the entity’s net asset value. The primary beneficiary consolidates the VIE. The primary beneficiary is defined as the enterprise that has the power to direct the activities and absorb losses or the right to receive benefits. The Corporation is a significant limited partner in two low income housing tax credit partnerships. These entities meet the definition of VIEs. The Corporation is not the primary beneficiary of either VIE in which it holds a limited partnership interest; therefore, the VIEs are not consolidated in the Corporation’s financial statements. Exposure to loss as a result of its involvement with VIEs at December 31, 2011 was limited to approximately $3.8 million recorded as the Corporation’s investment, which includes unfunded obligations to these projects of $2.6 million. The Corporation’s investment in these projects is recorded in interest receivable and other assets and the future financial obligations are recorded in interest payable and other liabilities in the consolidated statement of financial position at 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 O.A.K. Financial Corporation (OAK) for total consideration of $83.7 million. Pursuant to the guidance of 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. Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, interest-bearing deposits with unaffiliated banks and others and federal funds sold, with original maturities of less than 90 days. Generally, federal funds are sold for one-day periods. At December 31, 2011 and 2010, the Corporation did not have any federal funds sold. Amounts reported under interest-bearing deposits with unaffiliated banks and others include interest-bearing savings and time deposits held at other financial institutions and overnight funds held at the FRB in lieu of federal funds sold. Investment Securities Investment securities include investments in debt, trust preferred and preferred stock securities. Investment securities are accounted for in accordance with ASC Topic 320, Investments — Debt and Equity Securities (ASC 320), which requires investments to be classified within one of three categories (trading, held-to-maturity or available-for-sale). The Corporation held no trading investment securities at December 31, 2011 or 2010. Designation as an investment security held-to-maturity is based on the Corporation’s intent and ability to hold the security to maturity. Investment securities held-to-maturity are stated at cost, adjusted for purchase price premiums and discounts. Investment securities that are not held-to-maturity are accounted for as securities available-for-sale, and are stated at estimated fair value, with the aggregate unrealized gains and losses, not deemed other-than-temporary, classified as a component of accumulated other comprehensive income (loss), net of income taxes. Realized gains and losses on the sale of investment securities and other-than-temporary impairment (OTTI) charges are determined using the specific identification method and are included within noninterest income in the consolidated statements of income. Premiums and discounts on investment securities are amortized over the estimated lives of the related investment securities based on the effective interest yield method and are included in interest income in the consolidated statements of income. The Corporation assesses equity and debt securities that have fair values below amortized cost basis to determine whether declines (impairment) are other-than-temporary. If the Corporation intends to sell an impaired security or it is more-likely-than-not that the Corporation will be required to sell an impaired security prior to the recovery of its amortized cost, an OTTI write-down is recognized in earnings equal to the entire difference between the security’s amortized cost basis and its fair value. If the Corporation does not intend to sell an impaired security and it is not more-likely-than-not that the Corporation would be required to sell an impaired security before the recovery of its amortized cost basis, then the recognition of the impairment is bifurcated if a credit loss is deemed to have occurred. For a security where the impairment is bifurcated, the impairment is separated into an amount representing the credit loss, which is recognized in earnings, and an amount related to all other factors, which is recognized in other comprehensive income. In assessing whether OTTI exists, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, (iii) the potential for impairments in an entire industry or sub-sector and (iv) the potential for impairments in certain economically depressed geographical locations. Nonmarketable Equity Securities The Corporation is required to hold non-marketable equity securities, comprised of Federal Home Loan Bank of Indianapolis (FHLB) and Federal Reserve Bank (FRB) stock, as a condition of membership. These securities are accounted for at cost which equals par or redemption value. These securities do not have a readily determinable fair value as their ownership is restricted and there is no market for these securities. These securities can only be redeemed or sold at their par value and only to the respective issuing government supported institution or to another member institution. The Corporation records these non-marketable equity securities as a component of other assets and they are periodically evaluated for impairment. Management considers these non-marketable equity securities to be long-term investments. Accordingly, when evaluating these securities for impairment, management considers the ultimate recoverability of the par value rather than by recognizing temporary declines in value. The Corporation’s ownership in FHLB stock totaled $17.2 million and $18.7 million at December 31, 2011 and 2010, respectively, and in FRB stock totaled $8.4 million at both December 31, 2011 and 2010. 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. Loan interest income is recognized on the accrual basis. Deferred loan fees and costs are amortized over the loan term based on the level-yield method. Net loan commitment fees are deferred and amortized into fee income on a straight-line basis over the commitment period. The past due status of a loan is based on the loan’s contractual terms. A loan is placed in nonaccrual (accrual of interest is discontinued) 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. Subsequent receipts of interest while a loan is in nonaccrual are recorded as a reduction of principal. 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 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. 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 entails 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. 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 in 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 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 Topic 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 acquired loans 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 the 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 will result 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 consist of originated loans that continue to accrue interest at the loan’s original effective interest rate as the Corporation expects to collect the remaining principal and interest on the loan. The interest income recognized on TDRs may include accretion of an identified impairment at the time of modification which is attributable to a temporary reduction in the borrower’s interest rate. At the time of modification, a TDR is reported as a nonperforming loan (nonperforming TDR) until a six-month payment history of principal and interest payments, in accordance with the terms of the loan modification, is sustained, at which time the Corporation moves the loan to a performing status (performing TDR). All TDRs are accounted for as impaired loans and are included in the Corporation’s analysis of the allowance for loan losses. Loans in the Corporation’s commercial loan portfolio (comprised of commercial, real estate commercial, real estate construction and land development loans) that meet the definition of a TDR 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 reduce payments due to an extension 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 expected to be incurred on these loans, the loans 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. Loans in the Corporation’s consumer loan portfolio (comprised of real estate residential, consumer installment and home equity loans) that meet the definition of a TDR 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 an additional provision for loan losses related to impairment on these loans on an individual basis 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. The Corporation’s loans reported as TDRs do not include loans that are in a nonaccrual status that have been modified by the Corporation due to the borrower experiencing financial difficulty and for which a concession has been granted, as the Corporation does not expect to collect the full amount of principal and interest owed from the borrower on these modified loans. The Corporation’s nonaccrual loans at December 31, 2011 and 2010 included $41.8 million and $59.4 million, respectively, of these modified loans. 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 not performing in accordance with their original contractual terms. Impaired loans are accounted for 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. When the present value of expected cash flows or the fair value of collateral of an impaired loan is less than the amount of unpaid principal outstanding on the loan, the principal balance of the loan is reduced to its carrying value through either an allocation of the allowance for loan losses or a partial charge-off of the loan balance. Nonperforming Loans Nonperforming loans are comprised of loans for which the accrual of interest has been discontinued (nonaccrual loans), accruing originated 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 loan in the commercial loan portfolio (commercial, real estate commercial, real estate construction and land development loans) at the time of approval and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review on a quarterly basis 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 loans in the commercial loan portfolio, 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 loans in the commercial loan portfolio and nonaccrual real estate residential, consumer installment and home equity loans, (iii) allocations, by loan classes, on all other loans based principally on a five-year historical loan loss experience and loan loss trends and (iv) an unallocated allowance based on the imprecision in the allowance methodology for loans collectively evaluated for impairment. The first element reflects the Corporation’s estimate of probable losses based upon the systematic review of individually impaired loans in the originated commercial 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. 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 in the commercial loan portfolio that are primarily secured by real estate and have a loan balance of greater than $0.25 million. 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 weighted five-year average of loss experience for each class of loan with higher weighting placed on the most recent years. 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. 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 attributable to originated loans is available for any loan losses that occur in the originated loan portfolio. Loans that are deemed not collectible are charged off and reduce the allowance. The provision for loan losses and recoveries on loans previously charged off increase the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off. 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 result in a reduction in the allowance allocated to acquired loans for the particular pool, if applicable, and then 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 for loan losses. Such agencies may require additions to the allowance based on their judgment reflecting information available to them at the time of their examinations. Mortgage Banking Operations The origination of real estate residential (mortgage) loans is an integral component of the business of the Corporation. The Corporation generally sells its originations of conforming long-term fixed interest rate mortgage loans in the secondary market. Gains and losses on the sales of these loans are determined using the specific identification method. The Corporation sells mortgage loans in the secondary market on either a servicing retained or released basis. Mortgage loans held for sale are carried at the lower of aggregate cost or market. The value of mortgage loans held for sale and other residential mortgage loan commitments to customers are hedged by utilizing best efforts forward commitments to sell loans to investors in the secondary market. Such forward commitments are generally entered into at the time customer applications are taken to protect the value of the mortgage loans from increases in market interest rates during the period held. Mortgage loans originated for sale are generally sold within 45 days after closing. Forward loan commitments are accounted for as derivatives and recorded at fair value, with changes in fair value recorded through earnings. The Corporation recognizes revenue associated with the expected future cash flows of servicing loans for loans held for sale at the time a forward loan commitment is made, as required under SEC Staff Accounting Bulletin No. 109, Written Loan Commitments Recorded at Fair Value Through Earnings. The Corporation accounts for mortgage servicing rights (MSRs) by separately recognizing servicing assets. An asset is recognized for the rights to service mortgage loans that are created by the origination of mortgage loans that are sold with the servicing retained by the Corporation. The Corporation amortizes MSRs in proportion to and over the period of net servicing income and assesses MSRs for impairment, on a quarterly basis, based on fair value measurements. Unexpected prepayments of mortgage loans result in increased amortization of MSRs, as the remaining book value of the MSRs is expensed at the time of prepayment. Any temporary impairment of MSRs is recognized as a valuation allowance, resulting in a reduction of mortgage banking revenue. The valuation allowance is recovered when impairment that is believed to be temporary no longer exists. Other-than-temporary impairments are recognized if the recoverability of the carrying value is determined to be remote. When this occurs, the unrecoverable portion of the valuation allowance is recorded as a direct write-down to the carrying value of MSRs. This direct write-down permanently reduces the carrying value of the MSRs, precluding recognition of subsequent recoveries, and result in a reduction of mortgage banking revenue. For purposes of measuring fair value of MSRs, the Corporation utilizes a third-party modeling software program. Servicing income is recognized when earned and is offset by the amortization of MSRs. Premises and Equipment Land is recorded at cost. Premises and equipment are stated at cost less accumulated depreciation. Premises and equipment are depreciated over the estimated useful lives of the assets. The estimated useful lives are generally 25 to 39 years for buildings and three to ten years for all other depreciable assets. Depreciation is computed on the straight-line method. Maintenance and repairs are charged to expense as incurred. Other Real Estate Other real estate (ORE) is comprised of commercial and residential real estate properties, including vacant land and development properties, obtained in partial or total satisfaction of loan obligations. ORE is recorded at the lower of cost or the estimated fair value of the property, less anticipated selling costs based upon the property’s appraised value at the date of transfer to ORE and management’s estimate of the fair value of the collateral, with any difference between the net realizable value of the property and the carrying value of the loan charged to the allowance for loan losses. Subsequent changes in the fair value of ORE are recognized as adjustments to the carrying amount, not to exceed the initial carrying value of the assets at the time of transfer. Changes in the fair value of ORE, subsequent to the initial transfer to ORE, and costs incurred to maintain ORE are recorded in other operating expenses on the consolidated statements of income. Gains or losses not previously recognized resulting from the sale of ORE are also recognized in other operating expenses on the date of sale. ORE totaling $24.9 million and $27.0 million at December 31, 2011 and 2010, respectively, was included in the consolidated statements of financial position in interest receivable and other assets. Goodwill Goodwill is not amortized, but rather is subject to impairment tests annually, or more frequently if triggering events occur and indicate potential impairment. The Corporation’s annual goodwill impairment test was performed as of September 30, 2011, and based on a qualitative assessment, as permitted by FASB Accounting Standards Update (ASU) 2011-08, Testing Goodwill for Impairment (ASU 2011-08), which the Corporation early adopted as of September 30, 2011, the Corporation determined that it was not more-likely-than-not that the fair value of the Corporation’s sole reporting unit, Chemical Bank, was less than its carrying value, and that accordingly, no impairment existed for the Corporation’s goodwill at that date. During the fourth quarter of 2011, the Corporation changed the date of its annual impairment testing for goodwill from September 30 to October 31. The change in the date of the annual goodwill impairment test represents a change in the method of applying an accounting principle. Management believes this change in accounting principle is preferable, as the later date better coincides with the Corporation’s annual budgeting and strategic planning processes. Management also believes that the change in the Corporation’s annual goodwill impairment testing date did not delay, accelerate or avoid a goodwill impairment charge. A preferability letter from the Corporation’s independent registered public accounting firm regarding this change in accounting principle has been filed as an exhibit to the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2011. The Corporation elected to bypass the qualitative assessment of goodwill impairment that became acceptable as a result of adopting ASU 2011-08 and performed Step 1 of the goodwill impairment test as of October 31, 2011, consistent with the Corporation’s historical practice. The income and market approach methodologies prescribed in ASC Topic 820, Fair Value Measurements and Disclosures (ASC 820), were utilized to estimate the value of the Corporation’s goodwill under Step 1 of the goodwill impairment test. The income approach quantifies the present value of future economic benefits by capitalizing or discounting the cash flows of a business. This approach considers projected dividends, earnings, dividend paying capacity and future residual value. The market approach estimates the fair value of the entity by comparing it to similar companies that have recently been acquired or companies that are publicly traded on an organized exchange. The market approach includes a comparison of the financial condition of the entity against the financial characteristics and pricing information of comparable companies. As a result of performing the Step 1 goodwill impairment evaluation, the Corporation determined that its goodwill was not impaired at October 31, 2011. Other Intangible Assets Intangible assets consist of core deposit intangible assets, non-compete agreements and MSRs. Core deposit intangible assets are amortized over periods ranging from 10 to 15 years, primarily on an accelerated basis, as applicable. Non-compete agreements are amortized over the term of the agreement on a straight-line basis. MSRs are amortized in proportion to, and over the life of, the estimated net future servicing income of the underlying loans. 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 stock options using the modified-prospective transition method. Under that method, compensation expense is recognized for stock options based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance. The Corporation accounts for stock awards based on the closing stock price of the Corporation’s common stock on the date of the award. The fair value of stock options and stock awards are recognized as compensation expense on a straight-line basis over the requisite service period. The Corporation accounts for restricted stock performance units based on the closing stock price of the Corporation’s common stock on the date of grant, discounted by the present value of estimated future dividends to be declared over the requisite performance or service period. The fair value of restricted stock performance units is recognized as compensation expense over the expected requisite performance period, or requisite service period for awards with multiple performance and service conditions. 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. Short-term Borrowings Short-term borrowings are comprised of securities sold under agreements to repurchase with customers with original scheduled maturities of one year or less. These agreements are collateralized financing transactions and the obligations to repurchase securities sold are reflected as a liability in the accompanying consolidated statements of financial position. The dollar amount of the securities underlying the agreements remain in the Corporation’s investment securities portfolio. The Corporation’s securities sold under agreements to repurchase are considered a stable source of liquidity, much like its core deposit base, and are generally only provided to customers that have an established banking relationship with Chemical Bank. Federal Home Loan Bank Advances Federal Home Loan Bank advances are borrowings from the FHLB to fund short-term liquidity needs as well as a portion of the loan and investment securities portfolios. These advances are secured, under a blanket security agreement, by first lien real estate residential loans with an aggregate book value equal to at least 155% of the FHLB advances and the FHLB stock owned by the Corporation. FHLB advances with an original maturity of one year or less are classified as short-term and FHLB advances with an original maturity of more than one year are classified as long-term. 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 December 31, 2011 and 2010, the Corporation had not elected the fair value option for any financial assets or liabilities. Pension and Postretirement Benefit Plan Actuarial Assumptions The Corporation’s defined benefit pension, supplemental pension and postretirement benefit obligations and related costs are calculated using actuarial concepts and measurements. Two critical assumptions, the discount rate and the expected long-term rate of return on plan assets, are important elements of expense and/or benefit obligation measurements. Other assumptions involve employee demographic factors such as retirement patterns, mortality, turnover and the rate of future compensation increases, as well as future health care costs. The Corporation evaluates all assumptions annually. The discount rate enables the Corporation to state expected future benefit payments as a present value on the measurement date. The Corporation determined the discount rate at December 31, 2011 and 2010 by utilizing the results from a discount rate model which involves selecting a portfolio of bonds to settle the projected benefit payments of the defined benefit pension plan. The selected bond portfolio is derived from a universe of corporate bonds rated at Aa quality. After the bond portfolio is selected, a single rate is determined that equates the market value of the bonds purchased to the discounted value of the plan’s benefit payments which represents the discount rate. A lower discount rate increases the present value of benefit obligations and increases pension, supplemental pension and postretirement benefit expenses. To determine the expected long-term rate of return on defined benefit pension plan assets, the Corporation considers the current and expected asset allocation of the defined benefit pension plan, as well as historical and expected returns on each asset class. A lower expected rate of return on defined benefit pension plan assets will increase pension expense. The Corporation recognizes the over- or under-funded status of a plan as an other asset or other liability in the consolidated statements of financial position as measured by the difference between the fair value of the plan assets and the projected benefit obligation and any unrecognized prior service costs and actuarial gains and losses are recognized as a component of accumulated other comprehensive income (loss). The Corporation measures defined benefit plan assets and obligations as of December 31. Advertising Costs Advertising costs are expensed as incurred. Income and Other Taxes The Corporation is subject to the income and other tax laws of the United States, the State of Michigan and other states where nexus has been created. 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. Differences in the tax and book carrying amounts of assets and liabilities can also be generated when the Corporation acquires other banks or bank branches. 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. Uncertain 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 income 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 contingent income tax liabilities recorded at December 31, 2011 and 2010. Comprehensive Income Comprehensive income of the Corporation includes net income and adjustments to equity for changes in unrealized gains and losses on investment securities available-for-sale and the annual change in the difference between the fair value of pension and other postretirement plan assets and their respective projected benefit obligations, net of income taxes. The Corporation displays comprehensive income as a component in the consolidated statements of changes in shareholders’ equity. Adopted Accounting Pronouncements Fair Value Measurements and Disclosures: In January 2010, the FASB issued ASU No. 2010-06, Fair Value Measurements and Disclosures (Topic 820): Improving Disclosures about Fair Value Measurements (ASU 2010-06). ASU 2010-06 requires new disclosures about purchases, sales, issuances and settlements, on a gross basis, in the reconciliation of Level 3 fair value measurements for assets and liabilities measured on a recurring basis. The adoption of ASU 2010-06 on January 1, 2011 for the reconciliation of Level 3 fair value measurements did not have a material impact on the Corporation’s consolidated financial condition or results of operations. Testing Goodwill for Impairment: In December 2010, the FASB issued ASU No. 2010-28, Intangibles (Topic 350): When to Perform Step 2 of the Goodwill Impairment Test for Reporting Units with Zero or Negative Carrying Amounts (ASU 2010-28). ASU 2010-28 provides guidance on (i) the circumstances under which Step 2 of the goodwill impairment test must be performed for reporting units with zero or negative carrying amounts, and (ii) the qualitative factors to be taken into account when performing Step 2 in determining whether it is more-likely-than-not that an impairment exists. ASU 2010-28 is effective for public entities for fiscal years beginning after December 15, 2010, with early adoption prohibited. Upon initial application, all entities having reporting units with zero or negative carrying amounts are required to assess whether it is more-likely-than-not that impairment exists and any resulting goodwill impairment should be recognized as a cumulative-effect adjustment to opening retained earnings in the period of adoption. The adoption of ASU 2010-28 on January 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations. 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 be performed at least annually 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 early 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 6, Goodwill, to the consolidated financial statements for a further discussion of the Corporation’s annual goodwill impairment test. Pro Forma Disclosure Requirements for Business Combinations: In December 2010, the FASB issued ASU No. 2010-29, Business Combinations (Topic 805): Disclosure of Supplementary Pro Forma Information for Business Combinations (ASU 2010-29). ASU 2010-29 clarifies that pro forma revenue and earnings for a business combination occurring in the current year should be presented as though the business combination occurred as of the beginning of the year or, if comparative financial statements are presented, as though the business combination took place as of the beginning of the comparative year. ASU 2010-29 also amends existing guidance to expand the supplemental pro forma disclosures to include a description of the nature and amount of material, nonrecurring adjustments directly attributable to the business combination included in the pro forma revenue and earnings. ASU 2010-29 is effective prospectively for business combinations consummated on or after the start of the first annual reporting period beginning after December 15, 2010, with early adoption permitted. The adoption of ASU 2010-29 on January 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations. Determination of Troubled Debt Restructurings and Related Disclosures: In April 2011, the FASB issued 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 modifications and 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. 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). In December 2011, the FASB issued ASU No. 2011-12, Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in ASU No. 2011-05 (ASU 2011-12). ASU 2011-12 defers the effective date for some pending changes resulting from ASU 2011-05, including the requirement to present items that are reclassified from accumulated OCI to net income with the components of net income and OCI. All other requirements of ASU 2011-05 are not affected by ASU 2011-12. The requirements of ASU 2011-05 not affected by ASU 2011-12 are 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.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2011

Summary of Significant Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

NOTE 1 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

Chemical Financial Corporation (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.

The Corporation’s primary sources of revenue are from its loan products and investment securities.

Accounting Standards Codification

The Financial Accounting Standards Board’s (FASB) Accounting Standards Codification (ASC) became effective on July 1, 2009. At that date, the ASC became FASB’s officially recognized source of authoritative U.S. generally accepted accounting principles (GAAP) applicable to all public and non-public non-governmental entities, superseding existing FASB, American Institute of Certified Public Accountants (AICPA), Emerging Issues Task Force (EITF) and related literature. Rules and interpretive releases of the Securities and Exchange Commission (SEC) under the authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. All other accounting literature is considered non-authoritative. The switch to the ASC affects the way companies refer to GAAP in financial statements and accounting policies.

Reclassifications

The Corporation’s investments in Federal Home Loan Bank of Indianapolis (FHLB) and Federal Reserve Bank (FRB) stock have been reclassified from other securities to interest receivable and other assets on the Corporation’s consolidated statements of financial position and cash flows for all periods presented. Certain other amounts in the 2010 and 2009 consolidated financial statements and notes thereto have been reclassified to conform with the 2011 presentation. Such reclassifications had no effect on the Corporation’s shareholders’ equity or net income.

Basis of Presentation and Principles of Consolidation

The accounting and reporting policies of the Corporation and its subsidiaries conform to GAAP, SEC rules and interpretive releases and prevailing practices within the banking industry. The consolidated financial statements of the Corporation include the accounts of the Corporation and its wholly owned subsidiaries. All significant income and expenses are recorded on the accrual basis. Intercompany accounts and transactions have been eliminated in preparing the consolidated financial statements.

The Corporation consolidates variable interest entities (VIEs) in which it is the primary beneficiary. In general, a VIE is an entity that either (i) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (ii) has a group of equity owners that are unable to make significant decisions about its activities or (iii) has a group of equity owners that do not have the obligation to absorb losses or the right to receive return as generated by its operations. If any of these characteristics are present, the entity is subject to a variable interests consolidation model, and consolidation is based on variable interests, not on ownership of the entity’s outstanding voting stock. Variable interests are defined as contractual, ownership, or other monetary interests in an entity that change with fluctuations in the entity’s net asset value. The primary beneficiary consolidates the VIE. The primary beneficiary is defined as the enterprise that has the power to direct the activities and absorb losses or the right to receive benefits.

The Corporation is a significant limited partner in two low income housing tax credit partnerships. These entities meet the definition of VIEs. The Corporation is not the primary beneficiary of either VIE in which it holds a limited partnership interest; therefore, the VIEs are not consolidated in the Corporation’s financial statements. Exposure to loss as a result of its involvement with VIEs at December 31, 2011 was limited to approximately $3.8 million recorded as the Corporation’s investment, which includes unfunded obligations to these projects of $2.6 million. The Corporation’s investment in these projects is recorded in interest receivable and other assets and the future financial obligations are recorded in interest payable and other liabilities in the consolidated statement of financial position at 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 O.A.K. Financial Corporation (OAK) for total consideration of $83.7 million. Pursuant to the guidance of 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.

Cash and Cash Equivalents

For purposes of reporting cash flows, cash and cash equivalents include cash on hand, interest-bearing deposits with unaffiliated banks and others and federal funds sold, with original maturities of less than 90 days. Generally, federal funds are sold for one-day periods. At December 31, 2011 and 2010, the Corporation did not have any federal funds sold. Amounts reported under interest-bearing deposits with unaffiliated banks and others include interest-bearing savings and time deposits held at other financial institutions and overnight funds held at the FRB in lieu of federal funds sold.

Investment Securities

Investment securities include investments in debt, trust preferred and preferred stock securities. Investment securities are accounted for in accordance with ASC Topic 320, Investments — Debt and Equity Securities (ASC 320), which requires investments to be classified within one of three categories (trading, held-to-maturity or available-for-sale). The Corporation held no trading investment securities at December 31, 2011 or 2010.

Designation as an investment security held-to-maturity is based on the Corporation’s intent and ability to hold the security to maturity. Investment securities held-to-maturity are stated at cost, adjusted for purchase price premiums and discounts. Investment securities that are not held-to-maturity are accounted for as securities available-for-sale, and are stated at estimated fair value, with the aggregate unrealized gains and losses, not deemed other-than-temporary, classified as a component of accumulated other comprehensive income (loss), net of income taxes. Realized gains and losses on the sale of investment securities and other-than-temporary impairment (OTTI) charges are determined using the specific identification method and are included within noninterest income in the consolidated statements of income. Premiums and discounts on investment securities are amortized over the estimated lives of the related investment securities based on the effective interest yield method and are included in interest income in the consolidated statements of income.

The Corporation assesses equity and debt securities that have fair values below amortized cost basis to determine whether declines (impairment) are other-than-temporary. If the Corporation intends to sell an impaired security or it is more-likely-than-not that the Corporation will be required to sell an impaired security prior to the recovery of its amortized cost, an OTTI write-down is recognized in earnings equal to the entire difference between the security’s amortized cost basis and its fair value. If the Corporation does not intend to sell an impaired security and it is not more-likely-than-not that the Corporation would be required to sell an impaired security before the recovery of its amortized cost basis, then the recognition of the impairment is bifurcated if a credit loss is deemed to have occurred. For a security where the impairment is bifurcated, the impairment is separated into an amount representing the credit loss, which is recognized in earnings, and an amount related to all other factors, which is recognized in other comprehensive income. In assessing whether OTTI exists, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, (iii) the potential for impairments in an entire industry or sub-sector and (iv) the potential for impairments in certain economically depressed geographical locations.

Nonmarketable Equity Securities

The Corporation is required to hold non-marketable equity securities, comprised of Federal Home Loan Bank of Indianapolis (FHLB) and Federal Reserve Bank (FRB) stock, as a condition of membership. These securities are accounted for at cost which equals par or redemption value. These securities do not have a readily determinable fair value as their ownership is restricted and there is no market for these securities. These securities can only be redeemed or sold at their par value and only to the respective issuing government supported institution or to another member institution. The Corporation records these non-marketable equity securities as a component of other assets and they are periodically evaluated for impairment. Management considers these non-marketable equity securities to be long-term investments. Accordingly, when evaluating these securities for impairment, management considers the ultimate recoverability of the par value rather than by recognizing temporary declines in value. The Corporation’s ownership in FHLB stock totaled $17.2 million and $18.7 million at December 31, 2011 and 2010, respectively, and in FRB stock totaled $8.4 million at both December 31, 2011 and 2010.

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. Loan interest income is recognized on the accrual basis. Deferred loan fees and costs are amortized over the loan term based on the level-yield method. Net loan commitment fees are deferred and amortized into fee income on a straight-line basis over the commitment period.

The past due status of a loan is based on the loan’s contractual terms. A loan is placed in nonaccrual (accrual of interest is discontinued) 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. Subsequent receipts of interest while a loan is in nonaccrual are recorded as a reduction of principal. 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 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. 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 entails 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. 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 in 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 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 Topic 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 acquired loans 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 the 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 will result 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 consist of originated loans that continue to accrue interest at the loan’s original effective interest rate as the Corporation expects to collect the remaining principal and interest on the loan. The interest income recognized on TDRs may include accretion of an identified impairment at the time of modification which is attributable to a temporary reduction in the borrower’s interest rate. At the time of modification, a TDR is reported as a nonperforming loan (nonperforming TDR) until a six-month payment history of principal and interest payments, in accordance with the terms of the loan modification, is sustained, at which time the Corporation moves the loan to a performing status (performing TDR). All TDRs are accounted for as impaired loans and are included in the Corporation’s analysis of the allowance for loan losses.

Loans in the Corporation’s commercial loan portfolio (comprised of commercial, real estate commercial, real estate construction and land development loans) that meet the definition of a TDR 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 reduce payments due to an extension 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 expected to be incurred on these loans, the loans 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.

Loans in the Corporation’s consumer loan portfolio (comprised of real estate residential, consumer installment and home equity loans) that meet the definition of a TDR 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 an additional provision for loan losses related to impairment on these loans on an individual basis 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.

The Corporation’s loans reported as TDRs do not include loans that are in a nonaccrual status that have been modified by the Corporation due to the borrower experiencing financial difficulty and for which a concession has been granted, as the Corporation does not expect to collect the full amount of principal and interest owed from the borrower on these modified loans. The Corporation’s nonaccrual loans at December 31, 2011 and 2010 included $41.8 million and $59.4 million, respectively, of these modified loans.

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 not performing in accordance with their original contractual terms. Impaired loans are accounted for 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. When the present value of expected cash flows or the fair value of collateral of an impaired loan is less than the amount of unpaid principal outstanding on the loan, the principal balance of the loan is reduced to its carrying value through either an allocation of the allowance for loan losses or a partial charge-off of the loan balance.

Nonperforming Loans

Nonperforming loans are comprised of loans for which the accrual of interest has been discontinued (nonaccrual loans), accruing originated 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 loan in the commercial loan portfolio (commercial, real estate commercial, real estate construction and land development loans) at the time of approval and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review on a quarterly basis 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 loans in the commercial loan portfolio, 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 loans in the commercial loan portfolio and nonaccrual real estate residential, consumer installment and home equity loans, (iii) allocations, by loan classes, on all other loans based principally on a five-year historical loan loss experience and loan loss trends and (iv) an unallocated allowance based on the imprecision in the allowance methodology for loans collectively evaluated for impairment.

The first element reflects the Corporation’s estimate of probable losses based upon the systematic review of individually impaired loans in the originated commercial 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. 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 in the commercial loan portfolio that are primarily secured by real estate and have a loan balance of greater than $0.25 million. 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 weighted five-year average of loss experience for each class of loan with higher weighting placed on the most recent years. 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.

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 attributable to originated loans is available for any loan losses that occur in the originated loan portfolio. Loans that are deemed not collectible are charged off and reduce the allowance. The provision for loan losses and recoveries on loans previously charged off increase the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off.

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 result in a reduction in the allowance allocated to acquired loans for the particular pool, if applicable, and then 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 for loan losses. Such agencies may require additions to the allowance based on their judgment reflecting information available to them at the time of their examinations.

Mortgage Banking Operations

The origination of real estate residential (mortgage) loans is an integral component of the business of the Corporation. The Corporation generally sells its originations of conforming long-term fixed interest rate mortgage loans in the secondary market. Gains and losses on the sales of these loans are determined using the specific identification method. The Corporation sells mortgage loans in the secondary market on either a servicing retained or released basis.

Mortgage loans held for sale are carried at the lower of aggregate cost or market. The value of mortgage loans held for sale and other residential mortgage loan commitments to customers are hedged by utilizing best efforts forward commitments to sell loans to investors in the secondary market. Such forward commitments are generally entered into at the time customer applications are taken to protect the value of the mortgage loans from increases in market interest rates during the period held. Mortgage loans originated for sale are generally sold within 45 days after closing.

Forward loan commitments are accounted for as derivatives and recorded at fair value, with changes in fair value recorded through earnings. The Corporation recognizes revenue associated with the expected future cash flows of servicing loans for loans held for sale at the time a forward loan commitment is made, as required under SEC Staff Accounting Bulletin No. 109, Written Loan Commitments Recorded at Fair Value Through Earnings.

The Corporation accounts for mortgage servicing rights (MSRs) by separately recognizing servicing assets. An asset is recognized for the rights to service mortgage loans that are created by the origination of mortgage loans that are sold with the servicing retained by the Corporation. The Corporation amortizes MSRs in proportion to and over the period of net servicing income and assesses MSRs for impairment, on a quarterly basis, based on fair value measurements. Unexpected prepayments of mortgage loans result in increased amortization of MSRs, as the remaining book value of the MSRs is expensed at the time of prepayment. Any temporary impairment of MSRs is recognized as a valuation allowance, resulting in a reduction of mortgage banking revenue. The valuation allowance is recovered when impairment that is believed to be temporary no longer exists. Other-than-temporary impairments are recognized if the recoverability of the carrying value is determined to be remote. When this occurs, the unrecoverable portion of the valuation allowance is recorded as a direct write-down to the carrying value of MSRs. This direct write-down permanently reduces the carrying value of the MSRs, precluding recognition of subsequent recoveries, and result in a reduction of mortgage banking revenue. For purposes of measuring fair value of MSRs, the Corporation utilizes a third-party modeling software program. Servicing income is recognized when earned and is offset by the amortization of MSRs.

Premises and Equipment

Land is recorded at cost. Premises and equipment are stated at cost less accumulated depreciation. Premises and equipment are depreciated over the estimated useful lives of the assets. The estimated useful lives are generally 25 to 39 years for buildings and three to ten years for all other depreciable assets. Depreciation is computed on the straight-line method. Maintenance and repairs are charged to expense as incurred.

Other Real Estate

Other real estate (ORE) is comprised of commercial and residential real estate properties, including vacant land and development properties, obtained in partial or total satisfaction of loan obligations. ORE is recorded at the lower of cost or the estimated fair value of the property, less anticipated selling costs based upon the property’s appraised value at the date of transfer to ORE and management’s estimate of the fair value of the collateral, with any difference between the net realizable value of the property and the carrying value of the loan charged to the allowance for loan losses. Subsequent changes in the fair value of ORE are recognized as adjustments to the carrying amount, not to exceed the initial carrying value of the assets at the time of transfer. Changes in the fair value of ORE, subsequent to the initial transfer to ORE, and costs incurred to maintain ORE are recorded in other operating expenses on the consolidated statements of income. Gains or losses not previously recognized resulting from the sale of ORE are also recognized in other operating expenses on the date of sale. ORE totaling $24.9 million and $27.0 million at December 31, 2011 and 2010, respectively, was included in the consolidated statements of financial position in interest receivable and other assets.

Goodwill

Goodwill is not amortized, but rather is subject to impairment tests annually, or more frequently if triggering events occur and indicate potential impairment. The Corporation’s annual goodwill impairment test was performed as of September 30, 2011, and based on a qualitative assessment, as permitted by FASB Accounting Standards Update (ASU) 2011-08, Testing Goodwill for Impairment (ASU 2011-08), which the Corporation early adopted as of September 30, 2011, the Corporation determined that it was not more-likely-than-not that the fair value of the Corporation’s sole reporting unit, Chemical Bank, was less than its carrying value, and that accordingly, no impairment existed for the Corporation’s goodwill at that date.

During the fourth quarter of 2011, the Corporation changed the date of its annual impairment testing for goodwill from September 30 to October 31. The change in the date of the annual goodwill impairment test represents a change in the method of applying an accounting principle. Management believes this change in accounting principle is preferable, as the later date better coincides with the Corporation’s annual budgeting and strategic planning processes. Management also believes that the change in the Corporation’s annual goodwill impairment testing date did not delay, accelerate or avoid a goodwill impairment charge. A preferability letter from the Corporation’s independent registered public accounting firm regarding this change in accounting principle has been filed as an exhibit to the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2011.

The Corporation elected to bypass the qualitative assessment of goodwill impairment that became acceptable as a result of adopting ASU 2011-08 and performed Step 1 of the goodwill impairment test as of October 31, 2011, consistent with the Corporation’s historical practice. The income and market approach methodologies prescribed in ASC Topic 820, Fair Value Measurements and Disclosures (ASC 820), were utilized to estimate the value of the Corporation’s goodwill under Step 1 of the goodwill impairment test. The income approach quantifies the present value of future economic benefits by capitalizing or discounting the cash flows of a business. This approach considers projected dividends, earnings, dividend paying capacity and future residual value. The market approach estimates the fair value of the entity by comparing it to similar companies that have recently been acquired or companies that are publicly traded on an organized exchange. The market approach includes a comparison of the financial condition of the entity against the financial characteristics and pricing information of comparable companies. As a result of performing the Step 1 goodwill impairment evaluation, the Corporation determined that its goodwill was not impaired at October 31, 2011.

Other Intangible Assets

Intangible assets consist of core deposit intangible assets, non-compete agreements and MSRs. Core deposit intangible assets are amortized over periods ranging from 10 to 15 years, primarily on an accelerated basis, as applicable. Non-compete agreements are amortized over the term of the agreement on a straight-line basis. MSRs are amortized in proportion to, and over the life of, the estimated net future servicing income of the underlying loans.

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 stock options using the modified-prospective transition method. Under that method, compensation expense is recognized for stock options based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance. The Corporation accounts for stock awards based on the closing stock price of the Corporation’s common stock on the date of the award. The fair value of stock options and stock awards are recognized as compensation expense on a straight-line basis over the requisite service period. The Corporation accounts for restricted stock performance units based on the closing stock price of the Corporation’s common stock on the date of grant, discounted by the present value of estimated future dividends to be declared over the requisite performance or service period. The fair value of restricted stock performance units is recognized as compensation expense over the expected requisite performance period, or requisite service period for awards with multiple performance and service conditions.

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.

Short-term Borrowings

Short-term borrowings are comprised of securities sold under agreements to repurchase with customers with original scheduled maturities of one year or less. These agreements are collateralized financing transactions and the obligations to repurchase securities sold are reflected as a liability in the accompanying consolidated statements of financial position. The dollar amount of the securities underlying the agreements remain in the Corporation’s investment securities portfolio. The Corporation’s securities sold under agreements to repurchase are considered a stable source of liquidity, much like its core deposit base, and are generally only provided to customers that have an established banking relationship with Chemical Bank.

Federal Home Loan Bank Advances

Federal Home Loan Bank advances are borrowings from the FHLB to fund short-term liquidity needs as well as a portion of the loan and investment securities portfolios. These advances are secured, under a blanket security agreement, by first lien real estate residential loans with an aggregate book value equal to at least 155% of the FHLB advances and the FHLB stock owned by the Corporation. FHLB advances with an original maturity of one year or less are classified as short-term and FHLB advances with an original maturity of more than one year are classified as long-term.

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 December 31, 2011 and 2010, the Corporation had not elected the fair value option for any financial assets or liabilities.

Pension and Postretirement Benefit Plan Actuarial Assumptions

The Corporation’s defined benefit pension, supplemental pension and postretirement benefit obligations and related costs are calculated using actuarial concepts and measurements. Two critical assumptions, the discount rate and the expected long-term rate of return on plan assets, are important elements of expense and/or benefit obligation measurements. Other assumptions involve employee demographic factors such as retirement patterns, mortality, turnover and the rate of future compensation increases, as well as future health care costs. The Corporation evaluates all assumptions annually.

The discount rate enables the Corporation to state expected future benefit payments as a present value on the measurement date. The Corporation determined the discount rate at December 31, 2011 and 2010 by utilizing the results from a discount rate model which involves selecting a portfolio of bonds to settle the projected benefit payments of the defined benefit pension plan. The selected bond portfolio is derived from a universe of corporate bonds rated at Aa quality. After the bond portfolio is selected, a single rate is determined that equates the market value of the bonds purchased to the discounted value of the plan’s benefit payments which represents the discount rate. A lower discount rate increases the present value of benefit obligations and increases pension, supplemental pension and postretirement benefit expenses.

To determine the expected long-term rate of return on defined benefit pension plan assets, the Corporation considers the current and expected asset allocation of the defined benefit pension plan, as well as historical and expected returns on each asset class. A lower expected rate of return on defined benefit pension plan assets will increase pension expense.

The Corporation recognizes the over- or under-funded status of a plan as an other asset or other liability in the consolidated statements of financial position as measured by the difference between the fair value of the plan assets and the projected benefit obligation and any unrecognized prior service costs and actuarial gains and losses are recognized as a component of accumulated other comprehensive income (loss). The Corporation measures defined benefit plan assets and obligations as of December 31.

Advertising Costs

Advertising costs are expensed as incurred.

Income and Other Taxes

The Corporation is subject to the income and other tax laws of the United States, the State of Michigan and other states where nexus has been created. 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. Differences in the tax and book carrying amounts of assets and liabilities can also be generated when the Corporation acquires other banks or bank branches. 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.

Uncertain 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 income 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 contingent income tax liabilities recorded at December 31, 2011 and 2010.

Comprehensive Income

Comprehensive income of the Corporation includes net income and adjustments to equity for changes in unrealized gains and losses on investment securities available-for-sale and the annual change in the difference between the fair value of pension and other postretirement plan assets and their respective projected benefit obligations, net of income taxes. The Corporation displays comprehensive income as a component in the consolidated statements of changes in shareholders’ equity.

Adopted Accounting Pronouncements

Fair Value Measurements and Disclosures: In January 2010, the FASB issued ASU No. 2010-06, Fair Value Measurements and Disclosures (Topic 820): Improving Disclosures about Fair Value Measurements (ASU 2010-06). ASU 2010-06 requires new disclosures about purchases, sales, issuances and settlements, on a gross basis, in the reconciliation of Level 3 fair value measurements for assets and liabilities measured on a recurring basis. The adoption of ASU 2010-06 on January 1, 2011 for the reconciliation of Level 3 fair value measurements did not have a material impact on the Corporation’s consolidated financial condition or results of operations.

Testing Goodwill for Impairment: In December 2010, the FASB issued ASU No. 2010-28, Intangibles (Topic 350): When to Perform Step 2 of the Goodwill Impairment Test for Reporting Units with Zero or Negative Carrying Amounts (ASU 2010-28). ASU 2010-28 provides guidance on (i) the circumstances under which Step 2 of the goodwill impairment test must be performed for reporting units with zero or negative carrying amounts, and (ii) the qualitative factors to be taken into account when performing Step 2 in determining whether it is more-likely-than-not that an impairment exists. ASU 2010-28 is effective for public entities for fiscal years beginning after December 15, 2010, with early adoption prohibited. Upon initial application, all entities having reporting units with zero or negative carrying amounts are required to assess whether it is more-likely-than-not that impairment exists and any resulting goodwill impairment should be recognized as a cumulative-effect adjustment to opening retained earnings in the period of adoption. The adoption of ASU 2010-28 on January 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations.

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 be performed at least annually 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 early 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 6, Goodwill, to the consolidated financial statements for a further discussion of the Corporation’s annual goodwill impairment test.

Pro Forma Disclosure Requirements for Business Combinations: In December 2010, the FASB issued ASU No. 2010-29, Business Combinations (Topic 805): Disclosure of Supplementary Pro Forma Information for Business Combinations (ASU 2010-29). ASU 2010-29 clarifies that pro forma revenue and earnings for a business combination occurring in the current year should be presented as though the business combination occurred as of the beginning of the year or, if comparative financial statements are presented, as though the business combination took place as of the beginning of the comparative year. ASU 2010-29 also amends existing guidance to expand the supplemental pro forma disclosures to include a description of the nature and amount of material, nonrecurring adjustments directly attributable to the business combination included in the pro forma revenue and earnings. ASU 2010-29 is effective prospectively for business combinations consummated on or after the start of the first annual reporting period beginning after December 15, 2010, with early adoption permitted. The adoption of ASU 2010-29 on January 1, 2011 did not have a material impact on the Corporation’s consolidated financial condition or results of operations.

Determination of Troubled Debt Restructurings and Related Disclosures: In April 2011, the FASB issued 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 modifications and 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.

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). In December 2011, the FASB issued ASU No. 2011-12, Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in ASU No. 2011-05 (ASU 2011-12). ASU 2011-12 defers the effective date for some pending changes resulting from ASU 2011-05, including the requirement to present items that are reclassified from accumulated OCI to net income with the components of net income and OCI. All other requirements of ASU 2011-05 are not affected by ASU 2011-12. The requirements of ASU 2011-05 not affected by ASU 2011-12 are 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.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

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