STBA 10-Q Quarter ended Sept. 30, 2013

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SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

For the quarterly period ended September 30, 2013

OR

For the transition period from            To

Commission file number 0-12508

S&T BANCORP, INC.

(Exact name of registrant as specified in its charter)

800-325-2265

(Registrant’s telephone number, including area code)

Not Applicable

(Former name, former address, and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (Section 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes x No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definition of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No x

APPLICABLE ONLY TO CORPORATE ISSUERS:

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practical date.

Common Stock, $2.50 Par Value - 29,738,305 shares as of October 29, 2013

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INDEX

S&T BANCORP, INC. AND SUBSIDIARIES

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S&T BANCORP, INC. AND SUBSIDIARIES

See Notes to Consolidated Financial Statements

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S&T BANCORP, INC. AND SUBSIDIARIES

(Unaudited)

See Notes to Consolidated Financial Statements

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S&T BANCORP, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

(Unaudited)

See Notes to Consolidated Financial Statements

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S&T BANCORP, INC. AND SUBSIDIARIES

(Unaudited)

See Notes to Consolidated Financial Statements

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S&T BANCORP, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Principles of Consolidation

The interim Consolidated Financial Statements include the accounts of S&T Bancorp, Inc., or S&T, and its wholly owned subsidiaries. All significant intercompany transactions have been eliminated in consolidation. Investments of 20 percent to 50 percent of the outstanding common stock of investees are accounted for using the equity method of accounting.

Basis of Presentation

The accompanying unaudited interim Consolidated Financial Statements of S&T have been prepared in accordance with generally accepted accounting principles, or GAAP, in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with our annual report on Form 10-K for the year ended December 31, 2012, filed with the Securities and Exchange Commission, or SEC, on February 25, 2013. In the opinion of management, the accompanying interim financial information reflects all adjustments, including normal recurring adjustments, necessary to present fairly our financial position and the results of operations for each of the interim periods presented. Results of operations for interim periods are not necessarily indicative of the results of operations that may be expected for a full year or any future period.

Reclassification

Certain amounts in the prior periods’ financial statements and footnotes have been reclassified to conform to the current period’s presentation. The reclassifications had no significant effect on our results of operations or financial condition.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.

Recently Adopted Accounting Standards Updates

Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income

In February 2013, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2013-02, Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income. ASU 2013-02 requires reporting the effect of significant reclassifications out of accumulated other comprehensive income by component on the respective line items in the income statement parenthetically or in the notes to the financial statements if the amounts being reclassified are required under GAAP to be reclassified in their entirety to net income. This ASU is effective for public companies prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2012 and early adoption is permitted. We have elected the option of reporting in the notes to the financial statements. The adoption of ASU 2013-02 impacted only our disclosures and did not have an impact on our results of operations or financial position.

Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities

In January 2013, the FASB issued ASU No. 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities in order to clarify the scope of ASU 2011-11, Disclosures about Offsetting Assets and Liabilities, issued in December 2011. ASU 2011-11 required entities to disclose both gross and net information about instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an agreement similar to a master netting arrangement. This ASU was issued to allow investors to better compare financial statements prepared under GAAP with financial statements prepared under International Financial Reporting Standards, or IFRS. ASU 2013-01 clarified that ASU 2011-11 applies to derivatives, sale and repurchase agreements and reverse sale of repurchase agreements, and securities borrowing and securities lending arrangements, but does not apply to standard commercial contracts that permit either party to net in the event of default under the applicable contract or to broker-dealer unsettled regular-way trades. Both ASUs are effective for public companies retrospectively for fiscal years, and interim periods within those years, beginning on or after January 1, 2013. The adoption of ASU 2013-01 and ASU 2011-11 impacted only our disclosures and did not have an impact on our results of operations or financial position.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – continued

Recently Issued Accounting Standards Updates not yet Adopted

Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date

In February 2013, the FASB issued ASU No. 2013-04, Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date. The ASU requires the measurement of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement with its co-obligors as well as any additional amount that the entity expects to pay on behalf of its co-obligors. The new standard is effective retrospectively for fiscal years and interim periods within those years, beginning after December 15, 2013, and early adoption is permitted. The adoption of this ASU is not expected to have a material impact on our results of operations or financial position.

Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Tax Credit Carry forward Exists

In July 2013, the FASB issued ASU No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Tax Credit Carry forward Exists. The ASU requires that entities should present an unrecognized tax benefit as a reduction of the deferred tax asset for a net operating loss, or NOL, or similar tax loss or tax credit carry forward rather than as a liability when the uncertain tax position would reduce the NOL or other carry forward under the tax law. No new disclosures will be necessary. The new standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013, and should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The adoption of this ASU is expected to impact the presentation of our statement of financial position, but is not expected to have any impact on our results of operations.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – continued

The following table reconciles the numerators and denominators of basic earnings per share with that of diluted earnings per share for the periods presented:

We use fair value measurements when recording and disclosing certain financial assets and liabilities. Securities available-for-sale, trading assets and derivatives are recorded at fair value on a recurring basis. Additionally, from time to time, we may be required to record other assets at fair value on a nonrecurring basis, such as loans held for sale, impaired loans, other real estate owned, or OREO, mortgage servicing rights, or MSRs, and certain other assets.

Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants at the measurement date. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date to allow for marketing activities that are usual and customary for transactions involving such assets or liabilities; it is not a forced transaction. In determining fair value, we use various valuation approaches, including market, income and cost approaches. The fair value standard establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing an asset or liability, which is developed, based on market data we have obtained from independent sources. Unobservable inputs reflect our estimate of assumptions that market participants would use in pricing an asset or liability, which are developed based on the best information available in the circumstances.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – continued

NOTE 3. FAIR VALUE MEASUREMENTS – continued

The fair value hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The fair value hierarchy is broken down into three levels based on the reliability of inputs as follows:

Level 1: valuation is based upon unadjusted quoted market prices for identical instruments traded in active markets.

Level 2: valuation is based upon quoted market prices for similar instruments traded in active markets, quoted market prices for identical or similar instruments traded in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by market data.

Level 3: valuation is derived from other valuation methodologies, including discounted cash flow models and similar techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in determining fair value.

A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Our policy is to recognize transfers between any of the fair value hierarchy levels at the end of the reporting period in which the transfer occurred.

The following are descriptions of the valuation methodologies that we use for financial instruments recorded at fair value on either a recurring or nonrecurring basis.

Recurring Basis

Securities Available-for-Sale

Securities available-for-sale include both debt and equity securities. We obtain fair values for debt securities from a third-party pricing service which utilizes several sources for valuing fixed-income securities. We validate prices received from our pricing service through comparison to a secondary pricing service and broker quotes. We review the methodologies of the pricing service which provides us with a sufficient understanding of the valuation models, assumptions, inputs and pricing to reasonably measure the fair value of our securities. The market evaluation sources for debt securities include observable inputs rather than significant unobservable inputs and are classified as Level 2. The service provider utilizes pricing models that vary by asset class and include available trade, bid and other market information. Generally, the methodologies include broker quotes, proprietary models, vast descriptive terms and conditions databases, as well as extensive quality control programs.

Marketable equity securities that have an active, quotable market are classified as Level 1. Marketable equity securities that are quotable, but are thinly traded or inactive, are classified as Level 2 and securities that are not readily traded and do not have a quotable market are classified as Level 3.

Trading Assets

We use quoted market prices to determine the fair value of our trading assets. Our trading assets are held in a Rabbi Trust under a deferred compensation plan and are invested in readily quoted mutual funds. Accordingly, these assets are classified as Level 1.

Derivative Financial Instruments

We use derivative instruments including interest rate swaps for commercial loans with our customers and we sell mortgage loans in the secondary market and enter into interest rate lock commitments. We calculate the fair value for derivatives using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Each valuation considers the contractual terms of the derivative, including the period to maturity and uses observable market based inputs, such as interest rate curves and implied volatilities. Accordingly, derivatives are classified as Level 2. We incorporate credit valuation adjustments into the valuation models to appropriately reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in calculating fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we have considered the impact of netting and any applicable credit enhancements and collateral postings.

Nonrecurring Basis

Loans Held for Sale

Loans held for sale consist of 1-4 family residential loans originated for sale in the secondary market and, from time to time, certain loans transferred from the loan portfolio to loans held for sale, all of which are carried at the lower of cost or fair value. The fair value of 1-4 family residential loans is based on the principal or most advantageous market currently offered for similar loans using observable market data. The fair value of the loans transferred from the loan portfolio is based on the amounts offered for these loans in currently pending sales transactions. Loans held for sale carried at fair value are classified as Level 3.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – continued

NOTE 3. FAIR VALUE MEASUREMENTS – continued

Impaired Loans

Impaired loans are carried at the lower of carrying value or fair value. Fair value is determined as the recorded investment balance less any specific reserve. We establish a specific reserve based on the following three impairment methods: 1) the present value of expected future cash flows discounted at the loan’s original effective interest rate, 2) the loan’s observable market price or 3) the fair value of the collateral less estimated selling costs when the loan is collateral dependent and we expect to liquidate the collateral. However, if repayment is expected to come from the operation of the collateral, rather than liquidation, then we do not consider estimated selling costs in determining the fair value of the collateral. Collateral values are generally based upon appraisals by approved, independent state certified appraisers. Appraisals may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or our knowledge of the borrower and the borrower’s business. Impaired loans carried at fair value are classified as Level 3.

OREO and Other Repossessed Assets

OREO and other repossessed assets obtained in partial or total satisfaction of a loan are recorded at the lower of recorded investment in the loan or fair value less cost to sell. Subsequent to foreclosure, these assets are carried at the lower of the amount recorded at acquisition date or fair value less cost to sell. Accordingly, it may be necessary to record nonrecurring fair value adjustments. Fair value, when recorded, is generally based upon appraisals by approved, independent state certified appraisers. Like impaired loans, appraisals on OREO may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or other information available to us. OREO and other repossessed assets are classified as Level 3.

Mortgage Servicing Rights

The fair value of MSRs is determined by calculating the present value of estimated future net servicing cash flows, considering expected mortgage loan prepayment rates, discount rates, servicing costs and other economic factors, which are determined based on current market conditions. The expected rate of mortgage loan prepayments is the most significant factor driving the value of MSRs. MSRs are considered impaired if the carrying value exceeds fair value. The valuation model includes significant unobservable inputs; therefore, MSRs are classified as Level 3 within the fair value hierarchy.

Other Assets

We measure certain other assets at fair value on a nonrecurring basis. Fair value is based on the application of lower of cost or fair value accounting, or write-downs of individual assets. Valuation methodologies used to measure fair value are consistent with overall principles of fair value accounting and consistent with those described above.

Financial Instruments

In addition to financial instruments recorded at fair value in our financial statements, fair value accounting guidance requires disclosure of the fair value of all of an entity’s assets and liabilities that are considered financial instruments. The majority of our assets and liabilities are considered financial instruments. Many of these instruments lack an available trading market as characterized by a willing buyer and willing seller engaged in an exchange transaction. Also, it is our general practice and intent to hold our financial instruments to maturity and to not engage in trading or sales activities with respect to such financial instruments. For fair value disclosure purposes, we substantially utilize the fair value measurement criteria as required and explained above. In cases where quoted fair values are not available, we use present value methods to determine the fair value of our financial instruments.

Cash and Cash Equivalents and Other Short-Term Assets

The carrying amounts reported in the Consolidated Balance Sheets for cash and due from banks, including interest-bearing deposits, approximate fair value.

Loans

The fair value of variable rate performing loans is based on carrying values adjusted for credit risk. The fair value of fixed rate performing loans is estimated using a discounted cash flow analyses that utilizes interest rates currently being offered for similar loans and adjusted for credit risk. The fair value of nonperforming loans is based on their carrying values less any specific reserve. The carrying amount of accrued interest approximates fair value.

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Bank Owned Life Insurance

Fair value approximates net cash surrender value.

Deposits

The fair values disclosed for deposits without defined maturities (e.g., noninterest and interest-bearing demand, money market and savings accounts) are by definition equal to the amounts payable on demand. The carrying amounts for variable rate, fixed-term time deposits approximate their fair values. Estimated fair values for fixed rate and other time deposits are based on discounted cash flow analysis using interest rates currently offered for time deposits with similar terms. The carrying amount of accrued interest approximates fair value.

Short-Term Borrowings

The carrying amounts of securities sold under repurchase agreements, federal funds purchased and other short-term borrowings approximate their fair values.

Long-Term Borrowings

The fair values disclosed for fixed rate long-term borrowings are determined by discounting their contractual cash flows using current interest rates for long-term borrowings of similar remaining maturities. The carrying amounts of variable rate long-term borrowings approximate their fair values.

The variable rate junior subordinated debt securities reprice quarterly; therefore, the fair values are based on the carrying values.

Loan Commitments and Standby Letters of Credit

Off-balance sheet financial instruments consist of commitments to extend credit and letters of credit. Except for interest rate lock commitments, estimates of the fair value of these off-balance sheet items are not made because of the short-term nature of these arrangements and the credit standing of the counterparties.

Other

Estimates of fair value are not made for items that are not defined as financial instruments, including such items as our core deposit intangibles and the value of our trust operations.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – continued

NOTE 3. FAIR VALUE MEASUREMENTS – continued

The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at September 30, 2013 and December 31, 2012. There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented.