10-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

x    ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934.

For the fiscal year ended December 31, 2012

or

¨    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934.

For the transition period from                      to                     

Commission file number 0-12508

S&T BANCORP, INC.

(Exact name of registrant as specified in its charter)

Pennsylvania	25-1434426
(State or other jurisdiction of incorporation of organization)	(I.R.S. Employer Identification No.)
800 Philadelphia Street, Indiana, PA	15701
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code (800) 325-2265

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Name of each exchange on which registered
Common Stock, par value $2.50 per share	The NASDAQ Stock Market LLC (NASDAQ Global Select Market)

Securities registered pursuant to Section 12(g) of the Act: None

(Title of class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes  ¨    No   x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Yes  ¨    No   x

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 if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (229.405 of this chapter) is not contained herein and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this form 10-K or any amendment to this form 10-K.  ¨

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 (§ 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 smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer  ¨	Accelerated filer  x
Non-accelerated filer  ¨ (Do not check if a smaller reporting  company)	Smaller reporting company  ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).

Yes  ¨    No   x

The aggregate estimated fair value of the voting and non-voting common equity held by non-affiliates of the registrant as of June 30, 2012:

Common Stock, $2.50 par value – $520,833,295

The number of shares outstanding of the issuer’s classes of common stock as of January 31, 2013:

Common Stock, $2.50 par value – 29,728,005 shares

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the proxy statement to be filed with the Securities and Exchange Commission for the annual shareholders meeting to be held May 20, 2013 are incorporated by reference into Part III.

Part I
Item 1.	Business	3
Item 1A.	Risk Factors	13
Item 1B.	Unresolved Staff Comments	19
Item 2.	Properties	19
Item 3.	Legal Proceedings	20
Item 4.	Mine Safety Disclosures	20
Part II
Item 5.	Market for Registrant’s Common Equity, Related Shareholder Matters and Issuer Purchases of Equity Securities	21
Item 6.	Selected Financial Data	23
Item 7.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	24
Item 7A.	Quantitative and Qualitative Disclosures About Market Risk	61
Item 8.	Financial Statements and Supplementary Data	63
Item 9.	Changes in and Disagreements with Accountants on Accounting and Financial Disclosures	129
Item 9A.	Controls and Procedures	129
Item 9B.	Other Information	129
Part III
Item 10.	Directors, Executive Officers and Corporate Governance	130
Item 11.	Executive Compensation	130
Item 12.	Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	130
Item 13.	Certain Relationships and Related Transactions, and Director Independence	130
Item 14.	Principal Accountant Fees and Services	130
Part IV
Item 15.	Exhibits and Financial Statement Schedules	131
	Signatures	134

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PART I

Item 1.  BUSINESS

General

S&T Bancorp, Inc., or S&T, (also referred to below as “we”, “us” or “our”), including on a consolidated basis with our subsidiaries where appropriate, was incorporated on March 17, 1983 under the laws of the Commonwealth of Pennsylvania as a bank holding company and has three wholly owned subsidiaries, S&T Bank, 9th Street Holdings, Inc. and STBA Capital Trust I. We also own a one-half interest in Commonwealth Trust Credit Life Insurance Company, or CTCLIC. We are registered as a financial holding company with the Board of Governors of the Federal Reserve System, or the Federal Reserve Board, under the Bank Holding Company Act of 1956, as amended, or the BHCA. As of December 31, 2012, we had approximately $4.5 billion in assets, $3.4 billion in loans, $3.6 billion in deposits and $537.4 million in shareholder’s equity.

S&T Bank is a full service bank with its Main Office at 800 Philadelphia Street, Indiana, Pennsylvania, providing services to its customers through offices located in Allegheny, Armstrong, Blair, Butler, Cambria, Clarion, Clearfield, Indiana, Jefferson, Washington and Westmoreland counties of Pennsylvania. S&T Bank deposits are insured by the Federal Deposit Insurance Corporation, or FDIC, to the maximum extent provided by law.

S&T Bank has three wholly owned operating subsidiaries: S&T Insurance Group, LLC, S&T Bancholdings, Inc. and Stewart Capital Advisors, LLC. S&T Insurance Group, LLC, through its subsidiaries, offers a variety of insurance products. S&T Bancholdings, Inc. is an investment company. Stewart Capital Advisors, LLC, is a registered investment advisor that manages private investment accounts for individuals and institutions and advises the Stewart Capital Mid Cap Fund.

We operate three reportable operating segments including Community Banking, Wealth Management and Insurance. Our Community Banking segment offers services which include accepting time and demand deposits, originating commercial and consumer loans, and providing letters of credit and credit card services. We believe that we have a relatively stable deposit base and no material amount of deposits is obtained from a single depositor or group of depositors (including federal, state and local governments). Our core deposit base remained stable in 2012.

The Wealth Management segment offers discount brokerage services, services as executor and trustee under wills and deeds, guardian and custodian of employee benefits and other trust and brokerage services, as well as a registered investment advisor that manages private investment accounts for individuals and institutions. Total Wealth Management assets under management and administration were approximately $1.7 billion at December 31, 2012.

The Insurance segment includes a full-service insurance agency offering commercial property and casualty insurance, group life and health coverage, employee benefit solutions and personal insurance lines.

Refer to the financial statements and Note 25 of this Form 10-K for further details pertaining to our operating segments.

Recent Developments

On March 9, 2012, we completed the acquisition and conversion of Mainline Bancorp, Inc., or Mainline, a bank holding company based in Ebensburg, Pennsylvania. Mainline had one subsidiary, Mainline National Bank, with eight branches and $129.5 million in loans and $206.0 million in deposits. The acquisition expanded our market share and footprint throughout Cambria and Blair counties of Western Pennsylvania. The total acquisition cost of Mainline was $27.8 million.

On August 13, 2012, we completed the acquisition of Gateway Bank of Pennsylvania, a bank with $99.1 million in loans and $105.4 million in deposits, headquartered in McMurray, Pennsylvania. The total acquisition cost of Gateway Bank was $19.8 million. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T, with all transactions since the acquisition

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Item 1.  BUSINESS — continued

date consolidated in our financial statements. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank.

In August 2012, we expanded our commercial lending footprint into Northeastern Ohio through the opening of a loan production office in Akron.

Employees

As of December 31, 2012, we had 1,027 full-time equivalent employees.

Access to United States Securities and Exchange Commission Filings

All of our reports filed electronically with the United States Securities and Exchange Commission, or the SEC, including this Annual Report on Form 10-K for the fiscal year ended December 31, 2012, or the Report, our prior annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and our annual proxy statements, as well as any amendments to those reports are accessible at no cost on our website at www.stbancorp.com under Financial Information, SEC Filings. These filings are also accessible on the SEC’s website at www.sec.gov. You may read and copy any material we file with the SEC at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. Our charters of the Audit Committee, the Compensation and Benefits Committee, the Nominating and Corporate Governance Committee, the Wealth Management Oversight Committee, Complaints Regarding Accounting, Internal Accounting Controls or Auditing Matters, or the Whistleblower Policy, the Code of Conduct for the CEO and CFO, the General Code of Conduct, the Shareholder Communications Policy, and S&T Excessive and Luxury Expenditure Policy are also available at www.stbancorp.com under Corporate Governance.

Supervision and Regulation

General

S&T and S&T Bank are each extensively regulated under federal and state law. The following describes certain aspects of that regulation and does not purport to be a complete description of all regulations that affect S&T and S&T Bank or all aspects of any regulation discussed here.

To the extent statutory or regulatory provisions are described, the description is qualified in its entirety by reference to the particular statutory or regulatory provisions. Proposals to change the laws and regulations governing the banking industry are frequently raised in Congress, in state legislatures and before the various bank regulatory agencies. The likelihood and timing of any changes and the impact such changes might have on S&T or S&T Bank is impossible to determine with any certainty.

Any change in applicable laws or regulations, or in the way such laws or regulations are interpreted by regulatory agencies or courts, may have a material impact on our business, operations and earnings.

S&T

We are a bank holding company subject to regulation under the BHCA and the examination and reporting requirements of the Federal Reserve Board. Under the BHCA, a bank holding company may not directly or indirectly acquire ownership or control of more than five percent of the voting shares or substantially all of the assets of any additional bank, or merge or consolidate with another bank holding company, without the prior approval of the Federal Reserve Board. We have received approval from the Federal Reserve Board for a passive ownership position in Allegheny Valley Bancorp, Inc. (14.4 percent).

As a bank holding company, we are expected under statutory and regulatory provisions to serve as a source of financial and managerial strength to our subsidiary bank. A bank holding company is also expected to commit resources, including capital and other funds, to support its subsidiary bank.

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Item 1.  BUSINESS — continued

We elected to become a financial holding company under the BHCA in 2001 and thereby engage in a broader range of financial and other activities than are permissible for traditional bank holding companies. In order to maintain our status as a financial holding company, we must remain “well-capitalized” and “well-managed” and the depository institutions controlled by us must remain “well-capitalized,” “well-managed” (as defined in federal law) and have at least a “satisfactory” Community Reinvestment Act, or CRA rating. Refer to Item 8, Note 23 Regulatory Matters, of this Report for information concerning the current capital ratios of S&T and S&T Bank. No prior regulatory approval is required for a financial holding company with total consolidated assets less than $50 billion to acquire a company, other than a bank or savings association, engaged in activities that are financial in nature or incidental to activities that are financial in nature, as determined by the Federal Reserve Board, unless the total consolidated assets to be acquired exceed $10 billion. The BHCA identifies several activities as “financial in nature” including, among others, securities underwriting, dealing and market making; sponsoring mutual funds and investment companies; insurance underwriting and sales agency; investment advisory activities; merchant banking activities; and activities that the Federal Reserve Board has determined to be closely related to banking or a proper incident thereto. Banks may also engage, subject to limitations on investment, in activities that are financial in nature, other than insurance underwriting, insurance company portfolio investment, real estate development and real estate investment, through a financial subsidiary of the bank, if the bank is “well-capitalized,” “well-managed” and has at least a “satisfactory” CRA rating.

If S&T or S&T Bank ceases to be “well-capitalized” or “well-managed,” we will not be in compliance with the requirements of the BHCA regarding financial holding companies. If a financial holding company is notified by the Federal Reserve Board of such a change in the ratings of any of its subsidiary banks, it must take certain corrective actions within specified time frames. Furthermore, if S&T Bank was to receive a CRA rating of less than “satisfactory,” then we would be prohibited from engaging in new activities or acquiring companies engaged in certain financial activities until the rating is raised to “satisfactory” or better.

We are presently engaged in nonbanking activities through the following five entities:

• 9th Street Holdings, Inc. was formed in June 1988 to hold and manage a group of investments previously owned by S&T Bank and to give us additional latitude to purchase other investments.

• S&T Bancholdings, Inc. was formed in August 2002 to hold and manage a group of investments previously owned by S&T Bank and to give us additional latitude to purchase other investments.

• CTCLIC is a joint venture with another financial institution, acting as a reinsurer of credit life, accident and health insurance policies sold by S&T Bank and the other institution.

• S&T Insurance Group, LLC distributes life insurance and long-term disability income insurance products. During 2001, S&T Insurance Group, LLC and Attorneys Abstract Company, Inc. entered into an agreement to form S&T Settlement Services, LLC or STSS, with respective ownership interests of 55 percent and 45 percent. STSS is a title insurance agency servicing commercial customers. During 2002, S&T Insurance Group, LLC expanded into the property and casualty insurance business with the acquisition of S&T-Evergreen Insurance LLC.

• Stewart Capital Advisors, LLC was formed in August 2005 and is a registered investment advisor that manages private investment accounts for individuals and institutions and advises the Stewart Capital Mid Cap Fund.

S&T Bank

As a state-chartered, commercial bank, the deposits of which are insured by the FDIC, S&T Bank is subject to the supervision and regulation of the Pennsylvania Department of Banking and

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Item 1.  BUSINESS — continued

Securities, or PADB and the FDIC. We are also subject to various requirements and restrictions under federal and state law, including requirements to maintain reserves against deposits, restrictions on the types, amount and terms and conditions of loans that may be granted and limits on the type of other activities in which S&T Bank may engage and the investments it may make.

In addition, S&T Bank is subject to affiliate transaction rules in Sections 23A and 23B of the Federal Reserve Act that limit the amount of transactions between itself and S&T or S&T’s nonbank subsidiaries. Under these provisions, transactions between a bank and its parent company or any single nonbank affiliate generally are limited to 10 percent of the bank subsidiary’s capital and surplus, and with respect to all transactions with affiliates, are limited to 20 percent of the bank subsidiary’s capital and surplus. Loans and extensions of credit from a bank to an affiliate generally are required to be secured by eligible collateral in specified amounts. The Dodd-Frank Act Wall Street Reform and Consumer Protection Act, or Dodd-Frank Act, expands the affiliate transaction rules to broaden the definition of affiliate and to apply to securities lending, repurchase agreements and derivatives activities that we may have with an affiliate, as well as to strengthen collateral requirements and limit Federal Reserve exemptive authority. Also, the definition of “extension of credit” for transactions with executive officers, directors and principal shareholders is being expanded to include credit exposure arising from a derivative transaction, a repurchase or reverse repurchase agreement and a securities lending or borrowing transaction. These expansions became effective July 21, 2012. These provisions have not had a material effect on S&T or S&T Bank.

Insurance of Accounts; Depositor Preference

The deposits of S&T Bank are insured up to applicable limits per insured depositor by the FDIC. The Dodd-Frank Act codified FDIC deposit insurance coverage per separately insured depositor for all account types at $250,000. The Dodd-Frank Act also maintained federal deposit insurance coverage for noninterest-bearing transaction accounts at an unlimited amount from December 31, 2010 until this part of the Act expired on December 31, 2012. Deposits held in noninterest-bearing transaction accounts are now aggregated with any interest-bearing deposits the owner may hold in the same ownership category, and the combined total insured up to at least $250,000.

As an FDIC-insured bank, S&T Bank is also subject to FDIC insurance assessments, which are imposed based upon the risk the institution poses to the Deposit Insurance Fund, or DIF. Under this assessment system, risk is defined and measured using an institution’s supervisory ratings with other risk measures, including financial ratios. The current total base assessment rates on an annualized basis range from 2.5 basis points for certain “well-capitalized,” “well-managed” banks, with the highest ratings, to 45 basis points for institutions posing the most risk to the DIF. The FDIC may raise or lower these assessment rates on a quarterly basis based on various factors to achieve a reserve ratio, which the Dodd-Frank Act has mandated to be no less than 1.35 percent of insured deposits.

In February 2011, the FDIC Board of Directors adopted a final rule, Deposit Insurance Assessment Base, Assessment Rate Adjustments, Dividends, Assessment Rates and Large Bank Pricing Methodology. This final rule redefined the deposit insurance assessment base to equal average consolidated total assets minus average tangible equity as required by the Dodd-Frank Act, altered assessment rates, implemented the Dodd-Frank Act’s DIF dividend provisions and revised the risk-based assessment system for all large insured depository institutions (those with at least $10.0 billion in total assets). Many of the changes were made as a result of provisions of the Dodd-Frank Act that were intended to shift more of the cost of raising the reserve ratio from institutions with less than $10.0 billion in assets (such as S&T Bank) to the larger banks. Except for the future assessment rate schedules, all changes went into effect April 1, 2011 which lowered our FDIC expense in 2012 compared to 2011 and 2010. In addition to DIF assessments, the FDIC assesses all insured deposits a special assessment to fund the repayment of debt obligations of the Financing Corporation, or FICO. FICO is a government-sponsored entity that was formed to borrow the money necessary to carry out

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the closing and ultimate disposition of failed thrift institutions by the Resolution Trust Corporation in the 1990s. For the first quarter of 2013, the annualized rate established by the FDIC for the FICO assessment is 0.64 basis points.

Under federal law, deposits and certain claims for administrative expenses and employee compensation against insured depository institutions are afforded a priority over other general unsecured claims against such an institution, including federal funds and letters of credit, in the liquidation or other resolution of such an institution by a receiver. Such priority creditors would include the FDIC.

Capital

The Federal Reserve Board and FDIC have issued substantially similar risk-based and leverage capital guidelines applicable to banking organizations they supervise. Under current capital guidelines, S&T and S&T Bank are required to maintain certain capital standards based on ratios of capital to assets and capital to risk weighted assets. The guidelines define a bank’s total qualifying capital as having two components. Tier 1 capital, which must be at least 50 percent of total qualifying capital, is mainly comprised of common equity, retained earnings and qualifying preferred stock, less certain intangibles. Tier 2 capital may include the allowance for loan losses, or ALL, up to a maximum of 1.25 percent of risk weighted assets, qualifying subordinated debt, qualifying preferred stock, hybrid capital instruments and up to 45 percent of net unrealized gains on available-for-sale equity securities. The guideline also defines the weights assigned to assets and off-balance sheet items to determine the risk weighted asset component of the risk-based capital ratios.

The Federal Reserve Board and FDIC have established minimum and well-capitalized standards for banks and bank holding companies. The minimum capital standards are defined as a Tier 1 ratio of at least 4.00 percent, a Total capital ratio of at least 8.00 percent and a Leverage ratio of at least 3.00 percent. The Leverage ratio of 3.00 percent is for those bank and bank holding companies that meet certain specified criteria, including having received the highest regulatory rating and are not experiencing significant growth or expansion. All other banks and bank holding companies generally are required to maintain a leverage ratio of at least 4 percent. S&T and S&T Bank maintain capital levels to meet the well-capitalized regulatory standards, which are defined as a Tier 1 ratio of at least 6.00 percent, Total capital ratio of at least 10.00 percent and a Leverage ratio of at least 5.00 percent. At December 31, 2012 S&T’s Tier 1 capital, Total capital and Leverage ratios were 11.98 percent, 15.39 percent and 9.31 percent, respectively. S&T Bank’s Tier 1, Total capital and Leverage ratios were 10.88 percent, 14.35 percent, and 8.45 percent, respectively.

Both the Federal Reserve Board and the FDIC’s risk-based capital standards explicitly identify concentrations of credit risk and the risk arising from non-traditional activities, as well as an institution’s ability to manage these risks, as important factors to be taken into account by the agency in assessing an institution’s overall capital adequacy. The capital guidelines also provide that an institution’s exposure to a decline in the economic value of its capital due to changes in interest rates be considered by the agency as a factor in evaluating a bank’s capital adequacy. The Federal Reserve Board has also issued additional capital guidelines for certain bank holding companies that engage in trading activities. We do not believe that consideration of these additional factors will affect the regulators’ assessment of the capital position of S&T or S&T Bank. The Dodd-Frank Act contains a number of provisions intended to strengthen capital, including requiring minimum leverage and risk-based capital that are at least as stringent as those currently in effect. Also, the Dodd-Frank Act requires the Federal Reserve Board to implement capital regulations that are countercyclical so that the amount of capital required to be maintained by us would increase in times of economic expansion and decrease in times of economic contraction, consistent with the safety and soundness of the company. In addition to the Dodd-Frank Act, the international oversight body of the Basel Committee on Banking Supervision, or Basel III, reached agreements in July, 2010 to introduce a minimum

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common equity tier 1 capital requirement of 4.50 percent, along with a capital conservation buffer of 2.50 percent to bring total common equity capital requirements to 7.00 percent. The federal banking agencies issued proposed rules in June 2012 to implement Basel III and certain other recent revisions to the Basel capital framework, as well as the minimum leverage and risk-based capital requirements of the Dodd Frank Act, but they have yet to issue any final rules. Federal regulators periodically propose amendments to the risk-based capital guidelines and the related regulatory framework and consider changes to the capital standards that could significantly increase the amount of capital needed to meet applicable standards. The timing of adoption, ultimate form and effect of any such proposed amendments cannot be predicted.

Capital Purchase Program

On December 7, 2011, we redeemed all of the preferred stock that we sold to the federal government as part of the Capital Purchase Program, or CPP. As a participant in the CPP, we completed the $108.7 million capital raise on January 16, 2009.

In connection with the issuance of the preferred stock to the U.S. Treasury in 2009, we also issued the U.S. Treasury a warrant to purchase 517,012 shares of our common stock at an initial per share exercise price of $31.53, with an estimated fair value of $4.0 million on the date of issuance. The warrant remains outstanding as of the date of the filing of this Annual Report on Form 10-K. The warrant provides for the adjustment of the exercise price and the number of shares of our common stock issuable upon exercise pursuant to customary anti-dilution provisions. The U.S. Treasury agreed not to exercise voting power with respect to any shares of common stock issued upon exercise of the warrant. We did not repurchase the warrant concurrently with the redemption of the preferred stock. Unless we repurchase the warrant, it will remain outstanding and will expire 10 years from the issuance date.

Payment of Dividends

S&T is a legal entity separate and distinct from its banking and other subsidiaries. A substantial portion of our revenues consist of dividend payments we receive from S&T Bank. S&T Bank, in turn, is subject to state laws and regulations that limit the amount of dividends it can pay to S&T. In addition, both S&T and S&T Bank are subject to various general regulatory policies relating to the payment of dividends, including requirements to maintain adequate capital above regulatory minimums. The Federal Reserve Board has indicated that banking organizations should generally pay dividends only if (i) the organization’s net income available to common shareholders over the past year has been sufficient to fully fund the dividends and (ii) the prospective rate of earnings retention appears consistent with the organization’s capital needs, asset quality and overall financial condition. Thus, under certain circumstances based upon our financial condition, our ability to declare and pay quarterly dividends may require consultation with the Federal Reserve Board and may be prohibited by applicable Federal Reserve Board regulations. If we were to pay a dividend in contravention of Federal Reserve regulations, the Federal Reserve could raise supervisory concerns. During the year ended December 31, 2012, S&T Bank paid $17.4 million in cash dividends to us for dividends paid to common shareholders.

Other Safety and Soundness Regulations

There are a number of obligations and restrictions imposed on bank holding companies such as us and our depository institution subsidiary by federal law and regulatory policy. These obligations and restrictions are designed to reduce potential loss exposure to the FDIC’s deposit insurance fund in the event an insured depository institution becomes in danger of default or is in default. Under current federal law for example, the federal banking agencies possess broad powers to take prompt corrective

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action to resolve problems of insured depository institutions. The extent of these powers depends upon whether the institution in question is “well-capitalized,” “adequately capitalized,” “undercapitalized,” “significantly undercapitalized” or “critically undercapitalized,” as defined by the law. Under regulations established by the federal banking agencies, a “well-capitalized” institution must have a Tier 1 capital ratio of at least 6.00 percent, a Total capital ratio of at least 10.00 percent and a leverage ratio of at least 5.00 percent and must not be subject to a capital directive or order. An “adequately capitalized” institution must have a Tier 1 capital ratio of at least 4.00 percent, a Total capital ratio of at least 8.00 percent and a leverage ratio of at least 4.00 percent. The most highly-rated financial institutions minimum requirement for the leverage ratio is 3.00 percent. In the proposed rules to implement Basel III and the minimum leverage and risk-based capital requirements of the Dodd-Frank Act, the federal banking agencies have also proposed changes to the definition of these categories, including the introduction of a common equity tier 1 capital ratio in each definition. As of December 31, 2012, S&T and S&T Bank were classified as “well-capitalized.” The classification of depository institutions is primarily for the purpose of applying the federal banking agencies’ prompt corrective action provisions and is not intended to be and should not be interpreted as a representation of overall financial condition or prospects of any financial institution.

The federal banking agencies’ prompt corrective action powers (which increase depending upon the degree to which an institution is undercapitalized) can include, among other things, requiring an insured depository institution to adopt a capital restoration plan which cannot be approved unless guaranteed by the institution’s parent company; placing limits on asset growth and restrictions on activities, including restrictions on transactions with affiliates; restricting the interest rates the institution may pay on deposits; prohibiting the payment of principal or interest on subordinated debt; prohibiting the holding company from making capital distributions without prior regulatory approval; and, ultimately, appointing a receiver for the institution. For example, only a “well-capitalized” depository institution may accept brokered deposits without prior regulatory approval.

The federal banking agencies have also adopted guidelines prescribing safety and soundness standards relating to internal controls and information systems, internal audit systems, loan documentation, credit underwriting, interest rate exposure, asset growth and compensation, fees and benefits. In general, the guidelines require appropriate systems and practices to identify and manage specified risks and exposures. The guidelines prohibit excessive compensation as an unsafe and unsound practice and characterize compensation as excessive when the amounts paid are unreasonable or disproportionate to the services performed by an executive officer, employee, director or principal shareholder. In addition, the agencies have adopted regulations that authorize, but do not require an agency to order an institution that has been given notice by an agency that it is not in compliance with any of such safety and soundness standards to submit a compliance plan. If, after being so notified, an institution fails to submit an acceptable compliance plan, the agency must issue an order directing action to correct the deficiency and may issue an order directing other actions of the types to which an “undercapitalized” institution is subject under the prompt corrective action provisions described above.

Regulatory Enforcement Authority

The enforcement powers available to federal banking agencies are substantial and include, among other things and in addition to other powers described herein, the ability to assess civil money penalties, to issue cease-and-desist or removal orders and to initiate injunctive actions against banks and bank holding companies and “institution affiliated parties,” as defined in the Federal Deposit Insurance Act. In general, these enforcement actions may be initiated for violations of laws and regulations, as well as engagement in unsafe or unsound practices. Other actions or inactions may provide the basis for enforcement action, including misleading or untimely reports filed with regulatory authorities.

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At the state level, the PADB also has broad enforcement powers over S&T Bank, including the power to impose fines and other civil and criminal penalties and to appoint a conservator or receiver.

Interstate Banking and Branching

The BHCA currently permits bank holding companies from any state to acquire banks and bank holding companies located in any other state, subject to certain conditions, including certain nationwide and state-imposed deposit concentration limits. In addition, because of changes to law made by the Dodd-Frank Act, S&T Bank may now establish de novo interstate branches in any state to the same extent that a bank chartered in that state could establish a branch.

Community Reinvestment and Consumer Protection Laws

In connection with its lending activities, S&T Bank is subject to a number of federal laws designed to protect borrowers and promote lending to various sectors of the economy and population. These include, among other laws, the Equal Credit Opportunity Act, the Truth-in-Lending Act, the Home Mortgage Disclosure Act, the Real Estate Settlement Procedures Act, the Fair Credit Reporting Act and the CRA. In addition, rules developed by the federal banking agencies pursuant to federal law require disclosure of privacy policies to consumers and in some circumstances, allow consumers to prevent the disclosure of certain personal information to nonaffiliated third parties.

The CRA requires the appropriate federal banking agency, in connection with its examination of a bank, to assess the bank’s record in meeting the credit needs of the communities served by the bank, including low and moderate-income neighborhoods. Furthermore, such assessment is required of any bank that has applied, among other things, to merge or consolidate with or acquire the assets or assume the liabilities of an insured depository institution, or to open or relocate a branch office. In the case of a bank holding company (including a financial holding company) applying for approval to acquire a bank or bank holding company, the Federal Reserve Board will assess the record of each subsidiary bank of the applicant bank holding company in considering the application. Under the CRA, institutions are assigned a rating of “outstanding,” “satisfactory,” “needs to improve” or “unsatisfactory.” S&T Bank was rated “satisfactory” in its most recent CRA evaluation.

Anti-Money Laundering Rules

S&T Bank is subject to the Bank Secrecy Act, its implementing regulations and other anti-money laundering laws and regulations, including the USA Patriot Act of 2001. Among other things, these laws and regulations require S&T Bank to take steps to prevent the bank from being used to facilitate the flow of illegal or illicit money, to report large currency transactions and to file suspicious activity reports. S&T Bank is also required to develop and implement a comprehensive anti-money laundering compliance program. Banks must also have in place appropriate “know your customer” policies and procedures. Violations of these requirements can result in substantial civil and criminal sanctions. In addition, provisions of the USA Patriot Act of 2001 require the federal financial institution regulatory agencies to consider the effectiveness of a financial institution’s anti-money laundering activities when reviewing bank mergers and bank holding company acquisitions.

Government Actions and Legislation

The Dodd-Frank Act is significantly changing the current bank regulatory structure and affecting the lending, deposit, investment, trading and operating activities of financial institutions and their holding companies, including S&T and S&T Bank. The Dodd-Frank Act contains a number of provisions intended to strengthen capital. Refer to Capital within Item 1 for additional information. For example, the federal banking agencies are directed to establish minimum leverage and risk-based capital that are at least as stringent as those currently in effect.

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Item 1.  BUSINESS — continued

The Dodd-Frank Act requires various federal agencies to adopt a broad range of new rules and regulations, and to prepare numerous studies and reports for Congress. The federal agencies are given significant discretion in drafting the implementing rules and regulations, and consequently, many of the details and much of the impact of the Act may not be known for many years. The Dodd-Frank Act also contains provisions that expand the insurance assessment base and increase the scope of deposit insurance coverage.

Among other provisions, the SEC has enacted rules, required by the Dodd-Frank Act, giving stockholders a non-binding vote on executive compensation and so-called “golden parachute” payments. The Dodd-Frank Act also authorizes the SEC to promulgate rules that would allow stockholders to nominate their own candidates for election as directors using a company’s proxy materials. The legislation also directs the federal financial institution regulatory agencies to promulgate rules prohibiting excessive compensation being paid to financial institution executives.

The Dodd-Frank Act also created the Consumer Financial Protection Bureau, or CFPB that took over rulemaking responsibility on July 21, 2011 for the principal federal consumer protection laws, such as the Truth in Lending Act, the Equal Credit Opportunity Act, the Real Estate Settlement Procedures Act and the Truth in Saving Act, among others. Institutions that have assets of $10.0 billion or less, such as S&T Bank, will continue to be supervised in this area by their state and primary federal regulators (in the case of S&T Bank, the FDIC). The Act also gives the CFPB expanded data collection powers for fair lending purposes for both small business and mortgage loans, as well as expanded authority to prevent unfair, deceptive and abusive practices. The consumer complaint function also has been consolidated into the CFPB with respect to the institutions it supervises. The CFPB established an Office for Community Banks and Credit Unions, with a mission to ensure that the CFPB incorporates the perspectives of small depository institutions into the policy-making process, communicate relevant policy initiatives to community banks and credit unions and work with community banks and credit unions to identify potential areas for regulatory simplification. In addition, the Dodd-Frank Act required the Federal Reserve Board to adopt a rule addressing interchange fees applicable to debit card transactions. This rule, Regulation II, effective October 1, 2011, does not apply to banks with less than $10.0 billion in assets.

There have been delays in the rulemaking processes of the various federal agencies responsible for enacting the provisions of the Dodd-Frank Act. A substantial number of rules required to implement the Dodd-Frank Act have not been finalized, and many have not even been proposed. Not all of the Dodd-Frank Act provisions remaining to be finalized apply to banks the size of S&T Bank. As a result, we cannot predict the ultimate impact of the Act on S&T or S&T Bank at this time, including the extent to which it could increase costs or limit our ability to pursue business opportunities in an efficient manner, or otherwise adversely affect our business, financial condition and results of operations. Nor can we predict the impact or substance of other future legislation or regulation. However, it is expected that they, at a minimum, will increase our operating and compliance costs.

In 2012, Pennsylvania enacted three bills known as the “Banking Law Modernization Package.” The bills became effective on December 24, 2012. The overall goal of the Banking Law Modernization Package was to modernize the banking laws of Pennsylvania and reduce regulatory burden at the state level.

Federal and state regulatory agencies consistently propose and adopt changes to their regulations or change the manner in which existing regulations are applied. We cannot predict the substance or impact of pending or future legislation or regulation, or the application thereof, although enactment of the proposed legislation could affect how S&T and S&T Bank operate and could significantly increase costs, impede the efficiency of internal business processes, or limit our ability to pursue business opportunities in an efficient manner, any of which could materially and adversely affect our business, financial condition and results of operations.

11

Item 1.  BUSINESS — continued

Competition

S&T Bank competes with other local, regional and national financial service providers, such as other financial holding companies, commercial banks, savings associations, credit unions, finance companies and brokerage and insurance firms. Some of our competitors are not subject to the same level of regulation and oversight that is required of banks and bank holding companies, and are thus able to operate under lower cost structures.

Changes in bank regulation, such as changes in the products and services banks can offer and involvement in non-banking activities by bank holding companies, as well as bank mergers and acquisitions, can affect our ability to compete successfully. Legislation and regulations have also expanded the activities in which depository institutions may engage. Our ability to compete successfully will depend upon how successfully we can respond to the evolving competitive, regulatory, technological and demographic developments affecting our operations.

We face significant competition in both originating loans and attracting deposits. The western Pennsylvania area has a high density of financial institutions, some of which are significantly larger institutions with greater financial resources than us, and many of which are our competitors to varying degrees. Our competition for loans comes principally from commercial banks, savings associations, mortgage banking companies, credit unions and other financial service companies. Our most direct competition for deposits has historically come from commercial banks, savings banks and credit unions. We face additional competition for deposits from non-depository competitors such as the mutual fund industry, securities and brokerage firms and insurance companies. Because larger competitors have advantages in attracting business from larger corporations, we do not generally compete for that business. Instead, we concentrate our efforts on attracting the business of individuals and small and medium-size businesses. We generally compete on the basis of customer service and responsiveness to customer needs, the convenience of banking offices and hours, and the availability and pricing of our products and services. We emphasize personalized banking and the advantage of local decision-making in our banking business and this strategy appears to have been well received in our market area.

The financial service industry is likely to become more competitive as further technological advances enable more companies to provide financial services on a more efficient and convenient basis. Technological innovations have lowered traditional barriers of entry and enabled many of these companies to compete in financial services markets. Many customers now expect a choice of banking options for the delivery of services, including traditional banking offices, telephone, mail, internet, mobile banking, ATMs, self-service branches, and/or in-store branches. These products are offered by traditional banks and savings associations, as well as credit unions, brokerage firms, asset management groups, finance and insurance companies, internet-based companies, and mortgage banking firms. We believe that our current market area, consisting primarily of western Pennsylvania, provides long-term opportunity for growth in deposits and commercial lending. Commercial and residential real estate values in our market appear to have stabilized. Nevertheless, the national and local economies still remain fragile with high unemployment rates while business conditions remain subdued, with uncertainty that seems to limit both consumer and corporate spending in our area.

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Item 1A.  RISK FACTORS

Investments in our common stock involve risk. The following discussion highlights the risks that we believe are material to our company, but does not necessarily include all risks that we may face.

The market price of our common stock may fluctuate significantly in response to a number of factors.

Our quarterly and annual operating results have varied significantly in the past and could vary significantly in the future, which makes it difficult for us to predict our future operating results. Our operating results may fluctuate due to a variety of factors, many of which are outside of our control, including the changing and recently volatile U.S. economic environment and changes in the commercial and residential real estate market, any of which may cause our stock price to fluctuate. If our operating results fall below the expectations of investors or securities analysts, the price of our common stock could decline substantially. Our stock price can fluctuate significantly in response to a variety of factors including, among other things:

• volatility of stock market prices and volumes in general;

• changes in market valuations of similar companies;

• changes in conditions in credit markets;

• changes in accounting policies or procedures as required by the Financial Accounting Standards Board, or FASB, or other regulatory agencies;

• legislative and regulatory actions (including the impact of the Dodd-Frank Act and related regulations) subjecting us to additional regulatory oversight which may result in increased compliance costs and/or require us to change our business model;

• government intervention in the U.S. financial system and the effects of and changes in trade and monetary and fiscal policies and laws, including the interest rate policies of the Federal Reserve Board;

• additions or departures of key members of management;

• fluctuations in our quarterly or annual operating results; and

• changes in analysts’ estimates of our financial performance.

Risks Related to Credit

Our ability to assess the credit-worthiness of our customers may diminish, which may adversely affect our results of operations.

We take credit risk by virtue of making loans and extending loan commitments and letters of credit. Our exposure to credit risk is managed through the use of consistent underwriting standards that emphasize “in-market” lending while avoiding highly leveraged transactions as well as excessive industry and other concentrations. Our credit administration function employs risk management techniques to ensure that loans adhere to corporate policy and problem loans are promptly identified. There can be no assurance that such measures will be effective in avoiding undue credit risk. If the models and approaches we use to select, manage and underwrite our consumer and commercial customers become less predictive of future charge-offs (due, for example, to rapid changes in the economy, including the unemployment rate), our credit losses may increase.

The value of the collateral used to secure our loans may not be sufficient to compensate for the amount of an unpaid loan and we may be unsuccessful in recovering the remaining balance from our customers.

Decreases in real estate values, particularly with respect to our commercial lending and mortgage activities, could adversely affect the value of property used as collateral for our loans and our customers’ ability to repay these loans, which in turn could impact our profitability. Repayment of our commercial loans is often dependent on the cash flow of the borrower, which may become

13

Item 1A.  RISK FACTORS — continued

unpredictable in the current economy. If the value of the assets, such as real estate, serving as collateral for the loan portfolio were to decline materially, a significant part of the loan portfolio could become under-collateralized. If the loans that are secured by real estate become troubled when real estate market conditions are declining or have declined, in the event of foreclosure, we may not be able to realize the amount of collateral that was anticipated at the time of originating the loan. This could result in higher charge-offs which could have a material adverse effect on our operating results and financial condition.

Changes in the overall credit quality of our portfolio can have a significant impact on our earnings.

Like other lenders, we face the risk that our customers will not repay their loans. We reserve for losses in our loan portfolio based on our assessment of inherent credit losses. This process, which is critical to our financial results and condition, requires complex judgments, including our assessment of economic conditions, which are difficult to predict. Through a periodic review of the loan portfolio, management determines the amount of the allowance for loan loss, or ALL, by considering historical losses combined with qualitative factors including general and regional economic conditions, asset quality trends, loan policy and underwriting and changes in loan concentrations and collateral values. The amount of future losses is susceptible to changes in economic, operating and other conditions, including changes in interest rates, which may be beyond our control. We may underestimate our inherent losses and fail to hold an ALL sufficient to account for these losses. Incorrect assumptions could lead to material underestimates of inherent losses and inadequate ALL. As our assessment of inherent losses changes, we may need to increase or decrease our ALL, which could adversely impact our financial results and profitability.

Our loan portfolio is concentrated in western Pennsylvania, and our lack of geographic diversification increases our risk profile.

The regional economic conditions in western Pennsylvania affects the demand for our products and services as well as the ability of our customers to repay their loans and the value of the collateral securing these loans. We are less able than a larger institution to spread the risks of unfavorable local economic conditions across a large number of diversified economies. A significant decline in the regional economy caused by inflation, recession, unemployment or other factors could adversely affect our customers, the quality of our loan portfolio and the demand for our products and services. Any sustained period of increased payment delinquencies, foreclosures or losses caused by adverse market or economic conditions in our market area could adversely affect the value of our assets, revenues, results of operations and financial condition. Moreover, we cannot give any assurance we will benefit from any market growth or favorable economic conditions in our primary market area.

A significant portion of our loan portfolio includes commercial real estate loans that have higher risks, and we may experience higher credit losses.

The majority of our loans are to commercial borrowers. The commercial real estate segment of our loan portfolio has been more adversely impacted by the continuing economic downturn. Commercial real estate lending typically involves higher loan principal amounts, and the repayment of these loans generally are dependent, in large part, on sufficient income from the properties securing the loans to cover operating expenses and debt service. Because payments on loans secured by commercial real estate often depend upon the successful operating and management of the properties, repayment of these loans may be affected by factors outside the borrower’s control, including adverse conditions in the real estate market or the economy. Additionally, we have a number of significant credit exposures to commercial borrowers, and while the majority of these borrowers have numerous projects that

14

Item 1A.  RISK FACTORS — continued

make up the total aggregate exposure, if one or more of these borrowers default or have financial difficulties, we could experience higher credit losses, which could adversely impact our results of operations.

Risks Related to Our Operations

An interruption or breach in security of our information systems may result in financial losses or in a loss of customers.

We depend upon data processing, communication and information exchange on a variety of computing platforms and networks, including the internet. We have experienced cybersecurity incidents in the past, which we did not deem material, and may experience them in the future. We believe that we have implemented appropriate measures to mitigate potential risks to our technology and our operations from these information technology disruptions. However, we cannot be certain that all of our systems are entirely free from vulnerability to attack, despite safeguards we have instituted. The occurrence of any failures, interruptions or security breaches of our information systems could result in a material adverse impact to our business, financial condition and results of operations through damage to our reputation, loss of customer business, additional regulatory scrutiny or exposure to civil litigation and possible financial liability. Losses arising from such a breach could materially exceed the amount of insurance coverage we have, which could adversely affect our results of operation.

We rely on third-party providers and other suppliers for a number of services that are important to our business. An interruption or cessation of an important service by any third party could have a material adverse effect on our business.

We are dependent for the majority of our technology, including our core operating system, on third party providers. If these companies were to discontinue providing services to us, we may experience significant disruption to our business. If any of our third party service providers experience financial, operational or technological difficulties, or if there is any other disruption in our relationships with them, we may be required to locate alternative sources of such services. Assurance cannot be provided that we could negotiate terms with alternative service sources that are as favorable or could obtain services with similar functionality as found in existing systems without the need to expend substantial resources, if at all, thereby resulting in a material adverse impact on our business and results of operations.

Risks Related to Interest Rates and Investments

Our net interest income could be negatively affected by interest rate changes or by significant loan prepayments, which may adversely affect our financial condition.

Our results of operations are largely dependent on net interest income, which is the difference between the interest and fees earned on interest-earning assets and the interest paid on interest-bearing liabilities. There may be mismatches between the maturity and repricing of our assets and liabilities that could cause the net interest rate spread to compress, depending on the level and type of changes in the interest rate environment. Interest rates are highly sensitive to many factors that are beyond our control, including general economic conditions and the policies of various governmental agencies. In addition, some of our customers often have the ability to prepay loans or redeem deposits with either no penalties, or penalties that are insufficient to compensate us for the lost income. If customers continue to prepay loans at a higher rate, we may not be able to recover the lost revenues, which may affect our results of operations. A significant reduction in our net interest income will adversely affect our business and results of operations. If we are unable to manage interest rate risk effectively, our business, financial condition and results of operations could be materially harmed.

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Item 1A.  RISK FACTORS — continued

Declines in the value of investment securities held by us could require write-downs, which would reduce our earnings.

In order to diversify earnings and enhance liquidity, we own both debt and equity instruments of government agencies, municipalities and other companies. We may be required to record impairment charges on our investment securities if they suffer a decline in value that is considered other-than-temporary. Additionally, the value of these investments may fluctuate depending on the interest rate environment, general economic conditions and circumstances specific to the issuer. Volatile market conditions may detrimentally affect the value of these securities, such as through reduced valuations due to the perception of heightened credit or liquidity risks. Changes in the value of these instruments may result in a reduction to earnings and/or capital, which may adversely affect our results of operations.

Risks Related to Liquidity

We rely on a stable core deposit base and high quality unpledged liquid assets as our primary sources of liquidity.

We are dependent for our funding on a stable base of core deposits and high quality unpledged assets including cash held on deposit at the Federal Reserve. Our ability to maintain a stable core deposit base is a function of our financial performance, our reputation and the security provided by FDIC insurance, which combined, gives customers confidence in us. If any of these items are damaged or come into question, the stability of our core deposits could be harmed. If our high quality unpledged liquid assets lose value or can not be sold in an orderly fashion, it could harm our ability to meet our obligations.

Our ability to meet contingency funding needs, in the event of a crisis that causes a disruption to our core deposit base, is dependent on access to wholesale markets, including funds provided by the FHLB of Pittsburgh.

We own common stock of the FHLB in order to qualify for membership in the FHLB system, which enables us to borrow on our line of credit with the FHLB that is secured by a blanket lien on a significant portion of our loan portfolio. Changes or disruptions to the FHLB or the FHLB system in general may materially impact our ability to meet short and long-term liquidity needs or meet growth plans. Additionally, we cannot be assured that the FHLB will be able to provide funding to us when needed, nor can we be certain that the FHLB will provide funds specifically to us, should our financial condition and/or our regulators prevent access to our line of credit. The inability to access this source of funds could have a materially adverse effect on our ability to meet our customer’s needs. Our financial flexibility could be severely constrained if we were unable to maintain our access to funding or if adequate financing is not available at acceptable interest rates.

Risks Related to Regulatory Compliance and Legal Matters

Recent legislation enacted in response to market and economic conditions may significantly affect our operations, financial condition and earnings.

Disruptions in the financial system during the past several years have resulted in significantly reduced business activity throughout the global and U.S. economies, which have the potential to significantly affect financial institutions. The Dodd-Frank Act was enacted as a major reform in response to this financial crisis. The Dodd-Frank Act increases regulation and oversight of the financial services industry, and imposes restrictions on the ability of institutions within the industry to conduct business consistent with historical practices, including aspects such as capital requirements, affiliate transactions, compensation, consumer protection regulations and mortgage

16

Item 1A.  RISK FACTORS — continued

regulation, among others. It is not clear what impact the Dodd-Frank Act and the numerous implementing regulations will ultimately have on the financial markets or on the U.S. banking and financial services industries and the broader U.S. and global economies. They may increase our costs of regulatory compliance and of doing business and otherwise affect our operations, and will likely result in additional costs and a diversion of management’s time from other business activities, any of which may adversely impact our results of operations, liquidity or financial condition. They also may significantly affect the markets in which we do business, the markets for and value of our investments and our ongoing operations, costs and profitability.

Our deposit insurance premiums have decreased but may increase in the future, which could have a material adverse impact on our future earnings and financial condition.

The FDIC insures deposits at FDIC-insured financial institutions, including S&T Bank. The FDIC charges insured financial institutions premiums to maintain the DIF at a specific level. The Bank’s FDIC insurance premiums recently decreased after substantial increases beginning in 2009, but we may pay significantly higher premiums in the future. Current economic conditions have increased bank failures and additional failures are expected, all of which decrease the DIF. The Dodd-Frank Act increased the minimum target DIF ratio from 1.15 percent of estimated insured deposits to 1.35 percent of estimated insured deposits. The FDIC must seek to achieve the 1.35 percent ratio by September 30, 2020. Insured institutions with assets of $10 billion or more are supposed to fund the increase. The FDIC has issued regulations to implement these provisions of the Dodd-Frank Act. It has, in addition, established a higher reserve ratio of 2 percent as a long-term goal beyond what is required by statute. There is no implementation deadline for the 2 percent ratio. The FDIC may increase the assessment rates or impose additional special assessments in the future to keep the DIF at or above the statutory minimum target. Any increase in our FDIC premiums could have an adverse effect on the Bank’s profits and financial condition. Refer to Supervision and Regulation within Item 1 of this report for additional information.

Future governmental regulation and legislation could limit our growth.

We are subject to extensive state and federal regulation, supervision and legislation that govern nearly every aspect of our operations. The regulations are primarily intended to protect depositors, customers and the banking system as a whole, not shareholders. Failure to comply with applicable regulations could lead to penalties and damage to our reputation. Furthermore, as shown through the Dodd-Frank Act, the regulatory environment is constantly undergoing change and the impact of changes to laws, the rapid implementation of regulations, the interpretation of such laws or regulations or other actions by existing or new regulatory agencies could make regulatory compliance more difficult or expensive, and thus could affect our ability to deliver or expand services, or it could diminish the value of our business. The ramifications and uncertainties of the recent increase in government intervention in the U.S. financial system could also adversely affect us. Refer to Supervision and Regulation within Item 1 of this report for additional information.

Negative public opinion could damage our reputation and adversely impact our earnings and liquidity.

Reputational risk, or the risk to our business, earnings, liquidity and capital from negative public opinion, could result from our actual or alleged conduct in a variety of areas, including legal and regulatory compliance, lending practices, corporate governance, litigation, ethical issues or inadequate protection of customer information. We expend significant resources to comply with regulatory requirements, and the failure to comply with such regulations could result in reputational harm or significant legal or remedial costs. Damage to our reputation could adversely affect our ability to retain and attract new customers and adversely impact our earnings and liquidity.

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Item 1A.  RISK FACTORS — continued

We may be a defendant from time to time in a variety of litigation and other actions, which could have a material adverse effect on our financial condition and results of operations.

From time to time, customers and others make claims and take legal action pertaining to the performance of our responsibilities. Additionally, the current economic downturn has resulted in higher customer defaults and a resultant increase in litigation. Whether customer claims and legal action related to the performance of our responsibilities are founded or unfounded, if such claims and legal actions are not resolved in a manner favorable to us, they may result in significant expenses, attention from management and financial liability. Any financial liability or reputational damage could have a material adverse effect on our business, which, in turn, could have a material adverse effect on our financial condition and results of operations.

Risks Related to Our Business Strategy

Our strategy includes growth plans through organic growth and acquisitions. Our financial condition and results of operations could be negatively affected if we fail to grow or fail to manage our growth effectively.

We intend to continue pursuing a growth strategy, which may include organic growth, expansion or acquisitions. We cannot assure you that we will be able to expand our market presence in our existing markets or successfully enter new markets or that any such expansion will not adversely affect our results of operations. Failure to manage our growth effectively could have a material adverse effect on our business, future prospects, financial condition or results of operations and could adversely affect our ability to successfully implement our business strategy.

Our failure to find suitable acquisition candidates, or successfully bid against other competitors for acquisitions, could adversely affect our ability to successfully implement our business strategy. If we are successful in acquiring other entities, the process of integrating such entities will divert significant management time and resources. We may not be able to integrate successfully or operate profitably any entity we may acquire. We may experience disruption and incur unexpected expenses in integrating acquisitions. These failures could adversely impact our future prospects and results of operation.

We are subject to competition from both banks and non-banking companies.

The financial services industry is highly competitive, and we encounter strong competition for deposits, loans and other financial services in our market area. Our principal competitors include commercial banks of all types, finance companies, credit unions, mortgage brokers, insurance agencies, trust companies and various sellers of investments and investment advice. Many of our non-bank competitors are not subject to the same degree of regulation as we are and have advantages over us in providing certain services. Additionally, many of our competitors are significantly larger than we are and have greater access to capital and other resources. Failure to compete effectively for deposit, loan and other banking customers in our markets could cause us to lose market share, slow our growth rate and may have an adverse effect on our financial condition and results of operations.

We may be required to raise capital in the future, but that capital may not be available or may not be on acceptable terms when it is needed.

We are required by federal regulatory authorities to maintain adequate capital levels to support operations. Our ability to raise additional capital is dependent on capital market conditions at that time and on our financial performance and outlook. Pending regulatory changes, such as regulations to implement Basel III and the Dodd-Frank Act, may require us to have more capital than was

18

Item 1A.  RISK FACTORS — continued

previously required. If we cannot raise additional capital when needed, we may not be able to meet these requirements, and our ability to further expand our operations through organic growth or through acquisitions may be adversely affected.

The Warrant we issued to the U.S. Treasury may be dilutive to holders of our common stock.

The ownership interest of the existing holders of our common stock may be diluted to the extent the warrant we issued to the U.S. Treasury in connection with the sale to the U.S. Treasury of the Series A Preferred Stock is exercised. Although we redeemed all of the outstanding preferred stock previously issued to the U.S. Treasury, we did not repurchase the outstanding warrant and it will remain outstanding until 2019 or until we repurchase it. The shares of common stock underlying the warrant represent approximately 1.70 percent of the shares of our common stock outstanding as of January 31, 2013 (including the shares issuable upon exercise of the warrant in total shares outstanding). Although the U.S. Treasury has agreed not to vote any of the shares of common stock it receives upon exercise of the warrant, a purchaser of any portion of the warrant or of any shares of common stock acquired upon exercise of the warrant is not bound by this restriction.

Our ability to pay dividends on our common stock may be limited.

Holders of our common stock will be entitled to receive only such dividends as our Board of Directors may declare out of funds legally available for such payments. Although we have historically declared cash dividends on our common stock, we are not required to do so and our Board of Directors could reduce, suspend or eliminate our dividend at any time. Any decrease or elimination to the dividends on our common stock could adversely affect the market price of our common stock.

Item 1B.  UNRESOLVED STAFF COMMENTS

There are no unresolved SEC staff comments.

Item 2.  PROPERTIES

We own a four-story building in Indiana, Pennsylvania, located at 800 Philadelphia Street, which serves as our headquarters, executive and administrative offices. Our Community Banking and Wealth Management segments are also located at our headquarters. The executive office of our Insurance segment is located in a leased building in Ebensburg, Pennsylvania which is in Cambria County. Additionally, we lease a building in Indiana, Pennsylvania that serves as our data processing and technology center and we own a two-story building directly behind it that serves as additional administrative offices. Community Banking has 63 locations, including 59 branches located in eleven counties in Pennsylvania, of which 37 are owned and 22 are leased, as well as three separate drive up facilities and one loan production office in Akron, Ohio. Community Banking leases an office in Akron, Ohio, that is staffed by three commercial lenders. Community Banking also leases two offices to Insurance. Wealth Management leases two offices, one in Allegheny County, Pennsylvania and one in Westmoreland County, Pennsylvania. Wealth Management also has several staff located within the Community Banking offices to provide their services to retail customers. Insurance leases three offices located in three counties in Pennsylvania. Insurance also has staff located within the Community Banking offices in Jefferson and Blair counties. The operating and capital leases for Community Banking, Wealth Management and Insurance expire at various dates through the year 2054 and generally include options to renew. For additional information regarding the lease commitments, refer to Note 10 Premises and Equipment in the Notes to Consolidated Financial Statements, which is included in Item 8 of this Report.

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Item 3.  LEGAL PROCEEDINGS

The nature of our business generates a certain amount of litigation involving matters arising in the ordinary course of business. However, in management’s opinion, there are no proceedings pending to which we are a party or to which our property is subject, which, if determined adversely to us, would be material in relation to our shareholders’ equity or financial condition. In addition, no material proceedings are pending nor are known to be threatened or contemplated against us by governmental authorities or other parties.

Item 4.  MINE SAFETY DISCLOSURES

Not applicable.

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PART II

Item 5.  MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED SHAREHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Stock Prices and Dividend Information

Our common stock is listed on the NASDAQ Global Select Market System or NASDAQ under the symbol STBA. The range of sale prices for the years 2012 and 2011 is set forth in the table below and is based upon information obtained from NASDAQ. As of the close of business on January 31, 2013, we had 3,277 shareholders of record. Dividends paid by S&T are primarily provided from S&T Bank’s dividends to S&T. The payment of dividends by S&T Bank to S&T is subject to the restrictions described in Item 8, Note 6, Dividend and Loan Restrictions of this Report. The cash dividends declared per share are shown below.

	Price Range of Common Stock				Cash Dividends Declared
2012	Low		High
Fourth quarter	$	16.32	$	18.50	$	0.15
Third quarter		15.68		19.40		0.15
Second quarter		16.41		21.98		0.15
First quarter		19.65		23.34		0.15
2011
Fourth quarter	$	15.21	$	20.67	$	0.15
Third quarter		15.21		19.46		0.15
Second quarter		16.65		22.23		0.15
First quarter		20.90		23.86		0.15

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Item 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED SHAREHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES — continued

Five-Year Cumulative Total Return

The following chart compares the cumulative total shareholder return on our common stock with the cumulative total shareholder return of the NASDAQ Composite Index and NASDAQ Bank Index⁽¹⁾ assuming a $100 investment in each on December 31, 2007.

	Period Ending
Index	12/31/07		12/31/08		12/31/09		12/31/10		12/31/11		12/31/12
S&T Bancorp, Inc.	$	100.00	$	133.37	$	66.36	$	90.74	$	80.94	$	77.27
NASDAQ Composite		100.00		60.02		87.24		103.08		102.26		120.42
NASDAQ Bank		100.00		78.46		65.67		74.97		67.10		79.64

⁽¹⁾  The NASDAQ Bank Index contains securities of NASDAQ-listed companies classified according to the Industry Classification Benchmark as Banks. These companies include banks providing a broad range of financial services, including retail banking, loans and money transmissions.

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Item 6.  SELECTED FINANCIAL DATA

The tables below summarize selected consolidated financial data as of the dates or for the periods indicated and should be read in conjunction with Management’s Discussion and Analysis of Financial Condition and Results of Operations in Item 7 and the Consolidated Financial Statements and Notes in Item 8 of this report.

CONSOLIDATED BALANCE SHEETS

December 31	2012		2011		2010		2009		2008
(in thousands)
Total assets	$	4,526,702	$	4,119,994	$	4,114,339	$	4,170,475	$	4,438,368
Securities available-for-sale		453,096		357,596		288,025		354,860		452,713
Goodwill		175,733		165,273		165,273		165,167		163,546
Net loans and loans held for sale		3,322,637		3,083,768		3,312,540		3,344,827		3,526,027
Total deposits		3,638,428		3,335,859		3,317,524		3,304,541		3,228,416
Securities sold under repurchase agreements and federal funds purchased		62,582		30,370		40,653		44,935		113,419
Short-term borrowings		75,000		75,000		—		51,300		308,475
Long-term borrowings		34,101		31,874		29,365		85,894		180,331
Junior subordinated debt securities		90,619		90,619		90,619		90,619		90,619
Preferred stock, series A		—		—		106,137		105,370		—
Total shareholders’ equity		537,422		490,526		578,665		553,318		448,694

CONSOLIDATED STATEMENTS OF NET INCOME

Years Ended December 31	2012		2011		2010		2009			2008
(in thousands, except per share data)
Interest income	$	156,251	$	165,079	$	180,419	$	195,087		$	216,118
Interest expense		21,024		27,733		34,573		49,105			72,171
Provision for loan losses		22,815		15,609		29,511		72,354			12,878
Net Interest Income After Provision for Loan Losses		112,412		121,737		116,335		73,628			131,069
Noninterest income		51,912		44,057		47,210		38,580			37,452
Noninterest expense		122,863		103,908		105,633		108,126			83,801
Net Income Before Taxes		41,461		61,886		57,912		4,082			84,720
Provision (benefit) for income taxes		7,261		14,622		14,432		(3,869	)		24,517
Net Income		34,200		47,264		43,480		7,951			60,203
Preferred stock dividends and discount amortization		—		7,611		6,201		5,913			—
Net Income Available to Common Shareholders	$	34,200	$	39,653	$	37,279	$	2,038		$	60,203
Per Share Data
Earnings per common share—basic	$	1.18	$	1.41	$	1.34	$	0.07		$	2.30
Earnings per common share—diluted		1.18		1.41		1.34		0.07			2.28
Dividends declared per common share		0.60		0.60		0.60		0.61			1.24
Common book value		18.08		17.44		16.91		16.14			16.24

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

This section reviews our financial condition and results of operations for each of the past three years. Certain reclassifications have been made to prior periods to place them on a basis comparable with the current period presentation. Some tables may include additional time periods to illustrate trends within our financial statements. The results of operations reported in the accompanying Consolidated Financial Statements are not necessarily indicative of results to be expected in future periods.

Important Note Regarding Forward-Looking Statements

This Report on Form 10-K contains or incorporates statements that we believe are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These statements generally relate to our financial condition, results of operations, plans, objectives, future performance or business. They usually can be identified by the use of forward-looking language such as “will likely result,” “may,” “are expected to,” “is anticipated,” “estimate,” “forecast,” “projected,” “intends to” or other similar words. You should not place undue reliance on these statements, as they are subject to risks and uncertainties, including but not limited to, those identified under Risk Factors in Item 1A of this report, the documents incorporated by reference or other important factors disclosed in this report and from time to time in our other filings with the Securities and Exchange Commission, or SEC. When considering these forward-looking statements, you should keep in mind these risks and uncertainties, as well as any cautionary statements we may make. Moreover, you should treat these statements as speaking only as of the date they are made and based only on information actually known to us at that time. We undertake no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

These forward-looking statements are based on current expectations, estimates and projections about our business and beliefs and assumptions made by management. These Future Factors, are not guarantees of our future performance and involve certain risks, uncertainties and assumptions, which are difficult to predict. Therefore, actual outcomes and results may differ materially from what is expressed or forecasted in these forward-looking statements.

Future Factors include:

• changes in interest rates, spreads on interest-earning assets and interest-bearing liabilities, the shape of the yield curve and interest rate sensitivity;

• a prolonged period of low interest rates;

• credit losses;

• access to capital in the amounts, at the times and on the terms required to support our future businesses;

• legislation affecting the financial services industry as a whole, and/or S&T Bancorp, Inc., or S&T, in particular, including the effects of the Dodd-Frank Act;

• regulatory supervision and oversight, including required capital levels, and public policy changes, including environmental regulations;

• increasing price and product/service competition, including new entrants;

• rapid technological developments and changes;

• the ability to continue to introduce competitive new products and services on a timely, cost-effective basis;

• deterioration of the housing market and reduced demand for mortgages;

• containing costs and expenses;

• reliance on large customers;

• the outcome of pending and future litigation and governmental proceedings;

• managing our internal growth and acquisitions;

• the possibility that the anticipated benefits from our acquisitions cannot be fully realized in a timely manner or at all, or that integrating the acquired operations will be more difficult, disruptive or costly than anticipated;

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

• general economic or business conditions, either nationally or regionally in Western Pennsylvania, may be less favorable than expected, resulting in among other things, a reduced demand for credit and other services;

• a decline in market capitalization to common book value, which could warrant further analysis of the carrying value of goodwill and could result in an adjustment to its carrying value resulting in a non-cash charge to net income; and

• a continuation of recent turbulence in significant portions of the global financial and real estate markets could impact our performance, both directly, by affecting our revenues and the value of our assets and liabilities and indirectly, by affecting the economy generally.

These are representative of the Future Factors that could affect the outcome of the forward-looking statements. In addition, such statements could be affected by general industry and market conditions and growth rates, general economic conditions, including interest rate and currency exchange rate fluctuations and other Future Factors.

Critical Accounting Policies and Estimates

Our financial statements are prepared in accordance with U.S. generally accepted accounting principles, or GAAP. Application of these principles requires management to make estimates, assumptions and judgments that affect the amounts reported in the Consolidated Financial Statements and accompanying notes. These estimates, assumptions and judgments are based on information available as of the date of the Consolidated Financial Statements; accordingly, as this information changes, the Consolidated Financial Statements could reflect different estimates, assumptions and judgments. Certain policies inherently are based to a greater extent on estimates, assumptions and judgments of management and, as such, have a greater possibility of producing results that could be materially different than originally reported.

Our most significant accounting policies are presented in Note 1 Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements, which are included in Item 8 of this report. These policies, along with the disclosures presented in the Notes to Consolidated Financial Statements, provide information on how significant assets and liabilities are valued in the Consolidated Financial Statements and how those values are determined.

We view critical accounting policies to be those which are highly dependent on subjective or complex estimates, assumptions and judgments and where changes in those estimates and assumptions could have a significant impact on the Consolidated Financial Statements. We currently view the determination of the allowance for loan losses, or ALL, income taxes, securities valuation and goodwill and other intangible assets to be critical accounting policies. During 2012, we did not significantly change the manner in which we applied our critical accounting policies or developed related assumptions or estimates. We have reviewed these related critical accounting estimates and related disclosures with the Audit Committee.

Allowance for Loan Losses

Our loan portfolio is our largest category of assets on our Consolidated Balance Sheets. Accordingly, we have designed a systematic ALL methodology which is used to determine our provision for loan losses and ALL on a quarterly basis. The ALL represents management’s estimate of probable losses inherent in the loan portfolio at the balance sheet date and is presented as a reserve against loans in the Consolidated Balance Sheets. The ALL is increased by a provision charged to expense and reduced by charge-offs, net of recoveries. Determination of an adequate ALL is inherently subjective, as it requires estimations of the occurrence of future events, as well as the timing of such events. The ALL may be subject to significant changes from period to period.

25

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

The methodology for determining the ALL has two main components: evaluation and impairment tests of individual loans and evaluation and impairment tests of certain groups of homogeneous loans with similar risk characteristics.

We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. A loan is impaired when, based on current information and events, it is probable that a creditor will be unable to collect all amounts due according to the contractual terms of the loan agreement. For all troubled debt restructurings, or TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate. Specific reserves are established based upon the following three impairment methods: 1) the present value of expected future cash flows discounted at the loan’s effective interest rate, 2) the loan’s observable market price or 3) the estimated fair value of the collateral if the loan is collateral dependent. These analyses involve a high degree of judgment in estimating the amount of loss associated with specific impaired loans, including estimating the amount and timing of future cash flows, current estimated fair value of the loan and collateral values. Our impairment evaluations consist primarily of the fair value of collateral method since most loans are collateral dependent.

The ALL methodology for groups of homogeneous loans, known as the general reserve, is comprised of both a quantitative and qualitative analysis. We first apply historical loss rates to pools of loans with similar risk characteristics. Loss rates are calculated by historical charge-offs that have occurred within each pool of loans over the loss emergence period. Loss emergence refers to the length of time between a loss event and a charge-off of the loan. We estimate the loss emergence period to be two years for commercial real estate, or CRE, loans and one year for all other loan classes. We use a one year look back period that results, when considering our loss emergence periods, in capturing historic losses for three years for CRE and two years for our other portfolio segments. After consideration of the loss calculations, management applies additional qualitative adjustments so that the ALL is reflective of the inherent losses that exist in the loan portfolio at the balance sheet date. Qualitative adjustments are made based upon changes in economic conditions, loan portfolio and asset quality data and credit process changes, such as credit policies or underwriting standards. The evaluation of the various components of the ALL requires considerable judgment in order to estimate inherent loss exposures.

We enhanced our ALL model in the fourth quarter of 2010 to better align it with regulatory guidance. The calculation of the base historical loss utilizing an average method over the prior five years was shortened to include a one to two year loss emergence period depending on the loan category over a rolling four quarter average. With the volatility in the credit cycle at that time, the shorter time horizon was more indicative of the loss emergence periods we were experiencing in our portfolio. We believe this shorter time horizon provides a better indication of inherent losses in the loan portfolio given the recent economic downturn. We also refined the qualitative factors beginning in the fourth quarter of 2010 to better align with regulatory guidance. Qualitative factors became a basis point adjustment applied to the historical base loss. The combination of the enhancements to the average method and the qualitative factors did not materially change the ALL at December 31, 2010, resulting in an increase in the ALL and provision of less than $0.5 million. Since December 31, 2010, there have been no further enhancements to the ALL methodology.

Our ALL Committee meets quarterly to verify the overall adequacy of the ALL. Additionally, on an annual basis, the Committee meets to validate certain aspects of our ALL model. This validation includes reviewing the pools of loans to ensure the segmentation results in relevant homogeneous pools of loans. The Committee reviews the historical loss emergence period and look back periods used to calculate the loss rates. Further, the Committee reviews the qualitative factors for reasonableness. As a result of this ongoing monitoring process, we may make changes to our ALL methodology to be responsive to the economic environment.

26

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

At December 31, 2012, approximately 87 percent of the ALL related to the commercial loan portfolio. Commercial loans represent 72 percent of total portfolio loans. Commercial loans have been more impacted by the economic slowdown in our markets. The ability of customers to repay commercial loans is more dependent upon the success of their businesses, continuing income and general economic conditions. The risk of loss is higher on such loans compared to consumer loans, which have incurred lower losses in our market.

There are many factors affecting the ALL; some are quantitative, while others require qualitative judgment. Although we believe our process for determining the ALL adequately considers all of the factors that would likely result in credit losses, the process includes subjective elements and may be susceptible to significant change. To the extent actual outcomes differ from management estimates, additional provisions for loan losses could be required and could adversely affect our earnings or financial position in future periods.

Income Taxes

We estimate income tax expense based on amounts expected to be owed to the tax jurisdictions where we conduct business. The laws are complex and subject to different interpretations by us and various taxing authorities. On a quarterly basis, we assess the reasonableness of our effective tax rate based upon our current estimate of the amount and components of pre-tax income, tax credits and the applicable statutory tax rates expected for the full year.

Deferred income tax assets and liabilities are determined using the asset and liability method and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax bases of assets and liabilities and recognizes enacted changes in tax rate and laws. When deferred tax assets are recognized, they are subject to a valuation allowance based on management’s judgment as to whether realization is more likely than not.

Accrued taxes represent the net estimated amount due to taxing jurisdictions and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. We evaluate and assess the relative risks and appropriate tax treatment of transactions and filing positions after considering statutes, regulations, judicial precedent and other information and maintain tax accruals consistent with the evaluation of these relative risks and merits. Changes to the estimate of accrued taxes occur periodically due to changes in tax rates, interpretations of tax laws, the status of examinations being conducted by taxing authorities and changes to statutory, judicial and regulatory guidance. These changes, when they occur, can affect deferred taxes and accrued taxes, as well as the current period’s income tax expense and can be significant to our operating results.

Tax positions are recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

Securities Valuation

We determine the appropriate classification of securities at the time of purchase. All securities, including both debt and equity securities, are classified as available-for-sale. These securities are carried at fair value with net unrealized gains and losses deemed to be temporary reported separately as a component of other comprehensive income, net of tax. Realized gains and losses on the sale of

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

available-for-sale securities and other-than-temporary impairment, or OTTI, charges are recorded within noninterest income in the Consolidated Statements of Net Income. Realized gains and losses on the sale of securities are determined using the specific-identification method.

We perform a quarterly review of our securities to identify those that may indicate an OTTI. Our policy for OTTI within the marketable equity securities portfolio generally requires an impairment charge when the security is in a loss position for 12 consecutive months, unless facts and circumstances would suggest the need for an OTTI prior to that time. Our policy for OTTI within the debt securities portfolio is based upon a number of factors, including but not limited to, the length of time and extent to which the estimated fair value has been less than cost, the financial condition of the underlying issuer, the ability of the issuer to meet contractual obligations, the best estimate of impairment charge representing credit losses, the likelihood of the security’s ability to recover any decline in its estimated fair value and whether we intend to sell the investment security or if it is more likely than not that we will be required to sell the security prior to the security’s recovery. If the financial markets experience deterioration, charges to income could occur in future periods.

Goodwill and Other Intangible Assets

As a result of acquisitions, we have recorded goodwill and identifiable intangible assets on our Consolidated Balance Sheets. Goodwill represents the excess of the purchase price over the fair value of net assets purchased.

Goodwill relates to value inherent in the Community Banking and Insurance reporting units and the value is dependent upon our ability to provide quality, cost-effective services in the face of competition from other market participants. This ability relies upon continuing investments in processing systems, the development of value-added service features and the ease of use of our services. As such, goodwill value is supported ultimately by profitability that is driven by the volume of business transacted. A decline in earnings as a result of a lack of growth or the inability to deliver cost-effective services over sustained periods can lead to impairment of goodwill, which could adversely impact earnings in future periods.

We have three reporting units including: Community Banking, Wealth Management and Insurance. The carrying value of goodwill is tested annually for impairment each October 1 or more frequently if it is determined that we should do so. We first assess qualitatively whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Our qualitative assessment considers such factors as macroeconomic conditions, market conditions specifically related to the banking industry, our overall financial performance and various other factors. If we determine that it is more likely than not that the fair value is less than the carrying amount, we proceed to test for impairment. The evaluation for impairment involves comparing the current estimated fair value of each reporting unit to its carrying value, including goodwill. If the current estimated fair value of a reporting unit exceeds its carrying value, no additional testing is required and impairment loss is not recorded. If the estimated fair value of a reporting unit is less than the carrying value, further valuation procedures are performed and could result in impairment of goodwill being recorded. Further valuation procedures would include allocating the estimated fair value to all assets and liabilities of the reporting unit to determine an implied goodwill value. If the implied value of goodwill of a reporting unit is less than the carrying amount of that goodwill, an impairment loss is recognized in an amount equal to that excess. We completed the annual goodwill impairment assessment as required in 2012, 2011 and 2010; the results indicated that the fair value of each reporting unit exceeded the carrying value.

Based upon our qualitative assessment performed for our annual impairment analysis, we concluded that it is more likely than not that the fair value of the reporting units exceeds the carrying value. Both the national economy and the local western Pennsylvania economy where our business is concentrated showed signs of stabilization over the past year. General economic activity

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

and key indicators such as housing and unemployment showed modest improvement. While still challenging, the banking environment also improved with fewer bank failures, better asset quality, improved earnings and generally better stock prices. Activity in mergers and acquisition demonstrated that there is premium value of banking franchises and a number of banks of our size have been able to access the capital markets over the past year. While our stock price declined slightly over the course of the year after increasing in the first quarter, it has been fairly consistent for the past three quarters. Additionally, our overall performance has not significantly deteriorated and we did not identify any other facts or circumstances that would cause us to conclude that it is more likely than not that the fair value of the reporting units would be less than the carrying value.

We determine the amount of identifiable intangible assets based upon independent core deposit and insurance contract analyses at the time of acquisition. Intangible assets with finite useful lives, consisting primarily of core deposit and customer list intangibles, are amortized using straight-line or accelerated methods over their estimated weighted average useful lives, ranging from 10 to 16 years. Intangible assets with finite useful lives are evaluated for impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. No events or changes in circumstances occurred during the years ended December 31, 2012, 2011 and 2010.

The financial services industry and securities markets can be adversely affected by declining values. Although the economic weakness of recent years appears to be stabilizing, if economic conditions result in a prolonged period of economic weakness in the future, our business segments, including the Community Banking segment, may be adversely affected. In the event that we determine that either our goodwill or finite lived intangible assets are impaired, recognition of an impairment charge could have a significant adverse impact on our financial position or results of operations in the period in which the impairment occurs.

Recent Accounting Pronouncements and Developments

Note 1 Summary of Significant Accounting Policies, Recently Adopted Accounting Standards Updates and Recently Issued Accounting Standards Updates in the Notes to the Consolidated Financial Statements, which is included in Item 8 of this report, discusses new accounting pronouncements that we adopted and the expected impact of accounting pronouncements recently issued or proposed, but not yet required to be adopted.

Executive Overview

We are a bank holding company headquartered in Indiana, Pennsylvania with assets of $4.5 billion at December 31, 2012. We provide a full range of financial services through offices located in Allegheny, Armstrong, Blair, Butler, Cambria, Clarion, Clearfield, Indiana, Jefferson, Washington and Westmoreland counties of Pennsylvania. We provide full service retail and commercial banking products as well as cash management services, insurance, estate planning and administration, employee benefit plan investment management and administration, corporate services and other fiduciary services. Our common stock trades on the Nasdaq Global Select Market under the symbol “STBA.”

We earn revenue primarily from interest on loans and securities and fees charged for financial services provided to our customers. Offsetting these revenues are the cost of deposits and other funding sources, provision for loan losses and other operating costs such as: salaries and employee benefits, occupancy, data processing and tax expense.

Our mission is to become the financial services provider of choice in Western Pennsylvania by delivering exceptional service and value, one customer at a time. Our strategic plan focuses on growth through de novo expansion, acquisition or organic growth. Our strategic plan includes a collaborative model that combines expertise from all of our business segments and focuses on satisfying each customer’s individual financial objectives.

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

During 2012, we grew primarily through acquisition and successfully completed two mergers adding approximately $368 million in assets. On March 9, 2012, we completed our acquisition and conversion of Mainline Bancorp, Inc., or Mainline, a bank holding company located in Ebensburg, Pennsylvania. Mainline had one bank subsidiary, Mainline National Bank, with eight branches located throughout Cambria and Blair counties in Western Pennsylvania, adding $129.5 million in loans and $206.0 million in deposits. The total acquisition cost of Mainline was $27.8 million. On August 13, 2012, we further expanded our community banking network with the completion of our acquisition of Gateway Bank of Pennsylvania, a two branch bank with $99.1 million in loans and $105.4 million in deposits. The total acquisition cost of Gateway Bank was $19.8 million. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T, with all transactions since the acquisition date consolidated in our financial statements. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank.

As a result of these acquisitions, our earnings were impacted by one-time merger related expenses of $6.0 million.

Organic loan growth remained a challenge for a majority of 2012, however, we did experience positive trends in the later part of the year. An important strategic initiative as we move in to 2013 is loan growth. In August 2012, we expanded our commercial lending footprint into Northeastern Ohio through the opening of a loan production office in Akron. We are retaining 10, 15 and 20 year residential real estate loans in our portfolio, rather than selling these loans in the secondary market. Additionally, we are hiring seasoned lenders in both our commercial and residential real estate areas to improve organic loan growth.

Asset quality remained a challenge for us throughout 2012, especially in the first half of the year. The provision for loan losses increased $7.2 million to $22.8 million for 2012 compared to $15.6 million in 2011. Net loan charge-offs increased to $25.2 million compared to $18.2 million in 2011. During the first half of 2012, we experienced increased charge-offs primarily in our commercial construction loan portfolio as projects in this portfolio slowed due to the economic environment and as a result, appraised values declined. Asset quality stabilized in the second half of the year resulting in a lower provision for loan losses. Our nonperforming assets are at their lowest level since 2008 at $55.0 million at December 31, 2012. Additionally, we have been actively managing our substandard loans resulting in a decrease of $49.1 million, or 26.0 percent at December 31, 2012 compared to December 31, 2011.

Our capital ratios increased slightly from 2011 and remain significantly above the “well capitalized” thresholds of federal bank regulatory agencies with a leverage ratio of 9.31 percent, tier 1 risk-based capital ratio of 11.98 percent and total risk based capital ratio of 15.39 percent.

In 2013, our performance will be influenced by asset quality. If the economy improves, we should expect to see progress in reducing net charge-offs, nonperforming loans and provision for loan losses. However, a return of the economic slowdown, regionally or nationally, could cause deterioration in our asset quality. We recognize a greater dependence on commercial loans may expose us to credit risk and that we may have more volatility in nonperforming loans and loan charge-offs when problems do occur. We will mitigate this risk through our disciplined credit risk management practices, the review of such loans by our Criticized Asset Committee and continued sound underwriting practices. Because the majority of our revenue comes from net interest income, net loan and deposit growth, combined with the relative pricing and mix of that growth are major factors that affect our operations and financial condition. Our net interest margin will be a challenge as we move into 2013, especially if the low interest rate environment persists.

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Results of Operations

Year Ended December 31, 2012

Net Income

Our net income available to common shareholders decreased $5.5 million to $34.2 million or $1.18 per share in 2012 compared to $39.7 million or $1.41 per share in the previous year. The decrease in net income was primarily a result of an increase of $19.0 million in noninterest expense, which includes $6.0 million in one-time merger related expenses. Additionally, our provision for loan losses increased $7.2 million. We also experienced a decline in our net interest income of $2.1 million compared to the prior year, due to lack of organic loan growth and the low interest rate environment. These decreases were partially offset by a $7.9 million increase in noninterest income primarily due to increased mortgage banking and wealth management fees and gains on security sales, and a decrease of $7.4 million in provision for income taxes. Additionally, we did not have preferred dividend payments due to the redemption of $108.7 million of preferred stock from the U.S. Department of Treasury’s Capital Purchase Program in December of 2011.

Return on Equity and Assets

The table below presents our consolidated profitability and common equity to assets ratio for each of the last three years:

Years Ended December 31	2012			2011			2010
Common return on average assets		0.79	%		0.97	%		0.90	%
Common return on average equity		6.62	%		6.78	%		6.58	%
Dividend payout ratio		50.75	%		42.44	%		44.75	%
Common equity to asset ratio		11.87	%		11.91	%		11.48	%

Net Interest Income

Our principal source of revenue is net interest income. Net interest income represents the difference between the interest and fees earned on interest-earning assets and the interest paid on interest-bearing liabilities. Net interest income is affected by changes in the average balance of interest-earning assets and interest-bearing liabilities and changes in interest rates and spreads. Maintaining consistent spreads between interest-earning assets and interest-bearing liabilities is significant to our financial performance because net interest income comprised 73 percent of operating revenue (net interest income plus noninterest income, excluding security gains/losses) in 2012 and 76 percent of operating revenue in 2011. Refer to page 57 Explanation of Use of Non-GAAP Financial Measures for a discussion of operating revenue as a non-GAAP financial measure. The level and mix of interest-earning assets and interest-bearing liabilities are managed by our Asset and Liability Committee, or ALCO, in order to mitigate interest rate and liquidity risks of the balance sheet. A variety of ALCO strategies were implemented, within prescribed ALCO risk parameters, to maintain an acceptable net yield on interest-earning assets (net interest margin) given the challenges of the current interest rate environment.

The interest income on interest-earning assets and the net interest margin are presented on a fully taxable-equivalent basis. The fully taxable-equivalent basis adjusts for the tax benefit of income on certain tax-exempt loans and investments using the federal statutory tax rate of 35 percent for each period. We believe this measure to be the preferred industry measurement of net interest income that provides a relevant comparison between taxable and non-taxable amounts.

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

The following table reconciles interest income per the Consolidated Statements of Net Income to net interest income adjusted to a fully taxable-equivalent basis:

Years Ended December 31	2012		2011		2010
(in thousands)
Interest income per Consolidated Statements of Net Income	$	156,251	$	165,079	$	180,419
Adjustment to fully taxable-equivalent basis		4,471		4,154		4,627
Interest income adjusted to fully taxable-equivalent basis		160,722		169,233		185,046
Interest expense per Consolidated Statements of Net Income		21,024		27,733		34,573
Net Interest Income Adjusted to Fully Taxable-equivalent Basis (non-GAAP)	$	139,698	$	141,500	$	150,473

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Average Balance Sheet and Net Interest Income Analysis

The following table provides information regarding the average balances, interest and yields earned on interest-earning assets and the average balances, interest and rates paid on interest-bearing liabilities:

	2012								2011								2010
December 31	Average Balance			Interest		Yield/ Rate			Average Balance			Interest		Yield/ Rate			Average Balance			Interest		Yield/ Rate
(dollars in thousands)
ASSETS
Loans(1)(2)	$	3,213,018		$	147,819		4.59	%	$	3,216,856		$	156,845		4.88	%	$	3,386,103		$	172,319		5.09	%
Taxable investment securities		297,168			7,351		2.47	%		273,320			8,475		3.10	%		226,714			8,373		3.69	%
Tax-exempt investment securities(2)		90,527			4,801		5.30	%		62,607			3,611		5.77	%		76,707			4,354		5.68	%
Federal Home Loan Bank stock		17,115			33		0.19	%		20,091			—		—	%		23,336			—		—	%
Interest-bearing balance with banks		289,947			718		0.25	%		123,714			302		0.24	%		49			—		0.34	%
Total Interest-earning Assets		3,907,775			160,722		4.10	%		3,696,588			169,233		4.58	%		3,712,909			185,046		4.98	%
Noninterest-earning assets:
Cash and due from banks		53,517								50,458								90,462
Premises and equipment, net		38,460								38,425								39,142
Other assets		361,982								344,378								340,234
Less allowance for loan losses		(49,196	)							(57,241	)							(59,292	)
Total Assets	$	4,312,538							$	4,072,608							$	4,123,455
LIABILITIES AND SHAREHOLDERS’ EQUITY
Interest-bearing liabilities:
Interest-bearing demand and money market	$	615,713		$	674		0.11	%	$	536,085		$	739		0.14	%	$	518,383		$	1 220		0.24	%
Savings		902,889			2,356		0.26	%		761,274			1,267		0.17	%		749,325			2,127		0.28	%
Certificates of deposit		1,104,262			13,766		1.24	%		1,181,823			20,946		1.77	%		1,300,803			25,370		1.95	%
Securities sold under repurchase agreements		47,388			82		0.17	%		41,584			53		0.13	%		46,490			64		0.14	%
Short-term borrowings		50,212			123		0.24	%		551			2		0.32	%		32,473			146		0.45	%
Long-term borrowings		33,841			1,107		3.26	%		31,651			1,091		3.45	%		42,920			1,643		3.83	%
Junior subordinated debt securities		90,619			2,916		3.21	%		90,619			3,635		4.01	%		90,619			4,003		4.42	%
Total Interest-bearing Liabilities		2,844,924			21,024		0.74	%		2,643,587			27,733		1.05	%		2,781,013			34,573		1.24	%
Noninterest-bearing liabilities:
Noninterest-bearing demand		877,056								792,911								728,708
Other liabilities		73,746								50,924								47,064
Shareholders’ equity		516,812								585,186								566,670
Total Liabilities and Shareholders’ Equity	$	4,312,538							$	4,072,608							$	4,123,455
Net Interest Income				$	139,698							$	141,500							$	150,473
Net Yield on Interest-earning Assets							3.57	%							3.83	%							4.05	%

⁽¹⁾  For the purpose of these computations, nonaccruing loans are included in the daily average loan amounts outstanding.

⁽²⁾  Tax-exempt income is on a fully taxable-equivalent basis, including the dividend-received deduction for equity securities, using the statutory federal corporate income tax rate of 35 percent for 2012, 2011 and 2010.

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

The following table presents a summary of the changes in interest earned and interest paid resulting from changes in average balances and changes in rates:

	2012 Compared to 2011 Increase (Decrease) Due to(1)									2011 Compared to 2010 Increase (Decrease) Due to(1)
	Volume			Rate			Net			Volume			Rate			Net
(in thousands)
Interest earned on:
Loans(2)	$	(187	)	$	(8,839	)	$	(9,026	)	$	(8,613	)	$	(6,861	)	$	(15,474	)
Taxable investment securities		739			(1,863	)		(1,124	)		1,722			(1,620	)		102
Tax-exempt investment securities(2)		1,612			(420	)		1,192			(800	)		57			(743	)
Federal Home Loan Bank Stock		—			33			33			—			—			—
Interest-bearing balance with bank		406			9			415			419			(117	)		302
Total Interest-earning Assets		2,570			(11,080	)		(8,510	)		(7,272	)		(8,541	)		(15,813	)
Interest paid on:
Interest-bearing demand and money market	$	110		$	(175	)	$	(65	)	$	42		$	(523	)	$	(481	)
Savings		236			853			1,089			34			(894	)		(860	)
Certificates of deposit		(1,374	)		(5,806	)		(7,180	)		(2,321	)		(2,103	)		(4,424	)
Securities sold under repurchase agreements		7			22			29			(7	)		(4	)		(11	)
Short-term borrowings		157			(36	)		121			(143	)		(1	)		(144	)
Long-term borrowings		75			(58	)		17			(431	)		(121	)		(552	)
Junior subordinated debt securities		—			(719	)		(719	)		—			(368	)		(368	)
Total Interest-bearing Liabilities		(789	)		(5,919	)		(6,708	)		(2,826	)		(4,014	)		(6,840	)
Change in Net Interest Income	$	3,359		$	(5,161	)	$	(1,802	)	$	(4,446	)	$	(4,527	)	$	(8,973	)

⁽¹⁾  The change in interest due to both volume and rate has been allocated to volume and rate changes in proportion to the relationship of the absolute dollar amounts of the change in each.

⁽²⁾  Tax-exempt income is on a fully taxable-equivalent basis, including the dividend-received deduction for equity securities, using the statutory federal corporate income tax rate of 35 percent for 2012, 2011 and 2010.

Net interest income and net interest margin decreased by $1.8 million or 26 basis points compared to 2011. The low interest rate environment was a challenge to our net interest income in 2012, as earning assets rates reset faster than our ability to offset those decreases on the funding side.

Interest income decreased $8.5 million to $160.7 million in 2012 compared to $169.2 million in 2011. Rates decreased on almost all earning asset categories due to the low interest rate environment. The decrease in net interest income was primarily driven by a 29 basis point decrease in average loan yields to 4.59 percent compared to 4.88 percent in 2011. Average loan balances were relatively unchanged with a decline of $3.8 million despite the addition of approximately $143.0 million of average loans related to the acquisitions of Mainline and Gateway. Loans from acquisitions were offset by significant loan payoffs throughout the past two years, primarily in our commercial loan portfolio. We retained more residential mortgage loans in the portfolio during the year, rather than selling them in the secondary market. Average investments increased $51.8 million compared to the prior year; however, due to declining yields interest income was essentially unchanged. The interest-bearing balance with banks is primarily funds held at the Federal Reserve and increased $166.2 million, or 134.4 percent, during 2012 due to a lack of organic loan growth. Overall, the fully taxable-equivalent yield on total interest-earning assets decreased 48 basis points to 4.10 percent in 2012 as compared to 4.58 percent in 2011.

Interest expense decreased $6.7 million to $21.0 million for 2012 compared to $27.7 million for 2011. The primary driver of the decrease in interest expense was the maturities of higher costing CDs. For 2012, average interest-bearing deposits increased by $143.7 million to $2.6 billion as compared to $2.5 billion 2011. The increase in average interest-bearing deposits is attributed to a

34

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

$141.6 million average balance increase in savings deposits and a $79.6 million average balance increase in interest-bearing demand and money market accounts, partially offset by an average balance decrease of $77.6 million in CDs. The increase in deposits includes the addition of $171.0 million in average deposits related to the acquisitions of Mainline and Gateway. The cost of deposits was 0.48 percent, a decrease of 22 basis points from 2011 primarily due to CDs maturing and being replaced by demand and other lower interest rate deposits. The cost of long-term borrowed funds decreased 64 basis points, to 3.23 percent from 3.87 percent in 2011. However, the cost of securities sold under repurchase agreements, or REPOs, and other short-term borrowed funds increased 8 basis points to 0.21 percent as a result of increased utilization of more expensive short-term borrowings compared to customer repos. Overall, the yield on interest-bearing liabilities decreased 31 basis points to 0.74 percent for 2012 as compared to 2011.

Provision for Loan Losses

The provision for loan losses is the amount to be added to the ALL after adjusting for charge-offs and recoveries to bring the ALL to a level considered appropriate to absorb probable losses inherent in the loan portfolio. The provision for loan losses increased $7.2 million to $22.8 million for 2012 compared to $15.6 million for 2011. Net charge-offs were $25.2 million or 0.78 percent of average loans in 2012, compared to $18.2 million or 0.56 percent of average loans in 2011. During the first half of 2012, we experienced elevated charge-offs primarily in our commercial construction loan portfolio as projects in this portfolio slowed due to the economic environment and as a result, appraised values declined. Refer to the Allowance for Loan Losses section of this Management’s Discussion and Analysis of Financial Condition and Results of Operations, or MD&A, for further details.

Noninterest Income

Years Ended December 31	2012		2011			$ Change
(in thousands)
Security gains (losses), net	$	3,016	$	(124	)	$	3,140
Debit and credit card fees		11,134		10,889			245
Service charges on deposit accounts		9,992		9,978			14
Wealth management fees		9,808		8,180			1,628
Insurance fees		8,448		8,314			134
Mortgage banking		2,878		1,199			1,679
Other Income:
Interest rate swap fees		1,036		—			1,036
Other		5,600		5,621			(21	)
Total Other Noninterest Income		6,636		5,621			1,015
Total Noninterest Income	$	51,912	$	44,057		$	7,855

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Noninterest income increased $7.9 million in 2012 compared to 2011, with increases in almost all noninterest income categories. The primary drivers were gains on sales of securities, as well as increased fees from wealth management, mortgage banking and interest rate swap fee income.

The $3.1 million increase in security gains relates to the sales of two equity positions during the year as a result of increases in value after merger announcements. Mortgage interest rates remained at very attractive levels throughout 2012 driving strong customer demand. As a result, we experienced an increase of $1.7 million in mortgage banking fee activity in 2012 compared to the prior year. During 2012, we sold $82.9 million of 1-4 family mortgage loans to Fannie Mae compared to $67.9 million in 2011 which increased fees by $0.5 million. Additionally, in 2011 we recorded an impairment charge related to mortgage servicing rights of $0.4 million that reflected a decline in the remaining value of the mortgage servicing asset compared to no impairment in 2012. The remaining increase in mortgage banking activity primarily related to a net gain on our mortgage derivative due to a strong mortgage pipeline at the end of 2012 compared to a decrease in 2011. During the fourth quarter of 2012, we began to retain 20 year mortgages within the loan portfolio which were previously priced and underwritten using secondary market terms and guidelines. This retention of 20 year mortgages is in addition to the 10 and 15 year mortgages which we have been retaining in the portfolio since the second quarter of 2011.

Wealth management fees increased $1.6 million due to improved brokerage business of $0.8 million as a result of adding new producers and our trust income increased $0.6 million due to an increase in assets under management of $201.0 million compared to the prior year.

Interest rate swap fees have increased $1.0 million compared to the prior year as our customers have opted to lock in low interest rates for longer terms.

Noninterest Expense

Years Ended December 31	2012		2011			$ Change
(in thousands)
Salaries and employee benefits(1)	$	57,920	$	51,078		$	6,842
Data processing(1)		7,326		6,853			473
Net occupancy(1)		7,603		6,943			660
Professional services and legal(1)		4,610		5,437			(827	)
Furniture and equipment		5,262		4,941			321
Marketing(1)		3,206		3,019			187
Other taxes		3,200		3,381			(181	)
FDIC assessment		2,926		3,570			(644	)
Merger related expense		5,968		—			5,968
Other expenses:
Joint venture amortization		4,199		3,302			897
Other real estate owned		2,166		1,518			648
Unfunded loan commitments		1,811		(1,474	)		3,285
Amortization of intangibles		1,709		1,737			(28	)
Other(1)		14,957		13,603			1,354
Total Other Noninterest Expense		24,842		18,686			6,156
Total Noninterest Expense	$	122,863	$	103,908		$	18,955

⁽¹⁾ Excludes one-time merger related expenses for 2012.

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

We had an increase of $19.0 million in noninterest expense in 2012, compared to 2011, with the largest increases in salaries and employee benefits and one-time merger related expenses.

During the first quarter of 2012, we acquired Mainline Bancorp, Inc., an eight branch institution headquartered in Ebensburg, Pennsylvania and during the third quarter of 2012, we acquired Gateway Bank, a two branch institution headquartered in McMurray, Pennsylvania. In 2012, we incurred one-time merger related expenses of $2.3 million of change in control, severance and other employee costs, $2.3 million in data processing contract termination fees, $1.0 million for professional and legal fees and $0.4 million of other expenses. We expect to incur approximately $1.2 million of additional merger related expenses related to the conversion of Gateway Bank into S&T Bank on February 8, 2013.

Excluding one-time merger related expenses, salaries and employee benefits increased by $6.8 million, or 13.4 percent, compared to 2011. Approximately $2.3 million of the increase related to additional employees added as a result of the acquisitions. We added 53 former Mainline employees to our staff in March 2012 and 19 former Gateway employees in August 2012. Further increasing salary expenses in 2012 were annual merit increases of approximately $1.7 million. Our pension expense increased $2.0 million in 2012 due to an increase in our pension liability as a result of a significant decrease of 100 basis points in our discount rate from the prior year. Payroll incentives and commissions increased $0.4 million due to increased production in areas including wealth management and mortgage banking.

Excluding one-time merger related expenses, data processing expenses increased by $0.5 million, primarily due to $0.3 million related to an increased customer processing base due to the acquisitions and an additional $0.2 million related to an upgrade to our Wealth Management data processing system. Net occupancy expenses increased by $0.7 million due to the addition of 10 branches from the acquisitions.

We invest in partnerships that provide federal income tax benefits through tax credits. The partnerships are amortized over the life of the expected tax credits. Joint venture amortization increased by $0.9 million year over year due to three new projects going into service during 2012. Further, we recorded impairment charges of $0.3 million during the year where the benefit of the tax credits had been fully utilized and no future benefits were expected to be realized.

We did see decreases in several expense categories. Excluding one-time merger related expenses, legal and professional expense decreased by $0.8 million, due in part to one-time legal and accounting fees incurred in early 2011. FDIC expense decreased by $0.6 million as we benefited from a lower FDIC assessment based on the revisions made by the FDIC that went into effect April 1, 2011.

Within other noninterest expense, the reserve for unfunded loan commitments increased $3.3 million as a result of increased volume in our construction commitments coupled with higher historical loss rates. In the prior year we had a reversal of $1.5 million of unfunded loan commitments. The reversal in 2011 was primarily attributable to the decline in commitments at that time. Additionally, $0.8 million of the reserve reversal in 2011 related to an expense recognized in 2008 for a letter of credit that we were contractually obligated to fulfill. During 2011, the letter of credit was drawn upon and funded and a corresponding loan charge-off was recorded. We also had an increase of $0.6 million in other real estate owned, or OREO, expense, primarily due to two properties that were sold during 2012 at values significantly below the appraised values, as well as increases in selling expenses pertaining to these properties.

Our efficiency ratio, which measures noninterest expense as a percent of noninterest income plus net interest income, on a fully taxable-equivalent basis, excluding security gains/losses, was 65 percent for 2012, including the one-time merger related expenses of $6.0 million, and 56 percent for 2011. Refer to page 57 Explanation of Use of Non-GAAP Financial Measures for a discussion of this non-GAAP financial measure.

37

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Federal Income Taxes

We recorded a federal income tax provision of $7.3 million in 2012 compared to $14.6 million in 2011. The effective tax rate, which is the provision for income taxes as a percentage of pretax income was 17.5 percent in 2012 compared to 23.6 percent in 2011. The effective tax rate decreased due to tax-exempt income and tax credits remaining relatively constant on a declining pre-tax income. We ordinarily generate an annual effective tax rate that is less than the statutory rate of 35 percent due to benefits resulting from tax-exempt interest, excludable dividend income, tax-exempt interest on bank owned life insurance, or BOLI and tax benefits associated with Low Income Housing Tax Credits, or LIHTC, and Federal Historic Tax Credit Projects.

Results of Operations

Year Ended December 31, 2011

Net Income

Net income available to common shareholders for 2011 was $39.7 million resulting in diluted earnings per common share of $1.41 compared to $37.3 million or $1.34 diluted earnings per common share in 2010. The increase in net income was primarily a result of a reduction of $13.9 million in provision for loan losses, partially offset with decreases of $8.5 million in net interest income and $3.2 million in noninterest income.

Return on Equity and Assets

The table below presents our consolidated profitability and common equity to asset ratio for each of the last three years:

Years Ended December 31	2011			2010			2009
Common return on average assets		0.97	%		0.90	%		0.05	%
Common return on average equity		6.78	%		6.58	%		0.37	%
Dividend payout ratio		42.44	%		44.75	%		1247.64	%
Common equity to asset ratio		11.91	%		11.48	%		10.74	%

Net Interest Income

The interest income on interest-earning assets and the net interest margin are presented on a fully taxable-equivalent basis. The fully taxable-equivalent basis adjusts for the tax benefit of income on certain tax-exempt loans and investments using the federal statutory tax rate of 35 percent for each period. We believe this measure to be the preferred industry measurement of net interest income that provides a relevant comparison between taxable and non-taxable amounts.

The following table reconciles interest income per the Consolidated Statements of Net Income to net interest income adjusted to a fully taxable-equivalent basis:

Years Ended December 31	2011		2010		2009
(in thousands)
Interest income per Consolidated Statements of Net Income	$	165,079	$	180,419	$	195,087
Adjustment to fully taxable-equivalent basis		4,154		4,627		5, 202
Interest income adjusted to fully taxable-equivalent basis		169,233		185,046		200,289
Interest expense per Consolidated Statements of Net Income		27,733		34,573		49,105
Net Interest Income Adjusted to Fully Taxable-equivalent Basis (non-GAAP)	$	141,500	$	150,473	$	151,184

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Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Average Balance Sheet and Net Interest Income Analysis

The following table provides information regarding the average balances, interest and yields earned on interest-earning assets and the average balances, interest and rates paid on interest-bearing liabilities:

	2011								2010								2009
December 31	Average Balance			Interest		Yield/ Rate			Average Balance			Interest		Yield/ Rate			Average Balance			Interest		Yield/ Rate
(dollars in thousands)
ASSETS
Loans(1)(2)	$	3,216,856		$	156,845		4.88	%	$	3,386,103		$	172,319		5.09	%	$	3,473,169		$	182,767		5.26	%
Taxable investment securities		273,320			8,475		3.10	%		226,714			8,373		3.69	%		286,295			11,897		4.16	%
Tax-exempt investment securities(2)		62,607			3,611		5.77	%		76,707			4,354		5.68	%		103,832			5,624		5.42	%
Federal Home Loan Bank stock		20,091			—		—	%		23,336			—		—	%		23,542			—		—	%
Interest-bearing balance with banks		123,714			302		0.24	%		49			—		0.34	%		54			—		0.17	%
Federal funds sold		—			—		—	%		—			—		—	%		258			1		0.25	%
Total Interest-earning Assets		3,696,588			169,233		4.58	%		3,712,909			185,046		4.98	%		3,887,150			200,289		5.15	%
Noninterest-earning assets:
Cash and due from banks		50,458								90,462								67,405
Premises and equipment, net		38,425								39,142								41,915
Other assets		344,378								340,234								320,803
Less allowance for loan losses		(57,241	)							(59,292	)							(57,985	)
Total Assets	$	4,072,608							$	4,123,455							$	4,259,288
LIABILITIES AND SHAREHOLDERS’ EQUITY
Interest-bearing liabilities:
Interest-bearing demand and money market	$	536,085		$	739		0.14	%	$	518,383		$	1,220		0.24	%	$	485,742		$	1,616		0.33	%
Savings		761,274			1,267		0.17	%		749,325			2,127		0.28	%		758,216			3,465		0.46	%
Certificates of deposit		1,181,823			20,946		1.77	%		1,300,803			25,370		1.95	%		1,367,372			33,358		2.44	%
Federal funds purchased		—			—		—	%		—			—		—	%		115			1		0.79	%
Securities sold under repurchase agreements		41,584			53		0.13	%		46,490			64		0.14	%		86,616			140		0.16	%
Short-term borrowings		551			2		0.32	%		32,473			146		0.45	%		104,217			544		0.52	%
Long-term borrowings		31,651			1,091		3.45	%		42,920			1,643		3.83	%		127,045			5,568		4.38	%
Junior subordinated debt securities		90,619			3,635		4.01	%		90,619			4,003		4.42	%		90,619			4,413		4.38	%
Total Interest-bearing Liabilities		2,643,587			27,733		1.05	%		2,781,013			34,573		1.24	%		3,019,942			49,105		1.63	%
Noninterest-bearing liabilities:
Noninterest-bearing demand		792,911								728,708								637,434
Other liabilities		50,924								47,064								57,377
Shareholders’ equity		585,186								566,670								544,535
Total Liabilities and Shareholders’ Equity	$	4,072,608							$	4,123,455							$	4,259,288
Net Interest Income				$	141,500							$	150,473							$	151,184
Net Yield on Interest-earning Assets							3.83	%							4.05	%							3.89	%

⁽¹⁾  For the purpose of these computations, nonaccruing loans are included in the daily average loan amounts outstanding.

⁽²⁾  Tax-exempt income is on a fully taxable-equivalent basis, including the dividend-received deduction for equity securities, using the statutory federal corporate income tax rate of 35 percent for 2011, 2010 and 2009.

39

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

The following table presents a summary of the changes in interest earned and interest paid resulting from changes in average balance and changes in rates:

	2011 Compared to 2010 Increase (Decrease) Due to(1)									2010 Compared to 2009 Increase (Decrease) Due to(1)
	Volume			Rate			Net			Volume			Rate			Net
(in thousands)
Interest earned on:
Loans(2)	$	(8,613	)	$	(6,861	)	$	(15,474	)	$	(4,581	)	$	(5,867	)	$	(10,448	)
Taxable investment securities		1,722			(1,620	)		102			(2,476	)		(1,048	)		(3,524	)
Tax-exempt investment securities(2)		(800	)		57			(743	)		(1,469	)		199			(1,270	)
Interest bearing balance with bank		419			(117	)		302			—			—			—
Other investments		—			—			—			—			—			—
Federal funds sold		—			—			—			(1	)		—			(1	)
Total Interest-earning Assets		(7,272	)		(8,541	)		(15,815	)		(8,527	)		(6,716	)		(15,243	)
Interest paid on:
Interest-bearing demand and money market	$	42		$	(523	)	$	(481	)	$	109		$	(505	)	$	(396	)
Savings deposits		34			(894	)		(860	)		(41	)		(1,297	)		(1,338	)
Certificates of deposit		(2,321	)		(2,103	)		(4,424	)		(1,624	)		(6,364	)		(7,988	)
Federal funds purchased		—			—			—			(1	)		—			(1	)
Securities sold under repurchase agreements		(7	)		(4	)		(11	)		(65	)		(11	)		(76	)
Short-term borrowings		(143	)		(1	)		(144	)		(374	)		(24	)		(398	)
Long-term borrowings		(431	)		(121	)		(552	)		(3,687	)		(238	)		(3,925	)
Junior subordinated debt securities		—			(368	)		(368	)		—			(410	)		(410	)
Total Interest-bearing Liabilities		(2,826	)		(4,014	)		(6,840	)		(5,683	)		(8,849	)		(14,532	)
Change in Net Interest Income	$	(4,446	)	$	(4,527	)	$	(8,973	)	$	(2,844	)	$	2,133		$	(711	)

⁽¹⁾  The change in interest due to both volume and rate has been allocated to volume and rate changes in proportion to the relationship of the absolute dollar amounts of the change in each.

⁽²⁾  Tax-exempt income is on a fully taxable-equivalent basis, including the dividend-received deduction for equity securities, using the statutory federal corporate income tax rate of 35 percent for 2011, 2010 and 2009.

On a fully taxable-equivalent basis, net interest income decreased by $9.0 million in 2011 compared to 2010. The decline in the net interest margin from 4.05 percent in 2010 to 3.83 percent in 2011 is a result of loan repricing and replacement volume at lower rates and an unfavorable shift in asset mix, offset in part by lower rates paid on deposits and a better funding mix between deposits, including noninterest-bearing demand deposits and borrowings.

The shift in asset mix during 2011 is primarily reflected by the $169.2 million decrease in average loans and an increase in average interest-bearing balance with banks of $123.7 million. The interest-bearing balance with banks is primarily funds held at the Federal Reserve and had increased during 2011 as a result of loan pay downs and weak demand for new loans. The yield on average loans and taxable investment securities decreased 21 basis points and 59 basis points, respectively. Overall, the fully taxable-equivalent yield on total interest-earning assets decreased 40 basis points to 4.58 percent in 2011 as compared to 4.98 percent in 2010.

For 2011, average interest-bearing deposits decreased by $89.3 million to $2.5 billion as compared to $2.6 billion in 2010. The decrease in average interest-bearing deposits is attributed to a $119.0 million average balance decrease in CDs, primarily in brokered CDs. The cost of deposits totaled 0.93 percent, a decrease of 19 basis points from 2010 due to lower rates paid on deposits. The cost of securities sold under repurchase agreements, or REPOs, and other short-term borrowed funds decreased 14 basis points to 0.13 percent as a result of lower short-term rates as compared to 2010. Overall, the yield on interest-bearing liabilities decreased 19 basis points to 1.05 percent for 2011 as compared to 2010.

40

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Positively affecting net interest income was a $121.2 million increase in average net free funds during 2011, as compared to 2010. Average net free funds are the excess of noninterest-bearing demand deposits, other noninterest-bearing liabilities and shareholders’ equity over noninterest-earning assets. The largest driver of the increase in net free funds was an increase in noninterest-bearing demand deposit average balances, which is a result of limited investment options available to our customers in the low rate environment.

Provision for Loan Losses

The provision for loan losses is the amount to be added to the ALL after adjusting for charge-offs and recoveries to bring the ALL to a level considered appropriate to absorb probable losses inherent in our loan portfolio. The provision for loan losses decreased to $15.6 million for 2011 compared to $29.5 million for 2010. The substantial decrease in provision for loan losses was a result of the overall improving economic conditions from the prior year and a significant decrease in net charge-offs. Net charge-offs decreased to $18.2 million, 0.56 percent of average loans in 2011 from $37.7 million or 1.11 percent of average loans in 2010 as overall asset quality improved during 2011. Refer to the Allowance for Loan Losses section of this MD&A for further details.

Noninterest Income

Years Ended December 31	2011			2010		$ Change
(in thousands)
Security gains (losses), net	$	(124	)	$	274	$	(398	)
Debit and credit card fees		10,889			9,954		935
Service charges on deposit accounts		9,978			11,178		(1,200	)
Insurance fees		8,314			8,312		2
Wealth management fees		8,180			7,808		372
Mortgage banking		1,199			3,403		(2,204	)
Other income:
Commercial rate swap		(38	)		96		(134	)
Rabbi trust		(41	)		200		(241	)
Derivative fee income		—			136		(136	)
Other		5,700			5,849		(149	)
Total Other Noninterest Income		5,621			6,281		(660	)
Total Noninterest Income	$	44,057		$	47,210	$	(3,153	)

We experienced a decline of $3.2 million in our noninterest income in 2011 primarily as a result of regulatory changes and declining volumes in our mortgage banking area.

Service charges on deposit accounts decreased $1.2 million primarily relating to the impacts of Regulation E, which requires customers with existing accounts to opt in for overdraft coverage of certain types of electronic banking activities. Regulation E caused service charge income to decrease by $1.8 million in 2011, which we offset in part by the introduction of a new paper statement fee in August 2011. Paper statement fees generated $0.5 million in revenue in 2011. We expect customers to continue to elect to receive electronic bank statements; therefore it is expected that paper statement fee income will decline in future periods.

Mortgage banking includes fee income related to loans sold in the secondary market, mortgage servicing income and fair value adjustments associated with valuing mortgage derivatives. Although interest rates continue to be low, the volume of loan sales in the secondary market have decreased

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resulting in a $2.2 million decrease in mortgage banking income. During 2011, we sold $67.9 million of 1-4 family mortgage loans to Fannie Mae compared to $109.3 million in 2010 which resulted in a fee reduction of $0.9 million. In the second quarter of 2011, we began to retain within the loan portfolio 10 and 15 year mortgages which had previously been priced and underwritten using secondary market terms and guidelines. Additionally, we recorded higher impairment charges on our mortgage servicing asset in 2011 compared to 2010. This impairment charge reflects a decline in the value of the remaining mortgage servicing rights due to increased prepayment speeds resulting from decreases in interest rates.

We recognized $0.1 million in security losses in 2011 related to OTTI on two equity securities compared to realized gains of $0.3 million in the prior year. In the prior year, OTTI was not significant and we experienced gains as we sold several of our equity positions.

The decreases in noninterest income are partially offset by increases of $0.9 million in debit and credit card fees and $0.4 million in wealth management fees. Debit and credit card fees have increased $0.9 million in 2011 as a result of increased volume and successful marketing campaigns around signature based debit card transactions throughout 2011. Our wealth management fees increased $0.4 million from the prior year. We experienced increased fee income of $0.2 million as our customers moved to fixed annuities in this low interest rate environment. Additionally, wealth management fees were positively impacted by improving market conditions in 2011.

Noninterest Expense

Years Ended December 31	2011			2010			$ Change
(in thousands)
Salaries and employee benefits	$	51,078		$	48,715		$	2,363
Net Occupancy		6,943			6,928			15
Data processing		6,853			6,145			708
Professional services and legal		5,437			6,889			(1,452	)
Furniture and equipment		4,941			5,054			(113	)
FDIC assessment		3,570			5,426			(1,856	)
Other taxes		3,381			3,432			(51	)
Joint venture amortization		3,302			2,573			729
Marketing		3,019			2,795			224
Other expenses:
Amortization of intangibles		1,737			1,943			(206	)
Other real estate owned		1,518			1,921			(403	)
Loan collection fees		624			1,770			(1,146	)
Unfunded loan commitments		(1,474	)		(1,555	)		81
Other		12,979			13,597			(618	)
Total Other Noninterest Expense		15,384			17,676			(2,292	)
Total Noninterest Expense	$	103,908		$	105,633		$	(1,725	)

We had a slight decline in noninterest expense of $1.7 million during 2011. This was primarily a result of certain one-time expenses in 2010 and a significant decrease in our FDIC assessment in 2011.

The decrease in professional services and legal expense is due to $2.3 million of legal settlement costs that occurred in the first and second quarters of 2010. The decrease in the FDIC assessment of $1.9 million is the result of the FDIC changing the methodology used to calculate the assessment as of

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April 1, 2011 and the expiration of the FDIC’s Transaction Account Guarantee Program on December 31, 2010. Asset quality improved throughout 2011 resulting in $1.1 million less in loan collection fees. While these expenses have declined from the prior year, we expect to continue to experience elevated costs in this area as our criticized and classified loans remain above historic averages. For the year ended December 31, 2011, $1.5 million of unfunded loan commitments was reversed compared to $1.6 million for the year ended December 31, 2010. The reversal of the reserve is primarily attributable to the decline in available commitments. Additionally, $0.8 million of the reserve reversal in 2011 related to an expense recognized in 2008 for a letter of credit that we were contractually obligated to fulfill. During the third quarter of 2011, the letter of credit was drawn upon and funded and a corresponding loan charge-off was recorded. Other noninterest expense decreased $0.6 million primarily related to a $1.2 million write-off of an uncollectible receivable in the third quarter of 2010. The receivable related to expenses for a mutual fund advised by an affiliate.

We had a $2.4 million increase in salaries and employee benefits primarily due to the full year impact of our annual merit increase resulting in additional salary expense of $1.0 million for 2011. Additionally, restricted stock expense increased $0.7 million related to the 2010 incentive plan and a newly implemented long-term incentive plan. Incentive plans were re-instituted in 2010 which impacted the 2011 expense. Deferred loan origination costs are down by $0.9 million from 2010, which increases salaries and employee benefits in the current period since we are deferring less costs. These increases were offset by a decrease in the pension plan expense of $0.3 million due to a change in the number of participants in the plan. We do not expect to see a similar decrease in pension expense in 2012 as a result of a significant increase in our pension liability due to a decline in the discount rate of 100 basis points to 4.75%.

The $0.7 million in additional data processing costs relate to one-time charges for the implementation of mobile banking and other system conversion fees. The increase of $0.7 million in joint venture amortization reflects the addition of two low income housing projects that were completed in 2011.

Our efficiency ratio, which measures noninterest expense as a percent of noninterest income plus net interest income, on a fully taxable-equivalent basis, excluding security gains/losses, was 56 percent for 2011 and 54 percent for 2010. Refer to page 57 Explanation of Use of Non-GAAP Financial Measures for a discussion of this non-GAAP financial measure.

Federal Income Taxes

We recorded a federal income tax provision of $14.6 million in 2011 compared to $14.4 million in 2010. The effective tax rate, which is the provision for income taxes as a percentage of pre-tax income was 23.6 percent compared to 25.0 percent in 2010. We ordinarily generate an annual effective tax rate that is less than the statutory rate of 35 percent due to benefits resulting from tax-exempt interest, excludable dividend income, tax-exempt interest on BOLI and tax benefits associated with LIHTC, and Federal Historic Tax Credit Projects, which are relatively consistent regardless of the level of pretax income.

Financial Condition

December 31, 2012

Our total assets of $4.5 billion have increased by $406.7 million since December 31, 2011. The acquisition of Mainline and Gateway added $368.5 million in assets. Total gross loans increased $216.9 million to $3.3 billion at December 31, 2012 compared to $3.1 billion at December 31, 2011. Our commercial loan portfolio has grown by $121.8 million to $2.4 billion or by 5.3 percent and our consumer loan portfolio has increased by $95.1 million to $935.0 million or by 11.3 percent, due primarily to the two acquisitions. We did begin to see organic loan growth in the later part of

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2012. Our loan pay downs were significant throughout 2012, primarily in our commercial loan portfolio. Due to lack of loan growth, we increased our securities by $95.5 million and excess cash held at the Federal Reserve by $42.5 million. Our core deposit base remains strong with total deposits of $3.6 billion at December 31, 2012, a $302.6 million, or 9.1 percent increase since December 31, 2011. Our acquisitions added $311.4 million of deposits. We did see an improvement in our mix of deposits throughout 2012, with a decrease in CDs offset by increases in demand, money market and savings accounts.

Securities Activity

December 31	2012		2011		2010
(in thousands)
Obligations of U.S. government corporations and agencies	$	212,066	$	142,786	$	125,675
Collateralized mortgage obligations of U.S. government corporations and agencies		57,896		65,395		41,491
Mortgage-backed securities of U.S. government corporations and agencies		60,781		48,752		43,991
Obligations of states and political subdivisions		112,767		88,805		65,772
Marketable equity securities		9,586		11,858		11,096
Total Securities Available-for-Sale	$	453,096	$	357,596	$	288,025

We invest in various securities in order to provide a source of liquidity, to satisfy various pledging requirements, increase net interest income and as a tool of the ALCO to reposition the balance sheet for interest rate risk purposes. Securities are subject to market risks that could negatively affect the level of liquidity available to us. Risks associated with various securities portfolios are managed and monitored through investment policies which are annually approved by our Board of Directors and administered through ALCO and our treasury function.

The securities portfolio increased $95.5 million, or 26.7 percent, from December 31, 2011. The increase is due to the redeployment of deposits at banks which increased substantially as a result of our acquisitions and lack of organic growth. Additionally, we sold $5.7 million of equity securities since December 31, 2011 that resulted in a $3.0 million gain.

During 2012, 2011 and 2010, we did not record any significant OTTI. The performance of the debt and equity securities markets could generate impairment in future periods requiring realized losses to be reported.

At December 31, 2012, net unrealized gains on securities classified as available-for-sale were approximately $16.0 million as compared to $14.9 million at December 31, 2011. Net unrealized gains related to our debt securities portfolio totaled $14.9 million at December 31, 2012 and $13.2 million at December 31, 2011. The increase in unrealized gains related to debt securities is due to decreases in interest rates. The marketable equity securities portfolio had net unrealized gains of $1.1 million at December 31, 2012 compared to net unrealized gains of $1.7 million at December 31, 2011. At December 31, 2012, we had no securities that were in an unrealized loss position for greater than 12 months. We do not intend to sell and it is not likely that we will be required to sell any of the securities in an unrealized loss position before recovery of its amortized cost.

At December 31, 2012 and 2011, we held Federal Home Loan Bank, or FHLB, stock of $14.5 million and $18.2 million, respectively. This investment is carried at cost and evaluated for impairment based on the ultimate recoverability of the par value. We hold FHLB stock because we are a member of the FHLB of Pittsburgh. The FHLB requires members to purchase and hold a specified level of FHLB stock based upon on the members asset value, level of borrowings and participation in other programs offered. Stock in the FHLB is non-marketable and is redeemable at the discretion of

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the FHLB. Members do not purchase stock in the FHLB for the same reasons that traditional equity investors acquire stock in an investor-owned enterprise. Rather, members purchase stock to obtain access to the low-cost products and services offered by the FHLB. Unlike equity securities of traditional for-profit enterprises, the stock of the FHLB does not provide its holders with an opportunity for capital appreciation because, by regulation, FHLB stock can only be purchased, redeemed and transferred at par value.

On February 22, 2012, the FHLB of Pittsburgh announced that it would pay a dividend on the average capital stock balance held during the three month period ended December 31, 2011 at an annualized rate of 0.10% for the first time since late 2008. The FHLB noted future dividend payments and capital stock repurchases will continue to be reviewed on a quarterly basis. We had $5.7 million of redemptions from the FHLB throughout 2012. We reviewed and evaluated the FHLB capital stock for OTTI at December 31, 2012. Based upon our review of the FHLB’s current financial position, they reported improved earnings throughout 2012 compared to 2011 and continue to exceed all capital ratios required. Additionally, we considered that the FHLB began paying dividends and redeeming excess stock during 2012. Accordingly, we believe sufficient evidence exists to conclude that no OTTI exists at December 31, 2012.

The following table sets forth the maturities of securities at December 31, 2012 and the weighted average yields of such securities. Taxable-equivalent adjustments (using a 35 percent federal income tax rate) for 2012 have been made in calculating yields on obligations of state and political subdivisions.

	Maturing
	Within One Year					After One But Within Five Years					After Five But Within Ten Years					After Ten Years					No Fixed Maturity
	Amount		Yield			Amount		Yield			Amount		Yield			Amount		Yield			Amount
(dollars in thousands)
Available-for-Sale
Obligations of U.S. government corporations and agencies	$	30,562		2.00	%	$	125,266		1.62	%	$	52,644		1.47	%	$	3,594		0.72	%	$	—
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—	%		5,040		4.61	%		—		—	%		52,856		2.52	%		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—	%		149		4.19	%		17,747		2.66	%		42,885		3.41	%		—
Obligations of states and political subdivisions		8,408		5.38	%		8,926		5.70	%		13,863		3.94	%		81,571		4.59	%		—
Marketable equity securities		—		—	%		—		—	%		—		—	%		—		—	%		9,585
Total	$	38,970				$	139,381				$	84,254				$	180,906				$	9,585
Weighted Average Rate				2.73	%				1.99	%				2.13	%				3.63	%

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Lending Activity

The following table summarizes our loan distribution at the end of each of the last five years:

	2012					2011					2010					2009					2008
December 31	Amount		% of Total			Amount		% of Total			Amount		% of Total			Amount		% of Total			Amount		% of Total
(dollars in thousands)
Commercial
Commercial real estate	$	1,452,133		43.39	%	$	1,415,333		45.22	%	$	1,494,202		44.53	%	$	1,428,329		42.03	%	$	1,440,200		40.36%
Commercial and industrial		791,396		23.65	%		685,753		21.91	%		722,359		21.52	%		701,650		20.65	%		822,543		23.05%
Commercial construction		168,143		5.02	%		188,852		6.04	%		259,598		7.74	%		359,342		10.57	%		361,910		10.14%
Total Commercial Loans		2,411,672		72.06	%		2,289,938		73.17	%		2,476,159		73.79	%		2,489,321		73.25	%		2,624,653		73.55%
Consumer
Home equity		431,335		12.89	%		411,404		13.14	%		441,096		13.15	%		458,643		13.49	%		438,380		12.28%
Residential mortgage		427,303		12.77	%		358,846		11.47	%		359,536		10.71	%		357,393		10.52	%		408,603		11.45%
Installment and other consumer		73,875		2.21	%		67,131		2.14	%		74,780		2.23	%		81,141		2.39	%		84,065		2.36%
Consumer construction		2,437		0.07	%		2,440		0.08	%		4,019		0.12	%		11,836		0.35	%		13,014		0.36%
Total Consumer Loans		934,950		27.94	%		839,821		26.83	%		879,431		26.21	%		909,013		26.75	%		944,062		26.45%
Total Portfolio Loans	$	3,346,622		100	%	$	3,129,759		100	%	$	3,355,590		100	%	$	3,398,334		100	%	$	3,568,715		100%

The loan portfolio represents the most significant source of interest income for us. The risk that borrowers will be unable to pay such obligations is inherent in the loan portfolio. Other conditions such as the overall economic climate can significantly impact the borrower’s ability to pay.

At December 31, 2012 our total loans were $3.3 billion, a $216.9 million increase compared to the prior year. The overall composition of the loan portfolio did not change significantly from the prior year. The Mainline and Gateway acquisitions added $228.6 million in loans during 2012, which was a mix of both consumer and commercial loans. Organic loan growth was challenging during the year and we did experience significant loan pay downs, primarily in our commercial loan portfolio. We did see positive trends in our loan portfolio in the later part of 2012 with increased customer demand.

In August 2012, we expanded our commercial lending footprint into Northeastern Ohio through the opening of a loan production office in Akron. We are retaining 10, 15 and 20 year residential real estate loans in our portfolio, rather than selling these loans in the secondary market. Additionally, we are hiring seasoned lenders in both our commercial and residential real estate areas to improve organic loan growth.

Commercial loans, including commercial real estate, or CRE, commercial and industrial, or C&I, and commercial construction, comprised 72 percent and 73 percent of total portfolio loans at December 31, 2012 and 2011, respectively. Although commercial loans can have a relatively higher risk profile, management believes these risks are mitigated through active portfolio management, conservative underwriting standards and continuous portfolio review. The loan-to-value policy guidelines for CRE loans are generally 65-85 percent. At December 31, 2012, variable rate commercial loans were 78 percent of the commercial loan portfolio as compared to 79 percent at December 31, 2011.

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Home equity and residential mortgage loans comprised 26 percent of the loan portfolio in 2012 and 25 percent in 2011. Residential mortgage lending continues to be a strategic focus through a centralized mortgage origination department, ongoing product redesign, secondary market activities and the utilization of commission compensated originators. Management believes that continued adherence to our conservative mortgage lending policies for portfolio loans will be as important in a gradually growing economy as it was during the downturn in recent years. The loan-to-value policy guideline is 80 percent for residential first lien mortgages. Higher loan-to-value loans may be approved with the appropriate private mortgage insurance coverage. Portfolio loans permit a maximum term of 20 years for traditional mortgages. Balloon payment mortgages are also offered in the portfolio. The maximum balloon term is 15 years with a maximum amortization term of 30 years. Balloon mortgages with terms of 10 years or less may have a maximum amortization term for up to 40 years. Combo mortgage loans consisting of our residential first mortgage and home equity second mortgage are also available to credit-worthy borrowers. Second lien positions are assumed with home equity loans, but normally only to the extent that the combined credit exposure for both the first and second liens does not exceed 100 percent of the fair value of the property.

We also originate and price loans for sale into the secondary market, primarily to Fannie Mae. The rationale for these sales is to mitigate interest-rate risk associated with holding lower rate, long-term residential mortgages in the loan portfolio, generate fee revenue from sales and servicing and maintain the primary customer relationship. In 2011, we began to retain 10 and 15 year mortgages in our portfolio and just recently we began retaining the 20 year mortgages that had been priced and underwritten using secondary market terms and guidelines. During 2012 and 2011, we sold $82.9 million and $67.9 million, respectively, of 1–4 family mortgages to Fannie Mae and currently service $329.2 million of secondary market mortgage loans at December 31, 2012 compared to $332.6 million at December 31, 2011. Loans sold to Fannie Mae increased from the prior year due to the low interest rate environment and economic stabilization in our markets. We intend to continue to sell 30 year loans to Fannie Mae in the future, especially during periods of lower interest rates.

We offer a variety of unsecured and secured consumer loan and credit card products. Loan-to-value policy guidelines for direct loans are 90–100 percent of invoice for new automobiles and 80–90 percent of National Automobile Dealer Association, or NADA, value for used automobiles.

We maintain a General Lending Policy to control the quality of our loan portfolio. The policy delegates the authority to extend loans under specific guidelines and underwriting standards. The General Lending Policy is formulated by management and reviewed and ratified annually by the Board of Directors. Any exception to the General Lending Policy must be approved by the Senior Loan Committee or the Regional Loan Committee.

The following table presents the maturity of consumer and commercial loans outstanding as of December 31, 2012.

	Maturing
	Within One Year		After One But Within Five Years		After Five Years		Total
(in thousands)
Fixed interest rates	$	121,611	$	286,041	$	122,421	$	530,073
Variable interest rates		497,811		618,200		765,588		1,881,599
Total Commercial Loans	$	619,422	$	904,241	$	888,009	$	2,411,672
Fixed interest rates		69,390		253,681		301,491		624,562
Variable interest rates		217,794		25,844		66,750		310,388
Total Consumer Loans	$	287,184	$	279,525	$	368,241	$	934,950
Total Portfolio Loans	$	906,606	$	1,183,766	$	1,256,250	$	3,346,622

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Credit Quality

We have a Criticized Asset Committee that meets quarterly and monitors all special mention loans greater than $1.0 million and substandard loans greater than $0.5 million. Additional credit risk management practices include periodic review and updates to lending policies and procedures regarding sound underwriting practices and portfolio management expectations; a portfolio and loan stress testing initiative; and an independent loan review program developed to review underwriting decisions and adherence to policy, proper risk rating methodology and a review of all of our credit related business units. There can be no assurance that we will be successful in controlling the risk with these loans and consequently they could result in losses for us.

We determine loans to be impaired when based upon current information and events it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. All TDRs are classified as impaired loans. Impaired loans are continually monitored by our Managed Assets Division.

Nonperforming assets consist of nonaccrual loans, TDRs and OREO. The following represents nonperforming assets for the periods presented:

	2012			2011			2010			2009			2008
(dollars in thousands)
Nonaccrual Loans
Commercial real estate	$	20,972		$	20,777		$	14,674		$	52,380		$	19,386
Commercial and industrial		5,496			7,570			2,567			7,489			3,341
Commercial construction		1,454			3,604			5,844			21,674			13,848
Home equity		3,312			2,936			1,433			2,252			174
Residential mortgage		4,526			2,859			5,996			5,583			5,624
Installment and other consumer		40			4			65			20			73
Consumer construction		218			181			525			—			—
Total Nonaccrual Loans		36,018			37,931			31,104			89,398			42,446
Nonaccrual Troubled Debt Restructurings
Commercial real estate		9,584			10,871			29,636			1,409			—
Commercial and industrial		939			—			1,000			—			—
Commercial construction		5,324			2,943			2,143			—			—
Home Equity		341			—			—			—			—
Residential mortgage		2,752			4,370			—			—			—
Total Nonaccrual Troubled Debt Restructurings		18,940			18,184			32,779			1,409			—
Total Nonperforming Loans		54,958			56,115			63,883			90,807			42,446
OREO		911			3,967			5,820			4,607			851
Total Nonperforming Assets	$	55,869		$	60,082		$	69,703		$	95,414		$	43,297
Nonperforming loans as a percent of total loans		1.63	%		1.79	%		1.90	%		2.67	%		1.19%
Nonperforming assets as a percent of total loans plus OREO		1.66	%		1.92	%		2.07	%		2.80	%		1.21%

Nonperforming assets decreased 7.0 percent from the prior year as a result of resolution of several credits either through the foreclosure process and subsequent sale of the property or pay downs or payoffs of the loans. Additionally, our nonperforming loan formation was significantly less than the

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prior year with encouraging trends in the second half of 2012. Our CRE portfolio continues to represent a significant amount of our nonperforming loans at 55% of our total nonperforming loans. There are no loans 90 days or more past due and still accruing.

TDRs are loans where we, for economic or legal reasons related to a borrower’s financial difficulties, grant a concession to the borrower that we would not otherwise consider. Modifications to loans classified as TDR generally include reductions in contractual interest rates, principal deferment and extensions of maturity dates at a stated interest rate lower than the current market rate for a new loan with similar risk characteristics. Generally these concessions are for a period of at least six months. While unusual, there may be instances of loan principal forgiveness.

TDRs can be returned to accruing status if the following criteria are met: 1) the ultimate collectability of all contractual amounts due, according to the restructured agreement, is not in doubt and 2) there is a period of a minimum of six months of satisfactory payment performance by the borrower either immediately before or after the restructuring. We did not return any TDRs to accruing status during 2012.

All TDRs are considered to be impaired loans and will be reported as impaired loans for their remaining lives, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and we fully expected that the remaining principal and interest will be collected according to the restructured agreement. All impaired loans are reported as nonaccrual loans unless the loan is a TDR that has met the requirements noted above to be returned to accruing status.

As an example consider a substandard commercial construction loan that is currently 90 days past due where the loan is restructured to extend the maturity date for a period longer than would be considered an insignificant period of time. The post-modification interest rate is not increased to correspond with the current credit risk of the borrower, and all other terms remain the same according to the original loan agreement. This loan will be considered a TDR as the borrower is experiencing financial difficulty and a concession has been granted. The loan will be reported as nonaccrual status and as an impaired loan and a TDR. In addition, the loan could be charged down to the fair value of the collateral if a confirmed loss exists. If the loan subsequently performs, by means of making on-time principal and interest payments according to the newly restructured terms for a period of six months, and it is expected that all remaining principal and interest will be collected according to the terms of the restructured agreement, the loan will be returned to accrual status and reported as an accruing TDR. The loan will remain an impaired loan for the remaining life of the loan since the interest rate was not adjusted to be equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with the comparable risk of a longer term.

As of December 31, 2012, we had $60.4 million in TDRs of which $41.5 million were accruing and $18.9 were in nonaccrual status. This compared to $67.9 million at December 31, 2011 of which $49.7 million were accruing and $18.2 million were in nonaccrual status. During 2012, none of the TDRs met the above requirements for being placed back into accrual status. The decrease in total TDRs from prior year is due to loan pay downs or pay offs and loan charge-offs. We did have $6.9 million of new TDRs related to our consumer loan portfolio for borrowers who had their debt discharged and not reaffirmed through Chapter 7 bankruptcy. These loans are being reported as accruing TDRs as the borrowers are current on their payments and have no history of delinquency.

During the year ended December 31, 2012, we modified $6.6 million of C&I loans, $3.6 million of CRE loans and $1.2 million of commercial construction loans for financially troubled borrowers that were not considered to be TDRs. These borrowers received modifications that represented insignificant delays in the timing of payments that were not considered to be concessions or we concluded that the bank was adequately compensated through loan pay downs or additional collateral.

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OREO and other repossessed assets are comprised of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of a foreclosure. At December 31, 2012, OREO consists of 13 properties, none of which had a balance greater than $0.2 million. All OREO properties have current appraisals. It is our policy to obtain appraisals annually or sooner if indications of impairment exist. Foreclosures decreased to 22 in 2012 compared to 41 in 2011.

The following represents delinquency for the periods presented:

	2012					2011					2010					2009					2008
December 31	Amount		% of Loans			Amount		% of Loans			Amount		% of Loans			Amount		% of Loans			Amount		% of Loans
(dollars in thousands)
90 days or more:
Commercial real estate	$	30,556		2.10	%	$	31,648		2.24	%	$	44,310		2.97	%	$	53,789		3.77	%	$	19,386		1.35%
Commercial and Industrial		6,435		0.81	%		7,570		1.10	%		3,567		0.49	%		7,489		1.07	%		3,341		0.41%
Commercial construction		6,778		4.03	%		6,547		3.47	%		7,987		3.08	%		21,674		6.03	%		13,848		3.83%
Home equity		3,653		0.85	%		2,936		0.71	%		1,433		0.32	%		2,252		0.49	%		174		0.04%
Residential mortgage		7,278		1.70	%		7,229		2.01	%		5,996		1.67	%		5,583		1.56	%		5,624		1.38%
Installment and other consumer		40		0.05	%		4		0.01	%		65		0.09	%		20		0.02	%		73		0.09%
Consumer construction		218		8.95	%		181		7.42	%		525		13.06	%		—		—	%		—		—%
Total Loans	$	54,958		1.64	%	$	56,115		1.79	%	$	63,883		1.90	%	$	90,807		2.67	%	$	42,446		1.19%
30 to 89 days:
Commercial real estate	$	2,643		0.18	%	$	9,105		0.64	%	$	4,371		0.29	%	$	22,923		1.60	%	$	9,603		0.67%
Commercial and industrial		4,646		0.59	%		5,284		0.77	%		1,714		0.24	%		1,241		0.18	%		3,689		0.45%
Commercial construction		10,542		6.27	%		—		—	%		835		0.32	%		899		0.25	%		10,446		2.89%
Home equity		3,197		0.74	%		2,890		0.70	%		2,451		0.56	%		2,106		0.46	%		356		0.08%
Residential mortgage		3,661		0.86	%		2,403		0.67	%		1,346		0.37	%		5,151		1.44	%		5,093		1.25%
Installment and other consumer		501		0.68	%		452		0.67	%		342		0.46	%		852		1.05	%		449		0.53%
Consumer construction		—		—	%		—		—	%		—		—	%		—		—	%		—		—%
Total Loans	$	25,190		0.75	%	$	20,134		0.64	%	$	11,059		0.33	%	$	33,172		0.98	%	$	29,636		0.83%

Closed-end installment loans, amortizing loans secured by real estate and any other loans with payments scheduled monthly are reported past due when the borrower is in arrears two or more monthly payments. Other multi-payment obligations with payments scheduled other than monthly are reported past due when one scheduled payment is due and unpaid for 30 days or more. We monitor delinquency on a monthly basis, including early stage delinquencies in the 30 to 89 days past due for early identification of potential problem loans.

Allowance for Loan Losses

We maintain an ALL at a level determined to be adequate to absorb estimated probable credit losses inherent within the loan portfolio as of the balance sheet date. Determination of an adequate ALL is inherently subjective, as it requires estimations of the occurrence of future events, as well as the timing of such events, and it may be subject to significant changes from period to period. The methodology for determining the ALL has two main components: evaluation and impairment tests of individual loans and impairment tests of certain groups of homogeneous loans with similar risk characteristics.

We enhanced our ALL model in the fourth quarter of 2010 to better align it with regulatory guidance. The calculation of the base historical loss utilizing an average method over the prior five years was shortened to include a one to two year loss emergence period depending on the loan category over a rolling four quarter average. Loss emergence refers to the length of time between a loss event and a charge-off of the loan. With the volatility in the credit cycle at that time, the shorter

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time horizon was more responsive to the loss emergence periods we were experiencing in our portfolio. We believe this shorter time horizon provides a better indication of inherent losses in the loan portfolio given the recent economic downturn. We also refined the qualitative factors beginning in the fourth quarter of 2010 to better align with regulatory guidance. Qualitative factors became a basis point adjustment applied to the historical base loss. The combination of the enhancements to the average method and the qualitative factors did not materially change the ALL at December 31, 2010, resulting in an increase in the ALL of less than $0.5 million. Since December 31, 2010, there have been no further enhancements to the ALL methodology.

We develop and document a systematic ALL methodology based on the following portfolio segments: 1) CRE, 2) C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. The following is the ALL for the past 5 years by portfolio segment:

	2012					2011					2010					2009					2008
December 31	Amount		% of Total			Amount		% of Total			Amount		% of Total			Amount		% of Total			Amount		% of Total
(dollars in thousands)
Commercial real estate	$	25,246		54	%	$	29,804		61	%	$	30,424		59	%	$	27,322		46	%	$	18,781		44%
Commercial and industrial		7,759		17	%		11,274		23	%		9,777		19	%		21,393		36	%		20,170		47%
Commercial construction		7,500		16	%		3,703		8	%		5,905		11	%		8,008		13	%		73		—%
Consumer real estate		5,058		11	%		3,166		6	%		3,962		8	%		2,143		4	%		2,750		7%
Other consumer		921		2	%		894		2	%		1,319		3	%		714		1	%		915		2%
Total	$	46,484		100	%	$	48,841		100	%	$	51,387		100	%	$	59,580		100	%	$	42,689		100%

An inherent risk to the loan portfolio as a whole is the condition of the local economy. In addition, each loan segment carries with it risks specific to the segment.

CRE loans are secured by commercial purpose real estate, including both owner occupied properties and investment properties for various purposes such as hotels, strip malls and apartments. Individual project cash flows, as well as global cash flows, are generally the sources of repayment for these loans. Besides cash flow risks, CRE loans have collateral risk and risks based upon the business prospects of the lessee, if the project is not owner occupied.

C&I loans are made to operating companies or manufacturers for the purpose of production, operating capacity, accounts receivable, inventory or equipment financing. Collateral for these types of loans often do not have sufficient value in a distressed or liquidation scenario to satisfy the outstanding debt. Cash flow from the operations of the company is the primary source of repayment for these loans and the cash flow depends not only on the economy as a whole, but also on the health of the company’s industry.

Commercial construction loans are made to finance construction of buildings or other structures, as well as to finance the acquisition and development of raw land for various purposes. While the risk is generally confined to the construction period, if there are problems, the project may not be completed, and as such, may not provide sufficient cash flow on its own to service the debt or have sufficient value in a liquidation to cover the outstanding principal. There are also various risks depending on the type of project and the experience and resources of the developer.

Consumer real estate loans are secured by 1-4 family residences, including purchase money mortgages, first and second lien home equity loans and home equity lines of credit. The primary source of repayment for these loans is the income and assets of the borrower. The unemployment rate, as well as the state of the local housing markets have a significant impact on the risk determination, since low demand and/or declining home values can limit the ability of borrowers to sell a property and satisfy the debt.

Other consumer loans are made to individuals and may be secured by assets other than 1-4 family residences, or may be unsecured. This class of loans includes auto loans, unsecured lines and credit cards. The primary source of repayment for these loans is the income and assets of the borrower so

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the local unemployment rate is an important indicator of risk. The value of the collateral, if there is any, is less likely to be a source of repayment due to less certain collateral values.

Significant to the ALL is a higher mix of commercial loans. At December 31, 2012, approximately 87 percent of the ALL related to the commercial loan portfolio, while commercial loans comprise 72 percent of our loan portfolio. Our commercial loans, and more specifically, our CRE and construction loan portfolio, had been more impacted by the economic slowdown in our markets within the past few years. The ability of customers to repay commercial loans is more dependent upon the success of their business, continuing income and general economic conditions. Accordingly, the risk of loss is higher on such loans compared to consumer loans, which have incurred lower losses in our market.

The following table summarizes the ALL for each of the last five years as indicated:

December 31	2012		2011		2010		2009		2008
(in thousands)
General reserves	$	44,253	$	43,296	$	47,756	$	42,577	$	35,574
Specific reserves		2,231		5,545		3,631		17,003		7,115
Total Allowance for Loan Losses	$	46,484	$	48,841	$	51,387	$	59,580	$	42,689

The balance in the ALL decreased to $46.5 million or 1.38 percent of total loans at December 31, 2012 as compared to $48.8 million or 1.56 percent of total loans at December 31, 2011. The decrease in the ALL is due to a decrease of $3.3 million in specific reserves associated with loans individually evaluated for impairment offset by an increase of $1.0 million in the general reserve. The December 31, 2012 ALL includes $2.2 million that was specifically allocated for impaired loans of $82.6 million at December 31, 2012, compared to $5.5 million that was allocated for impaired loans of $94.0 million at December 31, 2011. The overall composition of the reserve has changed from 2011 with reserves decreasing in both the CRE and C&I portfolios and increasing in the commercial construction portfolio. We have experienced stress in our commercial construction portfolio during the year, with net charge-offs of $9.6 million compared to net recoveries of $0.7 million during 2011. The losses are primarily related to land development and construction projects that had slowed during the economic downturn, resulting in significant reductions in the appraised values. Many of these loans have been extended resulting in the loan becoming a TDR, and consequently an impaired loan. As a result of these losses the reserve allocated to commercial construction loans has increased $3.8 million to $7.5 million at December 31, 2012 compared to $3.7 million at December 31, 2011. The allowances for both the CRE and the C&I portfolios have decreased as loans evaluated individually for impairment and substandard loans have declined. Further, we have seen a decline in historic loss rates in both the CRE and C&I portfolios. The CRE reserve decreased $4.6 million from $29.8 million at December 31, 2011 to $25.2 million at December 31, 2012, while the C&I reserve decreased $3.5 million, from $11.3 million at December 31, 2011 to $7.8 million at December 31, 2012. Our acquired loans through the acquisition of Mainline and Gateway were recorded at fair value with no carryover of the related ALL.

Consumer unsecured loans and secured loans that are not real estate secured are evaluated for charge-off after the loan becomes 90 days past due. At that time, unsecured loans are fully charged-off and secured loans are charged-off to the estimated fair value of the collateral less the cost to sell. Consumer loans secured by real estate are evaluated for charge-off after the loan balance becomes 90 days past due and are charged down to the estimated fair value of the collateral less cost to sell.

Our charge-off policy for commercial loans requires that loans and other obligations that are not collectible be promptly charged-off when a confirmed loss exists, regardless of the delinquency status of the loan. We may elect to recognize a partial charge-off when management has determined that the

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value of collateral is less than the remaining investment in the loan. A loan or obligation does not need to be charged-off, regardless of delinquency status, if (i) management has determined there exists sufficient collateral to protect the remaining loan balance and (ii) there exists a strategy to liquidate the collateral. Management may also consider a number of other factors to determine when a charge-off is appropriate. These factors may include, but are not limited to:

• The status of a bankruptcy proceeding;

• The value of collateral and probability of successful liquidation; and/or

• The status of adverse proceedings or litigation that may result in collection.

The following summarizes our loan loss experience for each of the five years presented below:

Years Ended December 31	2012			2011			2010			2009			2008
(in thousands)
ALL Balance at Beginning of Year:	$	48,841		$	51,387		$	59,580		$	42,689		$	34,345
Charge-offs:
Commercial real estate		(9,627	)		(8,824	)		(23,925	)		(8,795	)		(828	)
Commercial and industrial		(5,278	)		(8,971	)		(7,277	)		(29,350	)		(4,681	)
Commercial construction		(10,521	)		(1,720	)		(6,353	)		(12,397	)		(1,869	)
Consumer real estate		(2,509	)		(2,617	)		(2,210	)		(4,558	)		(3,217	)
Other consumer		(1,078	)		(1,013	)		(1,262	)		(1,762	)		(1,575	)
Total		(29,013	)		(23,145	)		(41,027	)		(56,862	)		(12,170	)
Recoveries:
Commercial real estate		1,259			780			576			70			523
Commercial and industrial		1,153			357			328			532			1,035
Commercial construction		891			2,463			1,748			—			—
Consumer real estate		197			1,030			202			276			157
Other consumer		341			360			469			521			501
Total		3,841			4,990			3,323			1,399			2,216
Net Charge-offs		(25,172	)		(18,155	)		(37,704	)		(55,463	)		(9,954	)
Provision for loan losses		22,815			15,609			29,511			72,354			12,878
Acquired loan loss reserve		—			—			—			—			5,420
ALL Balance at End of Year:	$	46,484		$	48,841		$	51,387		$	59,580		$	42,689

Net loan charge-offs increased $7.0 million to $25.2 million or 0.78 percent of average loans for 2012 as compared to $18.2 million or 0.56 percent of average loans for 2011. The significant increase is primarily due to an increase of $10.4 in net loan charge-offs in the commercial construction portfolio. The commercial construction portfolio had $9.6 million of net loan charge-offs in 2012 compared to a net loan recovery of $0.7 million in 2011. The losses are primarily related to land development and construction projects that had slowed during the economic downturn, resulting in significant reductions in the appraised values. Many of these loans have been extended resulting in the loan becoming a TDR, and consequently an impaired loan.

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The following table summarizes net charge-offs as a percentage of average loans and other ratios:

December 31	2012			2011			2010			2009			2008
Commercial real estate		0.59	%		0.55	%		1.42	%		3.42	%		0.52%
Commercial and industrial		0.57	%		1.24	%		1.62	%		0.62	%		0.03%
Commercial construction		5.94	%		(0.34	)%		0.96	%		3.74	%		0.43%
Consumer real estate		0.28	%		0.20	%		0.24	%		0.50	%		0.40%
Other consumer		0.91	%		0.94	%		1.04	%		1.52	%		1.35%
Ratio of net charge-offs to average loans outstanding		0.78	%		0.56	%		1.11	%		1.60	%		0.31%
Allowance for loan losses as a percentage of total loans		1.38	%		1.56	%		1.53	%		1.75	%		1.20%
Allowance for loan losses to total nonperforming loans		85	%		87	%		80	%		66	%		101%
Provision for loan losses as a percentage of net loan charge-offs		91	%		86	%		78	%		130	%		184%

Deposits

The following table presents the composition of deposits at December 31:

December 31	2012		2011		$ Change
(in thousands)
Noninterest-bearing demand	$	960,980	$	818,686	$	142,294
Interest-bearing demand		316,760		283,611		33,149
Money market		361,233		278,092		83,141
Savings		965,571		802,942		162,629
Certificates of deposit		1,033,884		1,152,528		(118,644	)
Total	$	3,638,428	$	3,335,859	$	302,569

Deposits are the primary source of funds for us. We believe that our deposit base is stable and that we have the ability to attract new deposits, mitigating a funding dependency on other more volatile sources. During 2012, our demand, money market and savings deposit balances increased by $421.2 million as a result of our two acquisitions and a shift from our certificate of deposit balances due to the low rate environment. Additionally, savings have increased as a result of our preferred savings account which offers an attractive rate in the current low interest rate environment.

Certificates of deposit of $100,000 and over were ten percent of total deposits at December 31, 2012 and eleven percent of total deposits at December 31, 2011, and primarily represent deposit relationships with local customers in our market area. Maturities of certificates of deposit of $100,000 or more outstanding at December 31 are summarized as follows:

December 31	2012
(in thousands)
Three months or less	$	124,799
Over three through six months		59,157
Over six through twelve months		85,393
Over twelve months		98,774
Total	$	368,123

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Through the Promontory Interfinancial Network, LLC, we participate in the Certificate of Deposit Account Registry Services, or CDARS, reciprocal and One-Way Buy programs. We have been a member of Promontory and have utilized CDARS since 2009. Reciprocal deposits provide a stable and cost-effective source of funds with rates generally lower than traditional brokered deposits. Although reciprocal deposits are considered “brokered” under existing law, they tend to act more like core deposits. Reciprocal deposits are customer funds exchanged among insured depository institutions that are members of the CDARS deposit placement service. Through the exchange, we benefit from large, local customer deposits, while providing our customers with access to FDIC insurance protection beyond the maximum deposit insurance amount. Reciprocal deposits address the need to attract and retain valuable customer relationships. As of December 31, 2012 we had $9.8 million in CDARS reciprocal deposits. We also participate in the CDARS One-Way Buy program which allows us to obtain large blocks of wholesale funding. Through the One-Way Buy program, funding is effectively purchased from insured depository institutions that are member of the CDARS deposit placement service. As of December 31, 2012 we had $1.9 million in the CDARS One-Way Buy program.

The daily average amount of deposits and rates paid on deposits are summarized for the periods indicated in the following table:

	2012					2011					2010
Years Ended December 31	Amount		Rate			Amount		Rate			Amount		Rate
(dollars in thousands)
Noninterest-bearing demand	$	877,056				$	792,911				$	728,708
Interest-bearing demand		306,994		0.05	%		286,588		0.13	%		267,291		0.21%
Money market		308,719		0.17	%		249,497		0.15	%		251,092		0.26%
Savings		902,889		0.26	%		761,274		0.17	%		749,325		0.28%
Certificates of deposit		1,104,262		1.24	%		1,181,822		1.77	%		1,300,803		1.95%
Total	$	3,499,920		0.48	%	$	3,272,092		0.70	%	$	3,297,219		0.87%

Borrowings

The following table represents the composition of borrowings at December 31:

Years Ended December 31	2012		2011		$ Change
(in thousands)
Securities sold under repurchase agreements, retail	$	62,582	$	30,370	$	32,212
Short-term borrowings		75,000		75,000		—
Long-term borrowings		34,101		31,874		2,227
Junior subordinated debt securities		90,619		90,619		—
Total Borrowings	$	262,302	$	227,863	$	34,439

Borrowings are an additional source of funding for us. Short-term borrowings are for terms under one year and were comprised of REPOs and FHLB advances. We define repurchase agreements with our local retail customers as retail REPO. Securities pledged as collateral under these REPO financing arrangements cannot be sold or repledged by the secured party and are therefore accounted for as a secured borrowing. FHLB advances are for various terms secured by a blanket lien on residential mortgages and other real estate secured loans. The purpose of long-term borrowings is to match-fund selected new loan originations, to mitigate interest rate sensitivity risks and to take advantage of discounted borrowing rates through the FHLB for community investment projects. The increase in borrowings of $34.4 million is primarily within our retail REPOs and is primarily due to the expiration of the unlimited FDIC insurance on noninterest-bearing demand deposits.

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Information pertaining to REPOs is summarized in the table below:

	2012			2011			2010
(dollars in thousands)
Balance at December 31	$	62,582		$	30,370		$	40,653
Average balance during the year		47,388			41,584			46,489
Average interest rate during the year		0.17	%		0.13	%		0.14%
Maximum month-end balance during the year	$	62,582		$	42,409		$	52,046
Average interest rate at December 31		0.20	%		0.11	%		0.07%

Information pertaining to short-term FHLB advances is summarized in the table below:

	2012			2011			2010
(dollars in thousands)
Balance at December 31	$	75,000		$	75,000		$	—
Average balance during the year		50,212			551			32,473
Average interest rate during the year		0.24	%		0.32	%		0.45%
Maximum month-end balance during the year	$	75,000		$	75,000		$	141,800
Average interest rate at December 31		0.19	%		0.18	%		—%

During 2012, long-term borrowings increased $2.2 million as compared to December 31, 2011. At December 31, 2012, our long-term borrowings outstanding of $34.1 million included $31.0 million that were at a fixed rate and $3.1 million at a variable rate.

During the third quarter of 2006, we issued $25.0 million of junior subordinated debentures through a pooled transaction at an initial fixed rate of 6.78 percent. Beginning September 15, 2011 and quarterly thereafter, we have had the option to redeem the subordinated debt, subject to a 30 day written notice and prior approval by the FDIC. We chose not to exercise the option for early redemption in either 2011 or 2012 and the subordinated debt converted to a variable rate of 3-month LIBOR plus 160 basis points. The subordinated debt qualifies as Tier 2 capital under regulatory guidelines and will mature on December 15, 2036.

During the first quarter of 2008, we completed a private placement to a financial institution of $20.0 million of floating rate trust preferred securities. The trust preferred securities mature in March 2038, are callable at our option after five years, bear interest initially at a rate of 6.44 percent per annum and quarterly adjust with the three-month LIBOR plus 350 basis points. We began making interest payments to the trustee on June 15, 2008 and quarterly thereafter. The trust

preferred securities qualify as Tier 1 capital under regulatory guidelines. To issue these trust preferred securities, we formed STBA Capital Trust I, or the Trust, with $0.6 million of equity, which is owned 100 percent by us. The proceeds from the sale of the trust preferred securities and the issuance of common equity were invested in junior subordinated debt, which is the sole asset of the Trust. The Trust pays dividends on the trust preferred securities at the same rate as the interest we pay on the junior subordinate debt held by the Trust. Since the third-party investors are the primary beneficiaries, the Trust qualifies as a variable interest entity, or VIE, but is not consolidated in our financial statements.

During the second quarter of 2008, we issued $20.0 million of junior subordinated debt through a private placement with three financial institutions at an initial rate of 6.40 percent that floats quarterly with 3-month LIBOR plus 350 basis points. If all or any portion of the subordinated debt ceases to be deemed Tier 2 Capital due to a change in applicable capital regulations, we will have the right to redeem, on any interest payment date, subject to a 30 day written notice and prior approval

56

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

by the FDIC, the subordinated debt at the applicable redemption rate. The redemption rate starts at a high of 102.82 percent at June 15, 2009 and decreases yearly to 100 percent on June 15, 2013 and thereafter and can be called after five years. The subordinated debt qualifies as Tier 2 capital under regulatory guidelines and will mature on June 15, 2018.

Also during the second quarter of 2008, we issued $25.0 million of junior subordinated debt through a private placement with a financial institution at an initial rate of 5.15 percent that floats quarterly with 3-month LIBOR plus 250 basis points. At any time after May 30, 2013, we will have the right to redeem all or a portion of the subordinated debt, subject to a 30-day written notice and prior approval by the FDIC. The subordinated debt qualifies as Tier 2 capital under regulatory guidelines and will mature on May 30, 2018.

Wealth Management Assets

As of December 31, 2012, the fair value of the S&T Bank wealth management assets under management and administration, or AUM, which are not accounted for as part of our assets, increased to $1.7 billion from $1.5 billion as of December 31, 2011. AUM consist of $1.1 billion in S&T Trust and $0.6 billion in S&T Financial Services. The increase in 2012 is primarily attributable to the improved performance of the U.S. and global capital markets.

Explanation of Use of Non-GAAP Financial Measures

In addition to the results of operations presented in accordance with GAAP, our management uses and this Annual Report contains or references, certain non-GAAP financial measures, such as net interest income on a fully taxable-equivalent basis, operating revenue and the efficiency ratio. We believe these non-GAAP financial measures provide information useful to investors in understanding our underlying operational performance and our business and performance trends as they facilitate comparisons with the performance of other companies in the financial services industry. Although we believe that these non-GAAP financial measures enhance investors’ understanding of our business and performance, these non-GAAP financial measures should not be considered an alternative to GAAP or considered to be more important than financial results determined in accordance with GAAP, nor is it necessarily comparable with non-GAAP measures which may be presented by other companies.

We believe the presentation of net interest income on a fully taxable-equivalent basis ensures comparability of net interest income arising from both taxable and tax-exempt sources and is consistent with industry practice. Interest income per the Consolidated Statements of Net Income is reconciled to net interest income adjusted to a fully taxable-equivalent basis on pages 32 and 38.

Operating revenue is the sum of net interest income and noninterest income less security gains/losses. In order to understand the significance of net interest income to our business and operating results, we believe it is appropriate to evaluate the significance of net interest income as a component of operating revenue.

The efficiency ratio is recurring noninterest expense divided by recurring noninterest income plus net interest income, on a fully taxable-equivalent basis, which ensures comparability of net interest income arising from both taxable and tax-exempt sources and is consistent with industry practice.

Capital Resources

Shareholders’ equity increased $46.9 million to $537.4 million at December 31, 2012 compared to $490.5 million at December 31, 2011. The increase in shareholders’ equity is primarily due to the issuance of 1.5 million shares of common stock of $27.6 million, for the two acquisitions consummated in 2012, and the addition of $14.6 million in retained earnings, primarily comprised of

57

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

net income of $34.2 million reduced by common stock dividends of $17.4 million. Included in other comprehensive income was an increase of $4.1 million in unrealized gains on securities available-for-sale due to the continued low interest rate environment.

We continue to maintain a strong capital position with a leverage ratio of 9.31 percent as compared to the regulatory guideline of 5.00 percent to be well capitalized. Our risk-based Tier 1 and Total capital ratios were 11.98 percent and 15.39 percent, respectively, at December 31, 2012, which places us significantly above the Federal Reserve’s “well capitalized” guidelines of 6.00 percent and 10.00 percent for Tier 1 and Total capital. We believe that we have sufficient cash flow, on balance sheet liquidity and borrowing capacity to fund all outstanding commitments and letters of credit, while maintaining proper levels of liquidity. We believe that we have the ability to raise additional capital, if necessary.

In October 2012, we filed a shelf registration statement on Form S-3 under the Securities Act of 1933 as amended, with the SEC for the issuance of up to $300.0 million of a variety of securities including, debt and capital securities, preferred and common stock and warrants. We may use the proceeds from the issuance of any securities for general corporate purposes, which could include investments at the holding company level, investing in, or extending credit to, our subsidiaries, possible acquisitions and stock repurchases. As of December 31, 2012, we had not issued any securities pursuant to the shelf registration statement.

Contractual Obligations

Contractual obligations represent future cash commitments and liabilities under agreements with third parties and exclude contingent contractual liabilities for which we cannot reasonably predict future payments. We have various financial obligations, including contractual obligations and commitments that may require future cash payments.

The following table presents as of December 31, 2012, significant fixed and determinable contractual obligations to third parties by payment date:

	Payments Due In
	2013		2014-2015		2016-2017		Later Years		Total
(in thousands)
Deposits without a stated maturity(1)	$	2,604,544	$		$	—	$	—	$	2,604,544
Certificates of deposit(1)		643,635		248,792		131,071		10,386		1,033,884
Securities sold under repurchase agreements(1)		62,582		—		—		—		62,582
Short-term borrowings(1)		75,000		—		—		—		75,000
Long-term borrowings(1)		12,291		4,767		4,742		12,301		34,101
Junior subordinated debt securities(1)		—		—		—		90,619		90,619
Operating and capital leases		2,164		4,335		4,112		43,953		54,564
Purchase obligations		7,388		14,204		7,524		—		29,116
Total	$	3,407,604	$	272,098	$	147,449	$	157,259	$	3,984,410

⁽¹⁾  Excludes interest

Operating lease obligations represent short and long-term lease arrangements as described in Item 8, Note 10 Premises and Equipment, in the Consolidated Financial Statements. Purchase obligations primarily represent obligations under agreement with our third party data processing servicer and communications charges as described in Item 8, Note 17 Commitments and Contingencies.

58

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Off-Balance Sheet Arrangements

In the normal course of business, we offer off-balance sheet credit arrangements to enable our customers to meet their financing objectives. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. Our exposure to credit loss, in the event the customer does not satisfy the terms of the agreement, equals the contractual amount of the obligation less the value of any collateral. We apply the same credit policies in making commitments and standby letters of credit that are used for the underwriting of loans to customers. Commitments generally have fixed expiration dates, annual renewals or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The allowance for unfunded commitments is included in other liabilities in the Consolidated Balance Sheets.

The following table sets forth the commitments and letters of credit for the periods stated:

December 31	2012		2011
(in thousands)
Commitments to extend credit	$	874,137	$	816,160
Standby letters of credit		95,399		119,576
Total	$	969,536	$	935,736

Estimates of the fair value of these off-balance sheet items were not made because of the short-term nature of these arrangements and the credit standing of the counterparties.

Our allowance for unfunded commitments is determined using a methodology similar to that used to determine the ALL. Amounts are added to the allowance for unfunded commitments through a charge to current earnings in noninterest expense. The balance in the allowance for unfunded commitments increased by $1.8 million to $3.0 million a December 31, 2012 as compared to $1.2 million at December 31, 2011 due to increases in both the volume of construction commitments and higher historic loss rates.

Liquidity

Liquidity is defined as a financial institution’s ability to meet its cash and collateral obligations at a reasonable cost. This includes the ability to satisfy the financial needs of depositors who want to withdraw funds or of borrowers needing to access funds to meet their credit needs. Liquidity risk management involves monitoring and maintaining sufficient levels of a diverse set of funding sources that are available for normal operations and for unanticipated stress events. In order to manage liquidity risk our Board of Directors has delegated authority to the ALCO, for formulation, implementation and oversight of liquidity risk management. ALCO’s goal is to maintain adequate levels of liquidity to meet our funding needs in both a normal operating environment and for potential liquidity stress events.

Our primary funding and liquidity source is a stable deposit base. We believe that S&T bank has the ability to retain existing and attract new deposits, mitigating a funding dependency on other more volatile sources. Although deposits are the primary source of funds, we have identified various funding sources that can be used as part of our normal funding program when either a structure or cost efficiency has been identified. These funding sources include a cushion of highly liquid assets, borrowing availability at the FHLB, Federal Funds lines with other financial institutions and access to the brokered certificates of deposit market including CDARs.

59

Item 7.  MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS — continued

Since the beginning of the financial industry crisis in 2008, monitoring and maintaining appropriate liquidity levels has been a focus of regulators, bankers and investors. ALCO has enhanced the measurement, monitoring and reporting systems for liquidity risk management for potential liquidity stress events. Specific focus has been on maintaining an adequate level of asset liquidity, performing short-term and long-term stress tests and developing a more detailed contingency funding plan. We also work to ensure that access to various wholesale funding sources is available, even in a stress event.

ALCO uses a variety of ratios and reports to monitor our liquidity position. The ratios and reports include an asset liquidity ratio, a liquidity coverage ratio, a loan to deposit ratio, a noncore funding ratio, and a cash flow projections report. ALCO policy guidelines are in place for each ratio that defines graduated risk tolerance levels. If a ratio moves to high risk, specific actions are defined, such as increased monitoring or the development of an action plan to reduce the risk position. As of December 31, 2012 there were no liquidity ratios in the high risk tolerance level.

Inflation

Management is aware of the significant effect inflation has on interest rates and can have on financial performance. Our ability to cope with this is best determined by analyzing our capability to respond to changing interest rates and our ability to manage noninterest income and expense. We monitor the mix of interest-rate sensitive assets and liabilities through ALCO in order to reduce the impact of inflation on net interest income. We also control the effects of inflation by reviewing the prices of our products and services, by introducing new products and services and by controlling overhead expenses.

60

Item 7A.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Market risk is defined as the degree to which changes in interest rates, foreign exchange rates, commodity prices or equity prices can adversely affect a financial institution’s earnings or capital. For most financial institutions, including S&T, market risk primarily reflects exposures to changes in interest rates. Interest rate fluctuations affect earnings by changing net interest income and other interest-sensitive income and expense levels. Interest rate changes affect capital by changing the net present value of a bank’s future cash flows, and the cash flows themselves, as rates change. Accepting this risk is a normal part of banking and can be an important source of profitability and shareholder value. However, excessive interest rate risk can threaten banks’ earnings, capital, liquidity and solvency. Our sensitivity to changes in interest rate movements are continually monitored by the ALCO. ALCO monitors and manages market risk through rate shock analyses, economic value of equity, or EVE analysis and simulations in order to avoid unacceptable earnings and market value fluctuations due to changes in interest rates.

Rate shock analyses are performed on a static balance sheet to estimate the effect that specific interest rate changes would have on 12 months of pre-tax net interest income. Rate shock analyses assume an immediate parallel shift in market interest rates. Assumptions are modified in the decreasing rate shock analyses due to the very low level of interest rates. Rate shock analyses also incorporate management assumptions regarding the level of interest rate changes on non-maturity deposit products (noninterest-bearing demand, interest-bearing demand, money market and savings) and changes in the prepayment behavior of fixed rate loans and securities with optionality. S&T policy guidelines limit the change in pre-tax net interest income over a 12 month horizon using rate shocks of +/- 300 basis points. Policy guidelines define the percent change in pre-tax net interest income by graduated risk tolerance levels of minimal, moderate and high. The table below reflects the rate shock analyses results, which are in the minimal risk tolerance level.

In order to monitor interest rate risk beyond the 12 month time horizon of rate shocks, we also perform EVE analysis. EVE represents the present value of all asset cash flows minus the present value of all liability cash flows. As with rate shock analysis, EVE incorporates management assumptions regarding prepayment behavior of fixed rate loans and securities with optionality and core deposit behavior and value. S&T policy guidelines limit the change in EVE given changes in rates of +/- 300 basis points. Policy guidelines define the percent change in EVE by graduated risk tolerance levels of minimal, moderate and high.

The table below reflects the rate shock and EVE results, which are in the minimal risk tolerance level.

	December 31, 2012						December 31, 2011
Change in Interest Rate (basis points)	% Change in Pretax Net Interest Income			% Change in Economic Value of Equity			% Change in Pretax Net Interest Income			% Change in Economic Value of Equity
+300		8.2			23.2			11.3			20.9
+200		5.0			16.8			7.3			15.9
+100		2.0			9.1			3.5			9.1
-100		(2.4	)		(9.7	)		(3.9	)		(12.9	)
-200		(5.1	)		(7.5	)		(6.9	)		(15.2	)
-300		(6.7	)		(6.8	)		(8.9	)		(15.1	)

In addition to rate shocks and EVE, simulations are performed periodically to assess the sensitivity of scenario assumptions on pre-tax net interest income. Simulation analyses most often test for sensitivity to yield curve shape and slope changes, severe rate shocks, changes in prepayment assumptions and significant balance mix changes.

The results from the rate shock and EVE analyses are consistent with having an asset sensitive balance sheet. Having an asset sensitive balance sheet means more assets than liabilities will reprice during the measured time frames. The implications of an asset sensitive balance sheet will differ

61

Item 7A.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK — continued

depending upon the change in market interest rates. For example, with an asset sensitive balance sheet in a declining interest rate environment, more assets than liabilities will decrease in rate. This situation could result in a decrease in net interest income and operating income. Conversely, with an asset sensitive balance sheet in a rising interest rate environment, more assets than liabilities will increase in rate. This situation could result in an increase in net interest income and operating income. When comparing the results of December 31, 2012 to December 31, 2011 the percent changes are a result of the balance sheet becoming less asset sensitive. The Consolidated Balance Sheet became less asset sensitive during 2012 mainly as a result of slower prepayment behavior of fixed rate loans and customer preference for short term deposit products.

62

Item 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Consolidated Financial Statements

Consolidated Balance Sheets	64
Consolidated Statements of Net Income	65
Consolidated Statements of Comprehensive Income	66
Consolidated Statements of Changes in Shareholders’ Equity	67
Consolidated Statements of Cash Flows	68
Notes to Consolidated Financial Statements	69
Report of KPMG LLP, Independent Registered Public Accounting Firm on Effectiveness of Internal Control Over Financial Reporting	127
Report of KPMG LLP, Independent Registered Public Accounting Firm on Consolidated Financial Statements	128

63

CONSOLIDATED BALANCE SHEETS

S&T Bancorp, Inc. and Subsidiaries

	December 31,
(in thousands, except share and per share data)	2012			2011
ASSETS
Cash and due from banks, including interest-bearing deposits of $257,116 and $208,854 at December 31, 2012 and 2011, respectively	$	337,711		$	270,526
Securities available-for-sale, at fair value		453,096			357,596
Loans held for sale		22,499			2,850
Portfolio loans, net of unearned income of $216 and $715 at December 31, 2012 and 2011, respectively		3,346,622			3,129,759
Allowance for loan losses		(46,484	)		(48,841	)
Portfolio loans, net		3,300,138			3,080,918
Bank owned life insurance		58,619			56,755
Premises and equipment, net		38,676			37,755
Federal Home Loan Bank stock, at cost		14,485			18,216
Goodwill		175,733			165,273
Other intangibles, net		5,350			5,728
Other assets		120,395			124,377
Total Assets	$	4,526,702		$	4,119,994
LIABILITIES
Deposits:
Noninterest-bearing demand	$	960,980		$	818,686
Interest-bearing demand		316,760			283,611
Money market		361,233			278,092
Savings		965,571			802,942
Certificates of deposit		1,033,884			1,152,528
Total Deposits		3,638,428			3,335,859
Securities sold under repurchase agreements		62,582			30,370
Short-term borrowings		75,000			75,000
Long-term borrowings		34,101			31,874
Junior subordinated debt securities		90,619			90,619
Other liabilities		88,550			65,746
Total Liabilities		3,989,280			3,629,468
SHAREHOLDERS’ EQUITY
Common stock ($2.50 par value) Authorized—50,000,000 shares Issued—31,197,365 shares and 29,714,038 shares at December 31, 2012 and 2011, respectively Outstanding—29,732,209 shares and 28,131,249 shares at December 31, 2012 and 2011, respectively		77,993			74,285
Additional paid-in capital		77,458			52,637
Retained earnings		436,039			421,468
Accumulated other comprehensive loss		(13,582	)		(14,108	)
Treasury stock (1,465,156 shares and 1,582,789 shares, at December 31, 2012 and 2011, respectively, at cost)		(40,486	)		(43,756	)
Total Shareholders’ Equity		537,422			490,526
Total Liabilities and Shareholders’ Equity	$	4,526,702		$	4,119,994

See Notes to Consolidated Financial Statements

64

CONSOLIDATED STATEMENTS OF NET INCOME

S&T Bancorp, Inc. and Subsidiaries

	Years ended December 31,
(in thousands, except per share data)	2012		2011			2010
INTEREST INCOME
Loans, including fees	$	145,181	$	154,121		$	169,404
Investment Securities:
Taxable		7,544		8,169			7,685
Tax-exempt		3,121		2,347			2,830
Dividends		405		442			500
Total Interest Income		156,251		165,079			180,419
INTEREST EXPENSE
Deposits		16,796		22,952			28,717
Borrowings and junior subordinated debt securities		4,228		4,781			5,856
Total Interest Expense		21,024		27,733			34,573
NET INTEREST INCOME		135,227		137,346			145,846
Provision for loan losses		22,815		15,609			29,511
Net Interest Income After Provision for Loan Losses		112,412		121,737			116,335
NONINTEREST INCOME
Debit and credit card fees		11,134		10,889			9,954
Service charges on deposit accounts		9,992		9,978			11,178
Wealth management fees		9,808		8,180			7,808
Insurance fees		8,448		8,314			8,312
Securities gains (losses), net		3,016		(124	)		274
Mortgage banking		2,878		1,199			3,403
Other		6,636		5,621			6,281
Total Noninterest Income		51,912		44,057			47,210
NONINTEREST EXPENSE
Salaries and employee benefits		60,256		51,078			48,715
Data processing		9,620		6,853			6,145
Net occupancy		7,605		6,943			6,928
Professional services and legal		5,659		5,437			6,889
Furniture and equipment		5,262		4,941			5,054
Marketing		3,302		3,019			2,795
Other taxes		3,200		3,381			3,432
FDIC assessment		2,926		3,570			5,426
Other		25,033		18,686			20,249
Total Noninterest Expense		122,863		103,908			105,633
Income Before Taxes		41,461		61,886			57,912
Provision for income taxes		7,261		14,622			14,432
Net Income		34,200		47,264			43,480
Preferred stock dividends and discount amortization		—		7,611			6,201
Net Income Available to Common Shareholders	$	34,200	$	39,653		$	37,279
Earnings per common share—basic	$	1.18	$	1.41		$	1.34
Earnings per common share—diluted		1.18		1.41			1.34
Dividends declared per common share		0.60		0.60			0.60

See Notes to Consolidated Financial Statements

65

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

S&T Bancorp, Inc. and Subsidiaries

	Years ended December 31,
(in thousands)	2012			2011			2010
Net Income	$	34,200		$	47,264		$	43,480
Other Comprehensive Income (Loss), Before Tax and Net of Reclassifications into Net Income:
Change in unrealized gains on securities available-for-sale		4,097			6,702			695
Reclassification adjustment for net (gains) losses on securities available-for-sale included in net income		(3,016	)		124			(274	)
Adjustment to funded status of employee benefit plans		(271	)		(18,787	)		(606	)
Other Comprehensive Income (Loss), Before Tax and Net of Reclassifications into Net Income		810			(11,961	)		(185	)
Income tax (expense) benefit related to items of other comprehensive income		(284	)		4,187			65
Other Comprehensive Income (Loss), After Tax and Net of Reclassifications into Net Income		526			(7,774	)		(120	)
Comprehensive Income	$	34,726		$	39,490		$	43,360

See Notes to Consolidated Financial Statements

66

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

S&T Bancorp, Inc. and Subsidiaries

(thousands, except share and per share data)	Preferred Stock			Common Stock		Additional Paid-in Capital			Retained Earnings			Accumulated Other Comprehensive Income (Loss)			Treasury Stock			Total
Balance at December 31, 2009	$	105,370		$	74,285	$	51,158		$	383,118		$	(6,214	)	$	(54,399	)	$	553,318
Net income for 2010										43,480									43,480
Other comprehensive income (loss), net of tax													(120	)					(120	)
Preferred stock dividends and discount amortization		767								(6,201	)								(5,434	)
Cash dividends declared ($0.60 per share)										(16,683	)								(16,683	)
Treasury stock issued (205,135 shares)										(1,980	)					5,672			3,692
Recognition of restricted stock compensation expense							470												470
Tax benefit from stock-based compensation							46												46
Forfeitures of nonstatutory stock options (11,000 shares)							(104	)											(104	)
Balance at December 31, 2010	$	106,137		$	74,285	$	51,570		$	401,734		$	(6,334	)	$	(48,727	)	$	578,665
Net income for 2011										47,264									47,264
Other comprehensive income (loss), net of tax													(7,774	)					(7,774	)
Redemption of preferred stock		(108,676	)																(108,676	)
Preferred stock dividends and discount amortization		2,539								(7,611	)								(5,072	)
Cash dividends declared ($0.60 per share)										(16,830	)								(16,830	)
Treasury stock issued (182,507 shares, net)										(3,089	)					4,971			1,882
Recognition of restricted stock compensation expense							1,133												1,133
Tax expense from stock-based compensation							(66	)											(66	)
Balance at December 31, 2011	$	—		$	74,285	$	52,637		$	421,468		$	(14,108	)	$	(43,756	)	$	490,526
Net income for 2012										34,200									34,200
Other comprehensive income (loss), net of tax													526						526
Cash dividends declared ($0.60 per share)										(17,357	)								(17,357	)
Common stock issued in acquisition (1,483,327 shares)					3,708		23,902												27,610
Treasury stock issued (117,633 shares, net)										(2,272	)					3,270			998
Recognition of restricted stock compensation expense							949												949
Tax expense from stock-based compensation							(30	)											(30	)
Balance at December 31, 2012	$	—		$	77,993	$	77,458		$	436,039		$	(13,582	)	$	(40,486	)	$	537,422

See Notes to Consolidated Financial Statements

67

CONSOLIDATED STATEMENTS OF CASH FLOWS

S&T Bancorp, Inc. and Subsidiaries

	Years Ended December 31,
(in thousands)	2012			2011			2010
OPERATING ACTIVITIES
Net Income	$	34,200		$	47,264		$	43,480
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		22,815			15,609			29,511
Provision for unfunded loan commitments		1,811			(1,474	)		(1,555	)
Depreciation and amortization		7,000			6,323			6,587
Net amortization of discounts and premiums		2,280			1,191			881
Stock-based compensation expense		913			960			513
Securities (gains) losses, net		(3,016	)		124			(274	)
Deferred income taxes		1,038			2,448			(4,537	)
Tax expense (benefit) from stock-based compensation		30			66			(46	)
Mortgage loans originated for sale		(104,924	)		(68,261	)		(121,883	)
Proceeds from the sale of loans		86,886			74,780			119,617
Gain on the sale of loans, net		(1,612	)		(875	)		(1,809	)
Net decrease in interest receivable		973			589			2,752
Net decrease in interest payable		(1,376	)		(443	)		(1,678	)
Net decrease (increase) in other assets		18,815			4,132			(2,745	)
Net increase (decrease) increase in other liabilities		18,057			(8,531	)		20,170
Net Cash Provided by Operating Activities		83,890			73,902			88,984
INVESTING ACTIVITIES
Purchases of securities available-for-sale		(166,786	)		(135,447	)		(82,890	)
Proceeds from maturities, prepayments and calls of securities available-for-sale		87,604			71,318			146,960
Proceeds from sales of securities available-for-sale		66,575			70			2,579
Proceeds from the redemption of Federal Home Loan Bank stock		5,700			4,149			1,177
Net (increase) decrease in loans		(21,892	)		185,182			3,236
Proceeds from the sale of loans not originated for resale		3,874			8,595			—
Purchases of premises and equipment		(2,179	)		(2,531	)		(3,469	)
Proceeds from the sale of premises and equipment		142			404			60
Net cash acquired from bank acquisitions		18,639			—			—
Net Cash (Used in) Provided by Investing Activities		(8,323	)		131,740			67,653
FINANCING ACTIVITIES
Net increase in core deposits		207,653			105,776			63,383
Net decrease in certificates of deposit		(217,311	)		(87,553	)		(50,536	)
Net increase (decrease) in securities sold under repurchase agreements and federal funds purchased		28,442			(10,283	)		(4,281	)
Net (decrease) increase in short-term borrowings		—			75,000			(51,300	)
Proceeds from long-term borrowings		4,311			4,192			9,241
Repayments of long-term borrowings		(15,088	)		(1,682	)		(65,770	)
Redemption of preferred stock		—			(108,676	)		—
Purchase of treasury shares		(49	)		(64	)		—
Sale of treasury shares		1,047			1,946			3,692
Preferred stock dividends		—			(5,072	)		(5,434	)
Cash dividends paid to common shareholders		(17,357	)		(16,830	)		(16,683	)
Tax (expense) benefit from stock-based compensation		(30	)		(66	)		46
Net Cash Used in Financing Activities		(8,382	)		(43,312	)		(117,642	)
Net increase in cash and cash equivalents		67,185			162,330			38,995
Cash and cash equivalents at beginning of year		270,526			108,196			69,201
Cash and Cash Equivalents at End of Year	$	337,711		$	270,526		$	108,196
Supplemental Disclosures
Interest paid	$	22,329		$	27,733		$	36,251
Income taxes paid, net of refunds		4,063			15,100			14,818
Loans transferred to held for sale		19,255			8,753			—
Net assets (liabilities) from acquisitions, excluding cash and cash equivalents		(683	)		—			—
Transfers to other real estate owned and other repossessed assets		1,915			8,472			11,308

See Notes to Consolidated Financial Statements

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

S&T Bancorp, Inc. and Subsidiaries

NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

S&T Bancorp, Inc., or S&T, was incorporated on March 17, 1983 under the laws of the Commonwealth of Pennsylvania as a bank holding company and has three wholly owned subsidiaries, S&T Bank, 9th Street Holdings, Inc. and STBA Capital Trust I. We own a one-half interest in Commonwealth Trust Credit Life Insurance Company, or CTCLIC.

We are presently engaged in nonbanking activities through the following five entities: 9th Street Holdings, Inc.; S&T Bancholdings, Inc.; CTCLIC; S&T Insurance Group, LLC and Stewart Capital Advisors, LLC. 9th Street Holdings, Inc. and S&T Bancholdings, Inc. are investment holding companies. CTCLIC, which is a joint venture with another financial institution, acts as a reinsurer of credit life, accident and health insurance policies sold by S&T Bank and the other institution. S&T Insurance Group, LLC, through its subsidiaries, offers a variety of insurance products. Stewart Capital Advisors, LLC is a registered investment advisor that manages private investment accounts for individuals and institutions and advises the Stewart Capital Mid Cap Fund.

On March 9, 2012, we completed the acquisition and conversion of Mainline Bancorp, Inc., or Mainline, a bank holding company based in Ebensburg, Pennsylvania. Mainline had one subsidiary, Mainline National Bank, with eight branches and $129.5 million in loans and $206.0 million in deposits. The acquisition expanded our market share and footprint throughout Cambria and Blair counties of Western Pennsylvania. The total acquisition cost of Mainline was $27.8 million.

On August 13, 2012, we completed the acquisition of Gateway Bank of Pennsylvania, a bank with $99.1 million in loans and $105.4 million in deposits, headquartered in McMurray, Pennsylvania. The total acquisition cost of Gateway Bank was $19.8 million. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T, with all transactions since the acquisition date consolidated in our financial statements. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank.

Accounting Policies

Our financial statements have been prepared in accordance with U. S. generally accepted accounting principles, or GAAP. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the dates of the balance sheets and revenues and expenses for the periods then ended. Actual results could differ from those estimates. Our significant accounting policies are described below.

Principals of Consolidation

The Consolidated Financial Statements include the accounts of 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.

Reclassification

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

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NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES — continued

Business Combinations

We account for business combinations using the acquisition method of accounting. Under this method of accounting, the acquired company’s net assets are recorded at fair value at the date of acquisition, and the results of operations of the acquired company are combined with our results from that date forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identified intangibles) is recorded as goodwill.

Fair Value Measurements

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.

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.

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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. 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. Trading assets are recorded in other assets in the Consolidated Balance Sheets.

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.

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

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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. If the carrying value of MSRs exceeds fair value, they are considered impaired. As the valuation model includes significant unobservable inputs, 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. 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.

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NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES — continued

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 discounted cash flow analyses, utilizing interest rates currently being offered for loans with similar terms, 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.

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.

Junior Subordinated Debt Securities

The variable rate junior subordinated debt securities reprice quarterly and fair values are based on 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.

Cash and Cash Equivalents

We consider cash and due from banks, interest-bearing deposits with banks and federal funds sold as cash and cash equivalents.

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Securities

We determine the appropriate classification of securities at the time of purchase. All securities, including both debt and equity securities, are classified as available-for-sale. These are securities that we intend to hold for an indefinite period of time, but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Such securities are carried at fair value with net unrealized gains and losses deemed to be temporary, reported as a component of other comprehensive income, net of tax. Realized gains and losses on the sale of available-for-sale securities and other-than-temporary impairment, or OTTI, charges are recorded within noninterest income in the Consolidated Statements of Net Income. Realized gains and losses on the sale of securities are determined using the specific-identification method. Bond premiums are amortized to the call date and bond discounts are accreted to the maturity date, both on a level yield basis.

We perform a quarterly review of our securities to identify those that may indicate an OTTI. Our policy for OTTI within the marketable equity securities portfolio generally requires an impairment charge when the security is in a loss position for 12 consecutive months, unless facts and circumstances would suggest the need for an OTTI prior to that time. Our policy for OTTI within the debt securities portfolio is based upon a number of factors, including but not limited to, the length of time and extent to which the estimated fair value has been less than cost, the financial condition of the underlying issuer, the ability of the issuer to meet contractual obligations, the best estimate of impairment charge representing credit losses, the likelihood of the security’s ability to recover any decline in its estimated fair value and whether management intends to sell the security or if it is more likely than not that management will be required to sell the investment security prior to the security’s recovery.

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. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a charge-off against the allowance for loan loss, or ALL. Subsequent declines in fair value are recognized as a charge to noninterest income. When a loan is placed in the held-for-sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold. Gains and losses on sales of loans held for sale are included in other noninterest income in the Consolidated Statements of Net Income.

Loans

Loans are reported at the principal amount outstanding net of unearned income, unamortized premiums or discounts and deferred origination fees and costs. We defer certain nonrefundable loan origination and commitment fees. Accretion of discounts and amortization of premiums on loans are included in interest income in the Consolidated Statements of Net Income. Loan origination fees and direct loan origination costs are deferred and amortized as an adjustment of loan yield over the respective lives of the loans without consideration of anticipated prepayments. If a loan is paid off, the remaining unaccreted or unamortized net origination fees and costs are immediately recognized into income or expense. Interest is accrued on loans as earned. Interest income is recognized on loans as earned.

Closed-end installment loans, amortizing loans secured by real estate and any other loans with payments scheduled monthly are reported past due when the borrower is in arrears two or more monthly payments. Other multi-payment obligations with payments scheduled other than monthly are reported past due when one scheduled payment is due and unpaid for 30 days or more.

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Generally, consumer loans are charged off against the ALL upon the loan reaching 90 days past due. Commercial loans are charged off as management becomes aware of facts and circumstances that raise doubt as to the collectability of all or a portion of the principal and when we believe a confirmed loss exists.

Nonaccrual Loans

We stop accruing interest on a loan (nonaccrual loan) when the borrower’s payment is 90 days past due. Loans are also placed on nonaccrual status when payment is not past due, but we have doubt about the borrower’s ability to comply with existing repayment terms. When the interest accrual is discontinued, all unpaid accrued interest is reversed against interest income. Interest income is recognized on nonaccrual loans on a cash basis if recovery of the remaining principal is reasonably assured. As a general rule, a nonaccrual loan may be restored to accrual status when its principal and interest is paid current and the bank expects repayment of the remaining contractual principal and interest, or when the loan otherwise becomes well secured and in the process of collection.

Allowance for Loan Losses

The ALL reflects our estimates of probable losses inherent in the loan portfolio at the balance sheet date. The methodology for determining the ALL has two main components: evaluation and impairment tests of individual loans and evaluation and impairment tests of certain groups of homogeneous loans with similar risk characteristics.

A loan is considered impaired when it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. All troubled debt restructurings, or TDRs, are considered to be impaired loans and will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. For all TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate. Specific reserves are established based upon 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 estimated fair value of the collateral if the loan is collateral dependent. Our impairment evaluations consist primarily of the fair value of collateral method since most loans are collateral dependent. Collateral values are discounted to consider disposition costs when appropriate. A specific reserve is established or a charge-off is taken if the fair value of the impaired loan is less than the recorded investment in the loan balance.

The ALL for homogeneous loans is calculated using a systematic methodology that is applied on a quarterly basis. The ALL model is comprised of five distinct portfolio segments: 1) Commercial Real Estate, or CRE, 2) Commercial and Industrial, or C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. Each segment has a distinct set of risk characteristics monitored by management. We further assess and monitor risk and performance at a more disaggregated level which includes our internal risk rating system for the commercial segments and collateral position and loan-to-value, or LTV, for the consumer segments.

Historical loss rate calculations are performed whereby past losses from each pool of loans are aggregated over the respective loss emergence period. The loss emergence period is defined as the average time between the occurrence of a credit event (deterioration in the borrower’s financial condition) and the confirmation of a loss. Currently, we have estimated the loss emergence period to

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be two years for CRE loans and one year for all other loan classes. We use a one year look back period that results, when considering our loss emergence periods, in capturing historic losses for three years for CRE and two years for our other portfolio segments. These historic loss calculations are then aggregated and applied to each loan segment to determine the component of the ALL based upon historic losses. Since the losses captured in the historical loss analysis may not accurately represent the losses inherent in the loan portfolio at the balance sheet date, qualitative adjustments are then applied to loan segments to determine the total ALL. Qualitative adjustments are aggregated into five categories, including process, economic conditions, loan portfolio, asset quality and other external factors.

Within the five aforementioned categories, the following qualitative factors are considered:

1) Changes in our lending policies and procedures, including underwriting standards, collection, charge-off and recovery practices not considered elsewhere in estimating credit losses;

2) Changes in national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments;

3) Changes in the nature and volume of our loan portfolio and terms of loans;

4) Changes in the experience, ability and depth of our lending management and staff;

5) Changes in the volume and severity of past due loans, the volume of non accrual loans, and the volume and severity of adversely classified or graded loans;

6) Changes in the quality of our loan review system;

7) Changes in the value of the underlying collateral for collateral-dependent loans;

8) The existence and effect of any concentrations of credit and changes in the level of such concentrations; and

9) The effect of external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in our current loan portfolio.

Bank Owned Life Insurance

We have purchased life insurance policies on certain executive officers and employees. We receive the cash surrender value of each policy upon its termination or benefits are payable upon the death of the insured. Changes in net cash surrender value are recognized in noninterest income or expense in the Consolidated Statements of Net Income.

Premises and Equipment

Premises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation. Maintenance and repairs are charged to expense as incurred, while improvements that extend an asset’s useful life are capitalized and depreciated over the estimated remaining life of the asset. Depreciation expense is computed generally by the straight-line method for financial reporting purposes and accelerated methods for income tax purposes. Leasehold improvements are amortized over the shorter of the asset’s useful life or the remaining lease term, including renewal periods when reasonably assured.

Restricted Investment in Bank Stock

Federal Home Loan Bank, or FHLB, stock is carried at cost and evaluated for impairment based on the ultimate recoverability of the par value. We hold FHLB stock because we are a member of the FHLB of Pittsburgh. The FHLB requires members to purchase and hold a specified level of FHLB stock based upon on the members asset value, level of borrowings and participation in other programs offered. Stock in the FHLB is non-marketable and is redeemable at the discretion of the FHLB. Members do not purchase stock in the FHLB for the same reasons that traditional equity investors acquire stock in an investor-owned enterprise. Rather, members purchase stock to obtain access to

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the low-cost products and services offered by the FHLB. Unlike equity securities of traditional for-profit enterprises, the stock of the FHLB does not provide its holders with an opportunity for capital appreciation because, by regulation, FHLB stock can only be purchased, redeemed and transferred at par value. Both cash and stock dividends are reported as income in taxable investment securities in the Consolidated Statements of Net Income.

On February 22, 2012, the FHLB of Pittsburgh announced that it would pay a dividend on the average capital stock balance held during the three month period ended December 31, 2011 at an annualized rate of 0.10% for the first time since late 2008. The FHLB noted future dividend payments and capital stock repurchases will continue to be reviewed on a quarterly basis. We had $5.7 million of redemptions from the FHLB throughout 2012. We reviewed and evaluated the FHLB capital stock for OTTI at December 31, 2012. Based upon our review of the FHLB’s current financial position, they reported improved earnings throughout 2012 compared to 2011 and continue to exceed all capital ratios required. Additionally, we considered that the FHLB began paying dividends and redeeming excess stock during 2012. Accordingly, we believe sufficient evidence exists to conclude that no OTTI exists at December 31, 2012.

Goodwill and Other Intangible Assets

We have three reporting units: Community Banking, Wealth Management and Insurance. At December 31, 2012, we had goodwill of $175.7 million, including $171.5 million in Community Banking, representing 98 percent of total goodwill and $4.2 million in Insurance, representing two percent of total goodwill. The carrying value of goodwill is tested annually for impairment each October 1 or more frequently if it is determined that we should do so. We first assess qualitatively whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Our qualitative assessment considers such factors as macroeconomic conditions, market conditions specifically related to the banking industry, our overall financial performance and various other factors. If we determine that it is more likely than not that the fair value is less than the carrying amount, we proceed to test for impairment. The evaluation for impairment involves comparing the current estimated fair value of each reporting unit to its carrying value, including goodwill. If the current estimated fair value of a reporting unit exceeds its carrying value, no additional testing is required and impairment loss is not recorded. If the estimated fair value of a reporting unit is less than the carrying value, further valuation procedures are performed and could result in impairment of goodwill being recorded. Further valuation procedures would include allocating the estimated fair value to all assets and liabilities of the reporting unit to determine an implied goodwill value. If the implied value of goodwill of a reporting unit is less than the carrying amount of that goodwill, an impairment loss is recognized in an amount equal to that excess.

We have core deposit and other intangible assets resulting from acquisitions which are subject to amortization. We determine the amount of identifiable intangible assets based upon independent core deposit and insurance contract analyses at the time of the acquisition. Intangible assets with finite useful lives are evaluated for impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. No events or changes in circumstances that would indicate that the carrying amount of any identifiable intangible assets may not be recoverable had occurred during the years ended December 31, 2012, 2011 and 2010.

Joint Ventures

We have made investments directly in Low Income Housing Tax Credit, or LIHTC, partnerships formed with third parties. As a limited partner in these operating partnerships, we receive tax credits and tax deductions for losses incurred by the underlying properties. These investments are amortized

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over a maximum of 10 years, which represents the period that the tax credits will be utilized. We have determined that we are not the primary beneficiary of these investments because the general partners have the power to direct the activities that most significantly impact the economic performance of the partnership and have the obligation to absorb expected losses and the right to receive benefits.

OREO and Other Repossessed Assets

OREO and other repossessed assets are included in other assets in the Consolidated Balance Sheets and are comprised of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of a foreclosure. At the time of foreclosure, these properties are recorded at the lower of the recorded investment in the loan or fair value less cost to sell. Loan losses arising from the acquisition of such property initially are charged against the ALL. Subsequently, these assets are carried at the lower of carrying value or current fair value less cost to sell. Gains or losses realized subsequent to acquisition are recorded in other expenses in the Consolidated Statements of Net Income.

Mortgage Servicing Rights

MSRs are recognized as separate assets when commitments to fund a loan to be sold are made. Upon commitment, the MSR is established, which represents the then current estimated fair value of future net cash flows expected to be realized for performing the servicing activities. The estimated fair value of the MSRs is estimated 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. Increases in mortgage loan prepayments reduce estimated future net servicing cash flows because the life of the underlying loan is reduced. In determining the estimated fair value of MSRs, mortgage interest rates, which are used to determine prepayment rates, are held constant over the estimated life of the portfolio. MSRs are reported in other assets in the Consolidated Balance Sheets and are amortized into noninterest income in the Consolidated Statements of Net Income in proportion to, and over the period of, the estimated future net servicing income of the underlying mortgage loans.

MSRs are regularly evaluated for impairment based on the estimated fair value of those rights. The MSRs are stratified by certain risk characteristics, primarily loan term and note rate. If temporary impairment exists within a risk stratification tranche, a valuation allowance is established through a charge to income equal to the amount by which the carrying value exceeds the estimated fair value. If it is later determined all or a portion of the temporary impairment no longer exists for a particular tranche, the valuation allowance is reduced.

MSRs are also reviewed for OTTI. OTTI exists when the recoverability of a recorded valuation allowance is determined to be remote, taking into consideration historical and projected interest rates and loan pay-off activity. When this situation occurs, the unrecoverable portion of the valuation allowance is applied as a direct write-down to the carrying value of the MSR. Unlike a valuation allowance, a direct write-down permanently reduces the carrying value of the MSR and the valuation allowance, precluding subsequent recoveries.

Derivative Financial Instruments

Interest Rate Swaps

In accordance with applicable accounting guidance for derivatives and hedging, all derivatives are recognized as either assets or liabilities on the balance sheet at fair value. Interest rate swaps are contracts in which a series of interest rate flows (fixed and variable) are exchanged over a prescribed period. The notional amounts on which the interest payments are based are not exchanged. We

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NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES — continued

utilize interest rate swaps for commercial loans. These derivative positions relate to transactions in which we enter into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a same notional amount at a fixed rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate loan with us receiving a variable yield. These agreements could have floors or caps on the contracted interest rates.

Pursuant to our agreements with various financial institutions, we may receive collateral or may be required to post collateral based upon mark-to-market positions. Beyond unsecured threshold levels, collateral in the form of cash or securities may be made available to counterparties of interest rate swap transactions. Based upon our current positions and related future collateral requirements relating to them, we believe any effect on our cash flow or liquidity position to be immaterial. Derivatives contain an element of credit risk, the possibility that we will incur a loss because a counterparty, which may be a financial institution or a customer, fails to meet its contractual obligations. All derivative contracts with financial institutions may be executed only with counterparties approved by our Asset and Liability Committee, or ALCO, and derivatives with customers may only be executed with customers within credit exposure limits approved by our Senior Loan Committee. Interest rate swaps are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives are recorded in current earnings and included in other noninterest income in the Consolidated Statements of Net Income.

Interest Rate Lock Commitments and Forward Sale Contracts

In the normal course of business, we sell originated mortgage loans into the secondary mortgage loan market. We also offer interest rate lock commitments to potential borrowers. The commitments are generally for 60 days and guarantee a specified interest rate for a loan if underwriting standards are met, but the commitment does not obligate the potential borrower to close on the loan. Accordingly, some commitments expire prior to becoming loans. We can encounter pricing risks if interest rates increase significantly before the loan can be closed and sold. We may utilize forward sale contracts in order to mitigate this pricing risk. Whenever a customer desires these products, a mortgage originator quotes a secondary market rate guaranteed for that day by the investor. The rate lock is executed between the mortgagee and us and in turn a forward sale contract may be executed between us and the investor. Both the rate lock commitment and the corresponding forward sale contract for each customer are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives during the commitment period are recorded in current earnings and included in mortgage banking in the Consolidated Statements of Net Income.

Allowance for Unfunded Commitments

In the normal course of business, we offer off-balance sheet credit arrangements to enable our customers to meet their financing objectives. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. Our exposure to credit loss, in the event the customer does not satisfy the terms of the agreement, equals the contractual amount of the obligation less the value of any collateral. We apply the same credit policies in making commitments and standby letters of credit that are used for the underwriting of loans to customers. Commitments generally have fixed expiration dates, annual renewals or other termination clauses and may require payment of a fee. Since many of the commitments are expected

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to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The allowance for unfunded commitments is included in other liabilities in the Consolidated Balance Sheets. The allowance for unfunded commitments is determined using a similar methodology as our ALL. The reserve is calculated by applying historical loss rates from our ALL model to the estimated future utilization of our unfunded commitments.

Treasury Stock

The repurchase of our common stock is recorded at cost. At the time of reissuance, the treasury stock account is reduced using the average cost method. Gains and losses on the reissuance of common stock are recorded in additional paid-in capital, to the extent additional paid-in capital from previous treasury share transactions exists. Any deficiency is charged to retained earnings.

Wealth Management Fees

Assets held in a fiduciary capacity by the subsidiary bank, S&T Bank, are not our assets and are therefore not included in our Consolidated Financial Statements. Wealth management fee income is reported in the Consolidated Statements of Net Income on the accrual basis.

Stock-Based Compensation

Stock-based compensation may include stock options and restricted stock which is measured using the fair value method of accounting. The grant date fair value is recognized over the period during which the recipient is required to provide service in exchange for the award. Stock option expense is determined utilizing the Black-Scholes model. Restricted stock expense is determined using the grant date fair value. We estimate expected forfeitures when stock-based awards are granted and record compensation expense only for awards that are expected to vest.

Pensions

Pension expense for S&T Bank’s defined benefit pension plan is actuarially determined using the projected unit credit actuarial cost method. The funding policy for the plan is to contribute amounts to the plan sufficient to meet the minimum funding requirements of the Employee Retirement Income Security Act of 1974, or ERISA, plus such additional amounts as may be appropriate, subject to federal income tax limitation.

Marketing Costs

We expense all marketing-related costs, including advertising costs, as incurred.

Income Taxes

We estimate income tax expense based on amounts expected to be owed to the tax jurisdictions where we conduct business. On a quarterly basis, management assesses the reasonableness of our effective tax rate based upon our current estimate of the amount and components of net income, tax credits and the applicable statutory tax rates expected for the full year.

Deferred income tax assets and liabilities are determined using the asset and liability method and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax basis of assets and liabilities and recognizes enacted changes in tax rate and laws. When deferred tax assets are recognized, they are subject to a valuation allowance based on management’s judgment as to whether realization is more likely than not.

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NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES — continued

Accrued taxes represent the net estimated amount due to taxing jurisdictions and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. We evaluate and assess the relative risks and appropriate tax treatment of transactions and filing positions after considering statutes, regulations, judicial precedent and other information and maintain tax accruals consistent with the evaluation of these relative risks and merits. Changes to the estimate of accrued taxes occur periodically due to changes in tax rates, interpretations of tax laws, the status of examinations being conducted by taxing authorities and changes to statutory, judicial and regulatory guidance. These changes, when they occur, can affect deferred taxes and accrued taxes, as well as the current period’s income tax expense and can be significant to our operating results.

Tax positions are recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

Earnings Per Share

Basic earnings per share, or EPS, is calculated using the two-class method to determine income allocated to common shareholders. Unvested share-based payment awards that contain nonforfeitable rights to dividends are considered participating securities under the two-class method. Income allocated to common shareholders is then divided by the weighted average number of common shares outstanding during the period. Potentially dilutive securities are excluded from the basic EPS calculation.

Diluted earnings per share is calculated under the more dilutive of either the treasury stock method or the two-class method. Under the treasury stock method, the weighted average number of common shares outstanding is increased by the potentially dilutive common shares. For the two-class method, diluted earnings per share is calculated for each class of shareholders using the weighted average number of shares attributed to each class. Potentially dilutive common shares are common stock equivalents relating to our outstanding warrants, stock options and restricted stock.

Recently Adopted Accounting Standards Updates

Technical Corrections and Improvements

In October 2012, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2012-04, Technical Corrections and Improvements, which was meant to correct minor technical errors in the codification and to conform terminology and clarify certain guidance in various topics of the codification to fully reflect the fair value measurement and disclosure requirements of Topic 820. Since this includes minor corrections, terminology conformation and guidance clarification only of previously issued accounting guidance, it was adopted at December 31, 2012, and did not have an impact on our results of operations or financial position.

Technical Amendments and Corrections to SEC Sections

In August 2012, the FASB issued ASU No. 2012-03, Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 114, Technical Amendments Pursuant to SEC Release No. 33-9250, and Corrections Related to FASB Accounting Standards Update 2010-22 (SEC Update), which were meant to codify various amendments and corrections included in these previously issued bulletins and releases. Since this is codification only of previously issued accounting guidance, it was adopted at September 30, 2012, and did not have an impact on our results of operations or financial position.

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Presentation of Comprehensive Income

In December 2011, the FASB issued ASU No. 2011-12, which superseded certain pending paragraphs in ASU No. 2011-05, which had been issued in June 2011. ASU No. 2011-05 allowed an entity the option to present the total of comprehensive income, the components of net income and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. Under both options, an entity is required to present each component of net income along with total net income, each component of other comprehensive income along with a total for other comprehensive income and a total amount for comprehensive income. ASU 2011-05 eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity but permits companies to present in the annual period the comprehensive income components in a single continuous statement or two consecutive statements and to present in the interim periods only the total for comprehensive income in a single continuous statement or two consecutive statements. ASU No. 2011-12 effectively defers changes that relate to the presentation of reclassification adjustments out of accumulated other comprehensive income. The amendments will be temporary to allow the FASB time to redeliberate the presentation requirements for reclassifications out of accumulated other comprehensive income for annual and interim financial statements. The two amendments became effective at the same time. These ASUs should be applied retrospectively and were effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2011. We have elected the option of a single continuous statement format for interim periods, and two separate but consecutive statements for annual periods. The adoption of both ASU 2011-05 and 2011-12 impacted only our presentation of comprehensive income and did not have an impact on our results of operations or financial position.

Testing Goodwill for Impairment

In September 2011, the FASB issued ASU No. 2011-08, which permits an entity to make a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount before applying the two-step goodwill impairment test. If an entity concludes it is not more likely than not that its fair value is less than its carrying amount, it need not perform the two-step impairment test. This ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011. Early adoption is permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS

In May 2011, the FASB issued ASU No. 2011-04, which represents the convergence of the FASB’s and the International Accounting Standard Board’s, or IASB, guidance on fair value measurement. ASU 2011-04 reflects the common requirements under U.S. GAAP and international financial reporting standards, or IFRS, for measuring fair value and for disclosing information about fair value measurements, including a consistent meaning for the term “fair value.” The new guidance does not extend the use of fair value but, rather, provides guidance about how fair value should be applied where it is already required or permitted under U.S. GAAP or IFRS. For U.S. GAAP, most of the changes are clarifications of existing guidance or wording changes to align with IFRS 13 Fair Value Measurement. A public company is required to apply the ASU prospectively for interim and annual periods beginning after December 15, 2011. Early adoption is not permitted for a public company. The adoption of this ASU impacted only disclosure requirements and did not have a material impact on our results of operations or financial position.

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NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES — continued

Reconsideration of Effective Control for Repurchase Agreements

In April 2011, the FASB issued ASU No. 2011-03, which is intended to improve financial reporting of repurchase agreements, or repos, and other agreements that both entitle and obligate a transferor to repurchase or redeem financial assets before their maturity. When an entity enters into a typical repo arrangement, it transfers financial assets to a counterparty in exchange for cash with an agreement for the counterparty to return the same or equivalent financial assets for a fixed price in the future. Current guidance prescribes when an entity may or may not recognize a sale upon the transfer of financial assets subject to a repo agreement. That determination is based, in part, on whether the entity has maintained effective control over the transferred financial assets. This ASU improves the accounting for these transactions by removing from the assessment of effective control the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets and focuses the assessment on the transferor’s contractual rights. This guidance is effective for the first interim or annual period beginning on or after December 15, 2011. The guidance should be applied prospectively to transactions or modifications of existing transactions that occur on or after the effective date. Early adoption is not permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Recently Issued Accounting Standards Updates not yet Adopted

Disclosures About Offsetting Assets and Liabilities

In December 2011, the FASB issued ASU, No. 2011-11, in conjunction with the issuance by the IASB, of amendments to Disclosures—Offsetting Financial Assets and Financial Liabilities (Amendments to IFRS 7). The disclosure requirements apply to recognized financial instruments and derivative instruments that are offset or subject to an enforceable master netting arrangement. An entity shall disclose information to enable users of its financial statements to evaluate the effect or potential effect of netting arrangements on its financial position, including the effect or potential effect of rights of setoff associated with recognized assets and recognized liabilities. While both the FASB and the IASB retained the existing offsetting models under U.S. GAAP and IFRS, the new standards require disclosures to allow investors to better compare financial statements prepared under U.S. GAAP with financial statements prepared under IFRS. The new standards are effective for annual periods beginning January 1, 2013, and interim periods within those annual periods. Retrospective application is required. The adoption of this ASU is expected to impact only our disclosure requirements and is not expected to have a material impact on our results of operations or financial position.

NOTE 2. BUSINESS COMBINATIONS

During 2012, we completed two acquisitions, Mainline Bancorp, Inc., or Mainline and Gateway Bank of Pennsylvania, or Gateway. Goodwill was calculated as the excess of the consideration exchanged over the net identifiable assets acquired from each acquisition and will not be deductible for tax purposes. Goodwill from both acquisitions was assigned to our Community Banking segment.

On March 9, 2012, we acquired 100 percent of the voting shares of Mainline, located in Ebensburg, Pennsylvania, which was the holding company and sole shareholder of Mainline National Bank. The acquisition expanded our market share and footprint throughout Cambria and Blair Counties of Western Pennsylvania. Mainline shareholders were entitled to elect to receive for each share of Mainline common stock either $69.00 in cash or 3.6316 shares of S&T common stock. We also purchased Mainline’s preferred stock issued under the U.S. Treasury Capital Purchase Program, or CPP, for $4.7 million on March 9, 2012. The preferred stock was purchased and retired as part of the merger transaction. Purchase accounting guidance allows for a reasonable period of time following an acquisition for the acquirer to obtain the information necessary to complete the accounting for a

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NOTE 2. BUSINESS COMBINATIONS — continued

business combination. This period, known as the measurement period, shall not exceed one year from the acquisition date. The measurement period for the Mainline acquisition ends March 9, 2013. Based on new information received about facts and circumstances that existed as of the acquisition date one measurement period adjustment for $0.5 million was recorded relating to a contingent liability for an IRS proposed penalty for tax year 2010. Cash paid to former Mainline shareholders was $8.2 million and the fair value of common shares issued was $14.8 million. As of December 31, 2012, S&T recognized Goodwill of $6.7 million from the Mainline acquisition.

On August 13, 2012, we acquired 100 percent of the voting shares of Gateway, located in McMurray, Pennsylvania. The acquisition expanded our market share and footprint into Washington and Butler counties in Pennsylvania. Gateway shareholders were entitled to receive $3.08 in cash and 0.4657 shares of S&T common stock in exchange for one share of Gateway common stock. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank. Cash paid to former Gateway shareholders was $5.2 million and the fair value of common shares issued was $13.3 million. We also settled outstanding equity awards for $1.0 million. As of December 31, 2012, S&T recognized Goodwill of $3.8 million from the Gateway acquisition.

The following table summarizes total consideration paid, assets acquired and liabilities assumed as of December 31, 2012 for both the Mainline and Gateway acquisitions:

(in thousands)	Mainline		Gateway		Combined
Consideration Paid
Cash	$	12,904	$	6,238	$	19,142
Common stock		14,786		13,284		28,070
Fair value of previously held equity interest		74		272		346
Fair Value of Total Consideration	$	27,764	$	19,794	$	47,558
Fair Value of Assets Acquired
Cash and cash equivalents	$	17,763	$	20,018	$	37,781
Securities and other investments		73,328		9,564		82,892
Loans		129,501		99,090		228,591
Premises and other equipment		2,280		495		2,775
Core deposit intangible		900		431		1,331
Other assets		12,438		2,665		15,103
Total Assets Acquired	$	236,210	$	132,263	$	368,473
Fair Value of Liabilities Assumed
Deposits		205,989		105,400		311,389
Borrowings		6,997		9,777		16,774
Other liabilities		2,144		1,068		3,212
Total Liabilities Assumed	$	215,130	$	116,245	$	331,375
Total Fair Value of Identifiable Net Assets		21,080		16,018		37,098
Goodwill	$	6,684	$	3,776	$	10,460

Acquired loans were recorded at fair value with no carryover of the related allowance for loan losses. Determining the fair value of the loans involved estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. Loans acquired with evidence of credit quality deterioration were not significant. We acquired $231.9 million of gross loans and recognized a net combined yield and credit mark of $3.3 million.

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NOTE 2. BUSINESS COMBINATIONS — continued

Direct costs related to the acquisitions were expensed as incurred. As of December 31, 2012, we recognized a combined total of $6.0 million of one-time merger related expenses. For the Gateway acquisition, we recognized $1.5 million of one-time merger related expenses; consisting primarily of legal, professional and other expenses of $0.6 million, $0.6 million in change in control, severance and other employee costs and $0.3 million in data processing contract termination and conversion costs. For the Mainline acquisition, we recognized $4.5 million of one-time merger related expenses; including $1.8 million in change in control, severance and other employee costs, $2.0 million in data processing contract termination and conversion costs and $0.7 million in legal, professional and other expenses.

NOTE 3. EARNINGS PER SHARE

The following table reconciles the numerators and denominators of basic EPS with that of diluted EPS:

	Years ended December 31,
(in thousands, except share and per share data)	2012		2011		2010
Numerator for Earnings per Common Share—Basic:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Less: Income allocated to participating shares		126		130		42
Net Income Allocated to Common Shareholders	$	34,074	$	39,523	$	37,237
Numerator for Earnings per Common Share—Diluted:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Net Income Available to Common Shareholders	$	34,200	$	39,653	$	37,279
Denominators:
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Potentially dilutive common shares		32,261		23,169		22,261
Denominator for Treasury Stock Method—Diluted		29,008,880		27,990,150		27,813,406
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Average participating shares outstanding		107,274		92,212		33,899
Denominator for Two-Class Method—Diluted		29,083,893		28,059,193		27,825,044
Earnings per common share—basic	$	1.18	$	1.41	$	1.34
Earnings per common share—diluted	$	1.18	$	1.41	$	1.34
Warrants considered anti-dilutive excluded from dilutive potential common shares		517,012		517,012		517,012
Stock options considered anti-dilutive excluded from dilutive potential common shares		747,443		757,580		930,969
Restricted stock considered anti-dilutive excluded from dilutive potential common shares		75,012		69,043		11,638

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NOTE 4. FAIR VALUE MEASUREMENTS

Refer to Note 1 Summary of Significant Accounting Policies under Fair Value Measurements for our accounting policy including details of the valuation methods used to determine the fair values of our assets and liabilities.

The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	212,066	$	—	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		—		57,896		—		57,896
Mortgage-backed securities of U.S. government corporations and agencies		—		60,781		—		60,781
Obligations of states and political subdivisions		—		112,767		—		112,767
Marketable equity securities		140		8,316		1,130		9,586
Total securities available-for-sale		140		451,826		1,130		453,096
Trading securities held in a Rabbi Trust		2,223		—		—		2,223
Total securities		2,363		451,826		1,130		455,319
Derivative financial assets:
Interest rate swaps		—		23,748		—		23,748
Interest rate lock commitments		—		467		—		467
Total Assets	$	2,363	$	476,041	$	1,130	$	479,534
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,522	$	—	$	23,522
Forward sale contracts		—		48		—		48
Total Liabilities	$	—	$	23,570	$	—	$	23,570

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NOTE 4. FAIR VALUE MEASUREMENTS — continued

	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	142,786	$	—	$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		—		65,395		—		65,395
Mortgage-backed securities of U.S. government corporations and agencies		—		48,752		—		48,752
Obligations of states and political subdivisions		—		88,805		—		88,805
Marketable equity securities		2,855		7,316		1,687		11,858
Total securities available-for-sale		2,855		353,054		1,687		357,596
Trading securities held in a Rabbi Trust		1,949		—		—		1,949
Total securities		4,804		353,054		1,687		359,545
Derivative financial assets:
Interest rate swaps		—		23,764		—		23,764
Interest rate lock commitments		—		244		—		244
Total Assets	$	4,804	$	377,062	$	1,687	$	383,553
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,639	$	—	$	23,639
Forward sale contracts	$	—	$	95	$	—	$	95
Total Liabilities	$	—	$	23,734	$	—	$	23,734

We classify financial instruments as Level 3 when valuation models are used because significant inputs are not observable in the market. The following tables present the changes in assets measured at fair value on a recurring basis for which we have utilized Level 3 inputs to determine the fair value:

	Years Ended December 31,
(in thousands)	2012			2011
Balance at beginning of year	$	1,687		$	1,588
Total (losses) gains included in other comprehensive income/loss(1)		(350	)		99
Net purchases, sales, issuances and settlements		(207	)		—
Transfers out of Level 3		—			—
Balance at end of year	$	1,130		$	1,687

⁽¹⁾  Changes in estimated fair value of available-for-sale investments are recorded in accumulated other comprehensive income/loss, while gains and losses from sales are recorded in security gains (losses), net in the Consolidated Statements of Net Income.

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NOTE 4. FAIR VALUE MEASUREMENTS — continued

We may be required to measure certain assets and liabilities on a nonrecurring basis. The following tables present our assets that are measured at estimated fair value on a nonrecurring basis by the fair value hierarchy level at December 31, 2012 and 2011. There were no liabilities measured at estimated fair value on a nonrecurring basis during these periods. Loans held for sale are recorded at the lower of cost or fair value. At December 31, 2012 and 2011, we had no loans held for sale that were recorded at fair value.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	44,059	$	44,059
Other real estate owned		—		—		585		585
Mortgage servicing rights		—		—		2,106		2,106
Total Assets	$	—	$	—	$	46,750	$	46,750
	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	36,500	$	36,500
Other real estate owned		—		—		3,739		3,739
Mortgage servicing rights		—		—		2,153		2,153
Total Assets	$	—	$	—	$	42,392	$	42,392

The carrying values and fair values of our financial instruments at December 31, 2012 and 2011 are presented in the following tables:

			Fair Value Measurements at December 31, 2012
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	337,711	$	337,711	$	337,711	$	—	$	—
Securities available-for-sale		453,096		453,096		140		451,826		1,130
Loans held for sale		22,499		22,601		—		—		22,601
Portfolio loans		3,346,622		3,347,602		—		—		3,347,602
Federal Home Loan Bank stock, at cost		14,485		14,485		—		—		14,485
Bank owned life insurance		58,619		58,619		—		58,619		—
Trading securities held in a Rabbi Trust		2,223		2,223		2,223		—		—
Mortgage servicing rights		2,106		2,106		—		—		2,106
Interest rate swaps		23,748		23,748		—		23,748		—
Interest rate lock commitments		467		467		—		467		—
LIABILITIES
Deposits	$	3,638,428	$	3,643,683	$	—	$	—	$	3,643,683
Securities sold under repurchase agreements		62,582		62,582		—		—		62,582
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		34,101		36,235		—		—		36,235
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,522		23,522		—		23,522		—
Forward sale contracts		48		48		—		48		—

⁽¹⁾  As reported in the Consolidated Balance Sheets

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NOTE 4. FAIR VALUE MEASUREMENTS — continued

			Fair Value Measurements at December 31, 2011
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	270,526	$	270,526	$	270,526	$	—	$	—
Securities available-for-sale		357,596		357,596		2,855		353,054		1,687
Loans held for sale		2,850		2,958		—		—		2,958
Portfolio loans		3,129,759		3,120,352		—		—		3,120,352
Federal Home Loan Bank stock, at cost		18,216		18,216		—		—		18,216
Bank owned life insurance		56,755		56,755		—		56,755		—
Trading securities held in a Rabbi Trust		1,949		1,949		1,949		—		—
Mortgage servicing rights		2,153		2,153		—		—		2,153
Interest rate swaps		23,764		23,764		—		23,764		—
Interest rate lock commitments		244		244		—		244		—
LIABILITIES
Deposits	$	3,335,859	$	3,343,889	$	—	$	—	$	3,343,889
Securities sold under repurchase agreements		30,370		30,370		—		—		30,370
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		31,874		34,171		—		—		34,171
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,639		23,639		—		23,639		—
Forward sale contracts		95		95		—		95		—

⁽¹⁾ As reported in the Consolidated Balance Sheets

NOTE 5. RESTRICTIONS ON CASH AND DUE FROM BANK ACCOUNTS

The Board of Governors of the Federal Reserve System, or the Federal Reserve, imposes certain reserve requirements on all depository institutions. These reserves are maintained in the form of vault cash or as an interest-bearing balance with the Federal Reserve. During the years ended 2012, 2011 and 2010 the required reserves averaged $36.6 million, $36.6 million and $32.5 million, respectively.

NOTE 6. DIVIDEND AND LOAN RESTRICTIONS

S&T is a legal entity separate and distinct from its banking and other subsidiaries. A substantial portion of our revenues consist of dividend payments we receive from S&T Bank. S&T Bank, in turn, is subject to state laws and regulations that limit the amount of dividends it can pay to us. In addition, both S&T and S&T Bank are subject to various general regulatory policies relating to the payment of dividends, including requirements to maintain adequate capital above regulatory minimums. The Federal Reserve has indicated that banking organizations should generally pay dividends only if (i) the organization’s net income available to common shareholders over the past year has been sufficient to fully fund the dividends and (ii) the prospective rate of earnings retention appears consistent with the organization’s capital needs, asset quality and overall financial condition. Thus, under certain circumstances based upon our financial condition, our ability to declare and pay quarterly dividends may require consultation with the Federal Reserve and may be prohibited by

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NOTE 6. DIVIDEND AND LOAN RESTRICTIONS — continued

applicable Federal Reserve regulations. If we were to pay a dividend in contravention of Federal Reserve regulations, the Federal Reserve could raise supervisory concerns. We redeemed our Series A Preferred Stock on December 7, 2011, and therefore we are no longer subject to the dividend restriction imposed by participation in the CPP.

Federal law prohibits us from borrowing from S&T Bank unless such loans are collateralized by specific obligations. Further, such loans are limited to 10 percent of S&T Bank’s capital and additional paid-in capital, as defined. In April 2012, we closed a $5.0 million line of credit with S&T Bank that had been secured by investments of another subsidiary of S&T.

NOTE 7. SECURITIES AVAILABLE-FOR-SALE

The following tables present the amortized cost and fair value of available-for-sale securities for the periods shown:

	December 31, 2012
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	207,229	$	4,890	$	(53	)	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		1,811		—			57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		3,373		—			60,781
Obligations of states and political subdivisions		107,911		4,908		(52	)		112,767
Debt Securities		428,633		14,982		(105	)		443,510
Marketable equity securities		8,502		1,095		(11	)		9,586
Total	$	437,135	$	16,077	$	(116	)	$	453,096

	December 31, 2011
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	138,386	$	4,400	$	—		$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		63,202		2,193		—			65,395
Mortgage-backed securities of U.S. government corporations and agencies		45,289		3,463		—			48,752
Obligations of states and political subdivisions		85,689		3,128		(12	)		88,805
Debt Securities		332,566		13,184		(12	)		345,738
Marketable equity securities		10,152		2,179		(473	)		11,858
Total	$	342,718	$	15,363	$	(485	)	$	357,596

During 2012, there were $3.0 million in gross realized gains, compared to nominal gains in 2011 and $0.4 million in 2010. The $3.0 in gross realized gains relates to the sales of two equity positions during the year as a result of increases in value after merger announcements. There were nominal gross realized losses in 2012 and $0.1 million in gross realized losses in 2011 and 2010, relating to securities available-for-sale.

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NOTE 7. SECURITIES AVAILABLE-FOR-SALE — continued

The following tables present the fair value and the age of gross unrealized losses by investment category for the periods presented:

	December 31, 2012
	Less Than 12 Months					12 Months or More				Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	11,370	$	(53	)	$	—	$	—	$	11,370	$	(53	)
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—		—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—		—		—
Obligations of states and political subdivisions		11,285		(52	)		—		—		11,285		(52	)
Debt Securities		22,655		(105	)		—		—		22,655		(105	)
Marketable equity securities		228		(11	)		—		—		228		(11	)
Total Temporarily Impaired Securities	$	22,883	$	(116	)	$	—	$	—	$	22,883	$	(116	)

	December 31, 2011
	Less Than 12 Months					12 Months or More					Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	—	$	—		$	—	$	—		$	—	$	—
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—			—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—			—		—
Obligations of states and political subdivisions		502		(8	)		414		(4	)		916		(12	)
Debt Securities		502		(8	)		414		(4	)		916		(12	)
Marketable equity securities		5,143		(473	)		—		—			5,143		(473	)
Total Temporarily Impaired Securities	$	5,645	$	(481	)	$	414	$	(4	)	$	6,059	$	(485	)

We do not believe any individual unrealized loss as of December 31, 2012 represents an OTTI. Refer to Note 1 Summary of Significant Accounting Policies for our accounting policy for securities and OTTI.

As of December 31, 2012, the unrealized losses on five debt securities were primarily attributable to changes in interest rates. The unrealized losses on two marketable equity securities as of December 31, 2012 were attributable to temporary declines in the market value of these stocks. We do not intend to sell and it is not likely that we will be required to sell any of the securities, referenced in the table above, in an unrealized loss position before recovery of their amortized cost.

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NOTE 7. SECURITIES AVAILABLE-FOR-SALE — continued

Net unrealized gains of $10.4 million and $9.7 million were included in accumulated other comprehensive loss, net of tax, at December 31, 2012 and 2011, respectively. Gross unrealized gains of $10.5 million and $10.0 million, net of tax, were netted against gross unrealized losses of $0.1 million and $0.3 million, respectively, for these same periods. During 2012 unrealized gains reclassified out of accumulated other comprehensive income into earnings were $3.0 million, while unrealized losses reclassified into earnings to record OTTI were minimal. During 2011, unrealized gains reclassified out of accumulated other comprehensive loss into earnings were minimal, while $0.1 million of unrealized losses were reclassified into earnings to record OTTI.

The amortized cost and fair value of securities available-for-sale at December 31, 2012, by contractual maturity, are included in the table below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

	December 31, 2012
(in thousands)	Amortized Cost		Fair Value
Due in one year or less	$	38,434	$	38,969
Due after one year through five years		130,690		134,192
Due after five years through ten years		64,822		66,507
Due after ten years		81,194		85,165
		315,140		324,833
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		60,781
Debt Securities		428,633		443,510
Marketable equity securities		8,502		9,586
Total	$	437,135	$	453,096

At December 31, 2012 and 2011, securities with carrying values of $307.5 million and $233.9 million, respectively, were pledged to secure repurchase agreements, public funds and trust fund deposits and as collateral for our interest rate swaps.

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NOTE 8. LOANS AND LOANS HELD FOR SALE

The following table presents the composition of loans:

	December 31,
(in thousands)	2012			2011
Commercial
Commercial real estate	$	1,452,133		$	1,415,333
Commercial and industrial		791,396			685,753
Commercial construction		168,143			188,852
Total Commercial Loans		2,411,672			2,289,938
Consumer
Home equity		431,335			411,404
Residential mortgage		427,303			358,846
Installment and other consumer		73,875			67,131
Consumer construction		2,437			2,440
Total Consumer Loans		934,950			839,821
Total Portfolio Loans		3,346,622			3,129,759
Allowance for loan losses		(46,484	)		(48,841	)
Total Portfolio Loans, net		3,300,138			3,080,918
Loans held for sale		22,499			2,850
Total Loans, Net	$	3,322,637		$	3,083,768

The table above includes loans that were acquired from two bank acquisitions. Approximately $129.5 million of loans were acquired from the Mainline acquisition on March 9, 2012 which consisted of $57.7 million of consumer loans and $71.8 million of commercial loans. Additionally, on August 13, 2012, we acquired Gateway which added $99.1 million of loans, including $74.2 million of commercial and $24.9 million of consumer loans. Additionally, we had $19.3 million in loans held for sale that related to a participation loan that we had not received funds from the participating banks as of December 31, 2012.

We attempt to limit our exposure to credit risk by diversifying our loan portfolio and actively managing concentrations. When concentrations exist in certain segments, we mitigate this risk by monitoring the relevant economic indicators and internal risk rating trends and through stress testing of the loans in these classes. Total commercial loans represent 72 percent and 73 percent of total portfolio loans at December 31, 2012 and December 31, 2011, respectively. Within our commercial portfolio, the CRE and commercial construction portfolios combined comprise 67 percent of total commercial loans and 48 percent of total portfolio loans at December 31, 2012 and 70 percent of total commercial loans and 51 percent of total portfolio loans at December 31, 2011. Further segmentation of the CRE and commercial construction portfolios by industry and collateral type reveal no concentration in excess of nine percent of total loans. The majority of both commercial and consumer loans are made to businesses and individuals in our Western Pennsylvania market, resulting in a geographic concentration. The conditions of the local and regional economies are monitored closely through publicly available data as well as information supplied by our customers. Only the CRE and commercial construction portfolios combined have any significant out-of-state exposure, with 19 percent of the combined portfolio and nine percent of total loans being out-of-state loans at December 31, 2012 and 19 percent of the combined portfolio and 10 percent of total loans being out-of-state loans at December 31, 2011. Management believes underwriting guidelines and ongoing review by credit administration mitigates the concentration risk present in the loan portfolio.

In situations where, for economic or legal reasons related to a borrower’s financial difficulties, we may grant a concession for other than an insignificant period of time to the borrower that would not

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NOTE 8. LOANS AND LOANS HELD FOR SALE — continued

otherwise be granted, the related loan is classified as a TDR. We strive to identify borrowers in financial difficulty early and work with them to modify to more affordable terms before their loan reaches nonaccrual status. These modified terms generally include extensions of maturity dates at a stated interest rate lower than the current market rate for a new loan with similar risk characteristics, reductions in contractual interest rates, and principal deferment. These modifications are generally for longer term periods that would not be considered insignificant. While unusual, there may be instances of loan principal forgiveness. We may have borrowers classified as TDR wherein their debt obligation has been discharged by a chapter 7 bankruptcy without reaffirmation of debt.

We individually evaluate all substandard commercial loans that experienced a forbearance or change in terms agreement, as well as all substandard consumer and residential mortgage loans that entered into an agreement to modify their existing loan.

All TDRs are considered to be impaired loans and will be reported as impaired loans for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. Further, all impaired loans are reported as nonaccrual loans unless the loan is a TDR that has met the requirements to be returned to accruing status. TDRs can be returned to accruing status if the ultimate collectability of all contractual amounts due, according to the restructured agreement, is not in doubt and there is a period of a minimum of six months of satisfactory payment performance by the borrower either immediately before or after the restructuring. We did not return any TDRs to accruing status during 2012.

The following table summarizes the restructured loans as of the dates presented:

	December 31, 2012						December 31, 2011
(in thousands)	Performing TDRs		Nonperforming TDRs		Total TDRs		Performing TDRs		Nonperforming TDRs		Total TDRs
Commercial real estate	$	14,220	$	9,584	$	23,804	$	22,284	$	10,871	$	33,155
Commercial and industrial		8,270		939		9,209		6,180		—		6,180
Commercial construction		11,734		5,324		17,058		19,682		2,943		22,625
Home equity		4,195		341		4,536		—		—		—
Residential mortgage		3,078		2,752		5,830		1,570		4,370		5,940
Installment and other consumer		24		—		24		—		—		—
Total	$	41,521	$	18,940	$	60,461	$	49,716	$	18,184	$	67,900

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NOTE 8. LOANS AND LOANS HELD FOR SALE — continued

The following tables present the restructured loans for the years ending December 31:

	2012
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	704	$	693	$	(11	)
Interest rate reduction		2		1,785		1,768		(17	)
Commercial and industrial
Maturity date extension		4		2,825		2,601		(224	)
Commercial construction
Maturity date extension		6		2,894		1,874		(1,020	)
Home Equity
Discharge of debt		161		4,530		4,530		—
Residential mortgage
Maturity date extension		1		475		439		(36	)
Interest rate reduction		2		67		67		—
Discharge of debt		76		2,349		2,349		—
Installment and other consumer
Discharge of debt		5		25		25		—
Total by Concession Type
Maturity date extension		14		6,898		5,607		(1,291	)
Interest rate reduction		4		1,852		1,835		(17	)
Discharge of debt		242		6,904		6,904		—
Total		260	$	15,654	$	14,346	$	(1,308	)

⁽¹⁾ Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

	2011
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	3,361	$	3,817	$	456
Interest rate reduction		2		682		604		(78	)
Other		3		2,034		908		(1,126	)
Commercial and industrial
Maturity date extension		6		6,364		6,180		(184	)
Commercial construction
Maturity date extension		12		21,029		20,979		(50	)
Residential mortgage
Maturity date extension		6		5,201		4,825		(376	)
Interest rate reduction		2		336		308		(28	)
Other		1		75		40		(35	)
Total by Concession Type
Maturity date extension		27		35,955		35,801		(154	)
Interest rate reduction		4		1,018		912		(106	)
Other		4		2,109		948		(1,161	)
Total		35	$	39,082	$	37,661	$	(1,421	)

⁽¹⁾  Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

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NOTE 8. LOANS AND LOANS HELD FOR SALE — continued

We had $6.9 million of new TDRs related to our consumer loan portfolio for borrowers who had their debt discharged and not reaffirmed through Chapter 7 bankruptcy. These loans are being reported as accruing TDRs as the borrowers are current on their payments and almost all have no history of delinquency.

During 2012, we modified 7 C&I loans totaling $6.6 million, one commercial construction loan totaling $1.2 million and 8 commercial real estate loan totaling $3.6 million for financially troubled borrowers that were not considered to be TDRs. Modifications primarily represented insignificant delays in the timing of payments that were not considered to be concessions or we have been adequately compensated for the concession through principal reductions or additional collateral. As of December 31, 2012 we have no commitments to lend additional funds on any TDRs.

The following table is a summary of TDRs which defaulted (defined as 90 days past due since time of modification) during years ended December 31, 2012 and 2011 that had been restructured within the last twelve months prior to December 31, 2012 and 2011, respectively:

	Defaulted TDRs
	For the Year Ended December 31, 2012				For the Year Ended December 31, 2011
(dollars in thousands)	Number of Defaults		Recorded Investment		Number of Defaults		Recorded Investment
Commercial real estate		—	$	—		2	$	0.9
Total		—	$	—		2	$	0.9

The following table is a summary of nonperforming assets for the years ended December 31:

(in thousands)	2012		2011
Nonperforming Assets
Nonaccrual loans	$	36,018	$	37,931
Nonaccrual TDRs		18,940		18,184
Total nonperforming loans		54,958		56,115
OREO		911		3,967
Total Nonperforming Assets	$	55,869	$	60,082

OREO which is included in other assets in the Consolidated Balance Sheets consists of 13 properties. It is our policy to obtain OREO appraisals on an annual basis.

We have granted loans to certain officers and directors of S&T as well as to certain affiliates of the officers and directors in the ordinary course of business. These loans were made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated persons and did not involve more than normal risk of collectability.

The following table presents a summary of the aggregate amount of loans to any such persons as of December 31:

(in thousands)	2012			2011
Balance at beginning of year	$	31,821		$	34,373
New loans		29,465			23,751
Repayments		(25,211	)		(26,303	)
Balance at End of Year	$	36,075		$	31,821

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NOTE 9. ALLOWANCE FOR LOAN LOSSES

We maintain an ALL at a level determined to be adequate to absorb estimated probable credit losses inherent in the loan portfolio as of the balance sheet date. Refer to Note 1 Summary of Significant Accounting Policies for details of our ALL policy. During the fourth quarter of 2010, we implemented various enhancements to the ALL methodology to better align the calculation with the inherent risk identified within the loan portfolio and align it with regulatory guidance. Changes included consideration of additional loan risk characteristics such as internal risk rating, collateral, and loan-to-value, enhancing the base loss calculation to consider the estimated loss emergence period of each loan segment and expanding the qualitative adjustments to consider additional factors. The enhancements made to the ALL methodology did not materially change the ALL at December 31, 2010.

We develop and document a systematic ALL methodology based on the following portfolio segments: 1) CRE, 2) C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer.

The following are key risks within each portfolio segment:

CRE—Loans secured by commercial purpose real estate, including both owner occupied properties and investment properties for various purposes such as hotels, strip malls and apartments. Operation of the individual projects as well as global cash flows of the debtors are the primary sources of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the collateral type as well as the business prospects of the lessee, if the project is not owner occupied.

C&I—Loans made to operating companies or manufacturers for the purpose of production, operating capacity, accounts receivable, inventory or equipment financing. Cash flow from the operations of the company is the primary source of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the industry of the company. Collateral for these types of loans often do not have sufficient value in a distressed or liquidation scenario to satisfy the outstanding debt.

Commercial Construction—Loans made to finance construction of buildings or other structures, as well as to finance the acquisition and development of raw land for various purposes. While the risk of these loans is generally confined to the construction period, if there are problems, the project may not be complete, and as such, may not provide sufficient cash flow on its own to service the debt or have sufficient value in a liquidation to cover the outstanding principal. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the type of project and the experience and resources of the developer.

Consumer Real Estate—Loans secured by first and second liens such as home equity loans, home equity lines of credit and 1-4 family residences, including purchase money mortgages. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The state of the local housing market can also have a significant impact on this segment because low demand and/or declining home values can limit the ability of borrowers to sell a property and satisfy the debt.

Other Consumer—Loans made to individuals that may be secured by assets other than 1-4 family residences, as well as unsecured loans. This segment includes auto loans, unsecured lines and credit cards. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The value of the collateral, if there is any, is less likely to be a source of repayment due to less certain collateral values.

We further assess risk within each portfolio segment by pooling loans with similar risk characteristics. For the commercial loan classes, the most important indicator of risk is the internally assigned risk rating, including pass, special mention and substandard. Consumer loans are pooled by

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NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

type of collateral and first or second lien positions for consumer real estate loans. Historical loss rates are applied to these loan pools to determine the general reserve component of the ALL. Management monitors various credit quality indicators for both the commercial and consumer loan portfolios, including delinquency, nonperforming status and changes in risk ratings on a monthly basis. Refer to Note 1 Summary of Significant Accounting Policies for our policy for determining past due status of loans.

The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented:

	December 31, 2012
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,418,934	$	2,230	$	413	$	30,556	$	33,199	$	1,452,133
Commercial and industrial		780,315		4,409		237		6,435		11,081		791,396
Commercial construction		150,823		10,542		—		6,778		17,320		168,143
Home equity		424,485		2,332		865		3,653		6,850		431,335
Residential mortgage		416,364		1,713		1,948		7,278		10,939		427,303
Installment and other consumer		73,334		406		95		40		541		73,875
Consumer construction		2,219		—		—		218		218		2,437
Total	$	3,266,474	$	21,632	$	3,558	$	54,958	$	80,148	$	3,346,622

	December 31, 2011
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,374,580	$	7,657	$	1,448	$	31,648	$	40,753	$	1,415,333
Commercial and industrial		672,899		3,583		1,701		7,570		12,854		685,753
Commercial construction		182,305		—		—		6,547		6,547		188,852
Home equity		405,578		2,199		691		2,936		5,826		411,404
Residential mortgage		349,214		1,240		1,163		7,229		9,632		358,846
Installment and other consumer		66,675		382		70		4		456		67,131
Consumer construction		2,259		—		—		181		181		2,440
Total	$	3,053,510	$	15,061	$	5,073	$	56,115	$	76,249	$	3,129,759

We continually monitor the commercial loan portfolio through an internal risk rating system. Loan risk ratings are assigned based upon the creditworthiness of the borrower and are reviewed on an ongoing basis according to our internal policies. Loans within the pass rating generally have a lower risk of loss than loans risk rated as special mention and substandard, which generally have an increasing risk of loss.

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NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

Our risk ratings are consistent with regulatory guidance and are as follows:

Pass —The loan is currently performing and is of high quality.

Special Mention—A special mention loan has potential weaknesses that warrant management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects or in the strength of our credit position at some future date. Economic and market conditions, beyond the borrower’s control, may in the future necessitate this classification.

Substandard—A substandard loan is not adequately protected by the net worth and/or paying capacity of the borrower or by the collateral pledged, if any. Substandard loans have a well-defined weakness, or weaknesses that jeopardize the liquidation of the debt. These loans are characterized by the distinct possibility that we will sustain some loss if the deficiencies are not corrected.

The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented:

	December 31, 2012
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,265,810		87.2	%	$	718,070		90.7	%	$	118,841		70.7	%	$	2,102,721		87.2	%
Special mention		96,156		6.6	%		42,016		5.3	%		30,748		18.3	%		168,920		7.0	%
Substandard		90,167		6.2	%		31,310		4.0	%		18,554		11.0	%		140,031		5.8	%
Total	$	1,452,133		100.0	%	$	791,396		100.0	%	$	168,143		100.0	%	$	2,411,672		100.0	%

	December 31, 2011
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,229,005		86.8	%	$	600,895		87.6	%	$	136,270		72.1	%	$	1,966,170		85.9	%
Special mention		84,400		6.0	%		33,135		4.8	%		17,106		9.1	%		134,641		5.9	%
Substandard		101,928		7.2	%		51,723		7.6	%		35,476		18.8	%		189,127		8.2	%
Total	$	1,415,333		100.0	%	$	685,753		100.0	%	$	188,852		100.0	%	$	2,289,938		100.0	%

We monitor the delinquent status of the consumer portfolio on a monthly basis. The risk of loss is generally highest for nonperforming loans.

The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented:

	December 31, 2012
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	427,682	$	420,025	$	73,835	$	2,219	$	923,761
Nonperforming		3,653		7,278		40		218		11,189
Total	$	431,335	$	427,303	$	73,875	$	2,437	$	934,950

	December 31, 2011
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	408,468	$	351,617	$	67,127	$	2,259	$	829,471
Nonperforming		2,936		7,229		4		181		10,350
Total	$	411,404	$	358,846	$	67,131	$	2,440	$	839,821

99

NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. Loans are considered to be impaired when based upon current information and events it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. All TDRs are considered to be impaired loans and will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. For all TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate.

The following tables present investments in loans considered to be impaired and related information on those impaired loans at the dates and for the periods stated:

	December 31, 2012				Year ended December 31, 2012
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	6,138	$	6,864	$	1,226	$	5,796	$	218
Commercial and industrial		1,864		2,790		1,002		1,826		—
Commercial construction		799		896		3		4,446		—
Consumer real estate		—		—		—		—		—
Other consumer		—		—		—		—		—
Total with a Related Allowance Recorded		8,801		10,550		2,231		12,068		218
Without a related allowance recorded:
Commercial real estate		33,856		45,953		—		41,138		1,112
Commercial and industrial		11,419		12,227		—		11,672		329
Commercial construction		17,713		27,486		—		22,299		571
Consumer real estate		10,827		12,025				20,533		68
Other consumer		25		25		—		6		—
Total without a Related Allowance Recorded		73,840		97,716		—		95,648		2,080
Total:
Commercial real estate		39,994		52,817		1,226		46,934		1,330
Commercial and industrial		13,283		15,017		1,002		13,498		329
Commercial construction		18,512		28,382		3		26,745		571
Consumer real estate		10,827		12,025		—		20,533		68
Other consumer		25		25		—		6		—
Total	$	82,641	$	108,266	$	2,231	$	107,716	$	2,298

100

NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

	December 31, 2011				Year Ended December 31, 2011
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	9,049	$	9,276	$	3,487	$	12,045	$	320
Commercial and industrial		4,207		4,207		1,116		3,497		77
Commercial construction		1,975		1,975		942		3,326		4
Consumer real estate		—		—		—		173		—
Total with a Related Allowance Recorded		15,231		15,458		5,545		19,041		401
Without a related allowance recorded:
Commercial real estate		41,058		47,874		—		34,965		1,415
Commercial and industrial		7,784		7,784		—		4,128		132
Commercial construction		24,024		24,375		—		8,856		496
Consumer real estate		5,939		6,545		—		2,617		195
Total without a Related Allowance Recorded		78,805		86,578		—		50,566		2,238
Total:
Commercial real estate		50,107		57,150		3,487		47,010		1,735
Commercial and industrial		11,991		11,991		1,116		7,625		209
Commercial construction		25,999		26,350		942		12,182		500
Consumer real estate		5,939		6,545		—		2,790		195
Total	$	94,036	$	102,036	$	5,545	$	69,607	$	2,639

As of December 31, 2012, $40.0 million of CRE loans comprised 48 percent of the total impaired loans of $82.6 million. These impaired loans are collateralized primarily by commercial real estate properties such as retail or strip malls, office buildings, hotels and various other types of commercial purpose properties. These loans are generally considered collateral dependent and charge-offs are recorded when a confirmed loss exists. Approximately $13.3 million of charge-offs have been recorded relating to these CRE loans over the life of these loans. It is our policy to order appraisals on an annual basis on impaired loans or sooner if facts and circumstances warrant otherwise. As of December 31, 2012, these loans had collateral with an estimated fair value less cost to sell of approximately $55.2 million. We have current appraisals on all but four loans totaling $1.5 million of the $40.0 million impaired CRE loans. These $1.5 million of loans do not have updated appraisals due to bankruptcy proceedings that are awaiting resolution and one loan has a sales agreement in process. Appraisals outdated greater than 16 months are generally discounted an extra 10 percent in order to estimate the impact of aged appraisals, unless management is aware of other facts and circumstances that would imply a different discount should be applied. In determining this discount, management considers the market area of the collateral, the condition of the collateral, and other relevant factors that could impact the collateral value.

101

NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

The following tables detail activity in the ALL for the years ended December 31:

	2012
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841
Charge-offs		(9,627	)		(5,278	)		(10,521	)		(2,509	)		(1,078	)		(29,013	)
Recoveries		1,259			1,153			891			197			341			3,841
Net (Charge-offs)/ Recoveries		(8,368	)		(4,125	)		(9,630	)		(2,312	)		(737	)		(25,172	)
Provision for loan losses		3,810			610			13,427			4,204			764			22,815
Balance at End of Year	$	25,246		$	7,759		$	7,500		$	5,058		$	921		$	46,484

	2011
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	30,425		$	9,777		$	5,904		$	3,962		$	1,319		$	51,387
Charge-offs		(8,824	)		(8,971	)		(1,720	)		(2,617	)		(1,013	)		(23,145	)
Recoveries		780			357			2,463			1,030			360			4,990
Net (Charge-offs)/ Recoveries		(8,044	)		(8,614	)		743			(1,587	)		(653	)		(18,155	)
Provision for loan losses		7,423			10,111			(2,944	)		791			228			15,609
Balance at End of Year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841

The following tables present the ALL and recorded investments in loans by category as of December 31:

	2012
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	1,226	$	24,020	$	25,246	$	39,994	$	1,412,139	$	1,452,133
Commercial and industrial		1,002		6,757		7,759		13,283		778,113		791,396
Commercial construction		3		7,497		7,500		18,512		149,631		168,143
Consumer real estate		—		5,058		5,058		10,827		850,248		861,075
Other consumer		—		921		921		25		73,850		73,875
Total	$	2,231	$	44,253	$	46,484	$	82,641	$	3,263,981	$	3,346,622

102

NOTE 9. ALLOWANCE FOR LOAN LOSSES — continued

	2011
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	3,487	$	26,317	$	29,804	$	50,107	$	1,365,226	$	1,415,333
Commercial and industrial		1,116		10,158		11,274		11,991		673,762		685,753
Commercial construction		942		2,761		3,703		25,999		162,853		188,852
Consumer real estate		—		3,166		3,166		5,939		766,751		772,690
Other consumer		—		894		894		—		67,131		67,131
Total	$	5,545	$	43,296	$	48,841	$	94,036	$	3,035,723	$	3,129,759

NOTE 10. PREMISES AND EQUIPMENT

The following table is a summary of premises and equipment at December 31:

(in thousands)	2012			2011
Land	$	6,490		$	6,316
Premises		43,434			41,608
Furniture and equipment		24,944			22,941
Leasehold improvements		5,965			4,899
		80,833			75,764
Accumulated depreciation		(42,157	)		(38,009	)
Total	$	38,676		$	37,755

Depreciation expense related to premises and equipment was $3.9 million in 2012 and $4.3 million for both 2011 and 2010.

Certain banking facilities are leased under arrangements expiring at various dates until the year 2054. We account for these leases on a straight-line basis due to escalation clauses. All leases are accounted for as operating leases, except for one capital lease. Rental expense for premises amounted to $2.4 million, $1.9 million and $1.7 million in 2012, 2011 and 2010, respectively. Included in the rental expense for premises are leases entered into with two directors, which totaled $0.2 million for 2012, 2011 and 2010.

Minimum annual rental and renewal option payments for each of the following five years and thereafter are approximately:

(in thousands)	Operating		Capital		Total
2013	$	2,088	$	76	$	2,164
2014		2,107		76		2,183
2015		2,076		76		2,152
2016		2,006		76		2,082
2017		1,954		76		2,030
Thereafter		43,114		839		43,953
Total	$	53,345	$	1,219	$	54,564

103

NOTE 11. GOODWILL AND OTHER INTANGIBLE ASSETS

The following table represents a roll forward of goodwill:

(in thousands)	2012		2011
Balance at beginning of year	$	165,273	$	165,273
Additions		10,460		—
Balance at End of Year	$	175,733	$	165,273

Goodwill represents the excess of the purchase price over the fair value of net assets purchased. Additional goodwill of $10.5 million was recorded during 2012, including $6.7 for our acquisition of Mainline and $3.8 million for our acquisition of Gateway. Refer to Note 2 Business Combinations for further details on these acquisitions. There were no additions to goodwill in 2011.

Goodwill is reviewed for impairment annually with an interim analysis performed when necessary. Based upon our qualitative assessment performed for our annual impairment analysis, we concluded that it is more likely that not that the fair value of the reporting units exceeds the carrying value. In general, the overall macroeconomic conditions and more specifically the economic conditions of the banking industry have been improving recently. Additionally, our overall performance has not significantly deteriorated and we did not identify any other facts and circumstances causing us to conclude that it is more likely than not that the fair value of the reporting units would be less than the carrying value.

The following table shows a summary of intangible assets:

(in thousands)	2012			2011
Gross carrying amount at beginning of year	$	15,070		$	15,070
Additions		1,331			—
Accumulated amortization		(11,051	)		(9,342	)
Balance at End of Year	$	5,350		$	5,728

Intangible assets as of December 31, 2012 consisted of $4.6 million for the acquisition of core deposits, $0.2 million for the acquisition of wealth management relationships and $0.6 million for the acquisition of insurance contract relationships. The additions of $1.3 million includes core deposit intangibles as a result of our acquisitions of Mainline and Gateway. We determined the amount of these identifiable intangible assets as well as those acquired before 2012, based upon independent core deposit, wealth management and insurance contract analyses. Other intangible assets are evaluated for recoverability annually and more frequently if triggering events and changes in circumstances occur. We completed this review in 2012 and 2011 and determined that other intangible assets are not impaired.

Amortization expense on finite-lived intangible assets totaled $1.7 million, $1.7 million and $1.9 million for 2012, 2011 and 2010, respectively. The following is a summary of the expected amortization expense for finite-lived intangibles assets, assuming no new additions, for each of the five years following December 31, 2012:

(in thousands)	Amount
2013	$	1,590
2014		1,129
2015		883
2016		645
2017		500
Total	$	4,747

104

NOTE 12. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

In the normal course of business, we use derivative instruments and hedging activities as discussed under Derivative Financial Instruments in Note 1 Summary of Significant Accounting Policies.

The following table indicates the amount representing the value of derivative assets and derivative liabilities at December 31:

	Derivatives (included in Other Assets)				Derivatives (included in Other Liabilities)
(in thousands)	2012		2011		2012		2011
Derivatives not Designated as Hedging Instruments
Interest Rate Swap Contracts—Commercial Loans
Fair value	$	23,748	$	23,764	$	23,522	$	23,639
Notional amount		227,532		189,868		227,532		189,868
Collateral posted		—		—		19,595		20,273
Interest Rate Lock Commitments—Mortgage Loans
Fair value		467		244		—		—
Notional amount		14,287		7,093		—		—
Forward Sale Contracts—Mortgage Loans
Fair value		—		—		48		95
Notional amount		—		—		14,100		7,729

The following table indicates the gain or loss recognized in income on derivatives for the year ended December 31:

(in thousands)	2012		2011			2010
Derivatives not Designated as Hedging Instruments
Interest rate swap contracts—commercial loans	$	101	$	(38	)	$	96
Interest rate lock commitments—mortgage loans		223		27			62
Forward sale contracts—mortgage loans		47		(507	)		220
Total Derivative Gain (Loss)	$	371	$	(518	)	$	378

NOTE 13. MORTGAGE SERVICING RIGHTS

For the years ended December 31, 2012, 2011 and 2010, the 1-4 family mortgage loans that were sold to Federal National Mortgage Association, or FNMA, amounted to $82.9 million, $67.9 million and $109.3 million, respectively. At December 31, 2012, 2011 and 2010 our servicing portfolio totaled $329.2 million, $332.6 million and $318.2 million, respectively.

The following table indicates MSRs and the net carrying values:

(in thousands)	Servicing Rights			Valuation Allowance			Net Carrying Value
Balance at December 31, 2010	$	3,292		$	825		$	2,467
Additions		621			342			279
Amortization		(593	)		—			(593	)
Balance at December 31, 2011	$	3,320		$	1,167		$	2,153
Additions		826			(67	)		893
Amortization		(940	)		—			(940	)
Balance at December 31, 2012	$	3,206		$	1,100		$	2,106

105

NOTE 14. DEPOSITS

The following table presents the composition of deposits at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Noninterest-bearing demand	$	960,980	$	—	$	818,686	$	—	$	765,812	$	—
Interest-bearing demand		316,760		60		283,611		47		295,246		54
Money market		361,233		614		278,092		691		262,683		1,166
Savings		965,571		2,356		802,942		1,267		753,813		2,127
Certificates of deposit		1,033,884		13,766		1,152,528		20,947		1,239,970		25,370
Total	$	3,638,428	$	16,796	$	3,335,859	$	22,952	$	3,317,524	$	28,717

The aggregate of all certificates of deposit over $100,000 amounted to $368.1 million and $357.7 million at December 31, 2012 and 2011, respectively.

The following table indicates the scheduled maturities of certificates of deposit at December 31, 2012:

(in thousands)	Amount
2013	$	643,635
2014		129,963
2015		118,829
2016		53,735
2017		77,336
Thereafter		10,386
Total	$	1,033,884

NOTE 15. SHORT-TERM BORROWINGS

Short-term borrowings are for terms under one year and were comprised of retail repurchase agreements , or REPOs, and FHLB advances. We define repurchase agreements with our local retail customers as retail REPOs. Securities pledged as collateral under these REPO financing arrangements cannot be sold or repledged by the secured party and are therefore accounted for as a secured borrowing. FHLB advances are for various terms secured by a blanket lien on residential mortgages and other real estate secured loans. The following table represents the composition of short-term borrowings at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Securities sold under repurchase agreements, retail	$	62,582	$	82	$	30,370	$	53	$	40,653	$	64
Federal Home Loan Bank advances		75,000		123		75,000		2		—		146
Total	$	137,582	$	205	$	105,370	$	55	$	40,653	$	210

We had a $5.0 million line of credit with S&T Bank secured by investments of another subsidiary of S&T, which was closed in April 2012.

106

NOTE 15. SHORT-TERM BORROWINGS — continued

Information pertaining to REPOs are summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	62,582	$	30,370	$	40,653
Average balance during the year		47,388		41,584		46,489
Average interest rate during the year		0.17%		0.13%		0.14%
Maximum month-end balance during the year	$	62,582	$	42,409	$	52,046
Average interest rate at December 31		0.20%		0.11%		0.07%

Information pertaining to short-term FHLB advances is summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	75,000	$	75,000	$	—
Average balance during the year		50,212		551		32,473
Average interest rate during the year		0.24%		0.32%		0.45%
Maximum month-end balance during the year	$	75,000	$	75,000	$	141,800
Average interest rate at December 31		0.19%		0.18%		—

NOTE 16. LONG-TERM BORROWINGS

We had total borrowings as of December 31, 2012 and 2011 at the Pittsburgh FHLB of $108.9 million and $106.6 million, respectively. Total borrowings for 2012 consisted of $75 million in short-term borrowings and $33.9 million in long-term borrowings. The total borrowings of $106.6 million in 2011 consisted of $75.0 million in short-term borrowings and $31.6 million in long-term borrowings. FHLB borrowings are collateralized by a blanket lien on residential mortgages and other real estate secured loans. Total loans pledged as collateral at the FHLB were $2.0 billion at year end. We were eligible to borrow up to an additional $787.7 million based on qualifying collateral and up to $299.7 million more provided that additional collateral is pledged.

Interest expense of $1.1 million was recognized on long term borrowings for both 2012 and 2011, and $1.6 million was recognized for 2010. Scheduled annual maturities and average interest rates for all of the long-term debt, including a capital lease of $0.3 million, for each of the five years and thereafter subsequent to December 31, 2012 are as follows:

(dollars in thousands)	Balance		Average Rate
2013	$	12,291		3.46%
2014		2,368		3.36%
2015		2,399		3.41%
2016		2,330		3.44%
2017		2,412		3.53%
Thereafter		12,301		2.70%
Total	$	34,101		3.18%

107

NOTE 16. LONG-TERM BORROWINGS — continued

Junior Subordinated Debt Securities

The following table represents the composition of junior subordinated debt securities at December 31 and the interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
2006 Junior subordinated debt	$	25,000	$	523	$	25,000	$	1,344	$	25,000	$	1,695
2008 Junior subordinated debt—trust preferred securities		20,619		808		20,619		777		20,619		782
2008 Junior subordinated debt		20,000		818		20,000		786		20,000		791
2008 Junior subordinated debt		25,000		766		25,000		728		25,000		735
Total	$	90,619	$	2,915	$	90,619	$	3,635	$	90,619	$	4,003

The following table summarizes the key terms of our junior subordinated debt securities:

(dollars in thousands)	2006 Junior Subordinated Debt	2008 Trust Preferred Securities	2008 Junior Subordinated Debt	2008 Junior Subordinated Debt
Junior Subordinated Debt	$25,000	—	$20,000	$25,000
Trust Preferred Securities	—	$20,000	—	—
Stated Maturity Date	12/15/2036	3/15/2038	6/15/2018	5/30/2018
First optional redemption date at par	—	3/15/2013	6/15/2013	5/30/2013
Regulatory Capital	Tier 2	Tier 1	Tier 2	Tier 2
Interest Rate	3 month LIBOR plus 160 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 250 bps
Interest Rate at December 31, 2012	1.91%	3.81%	3.81%	2.81%

We completed a private placement of the trust preferred securities to a financial institution during the first quarter of 2008. As a result, we own 100 percent of the common equity of STBA Capital Trust I. The trust was formed to issue mandatorily redeemable capital securities to third-party investors. The proceeds from the sale of the securities and the issuance of the common equity by STBA Capital Trust I were invested in junior subordinated debt securities issued by us. The third party investors are considered the primary beneficiaries; therefore, the trust qualifies as a variable interest entity, or VIE, but is not consolidated into our financial statements. STBA Capital Trust I pays dividends on the securities at the same rate as the interest paid by us on the junior subordinated debt held by STBA Capital Trust I.

NOTE 17. COMMITMENTS AND CONTINGENCIES

Commitments

The following table sets forth the commitments and letters of credit at December 31:

(in thousands)	2012		2011
Commitments to extend credit	$	874,137	$	816,160
Standby letters of credit		95,399		119,576
Total	$	969,536	$	935,736

108

NOTE 17. COMMITMENTS AND CONTINGENCIES — continued

Estimates of the fair value of these off-balance sheet items were not made because of the short-term nature of these arrangements and the credit standing of the counterparties.

Our allowance for unfunded commitments totaled $3.0 million at December 31, 2012 and $1.2 million at December 31, 2011. Refer to Note 1 Summary of Significant Accounting Policies, Allowance for Unfunded Commitments for the methodology used to calculate the allowance for unfunded commitments.

We have future commitments with third party vendors for data processing and communication charges. Data processing and communication charges related to these commitments resulted in expense of $10.3 million for 2012, including $2.3 million in one-time merger related expenses for our acquisitions of Gateway and Mainline, $7.4 million in 2011 and $6.8 million in 2010.

The following table sets forth the future estimated payments related to data processing and communication charges for each of the five years following December 31, 2012:

(in thousands)	Total
2013	$	7,388	(1)
2014		7,032
2015		7,172
2016		6,816
2017		708
Total	$	29,116

(1) Included in this amount is $0.6 million related to the Gateway conversion in the first quarter of 2013.

The commitments in the above table show a decrease in 2014 due to the Gateway conversion expenses in February 2013. The commitments show a decrease again in 2016 and 2017 when two contracts with third party data processors expire.

Litigation

In the normal course of business, we are subject to various legal and administrative proceedings and claims. While any type of litigation contains a level of uncertainty, we believe that the outcome of such proceedings or claims pending will not have a material adverse effect on our consolidated financial position.

NOTE 18. INCOME TAXES

Income tax expense (benefit) for the years ended December 31 are comprised of:

(in thousands)	2012		2011		2010
Current	$	6,223	$	12,174	$	18,969
Deferred		1,038		2,448		(4,537	)
Total	$	7,261	$	14,622	$	14,432

The provision for income taxes differs from the amount computed by applying the statutory federal income tax rate to income before income taxes. We ordinarily generate an annual effective tax rate that is less that the statutory rate of 35 percent primarily due to benefits resulting from tax-exempt interest, excludable dividend income, tax-exempt interest on bank owned life insurance and tax benefits associated with LIHTC from certain partnership investments.

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NOTE 18. INCOME TAXES — continued

The statutory to effective tax rate reconciliation for the years ended December 31 is as follows:

	2012		2011		2010
Statutory tax rate		35.0 %		35.0 %		35.0 %
Low income housing and federal historic tax credits		(10.5)%		(5.5)%		(3.9)%
Tax-exempt interest		(6.7)%		(4.1)%		(4.8)%
Bank owned life insurance		(1.2)%		(1.2)%		(1.3)%
Acquisition costs		0.5 %		—		—
Dividend exclusion		(0.7)%		(0.6)%		(0.7)%
Other		1.1 %		—		0.6 %
Effective Tax Rate		17.5 %		23.6 %		24.9 %

Income taxes applicable to security gains were $1.1 million in 2012, insignificant in 2011 and $0.1 million in 2010.

Significant components of our temporary differences were as follows at December 31:

(in thousands)	2012			2011
Deferred Tax Liabilities:
Net unrealized holding gains on securities available-for-sale	$	(5,586	)	$	(5,208	)
Prepaid pension		(4,721	)		(5,007	)
Deferred loan income		(969	)		(736	)
Purchase accounting adjustments		(935	)		(3,160	)
Depreciation on premises and equipment		(1,963	)		(1,882	)
Other		(690	)		(701	)
Total Deferred Tax liabilities		(14,864	)		(16,694	)
Deferred Tax Assets:
Allowance for loan losses		16,536			15,593
Tax credit carryforwards (expires in 20 years)		1,430			—
Other employee benefits		2,701			2,148
Low income housing partnerships		2,890			2,608
Net adjustment to funded status of pension		12,899			12,804
Impairment of securities		1,375			2,119
Delinquent interest on nonaccrual loans		1,719			1,187
State net operating loss carryforwards		1,498			1,232
Other		3,157			3,559
Gross Deferred Tax Assets		44,205			41,250
Less: Valuation allowance for Pennsylvania net operating loss carryforwards		(1,498	)		(1,232	)
Total Deferred Tax Assets		42,707			40,018
Net Deferred Tax Asset	$	27,843		$	23,324

We establish a valuation allowance when it is more likely than not that we will not be able to realize the benefit of the deferred tax assets. Except for Pennsylvania net operating loss, or NOL, carryforwards, we have determined that a valuation allowance is unnecessary for the deferred tax assets because it is more likely than not that these assets will be realized through future reversals of existing temporary differences and through future taxable income. Periodically, the valuation

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NOTE 18. INCOME TAXES — continued

allowance is reviewed and adjusted based on management’s assessments of realizable deferred tax assets. Gross deferred tax assets were reduced by a valuation allowance related to Pennsylvania income tax NOLs generated by S&T, as utilization of these losses is not likely. These NOL carryforwards total $15.0 million and will expire in the years 2020-2032.

The period change in deferred taxes on our Consolidated Balance Sheet is comprised of the following at December 31:

(in thousands)	2012			2011
Deferred tax changes reflected in other comprehensive gain/loss	$	284		$	(4,186	)
Deferred tax changes resulting from purchase accounting adjustments		(5,843	)		—
Deferred tax changes reflected in federal income tax expense (benefit)		1,038			2,448

Unrecognized Tax Benefits

A reconciliation of the change in Federal and State gross unrecognized tax benefits, or UTB, for the years ended December 31:

(in thousands)	2012			2011			2010
Balance at beginning of year	$	200		$	242		$	286
Prior period tax positions
Increase		—			—			—
Decrease		—			—			(67	)
Current period tax positions		913			(42	)		23
Reductions for statute of limitations expirations		(135	)		—			—
Balance at End of Year	$	978		$	200		$	242
Amount That Would Affect the Effective Tax Rate if Recognized	$	147		$	197		$	239

We classify interest and penalties as an element of tax expense. We monitor changes in tax statutes and regulations to determine if significant changes will occur over the next 12 months. As of December 31, 2012 no significant changes to UTB are projected, however, tax audit examinations are possible.

We recognized $0.2 million related to interest in 2012 and insignificant amounts in both 2011 and 2010 in the Consolidated Statements of Net Income. Additionally, we recognized a $0.5 million liability for an IRS proposed penalty related to our Mainline acquisition. This amount was recognized as an adjustment to purchase accounting and had no impact on our Consolidated Statement of Net Income.

As of December 31, 2012, all income tax returns filed for the tax years 2009 through 2011 remain subject to examination by the IRS. Currently, our income tax return for the 2010 tax year is under examination by the IRS. We do not expect that the results of this examination will have a material effect on our financial condition or results of operations.

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NOTE 19. TAX EFFECTS ON OTHER COMPREHENSIVE INCOME

The following tables present the tax effects of the components of other comprehensive income for the years ended December 31:

(in thousands)	Pre-Tax Amount			Tax (Expense) Benefit			Net of Tax Amount
2012
Change in unrealized gains/losses on securities available-for-sale	$	4,097		$	(1,434	)	$	2,663
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(3,016	)		1,055			(1,961	)
Adjustment to funded status of employee benefit plans		(271	)		95			(176	)
Other Comprehensive Income	$	810		$	(284	)	$	526
2011
Change in unrealized gains/losses on securities available-for-sale	$	6,702		$	(2,346	)	$	4,356
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		124			(43	)		81
Adjustment to funded status of employee benefit plans		(18,787	)		6,576			(12,211	)
Other Comprehensive Income	$	(11,961	)	$	4,187		$	(7,774	)
2010
Change in unrealized gains/losses on securities available-for-sale	$	695		$	(243	)	$	452
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(274	)		96			(178	)
Adjustment to funded status of employee benefit plans		(606	)		212			(394	)
Other Comprehensive Income	$	(185	)	$	65		$	(120	)

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NOTE 20. EMPLOYEE BENEFITS

We maintain a defined benefit pension plan, or Plan, covering substantially all employees hired prior to January 1, 2008. The benefits are based on years of service and the employee’s compensation for the highest five consecutive years in the last ten years. Contributions are intended to provide for benefits attributed to employee service to date and for those benefits expected to be earned in the future.

The following table summarizes the activity in the benefit obligation and Plan assets deriving the funded status, which is recorded in other liabilities in the Consolidated Balance Sheets:

(in thousands)	2012			2011
Change in Projected Benefit Obligation
Projected benefit obligation at beginning of year	$	93,033		$	74,118
Service cost		2,788			2,371
Interest cost		4,358			4,162
Plan participants’ contributions		71			3,964
Plan amendments		—			(1,513	)
Actuarial loss		6,723			15,199
Benefits paid		(4,519	)		(5,268	)
Projected Benefit Obligation at End of Year	$	102,454		$	93,033
Change in Plan Assets
Fair value of plan assets at beginning of year	$	72,626		$	68,774
Actual return on plan assets		9,810			156
Employer contributions		3,100			5,000
Plan participants’ contributions		71			3,964
Benefits paid		(4,519	)		(5,268	)
Fair Value of Plan Assets at End of Year	$	81,088		$	72,626
Funded Status	$	(21,366	)	$	(20,407	)

The following table sets forth the amounts recognized in accumulated other comprehensive gain/loss at December 31:

(in thousands)	2012			2011
Prior service credit	$	(1,442	)	$	(1,579	)
Net actuarial loss		36,297			36,294
Total (Before Tax Effects)	$	34,855		$	34,715

Below are the actuarial weighted average assumptions used in determining the benefit obligation:

	2012			2011
Discount rate		4.00	%		4.75	%
Rate of compensation increase		3.00	%		4.00	%

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NOTE 20. EMPLOYEE BENEFITS — continued

The following table summarizes the components of net periodic pension cost and other changes in Plan assets and benefit obligation recognized in other comprehensive gain/loss for the years ended December 31:

(in thousands)	2012			2011			2010
Components of Net Periodic Pension Cost
Service cost—benefits earned during the period	$	2,788		$	2,371		$	2,245
Interest cost on projected benefit obligation		4,358			4,162			4,017
Expected return on plan assets		(5,564	)		(5,378	)		(4,882	)
Amortization of prior service credit		(137	)		(7	)		(7	)
Recognized net actuarial loss		2,474			773			824
Net Periodic Pension Cost	$	3,919		$	1,921		$	2,197
Other Changes in Plan Assets and Benefit Obligation Recognized in Other Comprehensive Loss
Net actuarial loss (gain)	$	2,477		$	20,422		$	1,261
Recognized net actuarial loss		(2,474	)		(773	)		(824	)
Prior service credit		(0	)		(1,513	)		—
Recognized prior service credit		137			7			7
Total (Before Tax Effects)	$	140		$	18,143		$	444
Total Recognized in Net Benefit Cost and Other Comprehensive Gain/Loss (Before Tax Effects)	$	4,059		$	20,064		$	2,641

The following table summarizes the actuarial weighted average assumptions used in determining net periodic pension cost:

	2012		2011		2010
Discount rate		4.75%		5.75%		6.25%
Rate of compensation increase		4.00%		4.00%		4.00%
Expected return on assets		8.00%		8.00%		8.00%

The net actuarial loss included in accumulated other comprehensive gain/loss expected to be recognized in net periodic pension cost during the year ended December 31, 2013 is $2.4 million. The prior service cost expected to be recognized during the same period is not significant.

The accumulated benefit obligation for the Plan was $93.5 million at December 31, 2012 and $82.0 million at December 31, 2011.

We consider many factors when setting the assumed rate of return on Plan assets. As a general guideline the assumed rate of return is equal to the weighted average of the expected returns for each asset category and is estimated based on historical returns as well as expected future returns. The weighted average discount rate is derived from corporate yield curves.

S&T Bank’s Retirement Plan Committee determines the investment policy for the Plan. In general, the targeted asset allocation is 50 percent to 70 percent equities and 30 percent to 50 percent fixed income. A strategic allocation within each asset class is employed based on the Plan’s time horizon, risk tolerances, performance expectations and asset class preferences. Investment managers have discretion to invest in any equity or fixed-income asset class, subject to the securities guidelines of the Plan’s Investment Policy Statement.

At this time, the Bank is not required to make a cash contribution to the Plan in 2013; however, the Bank contributed $3.1 million to the Plan in December 2012.

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NOTE 20. EMPLOYEE BENEFITS — continued

The following table provides information regarding estimated future benefit payments to be paid in each of the next five years and in the aggregate for the five years thereafter:

(in thousands)	Amount
2013	$	5,813
2014		5,547
2015		6,601
2016		6,225
2017		6,056
2018—2022		36,212

We also have supplemental executive retirement plans, or SERPs, for certain key employees. The SERPs are unfunded. The projected benefit obligations related to the SERPs were $3.5 million and $3.1 million at December 31, 2012 and 2011, respectively. These amounts also represent the net amount recognized in the statement of financial position for the SERPs. Net periodic benefit costs for the SERPs were $0.5 million, $0.3 million, and $0.3 million for each of the years ended December 31, 2012, 2011 and 2010, respectively. Additionally, $2.0 million and $1.9 million before tax were reflected in accumulated other comprehensive gain/loss at December 31, 2012 and 2011, respectively, in relation to the SERPs. The actuarial assumptions used for the SERPs are the same as those used for the Plan.

We maintain a Thrift Plan, a qualified defined contribution plan, in which substantially all employees are eligible to participate. We make matching contributions to the Thrift Plan up to 3.5 percent of participants’ eligible compensation and may make additional profit-sharing contributions as provided by the Thrift Plan. Expense related to these contributions amounted to $1.3 million in 2012 and $1.1 million in both 2011 and 2010.

Fair Value Measurements

The following tables present our Plan assets measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items of a recurring basis during the periods presented. The increase of $0.1 million in Level 3 plan assets since December 31, 2011 is due to an increase in unrealized gains in the investments. There were no purchases, transfers or sales of Level 3 plan assets.

	December 31, 2012
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	8,585	$	—	$	8,585
Fixed Income(3)		22,211		—		1,432		23,643
Equities:
Equity index mutual funds—domestic(4)		1,934		—		—		1,934
Equity index mutual funds—international(5)		4,218		—		—		4,218
Domestic Individual Equities(6)		39,631		—		—		39,631
International Individual Equities(7)		1,802		—		—		1,802
Equity—Partnerships(8)		—		—		1,275		1,275
Total Assets at Fair Value	$	69,796	$	8,585	$	2,707	$	81,088

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

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NOTE 20. EMPLOYEE BENEFITS — continued

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

	December 31, 2011
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	7,440	$	—	$	7,440
Fixed Income(3)		21,539		—		1,333		22,872
Equities:
Equity index mutual funds—domestic(4)		1,580		—		—		1,580
Equity index mutual funds—international(5)		3,437		—		—		3,437
Domestic Individual Equities(6)		34,600		—		—		34,600
International Individual Equities(7)		1,437		—		—		1,437
Equity—Partnerships(8)		—		—		1,260		1,260
Total Assets at Fair Value	$	62,593	$	7,440	$	2,593	$	72,626

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

NOTE 21. INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN

We adopted an Incentive Stock Plan in 1992 that provided for granting incentive stock options, nonstatutory stock options, restricted stock and appreciation rights. On October 17, 1994, the 1992 Stock Plan was amended to include outside directors. The 1992 Stock Plan had a maximum of 3,200,000 shares of our common stock and expired ten years from the date of board approval. At December 31, 2002, 3,180,822 nonstatutory stock options and restricted stock had been granted under the 1992 Stock Plan. No further awards will be made under the 1992 Stock Plan. All grants under the 1992 Stock Plan have expired at December 31, 2012.

We adopted an Incentive Stock Plan in 2003 that provides for granting incentive stock options, nonstatutory stock options, restricted stock and appreciation rights. The 2003 Stock Plan has a maximum of 1,500,000 shares of our common stock and expires ten years from the date of board approval. The 2003 Stock Plan is similar to the 1992 Stock Plan, which the 2003 Stock Plan replaced.

Stock Options

As of December 31, 2012, 675,500 nonstatutory stock options are outstanding under the 2003 Stock Plan. Nonstatutory stock options granted in 2006 and 2005 are fully vested and have a ten-year life. These stock options were fully expensed in 2010.

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NOTE 21. INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN — continued

The fair value of option awards under the nonstatutory stock option plan were estimated on the date of grant using the Black-Scholes valuation model, which is dependent upon certain assumptions. We use the simplified method in developing the estimated life of the option, whereby the expected life is presumed to be the mid point between the vesting date and the end of the contractual term. There have been no nonstatutory stock options granted since 2006.

The following table summarizes activity for nonstatutory stock options for the years ending December 31:

	2012							2011							2010
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at beginning of year		757,050		$	34.33				930,700		$	32.80				1,100,550		$	31.85
Granted		—			—				—			—				—			—
Exercised		—			—				—			—				(82,100	)		19.81
Forfeited		(81,550	)		27.29				(173,650	)		26.11				(87,750	)		33.04
Outstanding at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years
Exercisable at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years

The aggregate intrinsic value of options outstanding and exercisable was zero as of December 31, 2012, 2011 and 2010. The aggregate intrinsic value represents the total pretax intrinsic value (the difference between our closing stock price on the last trading day of the fourth quarter and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2012.

The following table provides information about non-vested options for the years ended December 31:

	Non-Vested Options		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		51,625	$	9.48
Granted		—		—
Vested		30,625		9.48
Forfeited		21,000		9.48
Non-vested at December 31, 2010		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2011		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2012		—	$	—

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NOTE 21. INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN — continued

The following table presents information about stock options exercised for the years ended December 31:

(in thousands, except share data)	2012		2011		2010
Number of options exercised		—		—		82,100
Total intrinsic value of options exercised	$	—	$	—	$	131
Cash received from options exercised		—		—		1,758
Tax deduction realized from options exercised	$	—	$	—	$	46

Restricted Stock

We periodically issue restricted stock to employees and directors, pursuant to the 2003 Stock Plan. As of December 31, 2012, 237,484 restricted shares have been granted under this plan.

During 2012, 2011 and 2010, we granted 19,362, 19,890 and 14,208 restricted shares of common stock, respectively, to outside directors. The grants are part of the compensation arrangement approved by the Compensation and Benefits Committee whereby the directors receive compensation in both the form of cash and restricted shares of common stock. These shares fully vest one year after the date of grant.

Also during 2012, 2011 and 2010, we granted 48,008, 60,157 and 4,688 restricted shares of common stock, respectively, to senior management. The awards to senior management were granted in accordance with performance levels set by the Compensation and Benefits Committee. The first grant or 9,897 restricted shares, vests fully on the second anniversary of the grant dates. The second grant or 38,111 restricted shares was granted under our Long Term Incentive Plan (2012 LTIP) and consists of both time and performance-based awards. Vesting for the time-based awards is 50 percent after two years and the remaining 50 percent at the end of the third year. The performance-based awards vest at the end of the three year period. During 2011 the restricted shares granted occurred on three occasions and have different vesting periods. The first grant, or 16,497 restricted shares, vests fully on the second anniversary of the grant date. The second grant, or 11,104 restricted shares, vested fully on January 1, 2012. The third grant, or 32,556 restricted shares, was granted under our Long Term Incentive Plan (2011 LTIP) and vests in the same manner as explained above. Of the 4,688 restricted shares granted in 2010, 1,881 shares fully vested one year after the date of grant. The remaining 2,807 shares granted vest 50 percent on each of the one and two year anniversaries from the date of grant.

During the vesting period, the recipient receives dividends and has the right to vote the unvested shares granted. If the recipient leaves S&T before the end of the vesting period, shares will be forfeited except in the case of retirement, disability or death where accelerated vesting provisions are defined within the plan agreement.

Compensation expense for time-based restricted stock is recognized ratably over the period of service, generally the entire vesting period, based on fair value on the date of grant. For grants made to directors, the fair value is determined by the closing price of the stock on the date of grant. The average of the high and low prices of the stock on the grant date is used for senior management. Compensation expense for performance-based restricted stock is recognized ratably over the remaining vesting period once the likelihood of meeting the performance measure is probable. During 2012, 2011 and 2010, we recognized compensation expense of $0.9 million, $1.1 million and $0.5 million and realized a tax benefit of $0.3 million, $0.4 million and $0.3 million, respectively.

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NOTE 21. INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN — continued

The following table provides information about restricted stock for the years ended December 31:

	Restricted Stock		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		41,342	$	24.75
Granted		18,896		21.44
Vested		25,006		21.86
Forfeited		3,562		29.15
Non-vested at December 31, 2010		31,670	$	24.56
Granted		80,047		21.39
Vested		23,915		23.69
Forfeited		1,652		23.64
Non-vested at December 31, 2011		86,150	$	21.88
Granted		67,370		21.53
Vested		37,118		19.75
Forfeited		1,383		19.54
Non-vested at December 31, 2012		115,019	$	22.39

As of December 31, 2012, there was $1.3 million of total unrecognized compensation cost related to restricted stock that will be recognized as compensation expense over a weighted average period of one year.

Dividend Reinvestment Plan

We also sponsor a Dividend Reinvestment and Stock Purchase Plan, or Dividend Plan, where shareholders may purchase shares of S&T common stock at the average fair value with reinvested dividends and voluntary cash contributions. The plan administrator and transfer agent, may purchase shares directly from us from shares held in treasury or purchase shares in the open market to fulfill the Dividend Plan’s needs.

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NOTE 22. PARENT COMPANY CONDENSED FINANCIAL INFORMATION

The following condensed financial statements summarize the financial position of S&T Bancorp, Inc. as of December 31, 2012 and 2011 and the results of its operations and cash flows for each of the three years ended December 31, 2012, 2011 and 2010.

BALANCE SHEETS

	December 31,
(in thousands)	2012		2011
ASSETS
Cash	$	12,202	$	13,684
Investments in:
Bank subsidiary		523,664		474,661
Nonbank subsidiaries		19,934		20,008
Other assets		3,129		2,937
Total Assets	$	558,929	$	511,290
LIABILITIES
Long-term debt	$	20,619	$	20,619
Other liabilities		888		145
Total Liabilities		21,507		20,764
Total Shareholders’ Equity		537,422		490,526
Total Liabilities and Shareholders’ Equity	$	558,929	$	511,290

STATEMENTS OF NET INCOME

	Years ended December 31,
(in thousands)	2012			2011		2010
Dividends from subsidiaries	$	35,603		$	23,029	$	22,634
Investment income		17			121		86
Interest expense on long-term debt		808			777		782
Other expenses		1,800			1,091		1,648
Income before Equity in Undistributed Net Income of Subsidiaries		33,012			21,282		20,290
Equity in undistributed net income (distribution in excess of net income) of:
Bank subsidiary		1,371			25,590		23,158
Nonbank subsidiaries		(183	)		392		32
Net Income	$	34,200		$	47,264	$	43,480

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NOTE 22. PARENT COMPANY CONDENSED FINANCIAL INFORMATION — continued

STATEMENTS OF CASH FLOWS

	Years ended December 31,
(in thousands)	2012			2011			2010
OPERATING ACTIVITIES
Net Income	$	34,200		$	47,264		$	43,480
Equity in (undistributed net income) distribution in excess of net income of subsidiaries		(1,188	)		(25,982	)		(23,190	)
Tax expense (benefit) from stock-based compensation		30			66			(46	)
Other		1,023			10,145			470
Net Cash Provided by Operating Activities		34,065			31,493			20,714
INVESTING ACTIVITIES
Net investments in subsidiaries		(5,035	)		—			—
Acquisitions		(14,123	)		—			—
Net Cash Used In Investing Activities		(19,158	)		—			—
FINANCING ACTIVITIES
Redemption of preferred stock		—			(108,676	)		—
Sale of treasury shares, net		998			1,946			3,692
Preferred stock dividends		—			(5,072	)		(5,434	)
Cash dividends paid to common shareholders		(17,357	)		(16,830	)		(16,683	)
Tax (expense) benefit from stock-based compensation		(30	)		(66	)		46
Net Cash Used in Financing Activities		(16,389	)		(128,698	)		(18,379	)
Net (decrease) increase in cash		(1,482	)		(97,205	)		2,335
Cash at beginning of year		13,684			110,889			108,554
Cash at End of Year	$	12,202		$	13,684		$	110,889

NOTE 23. REGULATORY MATTERS

We are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet the minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on our financial statements. Under capital guidelines and the regulatory framework for prompt corrective action, we must meet specific capital guidelines that involve quantitative measures of our assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. Our capital amounts and classification are also subject to qualitative judgments by the regulators about risk weightings and other factors.

The most recent notifications from the Federal Reserve and the FDIC categorized S&T and S&T Bank as well capitalized under the regulatory framework for corrective action. There have been no conditions or events that we believe have changed S&T or S&T Bank’s status during 2012 and 2011.

Tier 1 capital consists principally of shareholders’ equity, including preferred stock; excluding items recorded in accumulated other comprehensive gain/loss, less goodwill and other intangibles. For regulatory purposes, trust preferred securities totaling $20.0 million, issued by an unconsolidated trust subsidiary of S&T underlying such junior subordinated debt, are included in Tier 1 capital for S&T. Total capital consists of Tier 1 capital plus junior subordinated debt and the ALL subject to limitation. We currently have $70.0 million in junior subordinated debt which is included in Tier 2 capital for S&T in accordance with current regulatory reporting requirements.

121

NOTE 23. REGULATORY MATTERS — continued

Quantitative measures established by regulation to ensure capital adequacy require us to maintain minimum amounts and ratios of Total and Tier 1 capital to risk-weighted assets and Tier 1 capital to average assets. As of December 31, 2012 and 2011, we met all capital adequacy requirements to which we are subject.

The following table summarizes risk-based capital amounts and ratios for S&T and S&T Bank.

	Actual					For Capital Adequacy Purposes					To be Well Capitalized Under Prompt Corrective Action Provisions
(in thousands, except for ratios)	Amount		Ratio			Amount		Ratio			Amount		Ratio
As of December 31, 2012
Total Capital (to Risk-Weighted Assets)
S&T	$	504,041		15.39	%	$	262,029		8.00	%	$	327,536		10.00	%
S&T Bank		452,906		14.35	%		252,489		8.00	%		315,611		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		392,506		11.98	%		131,015		4.00	%		196,522		6.00	%
S&T Bank		343,331		10.88	%		126,244		4.00	%		189,366		6.00	%
Leverage Ratio(1)
S&T		392,506		9.31	%		168,563		4.00	%		210,704		5.00	%
S&T Bank		343,331		8.45	%		162,611		4.00	%		203,264		5.00	%
As of December 31, 2011
Total Capital (to Risk-Weighted Assets)
S&T	$	465,702		15.20	%	$	245,154		8.00	%	$	306,443		10.00	%
S&T Bank		429,837		14.11	%		243,699		8.00	%		304,623		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		356,484		11.63	%		122,577		4.00	%		183,866		6.00	%
S&T Bank		321,352		10.55	%		121,849		4.00	%		182,774		6.00	%
Leverage Ratio(1)
S&T		356,484		9.17	%		155,526		4.00	%		194,408		5.00	%
S&T Bank		321,352		8.30	%		154,789		4.00	%		193,486		5.00	%

⁽¹⁾  Minimum requirement is 3.00 percent for the most highly-rated financial institutions.

NOTE 24. CAPITAL PURCHASE PROGRAM

On December 7, 2011 we redeemed all of the $108.7 million, or 108,676 shares, of Series A Preferred Stock issued on January 16, 2009 in conjunction with our participation in the CPP. Upon redemption, a one-time non-cash reduction to net income available to common shareholders of $1.8 million, or $0.06 per common share, was recorded for the remaining unamortized discount of the preferred stock. Refer to Note 23 Regulatory Matters for additional disclosures regarding capital requirements.

As part of its original purchase of the Series A Preferred Stock, the U.S. Treasury received a warrant to purchase 517,012 shares of our common stock at an initial per share exercise price of $31.53. The warrant provides for the adjustment of the exercise price and the number of shares of our common stock issuable upon exercise pursuant to customary anti-dilution provisions, such as upon stock splits or distributions of securities or other assets to holders of our common stock and upon certain issuances of our common stock at or below a specified price relative to the initial exercise price. A binomial pricing model was used to calculate the fair value of the common stock warrant we issued on January 16, 2009 resulting in a fair value of $4.0 million.

122

NOTE 24. CAPITAL PURCHASE PROGRAM — continued

The assumptions used to calculate the fair value of the warrant are summarized below:

Assumption	Value
Contractual term		10 years
Exercise price	$	31.53
Estimated fair value of company stock	$	29.14
Expected life		10 years
Risk-free rate over expected life of the warrant		2.36	%
Expected volatility		28.40	%
Expected dividend yield		3.85	%

We utilized the average of daily and monthly historical volatility for purposes of this valuation. In addition, the U.S. Treasury has agreed not to exercise voting power with respect to any shares of common stock issued upon exercise of the warrant. We did not repurchase the warrant at the time of the Series A Preferred Stock redemption and it will remain outstanding until January 2019 or until we repurchase it from the U.S. Treasury or it is exercised by the owner.

NOTE 25. SEGMENTS

We operate three reportable operating segments including Community Banking, Wealth Management and Insurance.

• Our Community Banking segment offers services which include accepting time and demand deposits, originating commercial and consumer loans and providing letters of credit and credit card services.

• Our Wealth Management segment offers discount brokerage services, services as executor and trustee under wills and deeds, guardian and custodian of employee benefits and other trust and brokerage services, as well as a registered investment advisor that manages private investment accounts for individuals and institutions.

• Our Insurance segment includes a full-service insurance agency offering commercial property and casualty insurance, group life and health coverage, employee benefit solutions and personal insurance lines.

The following represents total assets by reportable operating segment as of December 31:

(in thousands)	2012		2011
Community Banking	$	4,516,194	$	4,110,462
Insurance		9,302		8,192
Wealth Management		1,206		1,340
Total Assets	$	4,526,702	$	4,119,994

123

NOTE 25. SEGMENTS — continued

The following tables provide financial information for our three segments. The financial results of the business segments include allocations for shared services based on an internal analysis that supports line of business and branch performance measurement. Shared services include expenses such as employee benefits, occupancy expense, computer support and other corporate overhead. Even with these allocations, the financial results are not necessarily indicative of the business segments’ financial condition and results of operations as if they existed as independent entities. The information provided under the caption “Eliminations” represents operations not considered to be reportable segments and/or general operating expenses and eliminations and adjustments, which are necessary for purposes of reconciling to the Consolidated Financial Statements.

	For the Year Ended December 31, 2012
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	155,865	$	454	$	1		$	(69	)	$	156,251
Interest expense		22,135		—		—			(1,111	)		21,024
Net interest income (expense)		133,730		454		1			1,042			135,227
Provision for loan losses		22,815		—		—			—			22,815
Noninterest income		36,422		9,788		5,262			440			51,912
Noninterest expense		97,687		9,448		5,415			4,692			117,242
Depreciation expense		3,833		31		48			—			3,912
Intangible amortization		1,600		57		52			—			1,709
Income tax expense (benefit)		10,207		352		(88	)		(3,210	)		7,261
Net Income (Loss)	$	34,010	$	354	$	(164	)	$	—		$	34,200

	For the Year Ended December 31, 2011
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	164,738	$	307	$	1		$	33		$	165,079
Interest expense		27,692		—		291			(250	)		27,733
Net interest income (expense)		137,046		307		(290	)		283			137,346
Provision for loan losses		15,609		—		—			—			15,609
Noninterest income		30,195		8,328		5,236			298			44,057
Noninterest expense		81,180		7,302		5,199			4,236			97,917
Depreciation expense		4,165		32		57			—			4,254
Intangible amortization		1,619		66		52			—			1,737
Income tax expense (benefit)		17,911		493		(127	)		(3,655	)		14,622
Net Income (Loss)	$	46,757	$	742	$	(235	)	$	—		$	47,264

	For the Year Ended December 31, 2010
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	180,319	$	471	$	2		$	(373	)	$	180,419
Interest expense		34,692		—		293			(412	)		34,573
Net interest income (expense)		145,627		471		(291	)		39			145,846
Provision for loan losses		29,511		—		—			—			29,511
Noninterest income		32,959		7,950		4,968			1,333			47,210
Noninterest expense		82,872		7,525		4,850			4,181			99,428
Depreciation expense		4,163		34		62			—			4,259
Intangible amortization		1,815		75		56			—			1,946
Income tax (benefit) expense		17,019		324		(102	)		(2,809	)		14,432
Net Income (Loss)	$	43,206	$	463	$	(189	)	$	—		$	43,480

124

NOTE 26. OTHER NONINTEREST EXPENSE

Other noninterest expenses are presented in the table below:

	Years ended December 31,
(in thousands)	2012		2011			2010
Other noninterest expenses:
Joint venture amortization	$	4,199	$	3,302		$	2,573
Other real estate owned		2,166		1,518			1,921
Unfunded loan commitments		1,811		(1,474	)		(1,555	)
Amortization of intangibles		1,709		1,737			1,943
Loan collection fees		430		624			1,770
Other		14,718		12,979			13,597
Total Other Noninterest Expenses	$	25,033	$	18,686		$	20,249

NOTE 27. SELECTED FINANCIAL DATA

The following table presents selected financial data for the most recent eight quarters:

(unaudited)

	2012								2011
(in thousands, except per share data)	Fourth Quarter		Third Quarter		Second Quarter		First Quarter		Fourth Quarter		Third Quarter			Second Quarter			First Quarter
SUMMARY OF OPERATIONS
Interest income	$	38,920	$	38,820	$	39,370	$	39,140	$	40,259	$	40,845		$	41,783		$	42,192
Interest expense		4,629		5,025		5,551		5,819		6,192		6,976			7,245			7,320
Provision for loan losses		4,215		2,305		7,023		9,272		2,337		1,535			1,097			10,640
Net interest income after provision for loan losses		30,076		31,490		26,796		24,049		31,730		32,334			33,441			24,232
Security gains (losses), net		—		2,170		6		840		—		(81	)		(56	)		13
Noninterest income		11,565		12,576		12,525		12,229		11,574		10,424			11,170			11,013
Noninterest expense		29,717		31,018		29,344		32,783		26,672		24,193			25,594			27,449
Income before taxes		11,924		15,218		9,983		4,335		16,632		18,484			18,961			7,809
Provision for income taxes		2,400		2,623		1,383		855		4,376		4,681			4,051			1,514
Net income		9,524		12,595		8,600		3,480		12,256		13,803			14,910			6,295
Preferred stock dividends and discount amortization		—		—		—		—		2,939		1,559			1,558			1,555
Net Income Available to Common Shareholders	$	9,524	$	12,595	$	8,600	$	3,480	$	9,317	$	12,244		$	13,352		$	4,740
Per Share Data
Common earnings per share — diluted	$	0.32	$	0.43	$	0.30	$	0.12	$	0.33	$	0.44		$	0.48		$	0.17
Dividends declared per common share		0.15		0.15		0.15		0.15		0.15		0.15			0.15			0.15
Common book value		18.08		17.97		17.65		17.47		17.44		17.68			17.31			16.90

On December 7, 2011 we redeemed all of the $108.7 million, or 108,676 shares, of Series A Preferred Stock issued on January 16, 2009 in conjunction with our participation in the CPP. Upon redemption, a one-time non-cash reduction to net income available to common shareholders of $1.8 million, or $0.06 per common share, was recorded for the remaining unamortized discount of the preferred stock.

125

NOTE 28. SUBSEQUENT EVENT

In the first quarter of 2013, we entered into a long-term agreement with a merchant processing company. We received an upfront fee and will receive future revenue based upon a revenue sharing agreement. As a result of this agreement, we will be terminating our current merchant processing agreement and expect to incur an early termination fee. We are working with our existing merchant processor to determine the amount of the fee. We are currently evaluating the transaction and the impact on our first quarter of 2013 financial statements.

126

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Shareholders

S&T Bancorp, Inc. and subsidiaries:

We have audited S&T Bancorp, Inc. and subsidiaries (the Company) internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audit also included performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated balance sheets of the Company as of December 31, 2012 and 2011, and the related consolidated statements of net income, comprehensive income and changes in shareholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2012, and our report dated February 22, 2013 expressed an unqualified opinion on those consolidated financial statements.

/s/ KPMG LLP

Pittsburgh, Pennsylvania

February 22, 2013

127

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Shareholders

S&T Bancorp, Inc. and subsidiaries:

We have audited the accompanying consolidated balance sheets of S&T Bancorp, Inc. and subsidiaries (the Company) as of December 31, 2012 and 2011, and the related consolidated statements of net income, comprehensive income and changes in shareholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2012. These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated financial statements based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of S&T Bancorp, Inc. and subsidiaries as of December 31, 2012 and 2011, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2012, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the Company’s internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), and our report dated February 22, 2013 expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

/s/ KPMG LLP

Pittsburgh, Pennsylvania

February 22, 2013

128

Item 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURES

None

Item 9A.  CONTROLS AND PROCEDURES

a) Evaluation of Disclosure Controls and Procedures

Under the supervision and with the participation of S&T’s Chief Executive Officer, or CEO, and Chief Financial Officer, or CFO (its principal executive officer and principal financial officer, respectively) management has evaluated the effectiveness of the design and operation of S&T’s disclosure controls and procedures as of December 31, 2012. In designing and evaluating the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives.

We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed by us in the reports that we file or submit under the Securities Exchange Act of 1934, as amended, or the Exchange Act, is recorded, processed, summarized and reported within the time periods required by the Securities and Exchange Commission, or the SEC, and that such information is accumulated and communicated to S&T’s management, including our CEO and CFO as appropriate, to allow timely decisions regarding required disclosure.

Based on and as of the date of such evaluation, our CEO and CFO concluded that the design and operation of our disclosure controls and procedures were effective in all material respects, as of the end of the period covered by this report.

b) Management’s Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rule 13a-15(f). Management assessed S&T’s system of internal control over financial reporting as of December 31, 2012, in relation to criteria for effective internal control over financial reporting as described in “Internal Control—Integrated Framework,” issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on this assessment, management concludes that, as of December 31, 2012, S&T’s system of internal control over financial reporting is effective and meets the criteria of the “Internal Control—Integrated Framework.”

KPMG LLP, independent registered public accounting firm, has issued a report on the effectiveness of S&T’s internal control over financial reporting as of December 31, 2012, which is included herein.

c) Changes in Internal Control Over Financial Reporting

No changes were made to S&T’s internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) during the last fiscal quarter that materially affected, or are reasonably likely to materially affect, S&T’s internal control over financial reporting.

Item 9B.  OTHER INFORMATION

Not applicable

129

PART III

Item 10.  DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The information required by Item 10 of Form 10-K is incorporated herein from the sections entitled “Section 16(a) Beneficial Ownership Reporting Compliance”, “Election of Directors”, “Executive Officers of the Registrant” and “Corporate Governance and Board and Committee Meetings” in our proxy statement relating to our May 20, 2013 annual meeting of shareholders.

Item 11.  EXECUTIVE COMPENSATION

This information required by Item 11 of Form 10-K is incorporated herein from the sections entitled “Compensation Discussion and Analysis;” “Executive Compensation;” “Director Compensation;” “Compensation Committee Interlocks and Insider Participation”; and “Compensation Committee Report” in our proxy statement relating to our May 20, 2013 annual meeting of shareholders.

Item 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS

Except as set forth below, the information required by Item 12 of Form 10-K is incorporated from the sections entitled “Principal Beneficial Owners of S&T Common Stock” and “Beneficial Ownership of S&T Common Stock by Directors and Officers” in our proxy statement relating to our May 20, 2013 annual meeting of shareholders.

EQUITY COMPENSATION PLAN INFORMATION UPDATE

The following table provides information as of December 31, 2012 related to the equity compensation plans in effect at that time.

	(a)		(b)		(c)
Plan category	Number of securities to be issued upon exercise of outstanding options, warrants and rights		Weighted average exercise price of outstanding options, warrants and rights		Number of securities remaining available for future issuance under equity compensation plan (excluding securities reflected in column (a))
Equity compensation plan approved by shareholders(1)		675,500	$	35.43		325,016
Equity compensation plans not approved by shareholders		—		—		—
Total		675,500	$	35.43		325,016

⁽¹⁾  Awards granted under the 2003 Incentive Stock Plan.

Item 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

The information required by Item 13 of Form 10-K is incorporated herein from the sections entitled “Related Person Transactions” and “Director Independence” in our proxy statement relating to our May 20, 2013 annual meeting of shareholders.

Item 14.  PRINCIPAL ACCOUNTING FEES AND SERVICES

The information required by Item 14 of Form 10-K is incorporated herein from the section entitled “Independent Registered Public Accounting Firm” in our proxy statement relating to our May 20, 2013 annual meeting of shareholders.

130

PART IV

Item 15.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES

(a) The following documents are filed as part of this report.

Consolidated Financial Statements: The following consolidated financial statements are included in Part II, Item 8 of this report. No financial statement schedules are being filed since the required information is inapplicable or is presented in the Consolidated Financial Statements or related notes.

Consolidated Balance Sheets	64
Consolidated Statements of Net Income	65
Consolidated Statements of Comprehensive Income	66
Consolidated Statements of Changes in Shareholders’ Equity	67
Consolidated Statements of Cash Flows	68
Notes to Consolidated Financial Statements	69
Report of KPMG LLP, Independent Registered Public Accounting Firm on Effectiveness of Internal Control Over Financial Reporting	127
Report of KPMG LLP, Independent Registered Public Accounting Firm on Consolidated Financial Statements	128

131

(b)    Exhibits
	2.1	Agreement and Plan of Merger, dated as of September 14, 2011, between S&T Bancorp, Inc. and Mainline Bancorp, Inc. Filed as Exhibit 2.1 to S&T Bancorp, Inc. Current Report on Form 8-K filed on September 16, 2011 and incorporated herein by reference.
	2.2	Amendment No. 1 to the Agreement and Plan of Merger, dated as of January 27, 2012, between S&T Bancorp, Inc. and Mainline Bancorp, Inc., dated September 14, 2012. Filed as Exhibit A to Form S-4 Registration Statement (No. 333-178424) dated January 30, 2012 and incorporated herein by reference.
	2.3	Agreement and Plan of Merger, dated March 29, 2012, between S&T Bancorp, Inc. and Gateway Bank of Pennsylvania filed as Exhibit 2.1 to the S&T Bancorp, Inc. Current report on Form 8-K filed on April 3, 2012 and incorporated herein by reference.
	3.1	Articles of Incorporation of S&T Bancorp, Inc. Filed as Exhibit B to Registration Statement (No. 2-83565) on Form S-4 of S&T Bancorp, Inc., dated May 5, 1983, and incorporated herein by reference.
	3.2	Amendment to Articles of Incorporation of S&T Bancorp, Inc. Filed as Exhibit 3.2 to Form S-4 Registration Statement (No. 33-02600) dated January 15, 1986, and incorporated herein by reference.
	3.3	Amendment to Articles of Incorporation of S&T Bancorp, Inc. effective May 8, 1989, incorporated herein by reference. Filed as exhibit 3.3 to S&T Bancorp, Inc. Annual Report on Form 10-K for year ending December 31, 1998 and incorporated herein by reference.
	3.4	Amendment to Articles of Incorporation of S&T Bancorp, Inc. effective July 21, 1995. Filed as exhibit 3.4 to S&T Bancorp, Inc. Annual Report on Form 10-K for year ending December 31, 1998 and incorporated here by reference.
	3.5	Amendment to Articles of Incorporation of S&T Bancorp, Inc. effective June 18, 1998. Filed as exhibit 3.5 to S&T Bancorp, Inc. Annual Report on Form 10-K for year ending December 31, 1998 and incorporated herein by reference.
	3.6	Amendment to Articles of Incorporation of S&T Bancorp, Inc. effective April 21, 2008. Filed as Exhibit 3.1 to S&T Bancorp, Inc. Quarterly Report on Form 10-Q filed on August 7, 2008 and incorporated herein by reference.
	3.7	Certificate of Designations for the Series A Preferred Stock. Filed as Exhibit 3.1 to S&T Bancorp, Inc. Current Report on Form 8-K filed on January 15, 2009 and incorporated herein by reference.
	3.8	By-laws of S&T Bancorp, Inc., as amended, April 21, 2008. Filed as Exhibit 3.2 to S&T Bancorp, Inc. Quarterly Report on Form 10-Q filed on August 7, 2008 and incorporated herein by reference.
	10.1	S&T Bancorp, Inc. Amended and Restated 1992 Incentive Stock Plan. Filed as Exhibit 4.2 to Form S-8 Registration Statement (No. 333-48549) dated March 24, 1998 and incorporated herein by reference.*
	10.2	S&T Bancorp, Inc. 2003 Incentive Stock Plan. Filed as Exhibit 4.2 to Form S-8 Registration Statement (No. 333-111557) dated December 24, 2003 and incorporated herein by reference.*

132

(b)    Exhibits
	10.3	S&T Bancorp, Inc. Thrift Plan for Employees of S&T Bank, as amended and restated. Filed as Exhibit 4.2 to Form S-8 Registration Statement (No. 333-156541) dated December 31, 2008 and incorporated herein by reference.*
	10.4	Dividend Reinvestment and Stock Purchase Plan of S&T Bancorp, Inc. Filed as Exhibit 4.2 to Form S-3 Registration Statement (No. 333-156555) dated January 2, 2009 and incorporated herein by reference. Filed as Exhibit 4.2 to S&T Bancorp, Inc. on Form S-8 filed on January 2, 2009 and incorporated herein by reference.*
	10.5	Severance Agreement, by and between Todd D. Brice and S&T Bancorp, Inc., dated December 31, 2008. Filed as Exhibit 10.1 to S&T Bancorp, Inc. Current Report on Form 8-K filed on January 2, 2009 and incorporated herein by reference.*
	10.6	Severance Agreement, by and between Edward C. Hauck and S&T Bancorp, Inc., dated December 31, 2008. Filed as Exhibit 10.3 to S&T Bancorp, Inc. Current Report on Form 8-K filed on January 2, 2009 and incorporated herein by reference.*
	10.7	Severance Agreement, by and between David G. Antolik and S&T Bancorp, Inc. dated December 31, 2008. Filed as Exhibit 10.4 to S&T Bancorp, Inc. Current Report on Form 8-K filed on January 2, 2009 and incorporated herein by reference.*
	10.8	Severance Agreement, by and between Gregor T. Young IV and S&T Bancorp, Inc. dated December 31, 2008. Filed as Exhibit 10.5 to S&T Bancorp, Inc. Current Report on Form 8-K filed on January 2, 2009 and incorporated herein by reference.*
	10.9	Severance Agreement, by and between Mark Kochvar and S&T Bancorp, Inc. dated as of January 1, 2009. Filed as Exhibit 10.1 to S&T Bancorp, Inc. Current Report on Form 8-K filed on February 26, 2010 and incorporated herein by reference.*
	21	Subsidiaries of the Registrant.
	23	Consent of KPMG LLP, Independent Registered Public Accounting Firm.
	24.1	Power of Attorney.
	24.2	Power of Attorney.
	31.1	Rule 13a-14(a) Certification of the Chief Executive Officer.
	31.2	Rule 13a-14(a) Certification of the Principal Financial Officer.
	32	Rule 13a-14(b) Certification of the Chief Executive Officer and Principal Financial Officer.
	101**	The following financial information from the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2012 is formatted in eXtensible Business Reporting Language (XBRL): (i) Consolidated Balance Sheets, (ii) Consolidated Statements of Net Income, (iii) Consolidated Statements of Comprehensive Income (iv) Consolidated Statements of Changes in Shareholders’ Equity and (v) Consolidated Statements of Cash Flows and (vi) Notes to Consolidated Financial Statements.

* Management Contract or Compensatory Plan or Arrangement

** This exhibit is furnished and will not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (15 U.S.C. 78r), or otherwise subject to the liability of that section. Such exhibit will not be deemed to be incorporated by reference into any filing under the Securities Act or of Securities Exchange Act, except to the extent that the Registrant specifically incorporates it by reference.

133

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

S&T BANCORP, INC. (Registrant)
	02/22/13
Todd D. Brice President and Chief Executive Officer (Principal Executive Officer)	Date
	02/22/13
Mark Kochvar Senior Executive Vice President, Chief Financial Officer (Principal Financial Officer)	Date

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

SIGNATURE	TITLE	DATE
Todd D. Brice	President and Chief Executive Officer (Principal Executive Officer)	02/22/13
Mark Kochvar	Senior Executive Vice President and Chief Financial Officer (Principal Financial Officer)	02/22/13
/s/ Melanie Lazzari Melanie Lazzari	Senior Vice President, Controller	02/22/13
* John N. Brenzia	Director	02/22/13
John J. Delaney	Director	02/22/13
Michael J. Donnelly	Director	02/22/13
* William J. Gatti	Director	02/22/13

134

SIGNATURE	TITLE	DATE
* Jeffrey D. Grube	Director	02/22/13
Frank W. Jones	Director	02/22/13
/s/ Joseph A. Kirk Joseph A. Kirk	Director	02/22/13
David L. Krieger	Director	02/22/13
* James C. Miller	Chairman of the Board and Director	02/22/13
Fred J. Morelli, Jr.	Director	02/22/13
* Frank J. Palermo, Jr.	Director	02/22/13
* Alan Papernick	Director	02/22/13
* Charles A. Spadafora	Director	02/22/13
* Christine J. Toretti	Director	02/22/13
Charles G. Urtin	Director	02/22/13
*By: /s/ Joseph A. Kirk         Joseph A. Kirk         Attorney-in-fact	Director	02/22/13

135

EX-21

Exhibit 21

SUBSIDIARIES OF THE REGISTRANT

S&T Bancorp, Inc., a Pennsylvania corporation, is a financial holding company. The table below sets forth all of our subsidiaries as to state or jurisdiction of organization.

Subsidiary	State or Jurisdiction of Organization
S&T Bank	Pennsylvania
Gateway Bank of Pennsylvania(1)	Pennsylvania
9th Street Holdings, Inc.	Delaware
S&T Bancholdings, Inc.	Delaware
S&T Insurance Group, LLC	Pennsylvania
S&T Professional Resources Group, LLC	Pennsylvania
S&T-Evergreen Insurance, LLC	Pennsylvania
S&T Settlement Services, LLC	Pennsylvania
Stewart Capital Advisors, LLC	Pennsylvania
STBA Capital Trust I	Delaware
Commonwealth Trust Credit Life Insurance Company	Arizona

⁽¹⁾ Gateway Bank of Pennsylvania was merged into S&T Bank on February 8, 2013.

EX-23

Exhibit 23

Consent of Independent Registered Public Accounting Firm

The Board of Directors

S&T Bancorp, Inc. and subsidiaries:

We consent to the incorporation by reference in the registration statement Nos. 333-183978, 333-161444, 333-157297 and 333-156555, on Form S-3, Nos. 333-181568 and 333-178424 on Form S-4, and No. 333-156541 on Form S-8 of S&T Bancorp, Inc. and subsidiaries of our reports dated February 22, 2013, with respect to the consolidated balance sheets of S&T Bancorp, Inc. and subsidiaries as of December 31, 2012 and 2011, and the related consolidated statements of net income, comprehensive income and changes in shareholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2012, and the effectiveness of internal control over financial reporting as of December 31, 2012, which reports appear in the December 31, 2012 annual report on Form 10-K of S&T Bancorp, Inc. and subsidiaries.

/s/ KPMG LLP

Pittsburgh, Pennsylvania

February 22, 2013

EX-24.1

Exhibit 24.1

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below (each, a “Signatory”) constitutes and appoints Joseph A. Kirk, Jeffrey D. Grube and Frank W. Jones (each an “Agent,” and collectively, “Agents”) or any of them, his true and lawful attorney-in-fact and agent for and in his name, place and stead, in any and all capacities, to sign the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 and to file the same, with all exhibits thereto, and all amendments or other documents in connection therewith, with the Securities and Exchange Commission. Each Signatory further grants to the Agent full power and authority to do and perform each and every act and thing requisite and necessary, in the judgment of such Agent, to be done in connection with any such signing and filing, as full to all intents and purposes as he might or could do in person, and hereby ratifies and confirms all that said Agent may lawfully do or cause to be done by virtue hereof.

This Power of Attorney may be executed simultaneously in one or more counterparts, each of which shall be deemed an original, but all of which constitute but one and the same instrument.

Signature	Title	Date
/s/ James C. Miller James C. Miller	Chairman of the Board and Director	February 22, 2013
/s/ Todd D. Brice Todd D. Brice	Chief Executive Officer and Director	February 22, 2013
/s/ John N. Brenzia John N. Brenzia	Director	February 22, 2013
John J. Delaney	Director	February 22, 2013
Michael J. Donnelly	Director	February 22, 2013
/s/ William J. Gatti William J. Gatti	Director	February 22, 2013
/s/ Jeffrey D. Grube Jeffrey D. Grube	Director	February 22, 2013
Frank W. Jones	Director	February 22, 2013
/s/ Joseph A. Kirk Joseph A. Kirk	Director	February 22, 2013
David L. Krieger	Director	February 22, 2013

Signature	Title	Date
/s/ Alan Papernick Alan Papernick	Director	February 22, 2013
/s/ Charles A. Spadafora Charles A. Spadafora	Director	February 22, 2013
/s/ Christine J. Toretti Christine J. Toretti	Director	February 22, 2013
Charles G. Urtin	Director	February 22, 2013

EX-24.2

Exhibit 24.2

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below (each, a “Signatory”) constitutes and appoints Joseph A. Kirk, Jeffrey D. Grube and Frank W. Jones (each an “Agent,” and collectively, “Agents”) or any of them, his true and lawful attorney-in-fact and agent for and in his name, place and stead, in any and all capacities, to sign the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 and to file the same, with all exhibits thereto, and all amendments or other documents in connection therewith, with the Securities and Exchange Commission. Each Signatory further grants to the Agent full power and authority to do and perform each and every act and thing requisite and necessary, in the judgment of such Agent, to be done in connection with any such signing and filing, as full to all intents and purposes as he might or could do in person, and hereby ratifies and confirms all that said Agent may lawfully do or cause to be done by virtue hereof.

This Power of Attorney may be executed simultaneously in one or more counterparts, each of which shall be deemed an original, but all of which constitute but one and the same instrument.

Signature	Title	Date
Fred J. Morelli, Jr.	Director	February 22, 2013
/s/ Frank J. Palermo, Jr. Frank J. Palermo, Jr.	Director	February 22, 2013

EX-31.1

Exhibit 31.1

Certification of Principal Executive Officer

Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

I, Todd D. Brice, certify that:

1. I have reviewed this Annual Report on Form 10-K of S&T Bancorp, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report), that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: February 22, 2013

/s/ Todd D. Brice

Todd D. Brice, President and Chief Executive Officer

EX-31.2

Exhibit 31.2

Certification of Principal Financial Officer

Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

I, Mark Kochvar, certify that:

1. I have reviewed this Annual Report on Form 10-K of S&T Bancorp, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report), that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: February 22, 2013

/s/ Mark Kochvar

Mark Kochvar, Senior Executive Vice President, Chief Financial Officer

EX-32

Exhibit 32

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

AND CHIEF FINANCIAL OFFICER

SARBANES-OXLEY ACT SECTION 906

Pursuant to 18 U.S.C. Section 1350 as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, in connection with the S&T Bancorp, Inc. (the “Company”) Annual Report on Form 10-K for the period ending December 31, 2012 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Todd D. Brice, President and Chief Executive Officer of the Company, and I, Mark Kochvar, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. 1350, as adopted pursuant to 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company for the dates and period covered by the report.

This certificate is being made for the exclusive purpose of compliance by the Chief Executive Officer and Chief Financial Officer of the Company with the requirements of Section 906 of the Sarbanes-Oxley Act of 2002, and may not be disclosed, distributed or used by any person or for any reason other than as specifically required by law.

Date: February 22, 2013

/s/ Todd D. Brice	/s/ Mark Kochvar
Todd D. Brice, President and Chief Executive Officer	Mark Kochvar, Senior Executive Vice President, Chief Financial Officer

XML

EARNINGS PER SHARE (Tables)

12 Months Ended

Dec. 31, 2012

Reconciles Numerators and Denominators of Basic Earnings Per Share with Diluted Earnings Per Share

The following table reconciles the numerators and denominators of basic EPS with that of diluted EPS:

	Years ended December 31,
(in thousands, except share and per share data)	2012		2011		2010
Numerator for Earnings per Common Share—Basic:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Less: Income allocated to participating shares		126		130		42
Net Income Allocated to Common Shareholders	$	34,074	$	39,523	$	37,237
Numerator for Earnings per Common Share—Diluted:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Net Income Available to Common Shareholders	$	34,200	$	39,653	$	37,279
Denominators:
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Potentially dilutive common shares		32,261		23,169		22,261
Denominator for Treasury Stock Method—Diluted		29,008,880		27,990,150		27,813,406
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Average participating shares outstanding		107,274		92,212		33,899
Denominator for Two-Class Method—Diluted		29,083,893		28,059,193		27,825,044
Earnings per common share—basic	$	1.18	$	1.41	$	1.34
Earnings per common share—diluted	$	1.18	$	1.41	$	1.34
Warrants considered anti-dilutive excluded from dilutive potential common shares		517,012		517,012		517,012
Stock options considered anti-dilutive excluded from dilutive potential common shares		747,443		757,580		930,969
Restricted stock considered anti-dilutive excluded from dilutive potential common shares		75,012		69,043		11,638

XML

Capital Purchase Program - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended			12 Months Ended
	Jan. 16, 2009	Dec. 31, 2012 Series A Preferred Stock [Member]	Dec. 07, 2011 Series A Preferred Stock [Member]	Dec. 31, 2012 One-time non-cash reduction [Member]
Redemption of share, value			$ 108.7
Preferred stock redemption shares			108,676
Net income available to common shareholders				1.8
Net income available to common shareholder, per share amount				$ 0.06
Purchase of common stock against Warrant		517,012
Purchase of common stock against warrant exercise price		$ 31.53
Common stock warrant issued	$ 4.0

XML

Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for unfunded commitments	$ 3.0	$ 1.2
Data processing and communication charges	10.3	7.4	6.8
Gateway and Mainline [Member]
Data processing contract termination and conversion cost expenses	$ 2.3

XML

EMPLOYEE BENEFITS (Tables)

12 Months Ended

Dec. 31, 2012

Benefit Obligation and Plan Assets Deriving Funded Status, in Other Liabilities

The following table summarizes the activity in the benefit obligation and Plan assets deriving the funded status, which is recorded in other liabilities in the Consolidated Balance Sheets:

(in thousands)	2012			2011
Change in Projected Benefit Obligation
Projected benefit obligation at beginning of year	$	93,033		$	74,118
Service cost		2,788			2,371
Interest cost		4,358			4,162
Plan participants’ contributions		71			3,964
Plan amendments		—			(1,513	)
Actuarial loss		6,723			15,199
Benefits paid		(4,519	)		(5,268	)
Projected Benefit Obligation at End of Year	$	102,454		$	93,033
Change in Plan Assets
Fair value of plan assets at beginning of year	$	72,626		$	68,774
Actual return on plan assets		9,810			156
Employer contributions		3,100			5,000
Plan participants’ contributions		71			3,964
Benefits paid		(4,519	)		(5,268	)
Fair Value of Plan Assets at End of Year	$	81,088		$	72,626
Funded Status	$	(21,366	)	$	(20,407	)

Accumulated Other Comprehensive Gain/Loss

The following table sets forth the amounts recognized in accumulated other comprehensive gain/loss at December 31:

(in thousands)	2012			2011
Prior service credit	$	(1,442	)	$	(1,579	)
Net actuarial loss		36,297			36,294
Total (Before Tax Effects)	$	34,855		$	34,715

Actuarial Weighted Average Assumptions Used in Determining Benefit Obligation

Below are the actuarial weighted average assumptions used in determining the benefit obligation:

	2012			2011
Discount rate		4.00	%		4.75	%
Rate of compensation increase		3.00	%		4.00	%

Components of Net Periodic Pension Cost and Other Changes in Plan Assets and Benefit

The following table summarizes the components of net periodic pension cost and other changes in Plan assets and benefit obligation recognized in other comprehensive gain/loss for the years ended December 31:

(in thousands)	2012			2011			2010
Components of Net Periodic Pension Cost
Service cost—benefits earned during the period	$	2,788		$	2,371		$	2,245
Interest cost on projected benefit obligation		4,358			4,162			4,017
Expected return on plan assets		(5,564	)		(5,378	)		(4,882	)
Amortization of prior service credit		(137	)		(7	)		(7	)
Recognized net actuarial loss		2,474			773			824
Net Periodic Pension Cost	$	3,919		$	1,921		$	2,197
Other Changes in Plan Assets and Benefit Obligation Recognized in Other Comprehensive Loss
Net actuarial loss (gain)	$	2,477		$	20,422		$	1,261
Recognized net actuarial loss		(2,474	)		(773	)		(824	)
Prior service credit		(0	)		(1,513	)		—
Recognized prior service credit		137			7			7
Total (Before Tax Effects)	$	140		$	18,143		$	444
Total Recognized in Net Benefit Cost and Other Comprehensive Gain/Loss (Before Tax Effects)	$	4,059		$	20,064		$	2,641

Actuarial Weighted Average Assumptions Used in Determining Net Periodic Pension Cost

The following table summarizes the actuarial weighted average assumptions used in determining net periodic pension cost:

	2012		2011		2010
Discount rate		4.75%		5.75%		6.25%
Rate of compensation increase		4.00%		4.00%		4.00%
Expected return on assets		8.00%		8.00%		8.00%

Estimated Future Benefit Payments

The following table provides information regarding estimated future benefit payments to be paid in each of the next five years and in the aggregate for the five years thereafter:

(in thousands)	Amount
2013	$	5,813
2014		5,547
2015		6,601
2016		6,225
2017		6,056
2018—2022		36,212

Pension Plan Assets Measured at Fair Value on Recurring Basis

The following tables present our Plan assets measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items of a recurring basis during the periods presented. The increase of $0.1 million in Level 3 plan assets since December 31, 2011 is due to an increase in unrealized gains in the investments. There were no purchases, transfers or sales of Level 3 plan assets.

	December 31, 2012
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	8,585	$	—	$	8,585
Fixed Income(3)		22,211		—		1,432		23,643
Equities:
Equity index mutual funds—domestic(4)		1,934		—		—		1,934
Equity index mutual funds—international(5)		4,218		—		—		4,218
Domestic Individual Equities(6)		39,631		—		—		39,631
International Individual Equities(7)		1,802		—		—		1,802
Equity—Partnerships(8)		—		—		1,275		1,275
Total Assets at Fair Value	$	69,796	$	8,585	$	2,707	$	81,088

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

	December 31, 2011
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	7,440	$	—	$	7,440
Fixed Income(3)		21,539		—		1,333		22,872
Equities:
Equity index mutual funds—domestic(4)		1,580		—		—		1,580
Equity index mutual funds—international(5)		3,437		—		—		3,437
Domestic Individual Equities(6)		34,600		—		—		34,600
International Individual Equities(7)		1,437		—		—		1,437
Equity—Partnerships(8)		—		—		1,260		1,260
Total Assets at Fair Value	$	62,593	$	7,440	$	2,593	$	72,626

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

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DEPOSITS (Tables)

12 Months Ended

Dec. 31, 2012

Composition of Deposits and Interest Expenses

The following table presents the composition of deposits at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Noninterest-bearing demand	$	960,980	$	—	$	818,686	$	—	$	765,812	$	—
Interest-bearing demand		316,760		60		283,611		47		295,246		54
Money market		361,233		614		278,092		691		262,683		1,166
Savings		965,571		2,356		802,942		1,267		753,813		2,127
Certificates of deposit		1,033,884		13,766		1,152,528		20,947		1,239,970		25,370
Total	$	3,638,428	$	16,796	$	3,335,859	$	22,952	$	3,317,524	$	28,717

Scheduled Maturities of Certificates of Deposit

The following table indicates the scheduled maturities of certificates of deposit at December 31, 2012:

(in thousands)	Amount
2013	$	643,635
2014		129,963
2015		118,829
2016		53,735
2017		77,336
Thereafter		10,386
Total	$	1,033,884

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Income Taxes - Schedule of Reconciliation of Change in Federal and State Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Unrecognized Tax Benefits [Line Items]
Balance at beginning of year	$ 200	$ 242	$ 286
Increase
Decrease			(67)
Current period tax positions	913	(42)	23
Reductions for statute of limitations expirations	(135)
Balance at End of Year	978	200	242
Amount That Would Affect the Effective Tax Rate if Recognized	$ 147	$ 197	$ 239

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Restrictions on Cash and Due from Bank Accounts - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash and Cash Equivalents [Line Items]
Interest-bearing average reserves	$ 36.6	$ 36.6	$ 32.5

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Employee Benefits - Accumulated Other Comprehensive Gain/Loss (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Prior service credit	$ (1,442)	$ (1,579)
Net actuarial loss	36,297	36,294
Total (Before Tax Effects)	$ 271	$ 18,787	$ 606

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INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Nonstatutory Stock Options Activity

The following table summarizes activity for nonstatutory stock options for the years ending December 31:

	2012							2011							2010
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at beginning of year		757,050		$	34.33				930,700		$	32.80				1,100,550		$	31.85
Granted		—			—				—			—				—			—
Exercised		—			—				—			—				(82,100	)		19.81
Forfeited		(81,550	)		27.29				(173,650	)		26.11				(87,750	)		33.04
Outstanding at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years
Exercisable at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years

Summary of Non-Vested Options

The following table provides information about non-vested options for the years ended December 31:

	Non-Vested Options		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		51,625	$	9.48
Granted		—		—
Vested		30,625		9.48
Forfeited		21,000		9.48
Non-vested at December 31, 2010		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2011		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2012		—	$	—

Summary of Stock Options Exercised

The following table presents information about stock options exercised for the years ended December 31:

(in thousands, except share data)	2012		2011		2010
Number of options exercised		—		—		82,100
Total intrinsic value of options exercised	$	—	$	—	$	131
Cash received from options exercised		—		—		1,758
Tax deduction realized from options exercised	$	—	$	—	$	46

Summary of Non-Vested Restricted Stock

The following table provides information about restricted stock for the years ended December 31:

	Restricted Stock		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		41,342	$	24.75
Granted		18,896		21.44
Vested		25,006		21.86
Forfeited		3,562		29.15
Non-vested at December 31, 2010		31,670	$	24.56
Granted		80,047		21.39
Vested		23,915		23.69
Forfeited		1,652		23.64
Non-vested at December 31, 2011		86,150	$	21.88
Granted		67,370		21.53
Vested		37,118		19.75
Forfeited		1,383		19.54
Non-vested at December 31, 2012		115,019	$	22.39

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Loans and Loans Held For Sale - Restructured Loans for Periods Stated (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 SecurityLoan	Dec. 31, 2011 SecurityLoan
Financing Receivable, Modifications [Line Items]
Number of Loans	260	35
Pre-Modification Outstanding Recorded Investment	$ 15,654	$ 39,082
Post-Modification Outstanding Recorded Investment	14,346	37,661
Total Difference in Recorded Investment	(1,308)	(1,421)
Maturity date extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	14	27
Pre-Modification Outstanding Recorded Investment	6,898	35,955
Post-Modification Outstanding Recorded Investment	5,607	35,801
Total Difference in Recorded Investment	(1,291)	(154)
Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	4
Pre-Modification Outstanding Recorded Investment	1,852	1,018
Post-Modification Outstanding Recorded Investment	1,835	912
Total Difference in Recorded Investment	(17)	(106)
Discharge of debt [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	242
Pre-Modification Outstanding Recorded Investment	6,904
Post-Modification Outstanding Recorded Investment	6,904
Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans		4
Pre-Modification Outstanding Recorded Investment		2,109
Post-Modification Outstanding Recorded Investment		948
Total Difference in Recorded Investment		(1,161)
Commercial real estate [Member] | Maturity date extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	3	3
Pre-Modification Outstanding Recorded Investment	704	3,361
Post-Modification Outstanding Recorded Investment	693	3,817
Total Difference in Recorded Investment	(11)	456
Commercial real estate [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	2	2
Pre-Modification Outstanding Recorded Investment	1,785	682
Post-Modification Outstanding Recorded Investment	1,768	604
Total Difference in Recorded Investment	(17)	(78)
Commercial real estate [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans		3
Pre-Modification Outstanding Recorded Investment		2,034
Post-Modification Outstanding Recorded Investment		908
Total Difference in Recorded Investment		(1,126)
Commercial and industrial [Member] | Maturity date extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	6
Pre-Modification Outstanding Recorded Investment	2,825	6,364
Post-Modification Outstanding Recorded Investment	2,601	6,180
Total Difference in Recorded Investment	(224)	(184)
Commercial construction [Member] | Maturity date extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	6	12
Pre-Modification Outstanding Recorded Investment	2,894	21,029
Post-Modification Outstanding Recorded Investment	1,874	20,979
Total Difference in Recorded Investment	(1,020)	(50)
Home Equity [Member] | Discharge of debt [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	161
Pre-Modification Outstanding Recorded Investment	4,530
Post-Modification Outstanding Recorded Investment	4,530
Residential mortgage [Member] | Maturity date extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	6
Pre-Modification Outstanding Recorded Investment	475	5,201
Post-Modification Outstanding Recorded Investment	439	4,825
Total Difference in Recorded Investment	(36)	(376)
Residential mortgage [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	2	2
Pre-Modification Outstanding Recorded Investment	67	336
Post-Modification Outstanding Recorded Investment	67	308
Total Difference in Recorded Investment		(28)
Residential mortgage [Member] | Discharge of debt [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	76
Pre-Modification Outstanding Recorded Investment	2,349
Post-Modification Outstanding Recorded Investment	2,349
Residential mortgage [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans		1
Pre-Modification Outstanding Recorded Investment		75
Post-Modification Outstanding Recorded Investment		40
Total Difference in Recorded Investment		(35)
Installment and other consumer [Member] | Discharge of debt [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	5
Pre-Modification Outstanding Recorded Investment	25
Post-Modification Outstanding Recorded Investment	$ 25

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Short-Term Borrowings - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Line of credit	$ 0	$ 5.0

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DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)

12 Months Ended

Dec. 31, 2012

Value of Derivative Assets and Derivative Liabilities

The following table indicates the amount representing the value of derivative assets and derivative liabilities at December 31:

	Derivatives (included in Other Assets)				Derivatives (included in Other Liabilities)
(in thousands)	2012		2011		2012		2011
Derivatives not Designated as Hedging Instruments
Interest Rate Swap Contracts—Commercial Loans
Fair value	$	23,748	$	23,764	$	23,522	$	23,639
Notional amount		227,532		189,868		227,532		189,868
Collateral posted		—		—		19,595		20,273
Interest Rate Lock Commitments—Mortgage Loans
Fair value		467		244		—		—
Notional amount		14,287		7,093		—		—
Forward Sale Contracts—Mortgage Loans
Fair value		—		—		48		95
Notional amount		—		—		14,100		7,729

Amount of Gain or Loss Recognized in Income on Derivatives

The following table indicates the gain or loss recognized in income on derivatives for the year ended December 31:

(in thousands)	2012		2011			2010
Derivatives not Designated as Hedging Instruments
Interest rate swap contracts—commercial loans	$	101	$	(38	)	$	96
Interest rate lock commitments—mortgage loans		223		27			62
Forward sale contracts—mortgage loans		47		(507	)		220
Total Derivative Gain (Loss)	$	371	$	(518	)	$	378

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SEGMENTS

12 Months Ended

Dec. 31, 2012

SEGMENTS

NOTE 25. SEGMENTS

We operate three reportable operating segments including Community Banking, Wealth Management and Insurance.

• Our Community Banking segment offers services which include accepting time and demand deposits, originating commercial and consumer loans and providing letters of credit and credit card services.

• Our Wealth Management segment offers discount brokerage services, services as executor and trustee under wills and deeds, guardian and custodian of employee benefits and other trust and brokerage services, as well as a registered investment advisor that manages private investment accounts for individuals and institutions.

• Our Insurance segment includes a full-service insurance agency offering commercial property and casualty insurance, group life and health coverage, employee benefit solutions and personal insurance lines.

The following represents total assets by reportable operating segment as of December 31:

(in thousands)	2012		2011
Community Banking	$	4,516,194	$	4,110,462
Insurance		9,302		8,192
Wealth Management		1,206		1,340
Total Assets	$	4,526,702	$	4,119,994

The following tables provide financial information for our three segments. The financial results of the business segments include allocations for shared services based on an internal analysis that supports line of business and branch performance measurement. Shared services include expenses such as employee benefits, occupancy expense, computer support and other corporate overhead. Even with these allocations, the financial results are not necessarily indicative of the business segments’ financial condition and results of operations as if they existed as independent entities. The information provided under the caption “Eliminations” represents operations not considered to be reportable segments and/or general operating expenses and eliminations and adjustments, which are necessary for purposes of reconciling to the Consolidated Financial Statements.

	For the Year Ended December 31, 2012
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	155,865	$	454	$	1		$	(69	)	$	156,251
Interest expense		22,135		—		—			(1,111	)		21,024
Net interest income (expense)		133,730		454		1			1,042			135,227
Provision for loan losses		22,815		—		—			—			22,815
Noninterest income		36,422		9,788		5,262			440			51,912
Noninterest expense		97,687		9,448		5,415			4,692			117,242
Depreciation expense		3,833		31		48			—			3,912
Intangible amortization		1,600		57		52			—			1,709
Income tax expense (benefit)		10,207		352		(88	)		(3,210	)		7,261
Net Income (Loss)	$	34,010	$	354	$	(164	)	$	—		$	34,200

	For the Year Ended December 31, 2011
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	164,738	$	307	$	1		$	33		$	165,079
Interest expense		27,692		—		291			(250	)		27,733
Net interest income (expense)		137,046		307		(290	)		283			137,346
Provision for loan losses		15,609		—		—			—			15,609
Noninterest income		30,195		8,328		5,236			298			44,057
Noninterest expense		81,180		7,302		5,199			4,236			97,917
Depreciation expense		4,165		32		57			—			4,254
Intangible amortization		1,619		66		52			—			1,737
Income tax expense (benefit)		17,911		493		(127	)		(3,655	)		14,622
Net Income (Loss)	$	46,757	$	742	$	(235	)	$	—		$	47,264

	For the Year Ended December 31, 2010
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	180,319	$	471	$	2		$	(373	)	$	180,419
Interest expense		34,692		—		293			(412	)		34,573
Net interest income (expense)		145,627		471		(291	)		39			145,846
Provision for loan losses		29,511		—		—			—			29,511
Noninterest income		32,959		7,950		4,968			1,333			47,210
Noninterest expense		82,872		7,525		4,850			4,181			99,428
Depreciation expense		4,163		34		62			—			4,259
Intangible amortization		1,815		75		56			—			1,946
Income tax (benefit) expense		17,019		324		(102	)		(2,809	)		14,432
Net Income (Loss)	$	43,206	$	463	$	(189	)	$	—		$	43,480

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Loans and Loans Held For Sale - Summary of TDRs (Detail) (USD $)	Dec. 31, 2011 Contract
Financing Receivable, Modifications [Line Items]
Number of Defaults	2
Recorded Investment	$ 900
Commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults	2
Recorded Investment	$ 900

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Income Taxes - Schedule of Significant Components of Temporary Differences with Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Liabilities:
Net unrealized holding gains on securities available-for-sale	$ (5,586)	$ (5,208)
Prepaid pension	(4,721)	(5,007)
Deferred loan income	(969)	(736)
Purchase accounting adjustments	(935)	(3,160)
Depreciation on premises and equipment	(1,963)	(1,882)
Other	(690)	(701)
Total Deferred Tax liabilities	(14,864)	(16,694)
Deferred Tax Assets:
Allowance for loan losses	16,536	15,593
Tax credit carryforwards (expires in 20 years)	1,430
Other employee benefits	2,701	2,148
Low income housing partnerships	2,890	2,608
Net adjustment to funded status of pension	12,899	12,804
Impairment of securities	1,375	2,119
Delinquent interest on nonaccrual loans	1,719	1,187
State net operating loss carryforwards	1,498	1,232
Other	3,157	3,559
Gross Deferred Tax Assets	44,205	41,250
Less: Valuation allowance for Pennsylvania net operating loss carryforwards	(1,498)	(1,232)
Total Deferred Tax Assets	42,707	40,018
Net Deferred Tax Asset	$ 27,843	$ 23,324

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Employee Benefits - Actuarial Weighted Average Assumptions Used in Determining Net Periodic Pension Cost (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.75%	5.75%	6.25%
Rate of compensation increase	4.00%	4.00%	4.00%
Expected return on assets	8.00%	8.00%	8.00%

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Incentive and Restricted Stock Plan and Dividend Reinvestment Plan - Summary of Non-Vested Options (Detail) (Non-Vested Options [Member])	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Non-Vested Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested Restricted Stock, Beginning period			51,625
Non-vested Options, Granted
Non-vested Options, Vested			30,625
Non-vested Options, Forfeited			21,000
Non-vested, Balance

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Securities Available-For-Sale - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Securities	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Gross realized gains	$ 3.0	$ 0	$ 0.4
Gross realized losses		(0.1)	(0.1)
Number of debt securities on which unrealized losses were primarily attributable to changes in interest	5
Number of marketable equity securities on which unrealized losses were primarily attributable to temporary declines in market value	2
Net unrealized gains included in accumulated other comprehensive loss, net of tax	10.4	9.7
Gross unrealized gains, net of taxes	10.5	10.0
Gross unrealized losses, net of taxes	0.1	0.3
Unrealized gains reclassified out of accumulated other comprehensive loss into earnings	3.0
Unrealized losses reclassified out of accumulated other comprehensive loss into earnings		0.1
Carrying values of securities	$ 307.5	$ 233.9

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Premises and Equipment - Summary of Premises and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 80,833	$ 75,764
Accumulated depreciation	(42,157)	(38,009)
Premises and equipment, net	38,676	37,755
Land [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Premises and equipment, gross	6,490	6,316
Premises [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Premises and equipment, gross	43,434	41,608
Furniture and equipment [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Premises and equipment, gross	24,944	22,941
Leasehold improvements [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 5,965	$ 4,899

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REGULATORY MATTERS (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Risk-Based Capital Amounts and Ratios for S&T and S&T Bank

The following table summarizes risk-based capital amounts and ratios for S&T and S&T Bank.

	Actual					For Capital Adequacy Purposes					To be Well Capitalized Under Prompt Corrective Action Provisions
(in thousands, except for ratios)	Amount		Ratio			Amount		Ratio			Amount		Ratio
As of December 31, 2012
Total Capital (to Risk-Weighted Assets)
S&T	$	504,041		15.39	%	$	262,029		8.00	%	$	327,536		10.00	%
S&T Bank		452,906		14.35	%		252,489		8.00	%		315,611		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		392,506		11.98	%		131,015		4.00	%		196,522		6.00	%
S&T Bank		343,331		10.88	%		126,244		4.00	%		189,366		6.00	%
Leverage Ratio(1)
S&T		392,506		9.31	%		168,563		4.00	%		210,704		5.00	%
S&T Bank		343,331		8.45	%		162,611		4.00	%		203,264		5.00	%
As of December 31, 2011
Total Capital (to Risk-Weighted Assets)
S&T	$	465,702		15.20	%	$	245,154		8.00	%	$	306,443		10.00	%
S&T Bank		429,837		14.11	%		243,699		8.00	%		304,623		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		356,484		11.63	%		122,577		4.00	%		183,866		6.00	%
S&T Bank		321,352		10.55	%		121,849		4.00	%		182,774		6.00	%
Leverage Ratio(1)
S&T		356,484		9.17	%		155,526		4.00	%		194,408		5.00	%
S&T Bank		321,352		8.30	%		154,789		4.00	%		193,486		5.00	%

⁽¹⁾  Minimum requirement is 3.00 percent for the most highly-rated financial institutions.

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Long-Term Borrowings - Schedule of Junior Subordinated Debt Securities and Interest Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Junior Subordinated Debentures [Line Items]
Balance	$ 90,619	$ 90,619	$ 90,619
Interest Expense	2,915	3,635	4,003
2006 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Balance	25,000	25,000	25,000
Interest Expense	523	1,344	1,695
2008 Junior subordinated debt-trust preferred securities [Member]
Junior Subordinated Debentures [Line Items]
Balance	20,619	20,619	20,619
Interest Expense	808	777	782
2008 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Balance	20,000	20,000	20,000
Interest Expense	818	786	791
2008 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Balance	25,000	25,000	25,000
Interest Expense	$ 766	$ 728	$ 735

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Incentive and Restricted Stock Plan and Dividend Reinvestment Plan - Summary of Stock Options Exercised (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options exercised	0	0	82,100
Total intrinsic value of options exercised	$ 0	$ 0	$ 131
Cash received from options exercised	0	0	1,758
Tax deduction realized from options exercised	$ 0	$ 0	$ 46

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Loans and Loans Held for Sale - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended									3 Months Ended
	Dec. 31, 2012 Property Business	Dec. 31, 2011	Dec. 31, 2012 Consumer loan [Member]	Mar. 09, 2012 Mainline [Member]	Mar. 09, 2012 Mainline [Member] Consumer loan [Member]	Mar. 09, 2012 Mainline [Member] Commercial Loans [Member]	Aug. 13, 2012 Gateway [Member]	Aug. 13, 2012 Gateway [Member] Consumer loan [Member]	Aug. 13, 2012 Gateway [Member] Commercial Loans [Member]	Dec. 31, 2012 Commercial real estate and commercial construction [Member]	Dec. 31, 2011 Commercial real estate and commercial construction [Member]	Dec. 31, 2012 Commercial and industrial [Member] Instruments	Dec. 31, 2012 Commercial construction [Member] Instruments	Dec. 31, 2012 Commercial real estate [Member] Instruments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of bank acquired	2
Loans from acquisition				$ 129.5	$ 57.7	$ 71.8	$ 99.1	$ 24.9	$ 74.2
Percentage of commercial loans in total portfolio loans	72.00%	73.00%
Combined percentage of commercial real estate and commercial construction in total commercial loans										67.00%	70.00%
Combined percentage of commercial real estate and commercial construction in total portfolio loans										48.00%	51.00%
Maximum concentration of commercial real estate and commercial construction portfolio in loans	9.00%
Out-of-state exposure of combined portfolio										19.00%	19.00%
Percentage of total loans out-of-state										9.00%	10.00%
Loans modified not considered to be troubled debt restructuring			$ 6.9									$ 6.6	$ 1.2	$ 3.6
Number of loans not considered to be troubled debt restructuring												7	1	8
Other real estate owned properties	13

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Selected Financial Data - Summary of Selected Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effect of Fourth Quarter Events [Line Items]
Interest income	$ 38,920	$ 38,820	$ 39,370	$ 39,140	$ 40,259	$ 40,845	$ 41,783	$ 42,192	$ 135,227	$ 137,346	$ 145,846
Interest expense	4,629	5,025	5,551	5,819	6,192	6,976	7,245	7,320	21,024	27,733	34,573
Provision for loan losses	4,215	2,305	7,023	9,272	2,337	1,535	1,097	10,640	22,815	15,609	29,511
Net interest income after provision for loan losses	30,076	31,490	26,796	24,049	31,730	32,334	33,441	24,232
Security gains (losses), net		2,170	6	840		(81)	(56)	13
Noninterest income	11,565	12,576	12,525	12,229	11,574	10,424	11,170	11,013	51,912	44,057	47,210
Noninterest expense	29,717	31,018	29,344	32,783	26,672	24,193	25,594	27,449	122,863	103,908	105,633
Income before taxes	11,924	15,218	9,983	4,335	16,632	18,484	18,961	7,809
Provision for income taxes	2,400	2,623	1,383	855	4,376	4,681	4,051	1,514	7,261	14,622	14,432
Net Income	9,524	12,595	8,600	3,480	12,256	13,803	14,910	6,295	34,200	47,264	43,480
Preferred stock dividends and discount amortization					2,939	1,559	1,558	1,555		7,611	6,201
Net Income Allocated to Common Shareholders	$ 9,524	$ 12,595	$ 8,600	$ 3,480	$ 9,317	$ 12,244	$ 13,352	$ 4,740	$ 34,074	$ 39,523	$ 37,237
Common earnings per share-diluted	$ 0.32	$ 0.43	$ 0.30	$ 0.12	$ 0.33	$ 0.44	$ 0.48	$ 0.17	$ 1.18	$ 1.41	$ 1.34
Dividends declared per common share	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.60	$ 0.60	$ 0.60
Common book value	$ 18.08	$ 17.97	$ 17.65	$ 17.47	$ 17.44	$ 17.68	$ 17.31	$ 16.90

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Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	$ 82,641	$ 94,036
Impaired Financing Receivable, Unpaid Principal Balance, Total	108,266	102,036
Impaired Financing Receivable, Related Allowance	2,231	5,545
Impaired Financing Receivable, Average Recorded Investment, Total	107,716	69,607
Impaired Financing Receivable, Interest Income Recognized, Total	2,298	2,639
Without a related allowance recorded, Recorded Investment	73,840	78,805
Without a related allowance recorded, Unpaid Principal Balance	97,716	86,578
Without a related allowance recorded, Average Recorded Investment	95,648	50,566
Without a related allowance recorded, Interest Income Recognized	2,080	2,238
With a related allowance recorded, Recorded Investment	8,801	15,231
With a related allowance recorded, Unpaid Principal Balance	10,550	15,458
Impaired Financing Receivable, Related Allowance	2,231	5,545
With a related allowance recorded, Average Recorded Investment	12,068	19,041
With a related allowance recorded, Interest Income Recognized	218	401
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	39,994	50,107
Impaired Financing Receivable, Unpaid Principal Balance, Total	52,817	57,150
Impaired Financing Receivable, Related Allowance	1,226	3,487
Impaired Financing Receivable, Average Recorded Investment, Total	46,934	47,010
Impaired Financing Receivable, Interest Income Recognized, Total	1,330	1,735
Without a related allowance recorded, Recorded Investment	33,856	41,058
Without a related allowance recorded, Unpaid Principal Balance	45,953	47,874
Without a related allowance recorded, Average Recorded Investment	41,138	34,965
Without a related allowance recorded, Interest Income Recognized	1,112	1,415
With a related allowance recorded, Recorded Investment	6,138	9,049
With a related allowance recorded, Unpaid Principal Balance	6,864	9,276
Impaired Financing Receivable, Related Allowance	1,226	3,487
With a related allowance recorded, Average Recorded Investment	5,796	12,045
With a related allowance recorded, Interest Income Recognized	218	320
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	13,283	11,991
Impaired Financing Receivable, Unpaid Principal Balance, Total	15,017	11,991
Impaired Financing Receivable, Related Allowance	1,002	1,116
Impaired Financing Receivable, Average Recorded Investment, Total	13,498	7,625
Impaired Financing Receivable, Interest Income Recognized, Total	329	209
Without a related allowance recorded, Recorded Investment	11,419	7,784
Without a related allowance recorded, Unpaid Principal Balance	12,227	7,784
Without a related allowance recorded, Average Recorded Investment	11,672	4,128
Without a related allowance recorded, Interest Income Recognized	329	132
With a related allowance recorded, Recorded Investment	1,864	4,207
With a related allowance recorded, Unpaid Principal Balance	2,790	4,207
Impaired Financing Receivable, Related Allowance	1,002	1,116
With a related allowance recorded, Average Recorded Investment	1,826	3,497
With a related allowance recorded, Interest Income Recognized		77
Commercial construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	18,512	25,999
Impaired Financing Receivable, Unpaid Principal Balance, Total	28,382	26,350
Impaired Financing Receivable, Related Allowance	3	942
Impaired Financing Receivable, Average Recorded Investment, Total	26,745	12,182
Impaired Financing Receivable, Interest Income Recognized, Total	571	500
Without a related allowance recorded, Recorded Investment	17,713	24,024
Without a related allowance recorded, Unpaid Principal Balance	27,486	24,375
Without a related allowance recorded, Average Recorded Investment	22,299	8,856
Without a related allowance recorded, Interest Income Recognized	571	496
With a related allowance recorded, Recorded Investment	799	1,975
With a related allowance recorded, Unpaid Principal Balance	896	1,975
Impaired Financing Receivable, Related Allowance	3	942
With a related allowance recorded, Average Recorded Investment	4,446	3,326
With a related allowance recorded, Interest Income Recognized		4
Consumer real estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	10,827	5,939
Impaired Financing Receivable, Unpaid Principal Balance, Total	12,025	6,545
Impaired Financing Receivable, Average Recorded Investment, Total	20,533	2,790
Impaired Financing Receivable, Interest Income Recognized, Total	68	195
Without a related allowance recorded, Recorded Investment	10,827	5,939
Without a related allowance recorded, Unpaid Principal Balance	12,025	6,545
Without a related allowance recorded, Average Recorded Investment	20,533	2,617
Without a related allowance recorded, Interest Income Recognized	68	195
With a related allowance recorded, Average Recorded Investment		173
Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment, Total	25
Impaired Financing Receivable, Unpaid Principal Balance, Total	25
Impaired Financing Receivable, Average Recorded Investment, Total	6
Without a related allowance recorded, Recorded Investment	25
Without a related allowance recorded, Unpaid Principal Balance	25
Without a related allowance recorded, Average Recorded Investment	$ 6

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Segments - Total Assets by Reportable Operating Segment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	$ 4,526,702	$ 4,119,994
Community Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	4,516,194	4,110,462
Insurance [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	9,302	8,192
Wealth Management [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	$ 1,206	$ 1,340

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Selected Financial Data - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 07, 2011 Series A Preferred Stock [Member]	Dec. 31, 2012 One-time non-cash reduction [Member]
Effect of Fourth Quarter Events [Line Items]
Redemption of share, value												$ 108,700,000
Preferred stock redemption shares										108,676,000		108,676
Net income available to common shareholders	$ 9,524,000	$ 12,595,000	$ 8,600,000	$ 3,480,000	$ 9,317,000	$ 12,244,000	$ 13,352,000	$ 4,740,000	$ 34,074,000	$ 39,523,000	$ 37,237,000		$ 1,800,000
Net income available to common shareholder, per share amount													$ 0.06

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Loans and Loans Held for Sale - Summary of Aggregate Amount of Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Balance at beginning of year	$ 31,821	$ 34,373
New loans	29,465	23,751
Repayments	(25,211)	(26,303)
Balance at End of Year	$ 36,075	$ 31,821

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Allowance for Loan Losses - Summary of Allowance for Loan Losses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	$ 48,841	$ 51,387
Charge-offs	(29,013)	(23,145)
Recoveries	3,841	4,990
Net (Charge-offs)/ Recoveries	(25,172)	(18,155)
Provision for loan losses	22,815	15,609
Balance at End of Year	46,484	48,841
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	29,804	30,425
Charge-offs	(9,627)	(8,824)
Recoveries	1,259	780
Net (Charge-offs)/ Recoveries	(8,368)	(8,044)
Provision for loan losses	3,810	7,423
Balance at End of Year	25,246	29,804
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	11,274	9,777
Charge-offs	(5,278)	(8,971)
Recoveries	1,153	357
Net (Charge-offs)/ Recoveries	(4,125)	(8,614)
Provision for loan losses	610	10,111
Balance at End of Year	7,759	11,274
Commercial construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	3,703	5,904
Charge-offs	(10,521)	(1,720)
Recoveries	891	2,463
Net (Charge-offs)/ Recoveries	(9,630)	743
Provision for loan losses	13,427	(2,944)
Balance at End of Year	7,500	3,703
Consumer real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	3,166	3,962
Charge-offs	(2,509)	(2,617)
Recoveries	197	1,030
Net (Charge-offs)/ Recoveries	(2,312)	(1,587)
Provision for loan losses	4,204	791
Balance at End of Year	5,058	3,166
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	894	1,319
Charge-offs	(1,078)	(1,013)
Recoveries	341	360
Net (Charge-offs)/ Recoveries	(737)	(653)
Provision for loan losses	764	228
Balance at End of Year	$ 921	$ 894

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Loans and Loans Held For Sale - Restructured Loans as of Dates Presented (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Restructured loans	$ 14,346	$ 37,661
Performing Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	41,521	49,716
Performing Financing Receivable [Member] | Commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	14,220	22,284
Performing Financing Receivable [Member] | Commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	8,270	6,180
Performing Financing Receivable [Member] | Commercial construction [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	11,734	19,682
Performing Financing Receivable [Member] | Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	4,195
Performing Financing Receivable [Member] | Residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	3,078	1,570
Performing Financing Receivable [Member] | Installment and other consumer [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	24
Nonperforming Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	18,940	18,184
Nonperforming Financing Receivable [Member] | Commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	9,584	10,871
Nonperforming Financing Receivable [Member] | Commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	939
Nonperforming Financing Receivable [Member] | Commercial construction [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	5,324	2,943
Nonperforming Financing Receivable [Member] | Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	341
Nonperforming Financing Receivable [Member] | Residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	2,752	4,370
Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	60,461	67,900
Financing Receivable [Member] | Commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	23,804	33,155
Financing Receivable [Member] | Commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	9,209	6,180
Financing Receivable [Member] | Commercial construction [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	17,058	22,625
Financing Receivable [Member] | Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	4,536
Financing Receivable [Member] | Residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	5,830	5,940
Financing Receivable [Member] | Installment and other consumer [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	$ 24

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Dividend and Loan Restrictions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Apr. 30, 2012
Schedule Of Dividend And Loans Restrictions [Line Items]
Preferred stock redemption date	Dec. 07, 2011
Percentage of collateralized loans	10.00%
Line of credit		$ 5.0

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COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2012

COMMITMENTS AND CONTINGENCIES

NOTE 17. COMMITMENTS AND CONTINGENCIES

Commitments

The following table sets forth the commitments and letters of credit at December 31:

(in thousands)	2012		2011
Commitments to extend credit	$	874,137	$	816,160
Standby letters of credit		95,399		119,576
Total	$	969,536	$	935,736

Estimates of the fair value of these off-balance sheet items were not made because of the short-term nature of these arrangements and the credit standing of the counterparties.

Our allowance for unfunded commitments totaled $3.0 million at December 31, 2012 and $1.2 million at December 31, 2011. Refer to Note 1 Summary of Significant Accounting Policies, Allowance for Unfunded Commitments for the methodology used to calculate the allowance for unfunded commitments.

We have future commitments with third party vendors for data processing and communication charges. Data processing and communication charges related to these commitments resulted in expense of $10.3 million for 2012, including $2.3 million in one-time merger related expenses for our acquisitions of Gateway and Mainline, $7.4 million in 2011 and $6.8 million in 2010.

The following table sets forth the future estimated payments related to data processing and communication charges for each of the five years following December 31, 2012:

(in thousands)	Total
2013	$	7,388	(1)
2014		7,032
2015		7,172
2016		6,816
2017		708
Total	$	29,116

(1) Included in this amount is $0.6 million related to the Gateway conversion in the first quarter of 2013.

The commitments in the above table show a decrease in 2014 due to the Gateway conversion expenses in February 2013. The commitments show a decrease again in 2016 and 2017 when two contracts with third party data processors expire.

Litigation

In the normal course of business, we are subject to various legal and administrative proceedings and claims. While any type of litigation contains a level of uncertainty, we believe that the outcome of such proceedings or claims pending will not have a material adverse effect on our consolidated financial position.

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Regulatory Matters - Summary of Risk-Based Capital Amounts and Ratios for S&T and S&T Bank (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2012
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum requirement for most highly-rated financial institutions	0.03

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LONG-TERM BORROWINGS (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Annual Maturities and Average Interest Rate of Long-Term Debt

Scheduled annual maturities and average interest rates for all of the long-term debt, including a capital lease of $0.3 million, for each of the five years and thereafter subsequent to December 31, 2012 are as follows:

(dollars in thousands)	Balance		Average Rate
2013	$	12,291		3.46%
2014		2,368		3.36%
2015		2,399		3.41%
2016		2,330		3.44%
2017		2,412		3.53%
Thereafter		12,301		2.70%
Total	$	34,101		3.18%

Schedule of Junior Subordinated Debt Securities and Interest Expense

The following table represents the composition of junior subordinated debt securities at December 31 and the interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
2006 Junior subordinated debt	$	25,000	$	523	$	25,000	$	1,344	$	25,000	$	1,695
2008 Junior subordinated debt—trust preferred securities		20,619		808		20,619		777		20,619		782
2008 Junior subordinated debt		20,000		818		20,000		786		20,000		791
2008 Junior subordinated debt		25,000		766		25,000		728		25,000		735
Total	$	90,619	$	2,915	$	90,619	$	3,635	$	90,619	$	4,003

Schedule of Junior Subordinated Debt Securities

The following table summarizes the key terms of our junior subordinated debt securities:

(dollars in thousands)	2006 Junior Subordinated Debt	2008 Trust Preferred Securities	2008 Junior Subordinated Debt	2008 Junior Subordinated Debt
Junior Subordinated Debt	$25,000	—	$20,000	$25,000
Trust Preferred Securities	—	$20,000	—	—
Stated Maturity Date	12/15/2036	3/15/2038	6/15/2018	5/30/2018
First optional redemption date at par	—	3/15/2013	6/15/2013	5/30/2013
Regulatory Capital	Tier 2	Tier 1	Tier 2	Tier 2
Interest Rate	3 month LIBOR plus 160 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 250 bps
Interest Rate at December 31, 2012	1.91%	3.81%	3.81%	2.81%

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LOANS AND LOANS HELD FOR SALE (Tables)

12 Months Ended

Dec. 31, 2012

Composition of Loans

The following table presents the composition of loans:

	December 31,
(in thousands)	2012			2011
Commercial
Commercial real estate	$	1,452,133		$	1,415,333
Commercial and industrial		791,396			685,753
Commercial construction		168,143			188,852
Total Commercial Loans		2,411,672			2,289,938
Consumer
Home equity		431,335			411,404
Residential mortgage		427,303			358,846
Installment and other consumer		73,875			67,131
Consumer construction		2,437			2,440
Total Consumer Loans		934,950			839,821
Total Portfolio Loans		3,346,622			3,129,759
Allowance for loan losses		(46,484	)		(48,841	)
Total Portfolio Loans, net		3,300,138			3,080,918
Loans held for sale		22,499			2,850
Total Loans, Net	$	3,322,637		$	3,083,768

Restructured Loans as of Dates Presented

The following table summarizes the restructured loans as of the dates presented:

	December 31, 2012						December 31, 2011
(in thousands)	Performing TDRs		Nonperforming TDRs		Total TDRs		Performing TDRs		Nonperforming TDRs		Total TDRs
Commercial real estate	$	14,220	$	9,584	$	23,804	$	22,284	$	10,871	$	33,155
Commercial and industrial		8,270		939		9,209		6,180		—		6,180
Commercial construction		11,734		5,324		17,058		19,682		2,943		22,625
Home equity		4,195		341		4,536		—		—		—
Residential mortgage		3,078		2,752		5,830		1,570		4,370		5,940
Installment and other consumer		24		—		24		—		—		—
Total	$	41,521	$	18,940	$	60,461	$	49,716	$	18,184	$	67,900

Restructured Loans for Periods Stated

The following tables present the restructured loans for the years ending December 31:

	2012
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	704	$	693	$	(11	)
Interest rate reduction		2		1,785		1,768		(17	)
Commercial and industrial
Maturity date extension		4		2,825		2,601		(224	)
Commercial construction
Maturity date extension		6		2,894		1,874		(1,020	)
Home Equity
Discharge of debt		161		4,530		4,530		—
Residential mortgage
Maturity date extension		1		475		439		(36	)
Interest rate reduction		2		67		67		—
Discharge of debt		76		2,349		2,349		—
Installment and other consumer
Discharge of debt		5		25		25		—
Total by Concession Type
Maturity date extension		14		6,898		5,607		(1,291	)
Interest rate reduction		4		1,852		1,835		(17	)
Discharge of debt		242		6,904		6,904		—
Total		260	$	15,654	$	14,346	$	(1,308	)

⁽¹⁾ Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

	2011
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	3,361	$	3,817	$	456
Interest rate reduction		2		682		604		(78	)
Other		3		2,034		908		(1,126	)
Commercial and industrial
Maturity date extension		6		6,364		6,180		(184	)
Commercial construction
Maturity date extension		12		21,029		20,979		(50	)
Residential mortgage
Maturity date extension		6		5,201		4,825		(376	)
Interest rate reduction		2		336		308		(28	)
Other		1		75		40		(35	)
Total by Concession Type
Maturity date extension		27		35,955		35,801		(154	)
Interest rate reduction		4		1,018		912		(106	)
Other		4		2,109		948		(1,161	)
Total		35	$	39,082	$	37,661	$	(1,421	)

⁽¹⁾  Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

Summary of TDRs

The following table is a summary of TDRs which defaulted (defined as 90 days past due since time of modification) during years ended December 31, 2012 and 2011 that had been restructured within the last twelve months prior to December 31, 2012 and 2011, respectively:

	Defaulted TDRs
	For the Year Ended December 31, 2012				For the Year Ended December 31, 2011
(dollars in thousands)	Number of Defaults		Recorded Investment		Number of Defaults		Recorded Investment
Commercial real estate		—	$	—		2	$	0.9
Total		—	$	—		2	$	0.9

Summary of Nonperforming Assets

The following table is a summary of nonperforming assets for the years ended December 31:

(in thousands)	2012		2011
Nonperforming Assets
Nonaccrual loans	$	36,018	$	37,931
Nonaccrual TDRs		18,940		18,184
Total nonperforming loans		54,958		56,115
OREO		911		3,967
Total Nonperforming Assets	$	55,869	$	60,082

Summary of Aggregate Amount of Loans

The following table presents a summary of the aggregate amount of loans to any such persons as of December 31:

(in thousands)	2012			2011
Balance at beginning of year	$	31,821		$	34,373
New loans		29,465			23,751
Repayments		(25,211	)		(26,303	)
Balance at End of Year	$	36,075		$	31,821

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Loans and Loans Held for Sale - Composition of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commercial
Commercial Loans	$ 2,411,672	$ 2,289,938
Consumer Loans	934,950	839,821
Total Portfolio Loans	3,346,622	3,129,759
Allowance for loan losses	(46,484)	(48,841)	(51,387)
Portfolio loans, net	3,300,138	3,080,918
Loans held for sale	22,499	2,850
Total Loans, Net	3,322,637	3,083,768
Commercial real estate [Member]
Commercial
Commercial Loans	1,452,133	1,415,333
Total Portfolio Loans	1,452,133	1,415,333
Allowance for loan losses	(25,246)	(29,804)	(30,425)
Commercial and industrial [Member]
Commercial
Commercial Loans	791,396	685,753
Total Portfolio Loans	791,396	685,753
Allowance for loan losses	(7,759)	(11,274)	(9,777)
Commercial construction [Member]
Commercial
Commercial Loans	168,143	188,852
Total Portfolio Loans	168,143	188,852
Allowance for loan losses	(7,500)	(3,703)	(5,904)
Home Equity [Member]
Commercial
Consumer Loans	431,335	411,404
Total Portfolio Loans	431,335	411,404
Residential mortgage [Member]
Commercial
Consumer Loans	427,303	358,846
Total Portfolio Loans	427,303	358,846
Installment and other consumer [Member]
Commercial
Consumer Loans	73,875	67,131
Total Portfolio Loans	73,875	67,131
Consumer construction [Member]
Commercial
Consumer Loans	2,437	2,440
Total Portfolio Loans	$ 2,437	$ 2,440

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Derivative Instruments and Hedging Activities - Amount of Gain or Loss Recognized in Income on Derivatives (Detail) (Not Designated as Hedging Instruments [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative Gain (Loss)	$ 371	$ (518)	$ 378
Interest Rate Swap Contracts-Commercial Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative Gain (Loss)	101	(38)	96
Interest Rate Lock Commitments-Mortgage Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative Gain (Loss)	223	27	62
Forward Sale Contracts-Mortgage Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative Gain (Loss)	$ 47	$ (507)	$ 220

XML

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2012

Nature of Operations

Nature of Operations

S&T Bancorp, Inc., or S&T, was incorporated on March 17, 1983 under the laws of the Commonwealth of Pennsylvania as a bank holding company and has three wholly owned subsidiaries, S&T Bank, 9th Street Holdings, Inc. and STBA Capital Trust I. We own a one-half interest in Commonwealth Trust Credit Life Insurance Company, or CTCLIC.

We are presently engaged in nonbanking activities through the following five entities: 9th Street Holdings, Inc.; S&T Bancholdings, Inc.; CTCLIC; S&T Insurance Group, LLC and Stewart Capital Advisors, LLC. 9th Street Holdings, Inc. and S&T Bancholdings, Inc. are investment holding companies. CTCLIC, which is a joint venture with another financial institution, acts as a reinsurer of credit life, accident and health insurance policies sold by S&T Bank and the other institution. S&T Insurance Group, LLC, through its subsidiaries, offers a variety of insurance products. Stewart Capital Advisors, LLC is a registered investment advisor that manages private investment accounts for individuals and institutions and advises the Stewart Capital Mid Cap Fund.

On March 9, 2012, we completed the acquisition and conversion of Mainline Bancorp, Inc., or Mainline, a bank holding company based in Ebensburg, Pennsylvania. Mainline had one subsidiary, Mainline National Bank, with eight branches and $129.5 million in loans and $206.0 million in deposits. The acquisition expanded our market share and footprint throughout Cambria and Blair counties of Western Pennsylvania. The total acquisition cost of Mainline was $27.8 million.

On August 13, 2012, we completed the acquisition of Gateway Bank of Pennsylvania, a bank with $99.1 million in loans and $105.4 million in deposits, headquartered in McMurray, Pennsylvania. The total acquisition cost of Gateway Bank was $19.8 million. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T, with all transactions since the acquisition date consolidated in our financial statements. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank.

Accounting Policies

Accounting Policies

Our financial statements have been prepared in accordance with U. S. generally accepted accounting principles, or GAAP. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the dates of the balance sheets and revenues and expenses for the periods then ended. Actual results could differ from those estimates. Our significant accounting policies are described below.

Principals of Consolidation

Principals of Consolidation

The Consolidated Financial Statements include the accounts of 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.

Reclassification

Reclassification

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

Business Combinations

Business Combinations

We account for business combinations using the acquisition method of accounting. Under this method of accounting, the acquired company’s net assets are recorded at fair value at the date of acquisition, and the results of operations of the acquired company are combined with our results from that date forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identified intangibles) is recorded as goodwill.

Fair Value Measurements

Fair Value Measurements

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.

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. 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. Trading assets are recorded in other assets in the Consolidated Balance Sheets.

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.

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. If the carrying value of MSRs exceeds fair value, they are considered impaired. As the valuation model includes significant unobservable inputs, 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

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. 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 discounted cash flow analyses, utilizing interest rates currently being offered for loans with similar terms, 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.

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.

Junior Subordinated Debt Securities

The variable rate junior subordinated debt securities reprice quarterly and fair values are based on 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.

Cash and Cash Equivalents

Cash and Cash Equivalents

We consider cash and due from banks, interest-bearing deposits with banks and federal funds sold as cash and cash equivalents.

Securities

Securities

We determine the appropriate classification of securities at the time of purchase. All securities, including both debt and equity securities, are classified as available-for-sale. These are securities that we intend to hold for an indefinite period of time, but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Such securities are carried at fair value with net unrealized gains and losses deemed to be temporary, reported as a component of other comprehensive income, net of tax. Realized gains and losses on the sale of available-for-sale securities and other-than-temporary impairment, or OTTI, charges are recorded within noninterest income in the Consolidated Statements of Net Income. Realized gains and losses on the sale of securities are determined using the specific-identification method. Bond premiums are amortized to the call date and bond discounts are accreted to the maturity date, both on a level yield basis.

We perform a quarterly review of our securities to identify those that may indicate an OTTI. Our policy for OTTI within the marketable equity securities portfolio generally requires an impairment charge when the security is in a loss position for 12 consecutive months, unless facts and circumstances would suggest the need for an OTTI prior to that time. Our policy for OTTI within the debt securities portfolio is based upon a number of factors, including but not limited to, the length of time and extent to which the estimated fair value has been less than cost, the financial condition of the underlying issuer, the ability of the issuer to meet contractual obligations, the best estimate of impairment charge representing credit losses, the likelihood of the security’s ability to recover any decline in its estimated fair value and whether management intends to sell the security or if it is more likely than not that management will be required to sell the investment security prior to the security’s recovery.

Loans Held for Sale

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. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a charge-off against the allowance for loan loss, or ALL. Subsequent declines in fair value are recognized as a charge to noninterest income. When a loan is placed in the held-for-sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold. Gains and losses on sales of loans held for sale are included in other noninterest income in the Consolidated Statements of Net Income.

Loans

Loans

Loans are reported at the principal amount outstanding net of unearned income, unamortized premiums or discounts and deferred origination fees and costs. We defer certain nonrefundable loan origination and commitment fees. Accretion of discounts and amortization of premiums on loans are included in interest income in the Consolidated Statements of Net Income. Loan origination fees and direct loan origination costs are deferred and amortized as an adjustment of loan yield over the respective lives of the loans without consideration of anticipated prepayments. If a loan is paid off, the remaining unaccreted or unamortized net origination fees and costs are immediately recognized into income or expense. Interest is accrued on loans as earned. Interest income is recognized on loans as earned.

Closed-end installment loans, amortizing loans secured by real estate and any other loans with payments scheduled monthly are reported past due when the borrower is in arrears two or more monthly payments. Other multi-payment obligations with payments scheduled other than monthly are reported past due when one scheduled payment is due and unpaid for 30 days or more.

Generally, consumer loans are charged off against the ALL upon the loan reaching 90 days past due. Commercial loans are charged off as management becomes aware of facts and circumstances that raise doubt as to the collectability of all or a portion of the principal and when we believe a confirmed loss exists.

Nonaccrual Loans

Nonaccrual Loans

We stop accruing interest on a loan (nonaccrual loan) when the borrower’s payment is 90 days past due. Loans are also placed on nonaccrual status when payment is not past due, but we have doubt about the borrower’s ability to comply with existing repayment terms. When the interest accrual is discontinued, all unpaid accrued interest is reversed against interest income. Interest income is recognized on nonaccrual loans on a cash basis if recovery of the remaining principal is reasonably assured. As a general rule, a nonaccrual loan may be restored to accrual status when its principal and interest is paid current and the bank expects repayment of the remaining contractual principal and interest, or when the loan otherwise becomes well secured and in the process of collection.

Allowance for Loan Losses

Allowance for Loan Losses

The ALL reflects our estimates of probable losses inherent in the loan portfolio at the balance sheet date. The methodology for determining the ALL has two main components: evaluation and impairment tests of individual loans and evaluation and impairment tests of certain groups of homogeneous loans with similar risk characteristics.

A loan is considered impaired when it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. All troubled debt restructurings, or TDRs, are considered to be impaired loans and will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. For all TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate. Specific reserves are established based upon 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 estimated fair value of the collateral if the loan is collateral dependent. Our impairment evaluations consist primarily of the fair value of collateral method since most loans are collateral dependent. Collateral values are discounted to consider disposition costs when appropriate. A specific reserve is established or a charge-off is taken if the fair value of the impaired loan is less than the recorded investment in the loan balance.

The ALL for homogeneous loans is calculated using a systematic methodology that is applied on a quarterly basis. The ALL model is comprised of five distinct portfolio segments: 1) Commercial Real Estate, or CRE, 2) Commercial and Industrial, or C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. Each segment has a distinct set of risk characteristics monitored by management. We further assess and monitor risk and performance at a more disaggregated level which includes our internal risk rating system for the commercial segments and collateral position and loan-to-value, or LTV, for the consumer segments.

Historical loss rate calculations are performed whereby past losses from each pool of loans are aggregated over the respective loss emergence period. The loss emergence period is defined as the average time between the occurrence of a credit event (deterioration in the borrower’s financial condition) and the confirmation of a loss. Currently, we have estimated the loss emergence period to be two years for CRE loans and one year for all other loan classes. We use a one year look back period that results, when considering our loss emergence periods, in capturing historic losses for three years for CRE and two years for our other portfolio segments. These historic loss calculations are then aggregated and applied to each loan segment to determine the component of the ALL based upon historic losses. Since the losses captured in the historical loss analysis may not accurately represent the losses inherent in the loan portfolio at the balance sheet date, qualitative adjustments are then applied to loan segments to determine the total ALL. Qualitative adjustments are aggregated into five categories, including process, economic conditions, loan portfolio, asset quality and other external factors.

Within the five aforementioned categories, the following qualitative factors are considered:

1) Changes in our lending policies and procedures, including underwriting standards, collection, charge-off and recovery practices not considered elsewhere in estimating credit losses;

2) Changes in national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments;

3) Changes in the nature and volume of our loan portfolio and terms of loans;

4) Changes in the experience, ability and depth of our lending management and staff;

5) Changes in the volume and severity of past due loans, the volume of non accrual loans, and the volume and severity of adversely classified or graded loans;

6) Changes in the quality of our loan review system;

7) Changes in the value of the underlying collateral for collateral-dependent loans;

8) The existence and effect of any concentrations of credit and changes in the level of such concentrations; and

9) The effect of external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in our current loan portfolio.

Bank Owned Life Insurance

Bank Owned Life Insurance

We have purchased life insurance policies on certain executive officers and employees. We receive the cash surrender value of each policy upon its termination or benefits are payable upon the death of the insured. Changes in net cash surrender value are recognized in noninterest income or expense in the Consolidated Statements of Net Income.

Premises and Equipment

Premises and Equipment

Premises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation. Maintenance and repairs are charged to expense as incurred, while improvements that extend an asset’s useful life are capitalized and depreciated over the estimated remaining life of the asset. Depreciation expense is computed generally by the straight-line method for financial reporting purposes and accelerated methods for income tax purposes. Leasehold improvements are amortized over the shorter of the asset’s useful life or the remaining lease term, including renewal periods when reasonably assured.

Restricted Investment in Bank Stock

Restricted Investment in Bank Stock

Federal Home Loan Bank, or FHLB, stock is carried at cost and evaluated for impairment based on the ultimate recoverability of the par value. We hold FHLB stock because we are a member of the FHLB of Pittsburgh. The FHLB requires members to purchase and hold a specified level of FHLB stock based upon on the members asset value, level of borrowings and participation in other programs offered. Stock in the FHLB is non-marketable and is redeemable at the discretion of the FHLB. Members do not purchase stock in the FHLB for the same reasons that traditional equity investors acquire stock in an investor-owned enterprise. Rather, members purchase stock to obtain access to the low-cost products and services offered by the FHLB. Unlike equity securities of traditional for-profit enterprises, the stock of the FHLB does not provide its holders with an opportunity for capital appreciation because, by regulation, FHLB stock can only be purchased, redeemed and transferred at par value. Both cash and stock dividends are reported as income in taxable investment securities in the Consolidated Statements of Net Income.

On February 22, 2012, the FHLB of Pittsburgh announced that it would pay a dividend on the average capital stock balance held during the three month period ended December 31, 2011 at an annualized rate of 0.10% for the first time since late 2008. The FHLB noted future dividend payments and capital stock repurchases will continue to be reviewed on a quarterly basis. We had $5.7 million of redemptions from the FHLB throughout 2012. We reviewed and evaluated the FHLB capital stock for OTTI at December 31, 2012. Based upon our review of the FHLB’s current financial position, they reported improved earnings throughout 2012 compared to 2011 and continue to exceed all capital ratios required. Additionally, we considered that the FHLB began paying dividends and redeeming excess stock during 2012. Accordingly, we believe sufficient evidence exists to conclude that no OTTI exists at December 31, 2012.

Goodwill and Other Intangible Assets

Goodwill and Other Intangible Assets

We have three reporting units: Community Banking, Wealth Management and Insurance. At December 31, 2012, we had goodwill of $175.7 million, including $171.5 million in Community Banking, representing 98 percent of total goodwill and $4.2 million in Insurance, representing two percent of total goodwill. The carrying value of goodwill is tested annually for impairment each October 1 or more frequently if it is determined that we should do so. We first assess qualitatively whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Our qualitative assessment considers such factors as macroeconomic conditions, market conditions specifically related to the banking industry, our overall financial performance and various other factors. If we determine that it is more likely than not that the fair value is less than the carrying amount, we proceed to test for impairment. The evaluation for impairment involves comparing the current estimated fair value of each reporting unit to its carrying value, including goodwill. If the current estimated fair value of a reporting unit exceeds its carrying value, no additional testing is required and impairment loss is not recorded. If the estimated fair value of a reporting unit is less than the carrying value, further valuation procedures are performed and could result in impairment of goodwill being recorded. Further valuation procedures would include allocating the estimated fair value to all assets and liabilities of the reporting unit to determine an implied goodwill value. If the implied value of goodwill of a reporting unit is less than the carrying amount of that goodwill, an impairment loss is recognized in an amount equal to that excess.

We have core deposit and other intangible assets resulting from acquisitions which are subject to amortization. We determine the amount of identifiable intangible assets based upon independent core deposit and insurance contract analyses at the time of the acquisition. Intangible assets with finite useful lives are evaluated for impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. No events or changes in circumstances that would indicate that the carrying amount of any identifiable intangible assets may not be recoverable had occurred during the years ended December 31, 2012, 2011 and 2010.

Joint Ventures

Joint Ventures

We have made investments directly in Low Income Housing Tax Credit, or LIHTC, partnerships formed with third parties. As a limited partner in these operating partnerships, we receive tax credits and tax deductions for losses incurred by the underlying properties. These investments are amortized over a maximum of 10 years, which represents the period that the tax credits will be utilized. We have determined that we are not the primary beneficiary of these investments because the general partners have the power to direct the activities that most significantly impact the economic performance of the partnership and have the obligation to absorb expected losses and the right to receive benefits.

OREO and Other Repossessed Assets

OREO and Other Repossessed Assets

OREO and other repossessed assets are included in other assets in the Consolidated Balance Sheets and are comprised of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of a foreclosure. At the time of foreclosure, these properties are recorded at the lower of the recorded investment in the loan or fair value less cost to sell. Loan losses arising from the acquisition of such property initially are charged against the ALL. Subsequently, these assets are carried at the lower of carrying value or current fair value less cost to sell. Gains or losses realized subsequent to acquisition are recorded in other expenses in the Consolidated Statements of Net Income.

Mortgage Servicing Rights

Mortgage Servicing Rights

MSRs are recognized as separate assets when commitments to fund a loan to be sold are made. Upon commitment, the MSR is established, which represents the then current estimated fair value of future net cash flows expected to be realized for performing the servicing activities. The estimated fair value of the MSRs is estimated 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. Increases in mortgage loan prepayments reduce estimated future net servicing cash flows because the life of the underlying loan is reduced. In determining the estimated fair value of MSRs, mortgage interest rates, which are used to determine prepayment rates, are held constant over the estimated life of the portfolio. MSRs are reported in other assets in the Consolidated Balance Sheets and are amortized into noninterest income in the Consolidated Statements of Net Income in proportion to, and over the period of, the estimated future net servicing income of the underlying mortgage loans.

MSRs are regularly evaluated for impairment based on the estimated fair value of those rights. The MSRs are stratified by certain risk characteristics, primarily loan term and note rate. If temporary impairment exists within a risk stratification tranche, a valuation allowance is established through a charge to income equal to the amount by which the carrying value exceeds the estimated fair value. If it is later determined all or a portion of the temporary impairment no longer exists for a particular tranche, the valuation allowance is reduced.

MSRs are also reviewed for OTTI. OTTI exists when the recoverability of a recorded valuation allowance is determined to be remote, taking into consideration historical and projected interest rates and loan pay-off activity. When this situation occurs, the unrecoverable portion of the valuation allowance is applied as a direct write-down to the carrying value of the MSR. Unlike a valuation allowance, a direct write-down permanently reduces the carrying value of the MSR and the valuation allowance, precluding subsequent recoveries.

Derivative Financial Instruments

Derivative Financial Instruments

Interest Rate Swaps

In accordance with applicable accounting guidance for derivatives and hedging, all derivatives are recognized as either assets or liabilities on the balance sheet at fair value. Interest rate swaps are contracts in which a series of interest rate flows (fixed and variable) are exchanged over a prescribed period. The notional amounts on which the interest payments are based are not exchanged. We utilize interest rate swaps for commercial loans. These derivative positions relate to transactions in which we enter into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a same notional amount at a fixed rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate loan with us receiving a variable yield. These agreements could have floors or caps on the contracted interest rates.

Pursuant to our agreements with various financial institutions, we may receive collateral or may be required to post collateral based upon mark-to-market positions. Beyond unsecured threshold levels, collateral in the form of cash or securities may be made available to counterparties of interest rate swap transactions. Based upon our current positions and related future collateral requirements relating to them, we believe any effect on our cash flow or liquidity position to be immaterial. Derivatives contain an element of credit risk, the possibility that we will incur a loss because a counterparty, which may be a financial institution or a customer, fails to meet its contractual obligations. All derivative contracts with financial institutions may be executed only with counterparties approved by our Asset and Liability Committee, or ALCO, and derivatives with customers may only be executed with customers within credit exposure limits approved by our Senior Loan Committee. Interest rate swaps are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives are recorded in current earnings and included in other noninterest income in the Consolidated Statements of Net Income.

Interest Rate Lock Commitments and Forward Sale Contracts

In the normal course of business, we sell originated mortgage loans into the secondary mortgage loan market. We also offer interest rate lock commitments to potential borrowers. The commitments are generally for 60 days and guarantee a specified interest rate for a loan if underwriting standards are met, but the commitment does not obligate the potential borrower to close on the loan. Accordingly, some commitments expire prior to becoming loans. We can encounter pricing risks if interest rates increase significantly before the loan can be closed and sold. We may utilize forward sale contracts in order to mitigate this pricing risk. Whenever a customer desires these products, a mortgage originator quotes a secondary market rate guaranteed for that day by the investor. The rate lock is executed between the mortgagee and us and in turn a forward sale contract may be executed between us and the investor. Both the rate lock commitment and the corresponding forward sale contract for each customer are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives during the commitment period are recorded in current earnings and included in mortgage banking in the Consolidated Statements of Net Income.

Allowance for Unfunded Commitments

Allowance for Unfunded Commitments

In the normal course of business, we offer off-balance sheet credit arrangements to enable our customers to meet their financing objectives. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. Our exposure to credit loss, in the event the customer does not satisfy the terms of the agreement, equals the contractual amount of the obligation less the value of any collateral. We apply the same credit policies in making commitments and standby letters of credit that are used for the underwriting of loans to customers. Commitments generally have fixed expiration dates, annual renewals or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The allowance for unfunded commitments is included in other liabilities in the Consolidated Balance Sheets. The allowance for unfunded commitments is determined using a similar methodology as our ALL. The reserve is calculated by applying historical loss rates from our ALL model to the estimated future utilization of our unfunded commitments.

Treasury Stock

Treasury Stock

The repurchase of our common stock is recorded at cost. At the time of reissuance, the treasury stock account is reduced using the average cost method. Gains and losses on the reissuance of common stock are recorded in additional paid-in capital, to the extent additional paid-in capital from previous treasury share transactions exists. Any deficiency is charged to retained earnings.

Wealth Management Fees

Wealth Management Fees

Assets held in a fiduciary capacity by the subsidiary bank, S&T Bank, are not our assets and are therefore not included in our Consolidated Financial Statements. Wealth management fee income is reported in the Consolidated Statements of Net Income on the accrual basis.

Stock-Based Compensation

Stock-Based Compensation

Stock-based compensation may include stock options and restricted stock which is measured using the fair value method of accounting. The grant date fair value is recognized over the period during which the recipient is required to provide service in exchange for the award. Stock option expense is determined utilizing the Black-Scholes model. Restricted stock expense is determined using the grant date fair value. We estimate expected forfeitures when stock-based awards are granted and record compensation expense only for awards that are expected to vest.

Pensions

Pensions

Pension expense for S&T Bank’s defined benefit pension plan is actuarially determined using the projected unit credit actuarial cost method. The funding policy for the plan is to contribute amounts to the plan sufficient to meet the minimum funding requirements of the Employee Retirement Income Security Act of 1974, or ERISA, plus such additional amounts as may be appropriate, subject to federal income tax limitation.

Marketing Costs

Marketing Costs

We expense all marketing-related costs, including advertising costs, as incurred.

Income Taxes

Income Taxes

We estimate income tax expense based on amounts expected to be owed to the tax jurisdictions where we conduct business. On a quarterly basis, management assesses the reasonableness of our effective tax rate based upon our current estimate of the amount and components of net income, tax credits and the applicable statutory tax rates expected for the full year.

Deferred income tax assets and liabilities are determined using the asset and liability method and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax basis of assets and liabilities and recognizes enacted changes in tax rate and laws. When deferred tax assets are recognized, they are subject to a valuation allowance based on management’s judgment as to whether realization is more likely than not.

Accrued taxes represent the net estimated amount due to taxing jurisdictions and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. We evaluate and assess the relative risks and appropriate tax treatment of transactions and filing positions after considering statutes, regulations, judicial precedent and other information and maintain tax accruals consistent with the evaluation of these relative risks and merits. Changes to the estimate of accrued taxes occur periodically due to changes in tax rates, interpretations of tax laws, the status of examinations being conducted by taxing authorities and changes to statutory, judicial and regulatory guidance. These changes, when they occur, can affect deferred taxes and accrued taxes, as well as the current period’s income tax expense and can be significant to our operating results.

Tax positions are recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

Earnings Per Share

Earnings Per Share

Basic earnings per share, or EPS, is calculated using the two-class method to determine income allocated to common shareholders. Unvested share-based payment awards that contain nonforfeitable rights to dividends are considered participating securities under the two-class method. Income allocated to common shareholders is then divided by the weighted average number of common shares outstanding during the period. Potentially dilutive securities are excluded from the basic EPS calculation.

Diluted earnings per share is calculated under the more dilutive of either the treasury stock method or the two-class method. Under the treasury stock method, the weighted average number of common shares outstanding is increased by the potentially dilutive common shares. For the two-class method, diluted earnings per share is calculated for each class of shareholders using the weighted average number of shares attributed to each class. Potentially dilutive common shares are common stock equivalents relating to our outstanding warrants, stock options and restricted stock.

Testing Goodwill for Impairment

Testing Goodwill for Impairment

In September 2011, the FASB issued ASU No. 2011-08, which permits an entity to make a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount before applying the two-step goodwill impairment test. If an entity concludes it is not more likely than not that its fair value is less than its carrying amount, it need not perform the two-step impairment test. This ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011. Early adoption is permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS

Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS

In May 2011, the FASB issued ASU No. 2011-04, which represents the convergence of the FASB’s and the International Accounting Standard Board’s, or IASB, guidance on fair value measurement. ASU 2011-04 reflects the common requirements under U.S. GAAP and international financial reporting standards, or IFRS, for measuring fair value and for disclosing information about fair value measurements, including a consistent meaning for the term “fair value.” The new guidance does not extend the use of fair value but, rather, provides guidance about how fair value should be applied where it is already required or permitted under U.S. GAAP or IFRS. For U.S. GAAP, most of the changes are clarifications of existing guidance or wording changes to align with IFRS 13 Fair Value Measurement. A public company is required to apply the ASU prospectively for interim and annual periods beginning after December 15, 2011. Early adoption is not permitted for a public company. The adoption of this ASU impacted only disclosure requirements and did not have a material impact on our results of operations or financial position.

Reconsideration of Effective Control for Repurchase Agreements

Reconsideration of Effective Control for Repurchase Agreements

In April 2011, the FASB issued ASU No. 2011-03, which is intended to improve financial reporting of repurchase agreements, or repos, and other agreements that both entitle and obligate a transferor to repurchase or redeem financial assets before their maturity. When an entity enters into a typical repo arrangement, it transfers financial assets to a counterparty in exchange for cash with an agreement for the counterparty to return the same or equivalent financial assets for a fixed price in the future. Current guidance prescribes when an entity may or may not recognize a sale upon the transfer of financial assets subject to a repo agreement. That determination is based, in part, on whether the entity has maintained effective control over the transferred financial assets. This ASU improves the accounting for these transactions by removing from the assessment of effective control the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets and focuses the assessment on the transferor’s contractual rights. This guidance is effective for the first interim or annual period beginning on or after December 15, 2011. The guidance should be applied prospectively to transactions or modifications of existing transactions that occur on or after the effective date. Early adoption is not permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Disclosures About Offsetting Assets and Liabilities

Disclosures About Offsetting Assets and Liabilities

In December 2011, the FASB issued ASU, No. 2011-11, in conjunction with the issuance by the IASB, of amendments to Disclosures—Offsetting Financial Assets and Financial Liabilities (Amendments to IFRS 7). The disclosure requirements apply to recognized financial instruments and derivative instruments that are offset or subject to an enforceable master netting arrangement. An entity shall disclose information to enable users of its financial statements to evaluate the effect or potential effect of netting arrangements on its financial position, including the effect or potential effect of rights of setoff associated with recognized assets and recognized liabilities. While both the FASB and the IASB retained the existing offsetting models under U.S. GAAP and IFRS, the new standards require disclosures to allow investors to better compare financial statements prepared under U.S. GAAP with financial statements prepared under IFRS. The new standards are effective for annual periods beginning January 1, 2013, and interim periods within those annual periods. Retrospective application is required. The adoption of this ASU is expected to impact only our disclosure requirements and is not expected to have a material impact on our results of operations or financial position.

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INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Income Tax Expense (Benefit)

Income tax expense (benefit) for the years ended December 31 are comprised of:

(in thousands)	2012		2011		2010
Current	$	6,223	$	12,174	$	18,969
Deferred		1,038		2,448		(4,537	)
Total	$	7,261	$	14,622	$	14,432

Schedule of Statutory to Effective Tax Rate Reconciliation

The statutory to effective tax rate reconciliation for the years ended December 31 is as follows:

	2012		2011		2010
Statutory tax rate		35.0 %		35.0 %		35.0 %
Low income housing and federal historic tax credits		(10.5)%		(5.5)%		(3.9)%
Tax-exempt interest		(6.7)%		(4.1)%		(4.8)%
Bank owned life insurance		(1.2)%		(1.2)%		(1.3)%
Acquisition costs		0.5 %		—		—
Dividend exclusion		(0.7)%		(0.6)%		(0.7)%
Other		1.1 %		—		0.6 %
Effective Tax Rate		17.5 %		23.6 %		24.9 %

Schedule of Significant Components of Temporary Differences with Deferred Tax Assets and Liabilities

Significant components of our temporary differences were as follows at December 31:

(in thousands)	2012			2011
Deferred Tax Liabilities:
Net unrealized holding gains on securities available-for-sale	$	(5,586	)	$	(5,208	)
Prepaid pension		(4,721	)		(5,007	)
Deferred loan income		(969	)		(736	)
Purchase accounting adjustments		(935	)		(3,160	)
Depreciation on premises and equipment		(1,963	)		(1,882	)
Other		(690	)		(701	)
Total Deferred Tax liabilities		(14,864	)		(16,694	)
Deferred Tax Assets:
Allowance for loan losses		16,536			15,593
Tax credit carryforwards (expires in 20 years)		1,430			—
Other employee benefits		2,701			2,148
Low income housing partnerships		2,890			2,608
Net adjustment to funded status of pension		12,899			12,804
Impairment of securities		1,375			2,119
Delinquent interest on nonaccrual loans		1,719			1,187
State net operating loss carryforwards		1,498			1,232
Other		3,157			3,559
Gross Deferred Tax Assets		44,205			41,250
Less: Valuation allowance for Pennsylvania net operating loss carryforwards		(1,498	)		(1,232	)
Total Deferred Tax Assets		42,707			40,018
Net Deferred Tax Asset	$	27,843		$	23,324

Schedule of Change in Deferred Taxes on Balance Sheet

The period change in deferred taxes on our Consolidated Balance Sheet is comprised of the following at December 31:

(in thousands)	2012			2011
Deferred tax changes reflected in other comprehensive gain/loss	$	284		$	(4,186	)
Deferred tax changes resulting from purchase accounting adjustments		(5,843	)		—
Deferred tax changes reflected in federal income tax expense (benefit)		1,038			2,448

Schedule of Reconciliation of Change in Federal and State Gross Unrecognized Tax Benefits

A reconciliation of the change in Federal and State gross unrecognized tax benefits, or UTB, for the years ended December 31:

(in thousands)	2012			2011			2010
Balance at beginning of year	$	200		$	242		$	286
Prior period tax positions
Increase		—			—			—
Decrease		—			—			(67	)
Current period tax positions		913			(42	)		23
Reductions for statute of limitations expirations		(135	)		—			—
Balance at End of Year	$	978		$	200		$	242
Amount That Would Affect the Effective Tax Rate if Recognized	$	147		$	197		$	239

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Fair Value Measurements - Changes in Assets Classified as Level 3 in Fair Value Hierarchy (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of year	$ 1,687	$ 1,588
Total (losses) gains included in other comprehensive income/loss	(350)	99
Net purchases, sales, issuances and settlements	(207)
Transfers out of Level 3
Balance at end of year	$ 1,130	$ 1,687

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Commitments and Contingencies - Commitments and Letters of Credit (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Commitment And Contingencies [Line Items]
Commitments and letters of credit	$ 969,536	$ 935,736
Commitments to extend credit [Member]
Commitment And Contingencies [Line Items]
Commitments and letters of credit	874,137	816,160
Standby letters of credit [Member]
Commitment And Contingencies [Line Items]
Commitments and letters of credit	$ 95,399	$ 119,576

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SELECTED FINANCIAL DATA (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Selected Financial Data

The following table presents selected financial data for the most recent eight quarters:

(unaudited)

	2012								2011
(in thousands, except per share data)	Fourth Quarter		Third Quarter		Second Quarter		First Quarter		Fourth Quarter		Third Quarter			Second Quarter			First Quarter
SUMMARY OF OPERATIONS
Interest income	$	38,920	$	38,820	$	39,370	$	39,140	$	40,259	$	40,845		$	41,783		$	42,192
Interest expense		4,629		5,025		5,551		5,819		6,192		6,976			7,245			7,320
Provision for loan losses		4,215		2,305		7,023		9,272		2,337		1,535			1,097			10,640
Net interest income after provision for loan losses		30,076		31,490		26,796		24,049		31,730		32,334			33,441			24,232
Security gains (losses), net		—		2,170		6		840		—		(81	)		(56	)		13
Noninterest income		11,565		12,576		12,525		12,229		11,574		10,424			11,170			11,013
Noninterest expense		29,717		31,018		29,344		32,783		26,672		24,193			25,594			27,449
Income before taxes		11,924		15,218		9,983		4,335		16,632		18,484			18,961			7,809
Provision for income taxes		2,400		2,623		1,383		855		4,376		4,681			4,051			1,514
Net income		9,524		12,595		8,600		3,480		12,256		13,803			14,910			6,295
Preferred stock dividends and discount amortization		—		—		—		—		2,939		1,559			1,558			1,555
Net Income Available to Common Shareholders	$	9,524	$	12,595	$	8,600	$	3,480	$	9,317	$	12,244		$	13,352		$	4,740
Per Share Data
Common earnings per share — diluted	$	0.32	$	0.43	$	0.30	$	0.12	$	0.33	$	0.44		$	0.48		$	0.17
Dividends declared per common share		0.15		0.15		0.15		0.15		0.15		0.15			0.15			0.15
Common book value		18.08		17.97		17.65		17.47		17.44		17.68			17.31			16.90

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MORTGAGE SERVICING RIGHTS (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Mortgage Servicing Rights and Net Carrying Values

The following table indicates MSRs and the net carrying values:

(in thousands)	Servicing Rights			Valuation Allowance			Net Carrying Value
Balance at December 31, 2010	$	3,292		$	825		$	2,467
Additions		621			342			279
Amortization		(593	)		—			(593	)
Balance at December 31, 2011	$	3,320		$	1,167		$	2,153
Additions		826			(67	)		893
Amortization		(940	)		—			(940	)
Balance at December 31, 2012	$	3,206		$	1,100		$	2,106

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2012

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

S&T Bancorp, Inc., or S&T, was incorporated on March 17, 1983 under the laws of the Commonwealth of Pennsylvania as a bank holding company and has three wholly owned subsidiaries, S&T Bank, 9th Street Holdings, Inc. and STBA Capital Trust I. We own a one-half interest in Commonwealth Trust Credit Life Insurance Company, or CTCLIC.

We are presently engaged in nonbanking activities through the following five entities: 9th Street Holdings, Inc.; S&T Bancholdings, Inc.; CTCLIC; S&T Insurance Group, LLC and Stewart Capital Advisors, LLC. 9th Street Holdings, Inc. and S&T Bancholdings, Inc. are investment holding companies. CTCLIC, which is a joint venture with another financial institution, acts as a reinsurer of credit life, accident and health insurance policies sold by S&T Bank and the other institution. S&T Insurance Group, LLC, through its subsidiaries, offers a variety of insurance products. Stewart Capital Advisors, LLC is a registered investment advisor that manages private investment accounts for individuals and institutions and advises the Stewart Capital Mid Cap Fund.

On March 9, 2012, we completed the acquisition and conversion of Mainline Bancorp, Inc., or Mainline, a bank holding company based in Ebensburg, Pennsylvania. Mainline had one subsidiary, Mainline National Bank, with eight branches and $129.5 million in loans and $206.0 million in deposits. The acquisition expanded our market share and footprint throughout Cambria and Blair counties of Western Pennsylvania. The total acquisition cost of Mainline was $27.8 million.

On August 13, 2012, we completed the acquisition of Gateway Bank of Pennsylvania, a bank with $99.1 million in loans and $105.4 million in deposits, headquartered in McMurray, Pennsylvania. The total acquisition cost of Gateway Bank was $19.8 million. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T, with all transactions since the acquisition date consolidated in our financial statements. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank.

Accounting Policies

Our financial statements have been prepared in accordance with U. S. generally accepted accounting principles, or GAAP. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the dates of the balance sheets and revenues and expenses for the periods then ended. Actual results could differ from those estimates. Our significant accounting policies are described below.

Principals of Consolidation

The Consolidated Financial Statements include the accounts of 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.

Reclassification

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

Business Combinations

We account for business combinations using the acquisition method of accounting. Under this method of accounting, the acquired company’s net assets are recorded at fair value at the date of acquisition, and the results of operations of the acquired company are combined with our results from that date forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identified intangibles) is recorded as goodwill.

Fair Value Measurements

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.

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. 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. Trading assets are recorded in other assets in the Consolidated Balance Sheets.

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.

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. If the carrying value of MSRs exceeds fair value, they are considered impaired. As the valuation model includes significant unobservable inputs, 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. 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 discounted cash flow analyses, utilizing interest rates currently being offered for loans with similar terms, 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.

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.

Junior Subordinated Debt Securities

The variable rate junior subordinated debt securities reprice quarterly and fair values are based on 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.

Cash and Cash Equivalents

We consider cash and due from banks, interest-bearing deposits with banks and federal funds sold as cash and cash equivalents.

Securities

We determine the appropriate classification of securities at the time of purchase. All securities, including both debt and equity securities, are classified as available-for-sale. These are securities that we intend to hold for an indefinite period of time, but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Such securities are carried at fair value with net unrealized gains and losses deemed to be temporary, reported as a component of other comprehensive income, net of tax. Realized gains and losses on the sale of available-for-sale securities and other-than-temporary impairment, or OTTI, charges are recorded within noninterest income in the Consolidated Statements of Net Income. Realized gains and losses on the sale of securities are determined using the specific-identification method. Bond premiums are amortized to the call date and bond discounts are accreted to the maturity date, both on a level yield basis.

We perform a quarterly review of our securities to identify those that may indicate an OTTI. Our policy for OTTI within the marketable equity securities portfolio generally requires an impairment charge when the security is in a loss position for 12 consecutive months, unless facts and circumstances would suggest the need for an OTTI prior to that time. Our policy for OTTI within the debt securities portfolio is based upon a number of factors, including but not limited to, the length of time and extent to which the estimated fair value has been less than cost, the financial condition of the underlying issuer, the ability of the issuer to meet contractual obligations, the best estimate of impairment charge representing credit losses, the likelihood of the security’s ability to recover any decline in its estimated fair value and whether management intends to sell the security or if it is more likely than not that management will be required to sell the investment security prior to the security’s recovery.

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. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a charge-off against the allowance for loan loss, or ALL. Subsequent declines in fair value are recognized as a charge to noninterest income. When a loan is placed in the held-for-sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold. Gains and losses on sales of loans held for sale are included in other noninterest income in the Consolidated Statements of Net Income.

Loans

Loans are reported at the principal amount outstanding net of unearned income, unamortized premiums or discounts and deferred origination fees and costs. We defer certain nonrefundable loan origination and commitment fees. Accretion of discounts and amortization of premiums on loans are included in interest income in the Consolidated Statements of Net Income. Loan origination fees and direct loan origination costs are deferred and amortized as an adjustment of loan yield over the respective lives of the loans without consideration of anticipated prepayments. If a loan is paid off, the remaining unaccreted or unamortized net origination fees and costs are immediately recognized into income or expense. Interest is accrued on loans as earned. Interest income is recognized on loans as earned.

Closed-end installment loans, amortizing loans secured by real estate and any other loans with payments scheduled monthly are reported past due when the borrower is in arrears two or more monthly payments. Other multi-payment obligations with payments scheduled other than monthly are reported past due when one scheduled payment is due and unpaid for 30 days or more.

Generally, consumer loans are charged off against the ALL upon the loan reaching 90 days past due. Commercial loans are charged off as management becomes aware of facts and circumstances that raise doubt as to the collectability of all or a portion of the principal and when we believe a confirmed loss exists.

Nonaccrual Loans

We stop accruing interest on a loan (nonaccrual loan) when the borrower’s payment is 90 days past due. Loans are also placed on nonaccrual status when payment is not past due, but we have doubt about the borrower’s ability to comply with existing repayment terms. When the interest accrual is discontinued, all unpaid accrued interest is reversed against interest income. Interest income is recognized on nonaccrual loans on a cash basis if recovery of the remaining principal is reasonably assured. As a general rule, a nonaccrual loan may be restored to accrual status when its principal and interest is paid current and the bank expects repayment of the remaining contractual principal and interest, or when the loan otherwise becomes well secured and in the process of collection.

Allowance for Loan Losses

The ALL reflects our estimates of probable losses inherent in the loan portfolio at the balance sheet date. The methodology for determining the ALL has two main components: evaluation and impairment tests of individual loans and evaluation and impairment tests of certain groups of homogeneous loans with similar risk characteristics.

A loan is considered impaired when it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. All troubled debt restructurings, or TDRs, are considered to be impaired loans and will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. For all TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate. Specific reserves are established based upon 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 estimated fair value of the collateral if the loan is collateral dependent. Our impairment evaluations consist primarily of the fair value of collateral method since most loans are collateral dependent. Collateral values are discounted to consider disposition costs when appropriate. A specific reserve is established or a charge-off is taken if the fair value of the impaired loan is less than the recorded investment in the loan balance.

The ALL for homogeneous loans is calculated using a systematic methodology that is applied on a quarterly basis. The ALL model is comprised of five distinct portfolio segments: 1) Commercial Real Estate, or CRE, 2) Commercial and Industrial, or C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. Each segment has a distinct set of risk characteristics monitored by management. We further assess and monitor risk and performance at a more disaggregated level which includes our internal risk rating system for the commercial segments and collateral position and loan-to-value, or LTV, for the consumer segments.

Historical loss rate calculations are performed whereby past losses from each pool of loans are aggregated over the respective loss emergence period. The loss emergence period is defined as the average time between the occurrence of a credit event (deterioration in the borrower’s financial condition) and the confirmation of a loss. Currently, we have estimated the loss emergence period to be two years for CRE loans and one year for all other loan classes. We use a one year look back period that results, when considering our loss emergence periods, in capturing historic losses for three years for CRE and two years for our other portfolio segments. These historic loss calculations are then aggregated and applied to each loan segment to determine the component of the ALL based upon historic losses. Since the losses captured in the historical loss analysis may not accurately represent the losses inherent in the loan portfolio at the balance sheet date, qualitative adjustments are then applied to loan segments to determine the total ALL. Qualitative adjustments are aggregated into five categories, including process, economic conditions, loan portfolio, asset quality and other external factors.

Within the five aforementioned categories, the following qualitative factors are considered:

1) Changes in our lending policies and procedures, including underwriting standards, collection, charge-off and recovery practices not considered elsewhere in estimating credit losses;

2) Changes in national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments;

3) Changes in the nature and volume of our loan portfolio and terms of loans;

4) Changes in the experience, ability and depth of our lending management and staff;

5) Changes in the volume and severity of past due loans, the volume of non accrual loans, and the volume and severity of adversely classified or graded loans;

6) Changes in the quality of our loan review system;

7) Changes in the value of the underlying collateral for collateral-dependent loans;

8) The existence and effect of any concentrations of credit and changes in the level of such concentrations; and

9) The effect of external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in our current loan portfolio.

Bank Owned Life Insurance

We have purchased life insurance policies on certain executive officers and employees. We receive the cash surrender value of each policy upon its termination or benefits are payable upon the death of the insured. Changes in net cash surrender value are recognized in noninterest income or expense in the Consolidated Statements of Net Income.

Premises and Equipment

Premises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation. Maintenance and repairs are charged to expense as incurred, while improvements that extend an asset’s useful life are capitalized and depreciated over the estimated remaining life of the asset. Depreciation expense is computed generally by the straight-line method for financial reporting purposes and accelerated methods for income tax purposes. Leasehold improvements are amortized over the shorter of the asset’s useful life or the remaining lease term, including renewal periods when reasonably assured.

Restricted Investment in Bank Stock

Federal Home Loan Bank, or FHLB, stock is carried at cost and evaluated for impairment based on the ultimate recoverability of the par value. We hold FHLB stock because we are a member of the FHLB of Pittsburgh. The FHLB requires members to purchase and hold a specified level of FHLB stock based upon on the members asset value, level of borrowings and participation in other programs offered. Stock in the FHLB is non-marketable and is redeemable at the discretion of the FHLB. Members do not purchase stock in the FHLB for the same reasons that traditional equity investors acquire stock in an investor-owned enterprise. Rather, members purchase stock to obtain access to the low-cost products and services offered by the FHLB. Unlike equity securities of traditional for-profit enterprises, the stock of the FHLB does not provide its holders with an opportunity for capital appreciation because, by regulation, FHLB stock can only be purchased, redeemed and transferred at par value. Both cash and stock dividends are reported as income in taxable investment securities in the Consolidated Statements of Net Income.

On February 22, 2012, the FHLB of Pittsburgh announced that it would pay a dividend on the average capital stock balance held during the three month period ended December 31, 2011 at an annualized rate of 0.10% for the first time since late 2008. The FHLB noted future dividend payments and capital stock repurchases will continue to be reviewed on a quarterly basis. We had $5.7 million of redemptions from the FHLB throughout 2012. We reviewed and evaluated the FHLB capital stock for OTTI at December 31, 2012. Based upon our review of the FHLB’s current financial position, they reported improved earnings throughout 2012 compared to 2011 and continue to exceed all capital ratios required. Additionally, we considered that the FHLB began paying dividends and redeeming excess stock during 2012. Accordingly, we believe sufficient evidence exists to conclude that no OTTI exists at December 31, 2012.

Goodwill and Other Intangible Assets

We have three reporting units: Community Banking, Wealth Management and Insurance. At December 31, 2012, we had goodwill of $175.7 million, including $171.5 million in Community Banking, representing 98 percent of total goodwill and $4.2 million in Insurance, representing two percent of total goodwill. The carrying value of goodwill is tested annually for impairment each October 1 or more frequently if it is determined that we should do so. We first assess qualitatively whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Our qualitative assessment considers such factors as macroeconomic conditions, market conditions specifically related to the banking industry, our overall financial performance and various other factors. If we determine that it is more likely than not that the fair value is less than the carrying amount, we proceed to test for impairment. The evaluation for impairment involves comparing the current estimated fair value of each reporting unit to its carrying value, including goodwill. If the current estimated fair value of a reporting unit exceeds its carrying value, no additional testing is required and impairment loss is not recorded. If the estimated fair value of a reporting unit is less than the carrying value, further valuation procedures are performed and could result in impairment of goodwill being recorded. Further valuation procedures would include allocating the estimated fair value to all assets and liabilities of the reporting unit to determine an implied goodwill value. If the implied value of goodwill of a reporting unit is less than the carrying amount of that goodwill, an impairment loss is recognized in an amount equal to that excess.

We have core deposit and other intangible assets resulting from acquisitions which are subject to amortization. We determine the amount of identifiable intangible assets based upon independent core deposit and insurance contract analyses at the time of the acquisition. Intangible assets with finite useful lives are evaluated for impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. No events or changes in circumstances that would indicate that the carrying amount of any identifiable intangible assets may not be recoverable had occurred during the years ended December 31, 2012, 2011 and 2010.

Joint Ventures

We have made investments directly in Low Income Housing Tax Credit, or LIHTC, partnerships formed with third parties. As a limited partner in these operating partnerships, we receive tax credits and tax deductions for losses incurred by the underlying properties. These investments are amortized over a maximum of 10 years, which represents the period that the tax credits will be utilized. We have determined that we are not the primary beneficiary of these investments because the general partners have the power to direct the activities that most significantly impact the economic performance of the partnership and have the obligation to absorb expected losses and the right to receive benefits.

OREO and Other Repossessed Assets

OREO and other repossessed assets are included in other assets in the Consolidated Balance Sheets and are comprised of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of a foreclosure. At the time of foreclosure, these properties are recorded at the lower of the recorded investment in the loan or fair value less cost to sell. Loan losses arising from the acquisition of such property initially are charged against the ALL. Subsequently, these assets are carried at the lower of carrying value or current fair value less cost to sell. Gains or losses realized subsequent to acquisition are recorded in other expenses in the Consolidated Statements of Net Income.

Mortgage Servicing Rights

MSRs are recognized as separate assets when commitments to fund a loan to be sold are made. Upon commitment, the MSR is established, which represents the then current estimated fair value of future net cash flows expected to be realized for performing the servicing activities. The estimated fair value of the MSRs is estimated 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. Increases in mortgage loan prepayments reduce estimated future net servicing cash flows because the life of the underlying loan is reduced. In determining the estimated fair value of MSRs, mortgage interest rates, which are used to determine prepayment rates, are held constant over the estimated life of the portfolio. MSRs are reported in other assets in the Consolidated Balance Sheets and are amortized into noninterest income in the Consolidated Statements of Net Income in proportion to, and over the period of, the estimated future net servicing income of the underlying mortgage loans.

MSRs are regularly evaluated for impairment based on the estimated fair value of those rights. The MSRs are stratified by certain risk characteristics, primarily loan term and note rate. If temporary impairment exists within a risk stratification tranche, a valuation allowance is established through a charge to income equal to the amount by which the carrying value exceeds the estimated fair value. If it is later determined all or a portion of the temporary impairment no longer exists for a particular tranche, the valuation allowance is reduced.

MSRs are also reviewed for OTTI. OTTI exists when the recoverability of a recorded valuation allowance is determined to be remote, taking into consideration historical and projected interest rates and loan pay-off activity. When this situation occurs, the unrecoverable portion of the valuation allowance is applied as a direct write-down to the carrying value of the MSR. Unlike a valuation allowance, a direct write-down permanently reduces the carrying value of the MSR and the valuation allowance, precluding subsequent recoveries.

Derivative Financial Instruments

Interest Rate Swaps

In accordance with applicable accounting guidance for derivatives and hedging, all derivatives are recognized as either assets or liabilities on the balance sheet at fair value. Interest rate swaps are contracts in which a series of interest rate flows (fixed and variable) are exchanged over a prescribed period. The notional amounts on which the interest payments are based are not exchanged. We utilize interest rate swaps for commercial loans. These derivative positions relate to transactions in which we enter into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a same notional amount at a fixed rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate loan with us receiving a variable yield. These agreements could have floors or caps on the contracted interest rates.

Pursuant to our agreements with various financial institutions, we may receive collateral or may be required to post collateral based upon mark-to-market positions. Beyond unsecured threshold levels, collateral in the form of cash or securities may be made available to counterparties of interest rate swap transactions. Based upon our current positions and related future collateral requirements relating to them, we believe any effect on our cash flow or liquidity position to be immaterial. Derivatives contain an element of credit risk, the possibility that we will incur a loss because a counterparty, which may be a financial institution or a customer, fails to meet its contractual obligations. All derivative contracts with financial institutions may be executed only with counterparties approved by our Asset and Liability Committee, or ALCO, and derivatives with customers may only be executed with customers within credit exposure limits approved by our Senior Loan Committee. Interest rate swaps are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives are recorded in current earnings and included in other noninterest income in the Consolidated Statements of Net Income.

Interest Rate Lock Commitments and Forward Sale Contracts

In the normal course of business, we sell originated mortgage loans into the secondary mortgage loan market. We also offer interest rate lock commitments to potential borrowers. The commitments are generally for 60 days and guarantee a specified interest rate for a loan if underwriting standards are met, but the commitment does not obligate the potential borrower to close on the loan. Accordingly, some commitments expire prior to becoming loans. We can encounter pricing risks if interest rates increase significantly before the loan can be closed and sold. We may utilize forward sale contracts in order to mitigate this pricing risk. Whenever a customer desires these products, a mortgage originator quotes a secondary market rate guaranteed for that day by the investor. The rate lock is executed between the mortgagee and us and in turn a forward sale contract may be executed between us and the investor. Both the rate lock commitment and the corresponding forward sale contract for each customer are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives during the commitment period are recorded in current earnings and included in mortgage banking in the Consolidated Statements of Net Income.

Allowance for Unfunded Commitments

In the normal course of business, we offer off-balance sheet credit arrangements to enable our customers to meet their financing objectives. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. Our exposure to credit loss, in the event the customer does not satisfy the terms of the agreement, equals the contractual amount of the obligation less the value of any collateral. We apply the same credit policies in making commitments and standby letters of credit that are used for the underwriting of loans to customers. Commitments generally have fixed expiration dates, annual renewals or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The allowance for unfunded commitments is included in other liabilities in the Consolidated Balance Sheets. The allowance for unfunded commitments is determined using a similar methodology as our ALL. The reserve is calculated by applying historical loss rates from our ALL model to the estimated future utilization of our unfunded commitments.

Treasury Stock

The repurchase of our common stock is recorded at cost. At the time of reissuance, the treasury stock account is reduced using the average cost method. Gains and losses on the reissuance of common stock are recorded in additional paid-in capital, to the extent additional paid-in capital from previous treasury share transactions exists. Any deficiency is charged to retained earnings.

Wealth Management Fees

Assets held in a fiduciary capacity by the subsidiary bank, S&T Bank, are not our assets and are therefore not included in our Consolidated Financial Statements. Wealth management fee income is reported in the Consolidated Statements of Net Income on the accrual basis.

Stock-Based Compensation

Stock-based compensation may include stock options and restricted stock which is measured using the fair value method of accounting. The grant date fair value is recognized over the period during which the recipient is required to provide service in exchange for the award. Stock option expense is determined utilizing the Black-Scholes model. Restricted stock expense is determined using the grant date fair value. We estimate expected forfeitures when stock-based awards are granted and record compensation expense only for awards that are expected to vest.

Pensions

Pension expense for S&T Bank’s defined benefit pension plan is actuarially determined using the projected unit credit actuarial cost method. The funding policy for the plan is to contribute amounts to the plan sufficient to meet the minimum funding requirements of the Employee Retirement Income Security Act of 1974, or ERISA, plus such additional amounts as may be appropriate, subject to federal income tax limitation.

Marketing Costs

We expense all marketing-related costs, including advertising costs, as incurred.

Income Taxes

We estimate income tax expense based on amounts expected to be owed to the tax jurisdictions where we conduct business. On a quarterly basis, management assesses the reasonableness of our effective tax rate based upon our current estimate of the amount and components of net income, tax credits and the applicable statutory tax rates expected for the full year.

Deferred income tax assets and liabilities are determined using the asset and liability method and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax basis of assets and liabilities and recognizes enacted changes in tax rate and laws. When deferred tax assets are recognized, they are subject to a valuation allowance based on management’s judgment as to whether realization is more likely than not.

Accrued taxes represent the net estimated amount due to taxing jurisdictions and are reported in other assets or other liabilities, as appropriate, in the Consolidated Balance Sheets. We evaluate and assess the relative risks and appropriate tax treatment of transactions and filing positions after considering statutes, regulations, judicial precedent and other information and maintain tax accruals consistent with the evaluation of these relative risks and merits. Changes to the estimate of accrued taxes occur periodically due to changes in tax rates, interpretations of tax laws, the status of examinations being conducted by taxing authorities and changes to statutory, judicial and regulatory guidance. These changes, when they occur, can affect deferred taxes and accrued taxes, as well as the current period’s income tax expense and can be significant to our operating results.

Tax positions are recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

Earnings Per Share

Basic earnings per share, or EPS, is calculated using the two-class method to determine income allocated to common shareholders. Unvested share-based payment awards that contain nonforfeitable rights to dividends are considered participating securities under the two-class method. Income allocated to common shareholders is then divided by the weighted average number of common shares outstanding during the period. Potentially dilutive securities are excluded from the basic EPS calculation.

Diluted earnings per share is calculated under the more dilutive of either the treasury stock method or the two-class method. Under the treasury stock method, the weighted average number of common shares outstanding is increased by the potentially dilutive common shares. For the two-class method, diluted earnings per share is calculated for each class of shareholders using the weighted average number of shares attributed to each class. Potentially dilutive common shares are common stock equivalents relating to our outstanding warrants, stock options and restricted stock.

Recently Adopted Accounting Standards Updates

Technical Corrections and Improvements

In October 2012, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2012-04, Technical Corrections and Improvements, which was meant to correct minor technical errors in the codification and to conform terminology and clarify certain guidance in various topics of the codification to fully reflect the fair value measurement and disclosure requirements of Topic 820. Since this includes minor corrections, terminology conformation and guidance clarification only of previously issued accounting guidance, it was adopted at December 31, 2012, and did not have an impact on our results of operations or financial position.

Technical Amendments and Corrections to SEC Sections

In August 2012, the FASB issued ASU No. 2012-03, Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 114, Technical Amendments Pursuant to SEC Release No. 33-9250, and Corrections Related to FASB Accounting Standards Update 2010-22 (SEC Update), which were meant to codify various amendments and corrections included in these previously issued bulletins and releases. Since this is codification only of previously issued accounting guidance, it was adopted at September 30, 2012, and did not have an impact on our results of operations or financial position.

Presentation of Comprehensive Income

In December 2011, the FASB issued ASU No. 2011-12, which superseded certain pending paragraphs in ASU No. 2011-05, which had been issued in June 2011. ASU No. 2011-05 allowed an entity the option to present the total of comprehensive income, the components of net income and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. Under both options, an entity is required to present each component of net income along with total net income, each component of other comprehensive income along with a total for other comprehensive income and a total amount for comprehensive income. ASU 2011-05 eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity but permits companies to present in the annual period the comprehensive income components in a single continuous statement or two consecutive statements and to present in the interim periods only the total for comprehensive income in a single continuous statement or two consecutive statements. ASU No. 2011-12 effectively defers changes that relate to the presentation of reclassification adjustments out of accumulated other comprehensive income. The amendments will be temporary to allow the FASB time to redeliberate the presentation requirements for reclassifications out of accumulated other comprehensive income for annual and interim financial statements. The two amendments became effective at the same time. These ASUs should be applied retrospectively and were effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2011. We have elected the option of a single continuous statement format for interim periods, and two separate but consecutive statements for annual periods. The adoption of both ASU 2011-05 and 2011-12 impacted only our presentation of comprehensive income and did not have an impact on our results of operations or financial position.

Testing Goodwill for Impairment

In September 2011, the FASB issued ASU No. 2011-08, which permits an entity to make a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount before applying the two-step goodwill impairment test. If an entity concludes it is not more likely than not that its fair value is less than its carrying amount, it need not perform the two-step impairment test. This ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011. Early adoption is permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS

In May 2011, the FASB issued ASU No. 2011-04, which represents the convergence of the FASB’s and the International Accounting Standard Board’s, or IASB, guidance on fair value measurement. ASU 2011-04 reflects the common requirements under U.S. GAAP and international financial reporting standards, or IFRS, for measuring fair value and for disclosing information about fair value measurements, including a consistent meaning for the term “fair value.” The new guidance does not extend the use of fair value but, rather, provides guidance about how fair value should be applied where it is already required or permitted under U.S. GAAP or IFRS. For U.S. GAAP, most of the changes are clarifications of existing guidance or wording changes to align with IFRS 13 Fair Value Measurement. A public company is required to apply the ASU prospectively for interim and annual periods beginning after December 15, 2011. Early adoption is not permitted for a public company. The adoption of this ASU impacted only disclosure requirements and did not have a material impact on our results of operations or financial position.

Reconsideration of Effective Control for Repurchase Agreements

In April 2011, the FASB issued ASU No. 2011-03, which is intended to improve financial reporting of repurchase agreements, or repos, and other agreements that both entitle and obligate a transferor to repurchase or redeem financial assets before their maturity. When an entity enters into a typical repo arrangement, it transfers financial assets to a counterparty in exchange for cash with an agreement for the counterparty to return the same or equivalent financial assets for a fixed price in the future. Current guidance prescribes when an entity may or may not recognize a sale upon the transfer of financial assets subject to a repo agreement. That determination is based, in part, on whether the entity has maintained effective control over the transferred financial assets. This ASU improves the accounting for these transactions by removing from the assessment of effective control the criterion requiring the transferor to have the ability to repurchase or redeem the financial assets and focuses the assessment on the transferor’s contractual rights. This guidance is effective for the first interim or annual period beginning on or after December 15, 2011. The guidance should be applied prospectively to transactions or modifications of existing transactions that occur on or after the effective date. Early adoption is not permitted. The adoption of this ASU did not have a material impact on our results of operations or financial position.

Recently Issued Accounting Standards Updates not yet Adopted

Disclosures About Offsetting Assets and Liabilities

In December 2011, the FASB issued ASU, No. 2011-11, in conjunction with the issuance by the IASB, of amendments to Disclosures—Offsetting Financial Assets and Financial Liabilities (Amendments to IFRS 7). The disclosure requirements apply to recognized financial instruments and derivative instruments that are offset or subject to an enforceable master netting arrangement. An entity shall disclose information to enable users of its financial statements to evaluate the effect or potential effect of netting arrangements on its financial position, including the effect or potential effect of rights of setoff associated with recognized assets and recognized liabilities. While both the FASB and the IASB retained the existing offsetting models under U.S. GAAP and IFRS, the new standards require disclosures to allow investors to better compare financial statements prepared under U.S. GAAP with financial statements prepared under IFRS. The new standards are effective for annual periods beginning January 1, 2013, and interim periods within those annual periods. Retrospective application is required. The adoption of this ASU is expected to impact only our disclosure requirements and is not expected to have a material impact on our results of operations or financial position.

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Regulatory Matters - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Regulatory Authorities [Line Items]
Junior subordinated debt, included in Tier 2 capital	$ 70.0
Total trust preferred securities	$ 20.0

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Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Income Taxes [Line Items]
Statutory tax rate	35.00%	35.00%	35.00%
Income taxes on gains (losses) of securities	$ 1.1		$ 0.1
Deferred tax assets operating loss carry forwards, total	15.0
Deferred tax assets operating loss carry forwards, expiry date	2020-2032
Tax related interest	0.2
Penalty related to Mainline acquisition	$ 0.5

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Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012 Financial_Institution	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Line Items]
Business acquisition, loans		$ 228,591,000
Business acquisition, deposits		311,389,000
Business acquisition cost		47,558,000
Percentage of outstanding common stock of investees accounted for using equity method of accounting		100.00%
Nonaccrual commercial loans		500,000
FHLB annualized dividend rate on average capital stock	0.10%
FHLB stock redemption		5,700,000
Carrying amount of goodwill	165,273,000	175,733,000	165,273,000
Impairment charges of intangible assets		0	0	0
Number of financial institutions acquired		2
Amortization period of intangible assets		10 years
Percentage of amount recognized of tax benefit		50.00%
Commercial real estate [Member]
Summary Of Significant Accounting Policies [Line Items]
Allowance for loan loss emergence period		Two years
Other loan [Member]
Summary Of Significant Accounting Policies [Line Items]
Allowance for loan loss emergence period		One year
Mainline [Member]
Summary Of Significant Accounting Policies [Line Items]
Business acquisition date		Mar. 09, 2012
Number of subsidiary		1
Number of branches		8
Business acquisition, loans		129,501,000
Business acquisition, deposits		205,989,000
Business acquisition cost		27,764,000
Gateway [Member]
Summary Of Significant Accounting Policies [Line Items]
Business acquisition date		Aug. 13, 2012
Number of branches		2
Business acquisition, loans		99,090,000
Business acquisition, deposits		105,400,000
Business acquisition cost		19,794,000
Community Banking [Member]
Summary Of Significant Accounting Policies [Line Items]
Carrying amount of goodwill		171,500,000
Percentage of goodwill to reporting units		98.00%
Insurance [Member]
Summary Of Significant Accounting Policies [Line Items]
Carrying amount of goodwill		$ 4,200,000
Percentage of goodwill to reporting units		2.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of outstanding common stock of investees accounted for using equity method of accounting		20.00%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of outstanding common stock of investees accounted for using equity method of accounting		50.00%

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Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss included in accumulated other comprehensive gain/loss	$ 2,400,000
Accumulated benefit obligation	93,500,000	82,000,000
Contribution by employer	3,100,000	5,000,000
Projected benefit obligation	102,454,000	93,033,000	74,118,000
Net periodic benefit cost	(3,919,000)	(1,921,000)	(2,197,000)
Defined benefit plan in accumulated other comprehensive gain/loss before tax	(140,000)	(18,143,000)	(444,000)
Increase in fair value of plan assets	100,000
Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to the Thrift Plan	3.50%
Compensation expense	1,300,000	1,100,000	1,100,000
Supplemental executive retirement plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	3,500,000	3,100,000
Net periodic benefit cost	500,000	300,000	300,000
Defined benefit plan in accumulated other comprehensive gain/loss before tax	$ 2,000,000	$ 1,900,000
Marketable equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted asset allocation minimum	50.00%
Targeted asset allocation maximum	70.00%
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Targeted asset allocation minimum	30.00%
Targeted asset allocation maximum	50.00%

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Parent Company Condensed Financial Information - Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Information [Line Items]
Other assets	$ 120,395	$ 124,377
Total Assets	4,526,702	4,119,994
Long-term debt	34,101	31,874
Other liabilities	88,550	65,746
Total Liabilities	3,989,280	3,629,468
Total Shareholders' Equity	537,422	490,526
Total Liabilities and Shareholders' Equity	4,526,702	4,119,994
Parent Company [Member]
Condensed Financial Information [Line Items]
Cash	12,202	13,684
Bank subsidiary	523,664	474,661
Nonbank subsidiaries	19,934	20,008
Other assets	3,129	2,937
Total Assets	558,929	511,290
Long-term debt	20,619	20,619
Other liabilities	888	145
Total Liabilities	21,507	20,764
Total Shareholders' Equity	537,422	490,526
Total Liabilities and Shareholders' Equity	$ 558,929	$ 511,290

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ALLOWANCE FOR LOAN LOSSES (Tables)

12 Months Ended

Dec. 31, 2012

Age Analysis of Past due Loans Segregated by Class of Loans

The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented:

	December 31, 2012
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,418,934	$	2,230	$	413	$	30,556	$	33,199	$	1,452,133
Commercial and industrial		780,315		4,409		237		6,435		11,081		791,396
Commercial construction		150,823		10,542		—		6,778		17,320		168,143
Home equity		424,485		2,332		865		3,653		6,850		431,335
Residential mortgage		416,364		1,713		1,948		7,278		10,939		427,303
Installment and other consumer		73,334		406		95		40		541		73,875
Consumer construction		2,219		—		—		218		218		2,437
Total	$	3,266,474	$	21,632	$	3,558	$	54,958	$	80,148	$	3,346,622

	December 31, 2011
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,374,580	$	7,657	$	1,448	$	31,648	$	40,753	$	1,415,333
Commercial and industrial		672,899		3,583		1,701		7,570		12,854		685,753
Commercial construction		182,305		—		—		6,547		6,547		188,852
Home equity		405,578		2,199		691		2,936		5,826		411,404
Residential mortgage		349,214		1,240		1,163		7,229		9,632		358,846
Installment and other consumer		66,675		382		70		4		456		67,131
Consumer construction		2,259		—		—		181		181		2,440
Total	$	3,053,510	$	15,061	$	5,073	$	56,115	$	76,249	$	3,129,759

Recorded Investment in Commercial Loan Classes by Internally Assigned Risk Ratings

The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented:

	December 31, 2012
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,265,810		87.2	%	$	718,070		90.7	%	$	118,841		70.7	%	$	2,102,721		87.2	%
Special mention		96,156		6.6	%		42,016		5.3	%		30,748		18.3	%		168,920		7.0	%
Substandard		90,167		6.2	%		31,310		4.0	%		18,554		11.0	%		140,031		5.8	%
Total	$	1,452,133		100.0	%	$	791,396		100.0	%	$	168,143		100.0	%	$	2,411,672		100.0	%

	December 31, 2011
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,229,005		86.8	%	$	600,895		87.6	%	$	136,270		72.1	%	$	1,966,170		85.9	%
Special mention		84,400		6.0	%		33,135		4.8	%		17,106		9.1	%		134,641		5.9	%
Substandard		101,928		7.2	%		51,723		7.6	%		35,476		18.8	%		189,127		8.2	%
Total	$	1,415,333		100.0	%	$	685,753		100.0	%	$	188,852		100.0	%	$	2,289,938		100.0	%

Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status

The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented:

	December 31, 2012
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	427,682	$	420,025	$	73,835	$	2,219	$	923,761
Nonperforming		3,653		7,278		40		218		11,189
Total	$	431,335	$	427,303	$	73,875	$	2,437	$	934,950

	December 31, 2011
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	408,468	$	351,617	$	67,127	$	2,259	$	829,471
Nonperforming		2,936		7,229		4		181		10,350
Total	$	411,404	$	358,846	$	67,131	$	2,440	$	839,821

Investments in Loans Considered to be Impaired and Related Information on Impaired Loans

The following tables present investments in loans considered to be impaired and related information on those impaired loans at the dates and for the periods stated:

	December 31, 2012				Year ended December 31, 2012
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	6,138	$	6,864	$	1,226	$	5,796	$	218
Commercial and industrial		1,864		2,790		1,002		1,826		—
Commercial construction		799		896		3		4,446		—
Consumer real estate		—		—		—		—		—
Other consumer		—		—		—		—		—
Total with a Related Allowance Recorded		8,801		10,550		2,231		12,068		218
Without a related allowance recorded:
Commercial real estate		33,856		45,953		—		41,138		1,112
Commercial and industrial		11,419		12,227		—		11,672		329
Commercial construction		17,713		27,486		—		22,299		571
Consumer real estate		10,827		12,025				20,533		68
Other consumer		25		25		—		6		—
Total without a Related Allowance Recorded		73,840		97,716		—		95,648		2,080
Total:
Commercial real estate		39,994		52,817		1,226		46,934		1,330
Commercial and industrial		13,283		15,017		1,002		13,498		329
Commercial construction		18,512		28,382		3		26,745		571
Consumer real estate		10,827		12,025		—		20,533		68
Other consumer		25		25		—		6		—
Total	$	82,641	$	108,266	$	2,231	$	107,716	$	2,298

	December 31, 2011				Year Ended December 31, 2011
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	9,049	$	9,276	$	3,487	$	12,045	$	320
Commercial and industrial		4,207		4,207		1,116		3,497		77
Commercial construction		1,975		1,975		942		3,326		4
Consumer real estate		—		—		—		173		—
Total with a Related Allowance Recorded		15,231		15,458		5,545		19,041		401
Without a related allowance recorded:
Commercial real estate		41,058		47,874		—		34,965		1,415
Commercial and industrial		7,784		7,784		—		4,128		132
Commercial construction		24,024		24,375		—		8,856		496
Consumer real estate		5,939		6,545		—		2,617		195
Total without a Related Allowance Recorded		78,805		86,578		—		50,566		2,238
Total:
Commercial real estate		50,107		57,150		3,487		47,010		1,735
Commercial and industrial		11,991		11,991		1,116		7,625		209
Commercial construction		25,999		26,350		942		12,182		500
Consumer real estate		5,939		6,545		—		2,790		195
Total	$	94,036	$	102,036	$	5,545	$	69,607	$	2,639

Summary of Allowance for Loan Losses

The following tables detail activity in the ALL for the years ended December 31:

	2012
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841
Charge-offs		(9,627	)		(5,278	)		(10,521	)		(2,509	)		(1,078	)		(29,013	)
Recoveries		1,259			1,153			891			197			341			3,841
Net (Charge-offs)/ Recoveries		(8,368	)		(4,125	)		(9,630	)		(2,312	)		(737	)		(25,172	)
Provision for loan losses		3,810			610			13,427			4,204			764			22,815
Balance at End of Year	$	25,246		$	7,759		$	7,500		$	5,058		$	921		$	46,484

	2011
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	30,425		$	9,777		$	5,904		$	3,962		$	1,319		$	51,387
Charge-offs		(8,824	)		(8,971	)		(1,720	)		(2,617	)		(1,013	)		(23,145	)
Recoveries		780			357			2,463			1,030			360			4,990
Net (Charge-offs)/ Recoveries		(8,044	)		(8,614	)		743			(1,587	)		(653	)		(18,155	)
Provision for loan losses		7,423			10,111			(2,944	)		791			228			15,609
Balance at End of Year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841

Summary of Allowance for Loan Losses and Recorded Investments

The following tables present the ALL and recorded investments in loans by category as of December 31:

	2012
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	1,226	$	24,020	$	25,246	$	39,994	$	1,412,139	$	1,452,133
Commercial and industrial		1,002		6,757		7,759		13,283		778,113		791,396
Commercial construction		3		7,497		7,500		18,512		149,631		168,143
Consumer real estate		—		5,058		5,058		10,827		850,248		861,075
Other consumer		—		921		921		25		73,850		73,875
Total	$	2,231	$	44,253	$	46,484	$	82,641	$	3,263,981	$	3,346,622

	2011
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	3,487	$	26,317	$	29,804	$	50,107	$	1,365,226	$	1,415,333
Commercial and industrial		1,116		10,158		11,274		11,991		673,762		685,753
Commercial construction		942		2,761		3,703		25,999		162,853		188,852
Consumer real estate		—		3,166		3,166		5,939		766,751		772,690
Other consumer		—		894		894		—		67,131		67,131
Total	$	5,545	$	43,296	$	48,841	$	94,036	$	3,035,723	$	3,129,759

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INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN

12 Months Ended

Dec. 31, 2012

INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN

NOTE 21. INCENTIVE AND RESTRICTED STOCK PLAN AND DIVIDEND REINVESTMENT PLAN

We adopted an Incentive Stock Plan in 1992 that provided for granting incentive stock options, nonstatutory stock options, restricted stock and appreciation rights. On October 17, 1994, the 1992 Stock Plan was amended to include outside directors. The 1992 Stock Plan had a maximum of 3,200,000 shares of our common stock and expired ten years from the date of board approval. At December 31, 2002, 3,180,822 nonstatutory stock options and restricted stock had been granted under the 1992 Stock Plan. No further awards will be made under the 1992 Stock Plan. All grants under the 1992 Stock Plan have expired at December 31, 2012.

We adopted an Incentive Stock Plan in 2003 that provides for granting incentive stock options, nonstatutory stock options, restricted stock and appreciation rights. The 2003 Stock Plan has a maximum of 1,500,000 shares of our common stock and expires ten years from the date of board approval. The 2003 Stock Plan is similar to the 1992 Stock Plan, which the 2003 Stock Plan replaced.

Stock Options

As of December 31, 2012, 675,500 nonstatutory stock options are outstanding under the 2003 Stock Plan. Nonstatutory stock options granted in 2006 and 2005 are fully vested and have a ten-year life. These stock options were fully expensed in 2010.

The fair value of option awards under the nonstatutory stock option plan were estimated on the date of grant using the Black-Scholes valuation model, which is dependent upon certain assumptions. We use the simplified method in developing the estimated life of the option, whereby the expected life is presumed to be the mid point between the vesting date and the end of the contractual term. There have been no nonstatutory stock options granted since 2006.

The following table summarizes activity for nonstatutory stock options for the years ending December 31:

	2012							2011							2010
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at beginning of year		757,050		$	34.33				930,700		$	32.80				1,100,550		$	31.85
Granted		—			—				—			—				—			—
Exercised		—			—				—			—				(82,100	)		19.81
Forfeited		(81,550	)		27.29				(173,650	)		26.11				(87,750	)		33.04
Outstanding at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years
Exercisable at End of Year		675,500		$	35.18		2.0 years		757,050		$	34.33		2.8 years		930,700		$	32.80		3.3 years

The aggregate intrinsic value of options outstanding and exercisable was zero as of December 31, 2012, 2011 and 2010. The aggregate intrinsic value represents the total pretax intrinsic value (the difference between our closing stock price on the last trading day of the fourth quarter and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2012.

The following table provides information about non-vested options for the years ended December 31:

	Non-Vested Options		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		51,625	$	9.48
Granted		—		—
Vested		30,625		9.48
Forfeited		21,000		9.48
Non-vested at December 31, 2010		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2011		—	$	—
Granted		—		—
Vested		—		—
Forfeited		—		—
Non-vested at December 31, 2012		—	$	—

The following table presents information about stock options exercised for the years ended December 31:

(in thousands, except share data)	2012		2011		2010
Number of options exercised		—		—		82,100
Total intrinsic value of options exercised	$	—	$	—	$	131
Cash received from options exercised		—		—		1,758
Tax deduction realized from options exercised	$	—	$	—	$	46

Restricted Stock

We periodically issue restricted stock to employees and directors, pursuant to the 2003 Stock Plan. As of December 31, 2012, 237,484 restricted shares have been granted under this plan.

During 2012, 2011 and 2010, we granted 19,362, 19,890 and 14,208 restricted shares of common stock, respectively, to outside directors. The grants are part of the compensation arrangement approved by the Compensation and Benefits Committee whereby the directors receive compensation in both the form of cash and restricted shares of common stock. These shares fully vest one year after the date of grant.

Also during 2012, 2011 and 2010, we granted 48,008, 60,157 and 4,688 restricted shares of common stock, respectively, to senior management. The awards to senior management were granted in accordance with performance levels set by the Compensation and Benefits Committee. The first grant or 9,897 restricted shares, vests fully on the second anniversary of the grant dates. The second grant or 38,111 restricted shares was granted under our Long Term Incentive Plan (2012 LTIP) and consists of both time and performance-based awards. Vesting for the time-based awards is 50 percent after two years and the remaining 50 percent at the end of the third year. The performance-based awards vest at the end of the three year period. During 2011 the restricted shares granted occurred on three occasions and have different vesting periods. The first grant, or 16,497 restricted shares, vests fully on the second anniversary of the grant date. The second grant, or 11,104 restricted shares, vested fully on January 1, 2012. The third grant, or 32,556 restricted shares, was granted under our Long Term Incentive Plan (2011 LTIP) and vests in the same manner as explained above. Of the 4,688 restricted shares granted in 2010, 1,881 shares fully vested one year after the date of grant. The remaining 2,807 shares granted vest 50 percent on each of the one and two year anniversaries from the date of grant.

During the vesting period, the recipient receives dividends and has the right to vote the unvested shares granted. If the recipient leaves S&T before the end of the vesting period, shares will be forfeited except in the case of retirement, disability or death where accelerated vesting provisions are defined within the plan agreement.

Compensation expense for time-based restricted stock is recognized ratably over the period of service, generally the entire vesting period, based on fair value on the date of grant. For grants made to directors, the fair value is determined by the closing price of the stock on the date of grant. The average of the high and low prices of the stock on the grant date is used for senior management. Compensation expense for performance-based restricted stock is recognized ratably over the remaining vesting period once the likelihood of meeting the performance measure is probable. During 2012, 2011 and 2010, we recognized compensation expense of $0.9 million, $1.1 million and $0.5 million and realized a tax benefit of $0.3 million, $0.4 million and $0.3 million, respectively.

The following table provides information about restricted stock for the years ended December 31:

	Restricted Stock		Weighted Average Grant Date Fair Value
Non-vested at December 31, 2009		41,342	$	24.75
Granted		18,896		21.44
Vested		25,006		21.86
Forfeited		3,562		29.15
Non-vested at December 31, 2010		31,670	$	24.56
Granted		80,047		21.39
Vested		23,915		23.69
Forfeited		1,652		23.64
Non-vested at December 31, 2011		86,150	$	21.88
Granted		67,370		21.53
Vested		37,118		19.75
Forfeited		1,383		19.54
Non-vested at December 31, 2012		115,019	$	22.39

As of December 31, 2012, there was $1.3 million of total unrecognized compensation cost related to restricted stock that will be recognized as compensation expense over a weighted average period of one year.

Dividend Reinvestment Plan

We also sponsor a Dividend Reinvestment and Stock Purchase Plan, or Dividend Plan, where shareholders may purchase shares of S&T common stock at the average fair value with reinvested dividends and voluntary cash contributions. The plan administrator and transfer agent, may purchase shares directly from us from shares held in treasury or purchase shares in the open market to fulfill the Dividend Plan’s needs.

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EMPLOYEE BENEFITS

12 Months Ended

Dec. 31, 2012

EMPLOYEE BENEFITS

NOTE 20. EMPLOYEE BENEFITS

We maintain a defined benefit pension plan, or Plan, covering substantially all employees hired prior to January 1, 2008. The benefits are based on years of service and the employee’s compensation for the highest five consecutive years in the last ten years. Contributions are intended to provide for benefits attributed to employee service to date and for those benefits expected to be earned in the future.

The following table summarizes the activity in the benefit obligation and Plan assets deriving the funded status, which is recorded in other liabilities in the Consolidated Balance Sheets:

(in thousands)	2012			2011
Change in Projected Benefit Obligation
Projected benefit obligation at beginning of year	$	93,033		$	74,118
Service cost		2,788			2,371
Interest cost		4,358			4,162
Plan participants’ contributions		71			3,964
Plan amendments		—			(1,513	)
Actuarial loss		6,723			15,199
Benefits paid		(4,519	)		(5,268	)
Projected Benefit Obligation at End of Year	$	102,454		$	93,033
Change in Plan Assets
Fair value of plan assets at beginning of year	$	72,626		$	68,774
Actual return on plan assets		9,810			156
Employer contributions		3,100			5,000
Plan participants’ contributions		71			3,964
Benefits paid		(4,519	)		(5,268	)
Fair Value of Plan Assets at End of Year	$	81,088		$	72,626
Funded Status	$	(21,366	)	$	(20,407	)

The following table sets forth the amounts recognized in accumulated other comprehensive gain/loss at December 31:

(in thousands)	2012			2011
Prior service credit	$	(1,442	)	$	(1,579	)
Net actuarial loss		36,297			36,294
Total (Before Tax Effects)	$	34,855		$	34,715

Below are the actuarial weighted average assumptions used in determining the benefit obligation:

	2012			2011
Discount rate		4.00	%		4.75	%
Rate of compensation increase		3.00	%		4.00	%

The following table summarizes the components of net periodic pension cost and other changes in Plan assets and benefit obligation recognized in other comprehensive gain/loss for the years ended December 31:

(in thousands)	2012			2011			2010
Components of Net Periodic Pension Cost
Service cost—benefits earned during the period	$	2,788		$	2,371		$	2,245
Interest cost on projected benefit obligation		4,358			4,162			4,017
Expected return on plan assets		(5,564	)		(5,378	)		(4,882	)
Amortization of prior service credit		(137	)		(7	)		(7	)
Recognized net actuarial loss		2,474			773			824
Net Periodic Pension Cost	$	3,919		$	1,921		$	2,197
Other Changes in Plan Assets and Benefit Obligation Recognized in Other Comprehensive Loss
Net actuarial loss (gain)	$	2,477		$	20,422		$	1,261
Recognized net actuarial loss		(2,474	)		(773	)		(824	)
Prior service credit		(0	)		(1,513	)		—
Recognized prior service credit		137			7			7
Total (Before Tax Effects)	$	140		$	18,143		$	444
Total Recognized in Net Benefit Cost and Other Comprehensive Gain/Loss (Before Tax Effects)	$	4,059		$	20,064		$	2,641

The following table summarizes the actuarial weighted average assumptions used in determining net periodic pension cost:

	2012		2011		2010
Discount rate		4.75%		5.75%		6.25%
Rate of compensation increase		4.00%		4.00%		4.00%
Expected return on assets		8.00%		8.00%		8.00%

The net actuarial loss included in accumulated other comprehensive gain/loss expected to be recognized in net periodic pension cost during the year ended December 31, 2013 is $2.4 million. The prior service cost expected to be recognized during the same period is not significant.

The accumulated benefit obligation for the Plan was $93.5 million at December 31, 2012 and $82.0 million at December 31, 2011.

We consider many factors when setting the assumed rate of return on Plan assets. As a general guideline the assumed rate of return is equal to the weighted average of the expected returns for each asset category and is estimated based on historical returns as well as expected future returns. The weighted average discount rate is derived from corporate yield curves.

S&T Bank’s Retirement Plan Committee determines the investment policy for the Plan. In general, the targeted asset allocation is 50 percent to 70 percent equities and 30 percent to 50 percent fixed income. A strategic allocation within each asset class is employed based on the Plan’s time horizon, risk tolerances, performance expectations and asset class preferences. Investment managers have discretion to invest in any equity or fixed-income asset class, subject to the securities guidelines of the Plan’s Investment Policy Statement.

At this time, the Bank is not required to make a cash contribution to the Plan in 2013; however, the Bank contributed $3.1 million to the Plan in December 2012.

The following table provides information regarding estimated future benefit payments to be paid in each of the next five years and in the aggregate for the five years thereafter:

(in thousands)	Amount
2013	$	5,813
2014		5,547
2015		6,601
2016		6,225
2017		6,056
2018—2022		36,212

We also have supplemental executive retirement plans, or SERPs, for certain key employees. The SERPs are unfunded. The projected benefit obligations related to the SERPs were $3.5 million and $3.1 million at December 31, 2012 and 2011, respectively. These amounts also represent the net amount recognized in the statement of financial position for the SERPs. Net periodic benefit costs for the SERPs were $0.5 million, $0.3 million, and $0.3 million for each of the years ended December 31, 2012, 2011 and 2010, respectively. Additionally, $2.0 million and $1.9 million before tax were reflected in accumulated other comprehensive gain/loss at December 31, 2012 and 2011, respectively, in relation to the SERPs. The actuarial assumptions used for the SERPs are the same as those used for the Plan.

We maintain a Thrift Plan, a qualified defined contribution plan, in which substantially all employees are eligible to participate. We make matching contributions to the Thrift Plan up to 3.5 percent of participants’ eligible compensation and may make additional profit-sharing contributions as provided by the Thrift Plan. Expense related to these contributions amounted to $1.3 million in 2012 and $1.1 million in both 2011 and 2010.

Fair Value Measurements

The following tables present our Plan assets measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items of a recurring basis during the periods presented. The increase of $0.1 million in Level 3 plan assets since December 31, 2011 is due to an increase in unrealized gains in the investments. There were no purchases, transfers or sales of Level 3 plan assets.

	December 31, 2012
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	8,585	$	—	$	8,585
Fixed Income(3)		22,211		—		1,432		23,643
Equities:
Equity index mutual funds—domestic(4)		1,934		—		—		1,934
Equity index mutual funds—international(5)		4,218		—		—		4,218
Domestic Individual Equities(6)		39,631		—		—		39,631
International Individual Equities(7)		1,802		—		—		1,802
Equity—Partnerships(8)		—		—		1,275		1,275
Total Assets at Fair Value	$	69,796	$	8,585	$	2,707	$	81,088

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

	December 31, 2011
	Fair Value Asset Classes(1)
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents(2)	$	—	$	7,440	$	—	$	7,440
Fixed Income(3)		21,539		—		1,333		22,872
Equities:
Equity index mutual funds—domestic(4)		1,580		—		—		1,580
Equity index mutual funds—international(5)		3,437		—		—		3,437
Domestic Individual Equities(6)		34,600		—		—		34,600
International Individual Equities(7)		1,437		—		—		1,437
Equity—Partnerships(8)		—		—		1,260		1,260
Total Assets at Fair Value	$	62,593	$	7,440	$	2,593	$	72,626

⁽¹⁾  Refer to Note 1 Summary of Significant Accounting Policies, Fair Value Measurements for a description of levels within the fair value hierarchy.

⁽²⁾  This asset class includes FDIC insured money market instruments.

⁽³⁾  This asset class includes a variety of fixed income mutual funds and a partnership which primarily invests in investment grade rated securities. Investment managers have discretion to invest in fixed income related securities including futures, options and other derivatives. Investments may be made in currencies other than the U.S. dollar.

⁽⁴⁾  The sole investment within this asset class is S&P 600 index iShares.

⁽⁵⁾  The sole investment within this asset class is MSCI EAFE Index iShares.

⁽⁶⁾  This asset class includes individual domestic equities invested in an active all-cap strategy. It may also include convertible bonds.

⁽⁷⁾  This asset class includes American Depository Receipts, or ADR.

⁽⁸⁾  This asset class includes a Partnership priced by the investment manager which invests in equities and T-Bills.

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Deposits - Composition of Deposits and Interest Expenses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	$ 3,638,428	$ 3,335,859	$ 3,317,524
Interest Expense	16,796	22,952	28,717
Noninterest-bearing demand [Member]
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	960,980	818,686	765,812
Interest Expense
Interest-bearing demand [Member]
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	316,760	283,611	295,246
Interest Expense	60	47	54
Money market [Member]
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	361,233	278,092	262,683
Interest Expense	614	691	1,166
Savings [Member]
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	965,571	802,942	753,813
Interest Expense	2,356	1,267	2,127
Certificates of deposit [Member]
Schedule Of Deposits And Borrowings Maturities [Line Items]
Balance	1,033,884	1,152,528	1,239,970
Interest Expense	$ 13,766	$ 20,947	$ 25,370

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PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Tables)

12 Months Ended

Dec. 31, 2012

Balance Sheet

BALANCE SHEETS

	December 31,
(in thousands)	2012		2011
ASSETS
Cash	$	12,202	$	13,684
Investments in:
Bank subsidiary		523,664		474,661
Nonbank subsidiaries		19,934		20,008
Other assets		3,129		2,937
Total Assets	$	558,929	$	511,290
LIABILITIES
Long-term debt	$	20,619	$	20,619
Other liabilities		888		145
Total Liabilities		21,507		20,764
Total Shareholders’ Equity		537,422		490,526
Total Liabilities and Shareholders’ Equity	$	558,929	$	511,290

Statements of Net Income

STATEMENTS OF NET INCOME

	Years ended December 31,
(in thousands)	2012			2011		2010
Dividends from subsidiaries	$	35,603		$	23,029	$	22,634
Investment income		17			121		86
Interest expense on long-term debt		808			777		782
Other expenses		1,800			1,091		1,648
Income before Equity in Undistributed Net Income of Subsidiaries		33,012			21,282		20,290
Equity in undistributed net income (distribution in excess of net income) of:
Bank subsidiary		1,371			25,590		23,158
Nonbank subsidiaries		(183	)		392		32
Net Income	$	34,200		$	47,264	$	43,480

Statements of Cash Flows

STATEMENTS OF CASH FLOWS

	Years ended December 31,
(in thousands)	2012			2011			2010
OPERATING ACTIVITIES
Net Income	$	34,200		$	47,264		$	43,480
Equity in (undistributed net income) distribution in excess of net income of subsidiaries		(1,188	)		(25,982	)		(23,190	)
Tax expense (benefit) from stock-based compensation		30			66			(46	)
Other		1,023			10,145			470
Net Cash Provided by Operating Activities		34,065			31,493			20,714
INVESTING ACTIVITIES
Net investments in subsidiaries		(5,035	)		—			—
Acquisitions		(14,123	)		—			—
Net Cash Used In Investing Activities		(19,158	)		—			—
FINANCING ACTIVITIES
Redemption of preferred stock		—			(108,676	)		—
Sale of treasury shares, net		998			1,946			3,692
Preferred stock dividends		—			(5,072	)		(5,434	)
Cash dividends paid to common shareholders		(17,357	)		(16,830	)		(16,683	)
Tax (expense) benefit from stock-based compensation		(30	)		(66	)		46
Net Cash Used in Financing Activities		(16,389	)		(128,698	)		(18,379	)
Net (decrease) increase in cash		(1,482	)		(97,205	)		2,335
Cash at beginning of year		13,684			110,889			108,554
Cash at End of Year	$	12,202		$	13,684		$	110,889

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PREMISES AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Premises and Equipment

The following table is a summary of premises and equipment at December 31:

(in thousands)	2012			2011
Land	$	6,490		$	6,316
Premises		43,434			41,608
Furniture and equipment		24,944			22,941
Leasehold improvements		5,965			4,899
		80,833			75,764
Accumulated depreciation		(42,157	)		(38,009	)
Total	$	38,676		$	37,755

Minimum Annual Rental and Renewal Option Payments

Minimum annual rental and renewal option payments for each of the following five years and thereafter are approximately:

(in thousands)	Operating		Capital		Total
2013	$	2,088	$	76	$	2,164
2014		2,107		76		2,183
2015		2,076		76		2,152
2016		2,006		76		2,082
2017		1,954		76		2,030
Thereafter		43,114		839		43,953
Total	$	53,345	$	1,219	$	54,564

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PARENT COMPANY CONDENSED FINANCIAL INFORMATION

12 Months Ended

Dec. 31, 2012

PARENT COMPANY CONDENSED FINANCIAL INFORMATION

NOTE 22. PARENT COMPANY CONDENSED FINANCIAL INFORMATION

The following condensed financial statements summarize the financial position of S&T Bancorp, Inc. as of December 31, 2012 and 2011 and the results of its operations and cash flows for each of the three years ended December 31, 2012, 2011 and 2010.

BALANCE SHEETS

	December 31,
(in thousands)	2012		2011
ASSETS
Cash	$	12,202	$	13,684
Investments in:
Bank subsidiary		523,664		474,661
Nonbank subsidiaries		19,934		20,008
Other assets		3,129		2,937
Total Assets	$	558,929	$	511,290
LIABILITIES
Long-term debt	$	20,619	$	20,619
Other liabilities		888		145
Total Liabilities		21,507		20,764
Total Shareholders’ Equity		537,422		490,526
Total Liabilities and Shareholders’ Equity	$	558,929	$	511,290

STATEMENTS OF NET INCOME

	Years ended December 31,
(in thousands)	2012			2011		2010
Dividends from subsidiaries	$	35,603		$	23,029	$	22,634
Investment income		17			121		86
Interest expense on long-term debt		808			777		782
Other expenses		1,800			1,091		1,648
Income before Equity in Undistributed Net Income of Subsidiaries		33,012			21,282		20,290
Equity in undistributed net income (distribution in excess of net income) of:
Bank subsidiary		1,371			25,590		23,158
Nonbank subsidiaries		(183	)		392		32
Net Income	$	34,200		$	47,264	$	43,480

STATEMENTS OF CASH FLOWS

	Years ended December 31,
(in thousands)	2012			2011			2010
OPERATING ACTIVITIES
Net Income	$	34,200		$	47,264		$	43,480
Equity in (undistributed net income) distribution in excess of net income of subsidiaries		(1,188	)		(25,982	)		(23,190	)
Tax expense (benefit) from stock-based compensation		30			66			(46	)
Other		1,023			10,145			470
Net Cash Provided by Operating Activities		34,065			31,493			20,714
INVESTING ACTIVITIES
Net investments in subsidiaries		(5,035	)		—			—
Acquisitions		(14,123	)		—			—
Net Cash Used In Investing Activities		(19,158	)		—			—
FINANCING ACTIVITIES
Redemption of preferred stock		—			(108,676	)		—
Sale of treasury shares, net		998			1,946			3,692
Preferred stock dividends		—			(5,072	)		(5,434	)
Cash dividends paid to common shareholders		(17,357	)		(16,830	)		(16,683	)
Tax (expense) benefit from stock-based compensation		(30	)		(66	)		46
Net Cash Used in Financing Activities		(16,389	)		(128,698	)		(18,379	)
Net (decrease) increase in cash		(1,482	)		(97,205	)		2,335
Cash at beginning of year		13,684			110,889			108,554
Cash at End of Year	$	12,202		$	13,684		$	110,889

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REGULATORY MATTERS

12 Months Ended

Dec. 31, 2012

REGULATORY MATTERS

NOTE 23. REGULATORY MATTERS

We are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet the minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on our financial statements. Under capital guidelines and the regulatory framework for prompt corrective action, we must meet specific capital guidelines that involve quantitative measures of our assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. Our capital amounts and classification are also subject to qualitative judgments by the regulators about risk weightings and other factors.

The most recent notifications from the Federal Reserve and the FDIC categorized S&T and S&T Bank as well capitalized under the regulatory framework for corrective action. There have been no conditions or events that we believe have changed S&T or S&T Bank’s status during 2012 and 2011.

Tier 1 capital consists principally of shareholders’ equity, including preferred stock; excluding items recorded in accumulated other comprehensive gain/loss, less goodwill and other intangibles. For regulatory purposes, trust preferred securities totaling $20.0 million, issued by an unconsolidated trust subsidiary of S&T underlying such junior subordinated debt, are included in Tier 1 capital for S&T. Total capital consists of Tier 1 capital plus junior subordinated debt and the ALL subject to limitation. We currently have $70.0 million in junior subordinated debt which is included in Tier 2 capital for S&T in accordance with current regulatory reporting requirements.

Quantitative measures established by regulation to ensure capital adequacy require us to maintain minimum amounts and ratios of Total and Tier 1 capital to risk-weighted assets and Tier 1 capital to average assets. As of December 31, 2012 and 2011, we met all capital adequacy requirements to which we are subject.

The following table summarizes risk-based capital amounts and ratios for S&T and S&T Bank.

	Actual					For Capital Adequacy Purposes					To be Well Capitalized Under Prompt Corrective Action Provisions
(in thousands, except for ratios)	Amount		Ratio			Amount		Ratio			Amount		Ratio
As of December 31, 2012
Total Capital (to Risk-Weighted Assets)
S&T	$	504,041		15.39	%	$	262,029		8.00	%	$	327,536		10.00	%
S&T Bank		452,906		14.35	%		252,489		8.00	%		315,611		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		392,506		11.98	%		131,015		4.00	%		196,522		6.00	%
S&T Bank		343,331		10.88	%		126,244		4.00	%		189,366		6.00	%
Leverage Ratio(1)
S&T		392,506		9.31	%		168,563		4.00	%		210,704		5.00	%
S&T Bank		343,331		8.45	%		162,611		4.00	%		203,264		5.00	%
As of December 31, 2011
Total Capital (to Risk-Weighted Assets)
S&T	$	465,702		15.20	%	$	245,154		8.00	%	$	306,443		10.00	%
S&T Bank		429,837		14.11	%		243,699		8.00	%		304,623		10.00	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T		356,484		11.63	%		122,577		4.00	%		183,866		6.00	%
S&T Bank		321,352		10.55	%		121,849		4.00	%		182,774		6.00	%
Leverage Ratio(1)
S&T		356,484		9.17	%		155,526		4.00	%		194,408		5.00	%
S&T Bank		321,352		8.30	%		154,789		4.00	%		193,486		5.00	%

⁽¹⁾  Minimum requirement is 3.00 percent for the most highly-rated financial institutions.

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Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
OPERATING ACTIVITIES
Net Income	$ 34,200	$ 47,264	$ 43,480
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	22,815	15,609	29,511
Provision for unfunded loan commitments	1,811	(1,474)	(1,555)
Depreciation and amortization	7,000	6,323	6,587
Net amortization of discounts and premiums	2,280	1,191	881
Stock-based compensation expense	913	960	513
Securities (gains) losses, net	(3,016)	124	(274)
Deferred income taxes	1,038	2,448	(4,537)
Tax expense (benefit) from stock-based compensation	30	66	(46)
Mortgage loans originated for sale	(104,924)	(68,261)	(121,883)
Proceeds from the sale of loans	86,886	74,780	119,617
Gain on the sale of loans, net	(1,612)	(875)	(1,809)
Net decrease in interest receivable	973	589	2,752
Net decrease in interest payable	(1,376)	(443)	(1,678)
Net decrease (increase) in other assets	18,815	4,132	(2,745)
Net increase (decrease) increase in other liabilities	18,057	(8,531)	20,170
Net Cash Provided by Operating Activities	83,890	73,902	88,984
INVESTING ACTIVITIES
Purchases of securities available-for-sale	(166,786)	(135,447)	(82,890)
Proceeds from maturities, prepayments and calls of securities available-for-sale	87,604	71,318	146,960
Proceeds from sales of securities available-for-sale	66,575	70	2,579
Proceeds from the redemption of Federal Home Loan Bank stock	5,700	4,149	1,177
Net (increase) decrease in loans	(21,892)	185,182	3,236
Proceeds from the sale of loans not originated for resale	3,874	8,595
Purchases of premises and equipment	(2,179)	(2,531)	(3,469)
Proceeds from the sale of premises and equipment	142	404	60
Net cash acquired from bank acquisitions	18,639
Net Cash (Used in) Provided by Investing Activities	(8,323)	131,740	67,653
FINANCING ACTIVITIES
Net increase in core deposits	207,653	105,776	63,383
Net decrease in certificates of deposit	(217,311)	(87,553)	(50,536)
Net increase (decrease) in securities sold under repurchase agreements and federal funds purchased	28,442	(10,283)	(4,281)
Net (decrease) increase in short-term borrowings		75,000	(51,300)
Proceeds from long-term borrowings	4,311	4,192	9,241
Repayments of long-term borrowings	(15,088)	(1,682)	(65,770)
Redemption of preferred stock		(108,676)
Purchase of treasury shares	(49)	(64)
Sale of treasury shares	1,047	1,946	3,692
Preferred stock dividends		(5,072)	(5,434)
Cash dividends paid to common shareholders	(17,357)	(16,830)	(16,683)
Tax (expense) benefit from stock-based compensation	(30)	(66)	46
Net Cash Used in Financing Activities	(8,382)	(43,312)	(117,642)
Net increase in cash and cash equivalents	67,185	162,330	38,995
Cash and cash equivalents at beginning of year	270,526	108,196	69,201
Cash and Cash Equivalents at End of Year	337,711	270,526	108,196
Supplemental Disclosures
Interest paid	22,329	27,733	36,251
Income taxes paid, net of refunds	4,063	15,100	14,818
Loans transferred to held for sale	19,255	8,753
Net assets (liabilities) from acquisitions, excluding cash and cash equivalents	(683)
Transfers to other real estate owned and other repossessed assets	$ 1,915	$ 8,472	$ 11,308

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CAPITAL PURCHASE PROGRAM

12 Months Ended

Dec. 31, 2012

CAPITAL PURCHASE PROGRAM

NOTE 24. CAPITAL PURCHASE PROGRAM

On December 7, 2011 we redeemed all of the $108.7 million, or 108,676 shares, of Series A Preferred Stock issued on January 16, 2009 in conjunction with our participation in the CPP. Upon redemption, a one-time non-cash reduction to net income available to common shareholders of $1.8 million, or $0.06 per common share, was recorded for the remaining unamortized discount of the preferred stock. Refer to Note 23 Regulatory Matters for additional disclosures regarding capital requirements.

As part of its original purchase of the Series A Preferred Stock, the U.S. Treasury received a warrant to purchase 517,012 shares of our common stock at an initial per share exercise price of $31.53. The warrant provides for the adjustment of the exercise price and the number of shares of our common stock issuable upon exercise pursuant to customary anti-dilution provisions, such as upon stock splits or distributions of securities or other assets to holders of our common stock and upon certain issuances of our common stock at or below a specified price relative to the initial exercise price. A binomial pricing model was used to calculate the fair value of the common stock warrant we issued on January 16, 2009 resulting in a fair value of $4.0 million.

The assumptions used to calculate the fair value of the warrant are summarized below:

Assumption	Value
Contractual term		10 years
Exercise price	$	31.53
Estimated fair value of company stock	$	29.14
Expected life		10 years
Risk-free rate over expected life of the warrant		2.36	%
Expected volatility		28.40	%
Expected dividend yield		3.85	%

We utilized the average of daily and monthly historical volatility for purposes of this valuation. In addition, the U.S. Treasury has agreed not to exercise voting power with respect to any shares of common stock issued upon exercise of the warrant. We did not repurchase the warrant at the time of the Series A Preferred Stock redemption and it will remain outstanding until January 2019 or until we repurchase it from the U.S. Treasury or it is exercised by the owner.

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Allowance for Loans Losses - Recorded Investment in Commercial Loan Classes By Internally Assigned Risk Ratings (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	$ 2,411,672	$ 2,289,938
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	2,102,721	1,966,170
Total percentage of recorded investment in commercial loan	87.20%	85.90%
Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	168,920	134,641
Total percentage of recorded investment in commercial loan	7.00%	5.90%
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	140,031	189,127
Total percentage of recorded investment in commercial loan	5.80%	8.20%
Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	1,452,133	1,415,333
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial real estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	1,265,810	1,229,005
Total percentage of recorded investment in commercial loan	87.20%	86.80%
Commercial real estate [Member] | Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	96,156	84,400
Total percentage of recorded investment in commercial loan	6.60%	6.00%
Commercial real estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	90,167	101,928
Total percentage of recorded investment in commercial loan	6.20%	7.20%
Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	791,396	685,753
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial and industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	718,070	600,895
Total percentage of recorded investment in commercial loan	90.70%	87.60%
Commercial and industrial [Member] | Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	42,016	33,135
Total percentage of recorded investment in commercial loan	5.30%	4.80%
Commercial and industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	31,310	51,723
Total percentage of recorded investment in commercial loan	4.00%	7.60%
Commercial construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	168,143	188,852
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	118,841	136,270
Total percentage of recorded investment in commercial loan	70.70%	72.10%
Commercial construction [Member] | Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	30,748	17,106
Total percentage of recorded investment in commercial loan	18.30%	9.10%
Commercial construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in commercial loan	$ 18,554	$ 35,476
Total percentage of recorded investment in commercial loan	11.00%	18.80%

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Commitments and Contingencies - Future Estimated Payments Related to Data Processing and Communication Charges (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitment And Contingencies [Line Items]
Data processing and communication charges related to first quarter of 2013	$ 10.3	$ 7.4	$ 6.8
Gateway [Member]
Commitment And Contingencies [Line Items]
Data processing and communication charges related to first quarter of 2013	$ 0.6

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FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2012

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	212,066	$	—	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		—		57,896		—		57,896
Mortgage-backed securities of U.S. government corporations and agencies		—		60,781		—		60,781
Obligations of states and political subdivisions		—		112,767		—		112,767
Marketable equity securities		140		8,316		1,130		9,586
Total securities available-for-sale		140		451,826		1,130		453,096
Trading securities held in a Rabbi Trust		2,223		—		—		2,223
Total securities		2,363		451,826		1,130		455,319
Derivative financial assets:
Interest rate swaps		—		23,748		—		23,748
Interest rate lock commitments		—		467		—		467
Total Assets	$	2,363	$	476,041	$	1,130	$	479,534
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,522	$	—	$	23,522
Forward sale contracts		—		48		—		48
Total Liabilities	$	—	$	23,570	$	—	$	23,570

	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	142,786	$	—	$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		—		65,395		—		65,395
Mortgage-backed securities of U.S. government corporations and agencies		—		48,752		—		48,752
Obligations of states and political subdivisions		—		88,805		—		88,805
Marketable equity securities		2,855		7,316		1,687		11,858
Total securities available-for-sale		2,855		353,054		1,687		357,596
Trading securities held in a Rabbi Trust		1,949		—		—		1,949
Total securities		4,804		353,054		1,687		359,545
Derivative financial assets:
Interest rate swaps		—		23,764		—		23,764
Interest rate lock commitments		—		244		—		244
Total Assets	$	4,804	$	377,062	$	1,687	$	383,553
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,639	$	—	$	23,639
Forward sale contracts	$	—	$	95	$	—	$	95
Total Liabilities	$	—	$	23,734	$	—	$	23,734

Changes in Assets Classified as Level 3 in Fair Value Hierarchy

The following tables present the changes in assets measured at fair value on a recurring basis for which we have utilized Level 3 inputs to determine the fair value:

	Years Ended December 31,
(in thousands)	2012			2011
Balance at beginning of year	$	1,687		$	1,588
Total (losses) gains included in other comprehensive income/loss(1)		(350	)		99
Net purchases, sales, issuances and settlements		(207	)		—
Transfers out of Level 3		—			—
Balance at end of year	$	1,130		$	1,687

⁽¹⁾  Changes in estimated fair value of available-for-sale investments are recorded in accumulated other comprehensive income/loss, while gains and losses from sales are recorded in security gains (losses), net in the Consolidated Statements of Net Income.

Assets Measured at Estimated Fair Value on Nonrecurring Basis by Fair Value Hierarchy

At December 31, 2012 and 2011, we had no loans held for sale that were recorded at fair value.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	44,059	$	44,059
Other real estate owned		—		—		585		585
Mortgage servicing rights		—		—		2,106		2,106
Total Assets	$	—	$	—	$	46,750	$	46,750
	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	36,500	$	36,500
Other real estate owned		—		—		3,739		3,739
Mortgage servicing rights		—		—		2,153		2,153
Total Assets	$	—	$	—	$	42,392	$	42,392

Carrying Values and Fair Values of Financial Instruments

The carrying values and fair values of our financial instruments at December 31, 2012 and 2011 are presented in the following tables:

			Fair Value Measurements at December 31, 2012
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	337,711	$	337,711	$	337,711	$	—	$	—
Securities available-for-sale		453,096		453,096		140		451,826		1,130
Loans held for sale		22,499		22,601		—		—		22,601
Portfolio loans		3,346,622		3,347,602		—		—		3,347,602
Federal Home Loan Bank stock, at cost		14,485		14,485		—		—		14,485
Bank owned life insurance		58,619		58,619		—		58,619		—
Trading securities held in a Rabbi Trust		2,223		2,223		2,223		—		—
Mortgage servicing rights		2,106		2,106		—		—		2,106
Interest rate swaps		23,748		23,748		—		23,748		—
Interest rate lock commitments		467		467		—		467		—
LIABILITIES
Deposits	$	3,638,428	$	3,643,683	$	—	$	—	$	3,643,683
Securities sold under repurchase agreements		62,582		62,582		—		—		62,582
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		34,101		36,235		—		—		36,235
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,522		23,522		—		23,522		—
Forward sale contracts		48		48		—		48		—

⁽¹⁾  As reported in the Consolidated Balance Sheets

			Fair Value Measurements at December 31, 2011
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	270,526	$	270,526	$	270,526	$	—	$	—
Securities available-for-sale		357,596		357,596		2,855		353,054		1,687
Loans held for sale		2,850		2,958		—		—		2,958
Portfolio loans		3,129,759		3,120,352		—		—		3,120,352
Federal Home Loan Bank stock, at cost		18,216		18,216		—		—		18,216
Bank owned life insurance		56,755		56,755		—		56,755		—
Trading securities held in a Rabbi Trust		1,949		1,949		1,949		—		—
Mortgage servicing rights		2,153		2,153		—		—		2,153
Interest rate swaps		23,764		23,764		—		23,764		—
Interest rate lock commitments		244		244		—		244		—
LIABILITIES
Deposits	$	3,335,859	$	3,343,889	$	—	$	—	$	3,343,889
Securities sold under repurchase agreements		30,370		30,370		—		—		30,370
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		31,874		34,171		—		—		34,171
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,639		23,639		—		23,639		—
Forward sale contracts		95		95		—		95		—

⁽¹⁾ As reported in the Consolidated Balance Sheets

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TAX EFFECTS ON OTHER COMPREHENSIVE INCOME (Tables)

12 Months Ended

Dec. 31, 2012

Tax Effects of Components of Other Comprehensive Income

The following tables present the tax effects of the components of other comprehensive income for the years ended December 31:

(in thousands)	Pre-Tax Amount			Tax (Expense) Benefit			Net of Tax Amount
2012
Change in unrealized gains/losses on securities available-for-sale	$	4,097		$	(1,434	)	$	2,663
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(3,016	)		1,055			(1,961	)
Adjustment to funded status of employee benefit plans		(271	)		95			(176	)
Other Comprehensive Income	$	810		$	(284	)	$	526
2011
Change in unrealized gains/losses on securities available-for-sale	$	6,702		$	(2,346	)	$	4,356
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		124			(43	)		81
Adjustment to funded status of employee benefit plans		(18,787	)		6,576			(12,211	)
Other Comprehensive Income	$	(11,961	)	$	4,187		$	(7,774	)
2010
Change in unrealized gains/losses on securities available-for-sale	$	695		$	(243	)	$	452
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(274	)		96			(178	)
Adjustment to funded status of employee benefit plans		(606	)		212			(394	)
Other Comprehensive Income	$	(185	)	$	65		$	(120	)

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Securities Available-For-Sale - Amortized Cost and Fair Value of Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 437,135	$ 342,718
Gross Unrealized Gains	16,077	15,363
Gross Unrealized Losses	(116)	(485)
Fair Value	453,096	357,596
Obligations of U.S. government corporations and agencies and Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Due in one year or less, Amortized Cost	38,434
Due after one year through five years, Amortized Cost	130,690
Due after five years through ten years, Amortized Cost	64,822
Due after ten years, Amortized Cost	81,194
Available-for-sale Securities, Debt Maturities, Amortized Cost	315,140
Due in one year or less, Fair Value	38,969
Due after one year through five years, Fair Value	134,192
Due after five years through ten years, Fair Value	66,507
Due after ten years, Fair Value	85,165
Fair Value, Debt securities	324,833
Collateralized mortgage obligations of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	56,085	63,202
Gross Unrealized Gains	1,811	2,193
Fair Value	57,896	65,395
Mortgage-backed securities of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	57,408	45,289
Gross Unrealized Gains	3,373	3,463
Fair Value	60,781	48,752
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	428,633	332,566
Gross Unrealized Gains	14,982	13,184
Gross Unrealized Losses	(105)	(12)
Fair Value	443,510	345,738
Marketable equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,502	10,152
Gross Unrealized Gains	1,095	2,179
Gross Unrealized Losses	(11)	(473)
Fair Value	9,586	11,858
Obligations of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	207,229	138,386
Gross Unrealized Gains	4,890	4,400
Gross Unrealized Losses	(53)
Fair Value	212,066	142,786
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	107,911	85,689
Gross Unrealized Gains	4,908	3,128
Gross Unrealized Losses	(52)	(12)
Fair Value	$ 112,767	$ 88,805

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Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Cash and due from banks, including interest-bearing deposits of $257,116 and $208,854 at December 31, 2012 and 2011, respectively	$ 337,711	$ 270,526
Securities available-for-sale, at fair value	453,096	357,596
Loans held for sale	22,499	2,850
Portfolio loans, net of unearned income of $216 and $715 at December 31, 2012 and 2011, respectively	3,346,622	3,129,759
Allowance for loan losses	(46,484)	(48,841)
Portfolio loans, net	3,300,138	3,080,918
Bank owned life insurance	58,619	56,755
Premises and equipment, net	38,676	37,755
Federal Home Loan Bank stock, at cost	14,485	18,216
Goodwill	175,733	165,273
Other intangibles, net	5,350	5,728
Other assets	120,395	124,377
Total Assets	4,526,702	4,119,994
LIABILITIES
Noninterest-bearing demand	960,980	818,686
Interest-bearing demand	316,760	283,611
Money market	361,233	278,092
Savings	965,571	802,942
Certificates of deposit	1,033,884	1,152,528
Total Deposits	3,638,428	3,335,859
Securities sold under repurchase agreements	62,582	30,370
Short-term borrowings	75,000	75,000
Long-term borrowings	34,101	31,874
Junior subordinated debt securities	90,619	90,619
Other liabilities	88,550	65,746
Total Liabilities	3,989,280	3,629,468
SHAREHOLDERS' EQUITY
Common stock ($2.50 par value) Authorized-50,000,000 shares Issued-31,197,365 shares and 29,714,038 shares at December 31, 2012 and 2011, respectively Outstanding-29,732,209 shares and 28,131,249 shares at December 31, 2012 and 2011, respectively	77,993	74,285
Additional paid-in capital	77,458	52,637
Retained earnings	436,039	421,468
Accumulated other comprehensive loss	(13,582)	(14,108)
Treasury stock (1,465,156 shares and 1,582,789 shares, at December 31, 2012 and 2011, respectively, at cost)	(40,486)	(43,756)
Total Shareholders' Equity	537,422	490,526
Total Liabilities and Shareholders' Equity	$ 4,526,702	$ 4,119,994

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GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

12 Months Ended

Dec. 31, 2012

Roll Forward of Goodwill

The following table represents a roll forward of goodwill:

(in thousands)	2012		2011
Balance at beginning of year	$	165,273	$	165,273
Additions		10,460		—
Balance at End of Year	$	175,733	$	165,273

Summary of Intangible Assets

The following table shows a summary of intangible assets:

(in thousands)	2012			2011
Gross carrying amount at beginning of year	$	15,070		$	15,070
Additions		1,331			—
Accumulated amortization		(11,051	)		(9,342	)
Balance at End of Year	$	5,350		$	5,728

Summary of Expected Amortization Expense for Finite-Lived Intangibles Assets

The following is a summary of the expected amortization expense for finite-lived intangibles assets, assuming no new additions, for each of the five years following December 31, 2012:

(in thousands)	Amount
2013	$	1,590
2014		1,129
2015		883
2016		645
2017		500
Total	$	4,747

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Derivative Instruments and Hedging Activities - Value of Derivative Assets and Derivative Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives not Designated as Hedging Instruments
Collateral posted, Derivatives (included in Other Assets)
Not Designated as Hedging Instruments [Member] | Other Assets [Member] | Interest Rate Swap Contracts-Commercial Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivative (included in Other Assets)	23,748	23,764
Notional amount, Derivatives (included in Other Assets)	227,532	189,868
Not Designated as Hedging Instruments [Member] | Other Assets [Member] | Interest Rate Lock Commitments-Mortgage Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivative (included in Other Assets)	467	244
Notional amount, Derivatives (included in Other Assets)	14,287	7,093
Not Designated as Hedging Instruments [Member] | Other Liabilities [Member] | Interest Rate Swap Contracts-Commercial Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities	23,522	23,639
Notional amount, Derivatives (included in Other Liabilities)	227,532	189,868
Collateral posted, Derivatives (included in Other Liabilities)	19,595	20,273
Not Designated as Hedging Instruments [Member] | Other Liabilities [Member] | Forward Sale Contracts-Mortgage Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities	48	95
Notional amount, Derivatives (included in Other Liabilities)	$ 14,100	$ 7,729

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Incentive and Restricted Stock Plan and Dividend Reinvestment Plan - Summary of Non-Vested Restricted Stock (Detail) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested Restricted Stock, Beginning period	86,150	31,670	41,342
Granted	67,370	80,047	18,896
Vested	37,118	23,915	25,006
Forfeited	1,383	1,652	3,562
Non-vested, Balance	115,019	86,150	31,670
Non-vested, Beginning balance	$ 21.88	$ 24.56	$ 24.75
Granted	$ 21.53	$ 21.39	$ 21.44
Vested	$ 19.75	$ 23.69	$ 21.86
Forfeited	$ 19.54	$ 23.64	$ 29.15
Non-vested, Ending balance	$ 22.39	$ 21.88	$ 24.56

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Commitments and Contingencies - Future Estimated Payments Related to Data Processing and Communication Charges (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Commitment And Contingencies [Line Items]
2013	$ 7,388
2014	7,032
2015	7,172
2016	6,816
2017	708
Total	$ 29,116

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Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2009	$ 553,318,000	$ 105,370,000	$ 74,285,000	$ 51,158,000	$ 383,118,000	$ (6,214,000)	$ (54,399,000)
Net Income	43,480,000				43,480,000
Other comprehensive income (loss), net of tax	(120,000)					(120,000)
Preferred stock dividends and discount amortization	(5,434,000)	767,000			(6,201,000)
Cash dividends declared ($0.60 per share)	(16,683,000)				(16,683,000)
Treasury stock issued	3,692,000				(1,980,000)		5,672,000
Recognition of restricted stock compensation expense	470,000			470,000
Tax benefit (expense)from stock-based compensation	46,000			46,000
Forfeitures of nonstatutory stock options	(104,000)			(104,000)
Balance at Dec. 31, 2010	578,665,000	106,137,000	74,285,000	51,570,000	401,734,000	(6,334,000)	(48,727,000)
Net Income	47,264,000				47,264,000
Other comprehensive income (loss), net of tax	(7,774,000)					(7,774,000)
Redemption of preferred stock	(108,676,000)	(108,676,000)
Preferred stock dividends and discount amortization	(5,072,000)	2,539,000			(7,611,000)
Cash dividends declared ($0.60 per share)	(16,830,000)				(16,830,000)
Treasury stock issued	1,882,000				(3,089,000)		4,971,000
Recognition of restricted stock compensation expense	1,133,000			1,133,000
Tax benefit (expense)from stock-based compensation	(66,000)			(66,000)
Balance at Dec. 31, 2011	490,526,000		74,285,000	52,637,000	421,468,000	(14,108,000)	(43,756,000)
Net Income	34,200,000				34,200,000
Other comprehensive income (loss), net of tax	526,000					526,000
Cash dividends declared ($0.60 per share)	(17,357,000)				(17,357,000)
Common stock issued in acquisition (1,483,327 shares)	27,610,000		3,708,000	23,902,000
Treasury stock issued	998,000				(2,272,000)		3,270,000
Recognition of restricted stock compensation expense	949,000			949,000
Tax benefit (expense)from stock-based compensation	(30,000)			(30,000)
Balance at Dec. 31, 2012	$ 537,422,000		$ 77,993,000	$ 77,458,000	$ 436,039,000	$ (13,582,000)	$ (40,486,000)

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Goodwill and Other Intangible Assets - Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Indefinite-lived Intangible Assets [Line Items]
Gross carrying amount at beginning of year	$ 15,070	$ 15,070
Additions	1331	-
Accumulated amortization	(11,051)	(9,342)
Gross carrying amount at end of year	$ 5,350	$ 5,728

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Parent Company Condensed Financial Information - Cash Flows (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Information [Line Items]
Net Income	$ 9,524,000	$ 12,595,000	$ 8,600,000	$ 3,480,000	$ 12,256,000	$ 13,803,000	$ 14,910,000	$ 6,295,000	$ 34,200,000	$ 47,264,000	$ 43,480,000
Tax expense (benefit) from stock-based compensation									(300,000)	(400,000)	(300,000)
Net Cash Provided by Operating Activities									83,890,000	73,902,000	88,984,000
Net Cash Used In Investing Activities									(8,323,000)	131,740,000	67,653,000
Redemption of preferred stock										108,676,000
Sale of treasury shares, net									1,047,000	1,946,000	3,692,000
Cash dividends paid to common shareholders									17,357,000	16,830,000	16,683,000
Tax (expense) benefit from stock-based compensation									(30,000)	(66,000)	46,000
Net Cash Used in Financing Activities									(8,382,000)	(43,312,000)	(117,642,000)
Net (decrease) increase in cash									67,185,000	162,330,000	38,995,000
Cash and cash equivalents at beginning of year				270,526,000				108,196,000	270,526,000	108,196,000	69,201,000
Cash and Cash Equivalents at End of Year	337,711,000				270,526,000				337,711,000	270,526,000	108,196,000
Parent Company [Member]
Condensed Financial Information [Line Items]
Net Income									34,200,000	47,264,000	43,480,000
Equity in (undistributed net income) distribution in excess of net income of subsidiaries									(1,188,000)	(25,982,000)	(23,190,000)
Tax expense (benefit) from stock-based compensation									30,000	66,000	(46,000)
Other									1,023,000	10,145,000	470,000
Net Cash Provided by Operating Activities									34,065,000	31,493,000	20,714,000
Net investments in subsidiaries	(5,035,000)								(5,035,000)
Acquisitions									(14,123,000)
Net Cash Used In Investing Activities									(19,158,000)
Redemption of preferred stock										(108,676,000)
Sale of treasury shares, net									998,000	1,946,000	3,692,000
Preferred stock dividends										(5,072,000)	(5,434,000)
Cash dividends paid to common shareholders									(17,357,000)	(16,830,000)	(16,683,000)
Tax (expense) benefit from stock-based compensation									(30,000)	(66,000)	46,000
Net Cash Used in Financing Activities									(16,389,000)	(128,698,000)	(18,379,000)
Net (decrease) increase in cash									(1,482,000)	(97,205,000)	2,335,000
Cash and cash equivalents at beginning of year				13,684,000				110,889,000	13,684,000	110,889,000	108,554,000
Cash and Cash Equivalents at End of Year	$ 12,202,000				$ 13,684,000				$ 12,202,000	$ 13,684,000	$ 110,889,000

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Regulatory Matters - Summary of Risk-Based Capital Amounts and Ratios for S&T and S&T Bank (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
S&T [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 504,041	$ 465,702
Total Capital (to Risk-Weighted Assets), Actual Ratio	15.39%	15.20%
Total Capital (to Risk-Weighted Assets), Capital Adequacy Amount	262,029	245,154
Total Capital (to Risk-Weighted Assets), Capital adequacy ratio	8.00%	8.00%
Total Capital (to Risk-Weighted Assets), To be Well Capitalized Amount	327,536	306,443
Total Capital (to Risk-Weighted Assets), To be Well Capitalized Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	392,506	356,484
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	11.98%	11.63%
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Amount	131,015	122,577
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	4.00%	4.00%
Tier 1 Capital (to Risk-Weighted Assets), To be Well Capitalized Amount	196,522	183,866
Tier 1 Capital (to Risk-Weighted Assets), To be Well Capitalized Ratio	6.00%	6.00%
Leverage Ratio, Actual Amount	392,506	356,484
Leverage Ratio, Actual Ratio	9.31%	9.17%
Leverage Ratio, Capital Adequacy Amount	168,563	155,526
Leverage Ratio, Capital Adequacy Ratio	4.00%	4.00%
Leverage Ratio, To be Well Capitalized Amount	210,704	194,408
Leverage Ratio, To be Well Capitalized Ratio	5.00%	5.00%
S&T Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	452,906	429,837
Total Capital (to Risk-Weighted Assets), Actual Ratio	14.35%	14.11%
Total Capital (to Risk-Weighted Assets), Capital Adequacy Amount	252,489	243,699
Total Capital (to Risk-Weighted Assets), Capital adequacy ratio	8.00%	8.00%
Total Capital (to Risk-Weighted Assets), To be Well Capitalized Amount	315,611	304,623
Total Capital (to Risk-Weighted Assets), To be Well Capitalized Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	343,331	321,352
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	10.88%	10.55%
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Amount	126,244	121,849
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	4.00%	4.00%
Tier 1 Capital (to Risk-Weighted Assets), To be Well Capitalized Amount	189,366	182,774
Tier 1 Capital (to Risk-Weighted Assets), To be Well Capitalized Ratio	6.00%	6.00%
Leverage Ratio, Actual Amount	343,331	321,352
Leverage Ratio, Actual Ratio	8.45%	8.30%
Leverage Ratio, Capital Adequacy Amount	162,611	154,789
Leverage Ratio, Capital Adequacy Ratio	4.00%	4.00%
Leverage Ratio, To be Well Capitalized Amount	$ 203,264	$ 193,486
Leverage Ratio, To be Well Capitalized Ratio	5.00%	5.00%

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SEGMENTS (Tables)

12 Months Ended

Dec. 31, 2012

Total Assets by Reportable Operating Segment

The following represents total assets by reportable operating segment as of December 31:

(in thousands)	2012		2011
Community Banking	$	4,516,194	$	4,110,462
Insurance		9,302		8,192
Wealth Management		1,206		1,340
Total Assets	$	4,526,702	$	4,119,994

Financial Information of Segments

The following tables provide financial information for our three segments. The financial results of the business segments include allocations for shared services based on an internal analysis that supports line of business and branch performance measurement. Shared services include expenses such as employee benefits, occupancy expense, computer support and other corporate overhead. Even with these allocations, the financial results are not necessarily indicative of the business segments’ financial condition and results of operations as if they existed as independent entities. The information provided under the caption “Eliminations” represents operations not considered to be reportable segments and/or general operating expenses and eliminations and adjustments, which are necessary for purposes of reconciling to the Consolidated Financial Statements.

	For the Year Ended December 31, 2012
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	155,865	$	454	$	1		$	(69	)	$	156,251
Interest expense		22,135		—		—			(1,111	)		21,024
Net interest income (expense)		133,730		454		1			1,042			135,227
Provision for loan losses		22,815		—		—			—			22,815
Noninterest income		36,422		9,788		5,262			440			51,912
Noninterest expense		97,687		9,448		5,415			4,692			117,242
Depreciation expense		3,833		31		48			—			3,912
Intangible amortization		1,600		57		52			—			1,709
Income tax expense (benefit)		10,207		352		(88	)		(3,210	)		7,261
Net Income (Loss)	$	34,010	$	354	$	(164	)	$	—		$	34,200

	For the Year Ended December 31, 2011
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	164,738	$	307	$	1		$	33		$	165,079
Interest expense		27,692		—		291			(250	)		27,733
Net interest income (expense)		137,046		307		(290	)		283			137,346
Provision for loan losses		15,609		—		—			—			15,609
Noninterest income		30,195		8,328		5,236			298			44,057
Noninterest expense		81,180		7,302		5,199			4,236			97,917
Depreciation expense		4,165		32		57			—			4,254
Intangible amortization		1,619		66		52			—			1,737
Income tax expense (benefit)		17,911		493		(127	)		(3,655	)		14,622
Net Income (Loss)	$	46,757	$	742	$	(235	)	$	—		$	47,264

	For the Year Ended December 31, 2010
(in thousands)	Community Banking		Wealth Management		Insurance			Eliminations			Consolidated
Interest income	$	180,319	$	471	$	2		$	(373	)	$	180,419
Interest expense		34,692		—		293			(412	)		34,573
Net interest income (expense)		145,627		471		(291	)		39			145,846
Provision for loan losses		29,511		—		—			—			29,511
Noninterest income		32,959		7,950		4,968			1,333			47,210
Noninterest expense		82,872		7,525		4,850			4,181			99,428
Depreciation expense		4,163		34		62			—			4,259
Intangible amortization		1,815		75		56			—			1,946
Income tax (benefit) expense		17,019		324		(102	)		(2,809	)		14,432
Net Income (Loss)	$	43,206	$	463	$	(189	)	$	—		$	43,480

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Mortgage Servicing Rights - Schedule of Mortgage Servicing Rights and Net Carrying Values (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Servicing Rights [Member]
Mortgage Loans on Real Estate, Write-down or Reserve [Line Items]
Beginning balance	$ 3,320	$ 3,292
Additions	826	621
Amortization	(940)	(593)
Ending balance	3,206	3,320
Valuation Allowance [Member]
Mortgage Loans on Real Estate, Write-down or Reserve [Line Items]
Beginning balance	1,167	825
Additions	(67)	342
Ending balance	1,100	1,167
Net Carrying Value [Member]
Mortgage Loans on Real Estate, Write-down or Reserve [Line Items]
Beginning balance	2,153	2,467
Additions	893	279
Amortization	(940)	(593)
Ending balance	$ 2,106	$ 2,153

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SELECTED FINANCIAL DATA

12 Months Ended

Dec. 31, 2012

SELECTED FINANCIAL DATA

NOTE 27. SELECTED FINANCIAL DATA

The following table presents selected financial data for the most recent eight quarters:

(unaudited)

	2012								2011
(in thousands, except per share data)	Fourth Quarter		Third Quarter		Second Quarter		First Quarter		Fourth Quarter		Third Quarter			Second Quarter			First Quarter
SUMMARY OF OPERATIONS
Interest income	$	38,920	$	38,820	$	39,370	$	39,140	$	40,259	$	40,845		$	41,783		$	42,192
Interest expense		4,629		5,025		5,551		5,819		6,192		6,976			7,245			7,320
Provision for loan losses		4,215		2,305		7,023		9,272		2,337		1,535			1,097			10,640
Net interest income after provision for loan losses		30,076		31,490		26,796		24,049		31,730		32,334			33,441			24,232
Security gains (losses), net		—		2,170		6		840		—		(81	)		(56	)		13
Noninterest income		11,565		12,576		12,525		12,229		11,574		10,424			11,170			11,013
Noninterest expense		29,717		31,018		29,344		32,783		26,672		24,193			25,594			27,449
Income before taxes		11,924		15,218		9,983		4,335		16,632		18,484			18,961			7,809
Provision for income taxes		2,400		2,623		1,383		855		4,376		4,681			4,051			1,514
Net income		9,524		12,595		8,600		3,480		12,256		13,803			14,910			6,295
Preferred stock dividends and discount amortization		—		—		—		—		2,939		1,559			1,558			1,555
Net Income Available to Common Shareholders	$	9,524	$	12,595	$	8,600	$	3,480	$	9,317	$	12,244		$	13,352		$	4,740
Per Share Data
Common earnings per share — diluted	$	0.32	$	0.43	$	0.30	$	0.12	$	0.33	$	0.44		$	0.48		$	0.17
Dividends declared per common share		0.15		0.15		0.15		0.15		0.15		0.15			0.15			0.15
Common book value		18.08		17.97		17.65		17.47		17.44		17.68			17.31			16.90

On December 7, 2011 we redeemed all of the $108.7 million, or 108,676 shares, of Series A Preferred Stock issued on January 16, 2009 in conjunction with our participation in the CPP. Upon redemption, a one-time non-cash reduction to net income available to common shareholders of $1.8 million, or $0.06 per common share, was recorded for the remaining unamortized discount of the preferred stock.

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Other Noninterest Expense - Summary of Other Noninterest Expenses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other noninterest expenses:
Joint venture amortization	$ 4,199	$ 3,302	$ 2,573
Unfunded loan commitments	1,811	(1,474)	(1,555)
Amortization of intangibles	1,709	1,737	1,946
Total Other Noninterest Expenses	25,033	18,686	20,249
Other Noninterest Expense [Member]
Other noninterest expenses:
Other real estate owned	2,166	1,518	1,921
Unfunded loan commitments	1,811	(1,474)	(1,555)
Amortization of intangibles	1,709	1,737	1,943
Loan collection fees	430	624	1,770
Other	14,718	12,979	13,597
Total Other Noninterest Expenses	$ 25,033	$ 18,686	$ 20,249

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Incentive and Restricted Stock Plan and Dividend Reinvestment Plan - Additional Information (Detail) (USD $)	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Outside directors [Member]	Dec. 31, 2011 Outside directors [Member]	Dec. 31, 2010 Outside directors [Member]	Dec. 31, 2012 Senior management [Member]	Dec. 31, 2011 Senior management [Member]	Dec. 31, 2010 Senior management [Member]	Dec. 31, 2012 First grant [Member]	Dec. 31, 2011 First grant [Member]	Dec. 31, 2010 First grant [Member]	Dec. 31, 2012 Second grant [Member]	Dec. 31, 2011 Second grant [Member]	Dec. 31, 2010 Second grant [Member]	Dec. 31, 2012 Time-based awards [Member]	Dec. 31, 2011 Time-based awards [Member]	Dec. 31, 2011 Third grant [Member]	Dec. 31, 2012 2003 Stock Plan [Member]	Dec. 31, 2012 1992 Stock Plan [Member]	Dec. 31, 2002 1992 Stock Plan [Member]
Maximum number of common stock authorized																				1,500,000	3,200,000
Stock plan expiration date																				10 years	10 years
Nonstatutory stock options and restricted stock granted																						3,180,822
Stock plan exiration date																					Dec. 31, 2012
Nonstatutory stock options, outstanding	675,500	757,050	930,700	1,100,550																675,500
Vesting period																				10 years
Aggregate intrinsic value of options outstanding	$ 0	$ 0	$ 0
Aggregate intrinsic value of options exercisable	0	0	0
Restricted shares granted					19,362	19,890	14,208	48,008	60,157	4,688	9,897	16,497	1,881	38,111	11,104	2,807			32,556	237,484
Restricted stock vesting period											The first grant or 9,897 restricted shares, vests fully on the second anniversary of the grant dates	The first grant, or 16,497 restricted shares, vests fully on the second anniversary of the grant date	1,881 shares fully vested one year after the date of grant.		The second grant, or 11,104 restricted shares, vested fully on January 1, 2012	The remaining 2,807 shares granted vest 50 percent on each of the one and two year anniversaries from the date of grant	Vesting for the time-based awards is 50 percent after two years and the remaining 50 percent at the end of the third year	Vesting for the time-based awards is 50 percent after two years and the remaining 50 percent at the end of the third year
Restricted stock vesting percentage, per year			50.00%														50.00%	50.00%
Compensation expense	900,000	1,100,000	500,000
Tax benefit realized on compensation expense	300,000	400,000	300,000
Unrecognized compensation expense to be recognized	$ 1,300,000
Weighted average compensation expense recognize period	1 year

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Earnings Per Share - Reconciles Numerators and Denominators of Basic Earnings Per Share with Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator for Earnings per Common Share-Basic:
Net Income	$ 9,524	$ 12,595	$ 8,600	$ 3,480	$ 12,256	$ 13,803	$ 14,910	$ 6,295	$ 34,200	$ 47,264	$ 43,480
Less: Preferred stock dividends and discount amortization					2,939	1,559	1,558	1,555		7,611	6,201
Less: Income allocated to participating shares									126	130	42
Net Income Allocated to Common Shareholders	9,524	12,595	8,600	3,480	9,317	12,244	13,352	4,740	34,074	39,523	37,237
Numerator for Earnings per Common Share-Diluted:
Net Income	9,524	12,595	8,600	3,480	12,256	13,803	14,910	6,295	34,200	47,264	43,480
Less: Preferred stock dividends and discount amortization					2,939	1,559	1,558	1,555		7,611	6,201
Net Income Available to Common Shareholders									$ 34,200	$ 39,653	$ 37,279
Denominators:
Weighted Average Common Shares Outstanding-Basic									28,976,619	27,966,981	27,791,145
Add: Potentially dilutive common shares									32,261	23,169	22,261
Denominator for Treasury Stock Method-Diluted									29,008,880	27,990,150	27,813,406
Add: Average participating shares outstanding									107,274	92,212	33,899
Denominator for Two-Class Method-Diluted									29,083,893	28,059,193	27,825,044
Earnings per common share basic									$ 1.18	$ 1.41	$ 1.34
Earnings per common share diluted	$ 0.32	$ 0.43	$ 0.30	$ 0.12	$ 0.33	$ 0.44	$ 0.48	$ 0.17	$ 1.18	$ 1.41	$ 1.34
Warrants [Member]
Denominators:
Anti-dilutive excluded from dilutive potential common shares									517,012	517,012	517,012
Stock options [Member]
Denominators:
Anti-dilutive excluded from dilutive potential common shares									747,443	757,580	930,969
Restricted Stock [Member]
Denominators:
Anti-dilutive excluded from dilutive potential common shares									75,012	69,043	11,638

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DEPOSITS

12 Months Ended

Dec. 31, 2012

DEPOSITS

NOTE 14. DEPOSITS

The following table presents the composition of deposits at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Noninterest-bearing demand	$	960,980	$	—	$	818,686	$	—	$	765,812	$	—
Interest-bearing demand		316,760		60		283,611		47		295,246		54
Money market		361,233		614		278,092		691		262,683		1,166
Savings		965,571		2,356		802,942		1,267		753,813		2,127
Certificates of deposit		1,033,884		13,766		1,152,528		20,947		1,239,970		25,370
Total	$	3,638,428	$	16,796	$	3,335,859	$	22,952	$	3,317,524	$	28,717

The aggregate of all certificates of deposit over $100,000 amounted to $368.1 million and $357.7 million at December 31, 2012 and 2011, respectively.

The following table indicates the scheduled maturities of certificates of deposit at December 31, 2012:

(in thousands)	Amount
2013	$	643,635
2014		129,963
2015		118,829
2016		53,735
2017		77,336
Thereafter		10,386
Total	$	1,033,884

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SUBSEQUENT EVENT

12 Months Ended

Dec. 31, 2012

SUBSEQUENT EVENT

NOTE 28. SUBSEQUENT EVENT In the first quarter of 2013, we entered into a long-term agreement with a merchant processing company. We received an upfront fee and will receive future revenue based upon a revenue sharing agreement. As a result of this agreement, we will be terminating our current merchant processing agreement and expect to incur an early termination fee. We are working with our existing merchant processor to determine the amount of the fee. We are currently evaluating the transaction and the impact on our first quarter of 2013 financial statements.

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Mortgage Servicing Rights - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Mortgage Loan Activity [Line Items]
Sale of 1-4 family mortgage loans to Federal National Mortgage Association (FNMA)	$ 86,886,000	$ 74,780,000	$ 119,617,000
Total servicing portfolio	329,200,000	332,600,000	318,200,000
Federal National Mortgage Association or (FNMA) [Member]
Mortgage Loan Activity [Line Items]
Sale of 1-4 family mortgage loans to Federal National Mortgage Association (FNMA)	$ 82,900,000	$ 67,900,000	$ 109,300,000

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Employee Benefits - Benefit Obligation and Plan Assets Deriving Funded Status, in Other Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Change in Projected Benefit Obligation
Projected benefit obligation at beginning of year	$ 93,033	$ 74,118
Service cost	2,788	2,371	2,245
Interest cost	4,358	4,162	4,017
Plan participants' contributions	71	3,964
Plan amendments		(1,513)
Actuarial loss	6,723	15,199
Benefits paid	(4,519)	(5,268)
Projected Benefit Obligation at End of Year	102,454	93,033	74,118
Change in Plan Assets
Fair value of plan assets at beginning of year	72,626	68,774
Actual return on plan assets	9,810	156
Employer contributions	3,100	5,000
Plan participants' contributions	71	3,964
Benefits paid	(4,519)	(5,268)
Fair Value of Plan Assets at End of Year	81,088	72,626	68,774
Funded Status	$ (21,366)	$ (20,407)

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LONG-TERM BORROWINGS

12 Months Ended

Dec. 31, 2012

LONG-TERM BORROWINGS

NOTE 16. LONG-TERM BORROWINGS

We had total borrowings as of December 31, 2012 and 2011 at the Pittsburgh FHLB of $108.9 million and $106.6 million, respectively. Total borrowings for 2012 consisted of $75 million in short-term borrowings and $33.9 million in long-term borrowings. The total borrowings of $106.6 million in 2011 consisted of $75.0 million in short-term borrowings and $31.6 million in long-term borrowings. FHLB borrowings are collateralized by a blanket lien on residential mortgages and other real estate secured loans. Total loans pledged as collateral at the FHLB were $2.0 billion at year end. We were eligible to borrow up to an additional $787.7 million based on qualifying collateral and up to $299.7 million more provided that additional collateral is pledged.

Interest expense of $1.1 million was recognized on long term borrowings for both 2012 and 2011, and $1.6 million was recognized for 2010. Scheduled annual maturities and average interest rates for all of the long-term debt, including a capital lease of $0.3 million, for each of the five years and thereafter subsequent to December 31, 2012 are as follows:

(dollars in thousands)	Balance		Average Rate
2013	$	12,291		3.46%
2014		2,368		3.36%
2015		2,399		3.41%
2016		2,330		3.44%
2017		2,412		3.53%
Thereafter		12,301		2.70%
Total	$	34,101		3.18%

Junior Subordinated Debt Securities

The following table represents the composition of junior subordinated debt securities at December 31 and the interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
2006 Junior subordinated debt	$	25,000	$	523	$	25,000	$	1,344	$	25,000	$	1,695
2008 Junior subordinated debt—trust preferred securities		20,619		808		20,619		777		20,619		782
2008 Junior subordinated debt		20,000		818		20,000		786		20,000		791
2008 Junior subordinated debt		25,000		766		25,000		728		25,000		735
Total	$	90,619	$	2,915	$	90,619	$	3,635	$	90,619	$	4,003

The following table summarizes the key terms of our junior subordinated debt securities:

(dollars in thousands)	2006 Junior Subordinated Debt	2008 Trust Preferred Securities	2008 Junior Subordinated Debt	2008 Junior Subordinated Debt
Junior Subordinated Debt	$25,000	—	$20,000	$25,000
Trust Preferred Securities	—	$20,000	—	—
Stated Maturity Date	12/15/2036	3/15/2038	6/15/2018	5/30/2018
First optional redemption date at par	—	3/15/2013	6/15/2013	5/30/2013
Regulatory Capital	Tier 2	Tier 1	Tier 2	Tier 2
Interest Rate	3 month LIBOR plus 160 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 350 bps	3 month LIBOR plus 250 bps
Interest Rate at December 31, 2012	1.91%	3.81%	3.81%	2.81%

We completed a private placement of the trust preferred securities to a financial institution during the first quarter of 2008. As a result, we own 100 percent of the common equity of STBA Capital Trust I. The trust was formed to issue mandatorily redeemable capital securities to third-party investors. The proceeds from the sale of the securities and the issuance of the common equity by STBA Capital Trust I were invested in junior subordinated debt securities issued by us. The third party investors are considered the primary beneficiaries; therefore, the trust qualifies as a variable interest entity, or VIE, but is not consolidated into our financial statements. STBA Capital Trust I pays dividends on the securities at the same rate as the interest paid by us on the junior subordinated debt held by STBA Capital Trust I.

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Fair Value Measurements - Assets Measured at Estimated Fair Value on Nonrecurring Basis by Fair Value Hierarchy (Detail) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Impaired Loans	$ 44,059	$ 36,500
Other real estate owned	585	3,739
Mortgage servicing rights	2,106	2,153
Total Assets	46,750	42,392
Level 1 [Member]
ASSETS
Impaired Loans
Other real estate owned
Mortgage servicing rights
Total Assets
Level 2 [Member]
ASSETS
Impaired Loans
Other real estate owned
Mortgage servicing rights
Total Assets
Level 3 [Member]
ASSETS
Impaired Loans	44,059	36,500
Other real estate owned	585	3,739
Mortgage servicing rights	2,106	2,153
Total Assets	$ 46,750	$ 42,392

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Long-Term Borrowings - Schedule of Annual Maturities and Average Interest Rate of Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Long Term Debt Maturity [Line Items]
2013, Balance	$ 12,291
2014, Balance	2,368
2015, Balance	2,399
2016, Balance	2,330
2017, Balance	2,412
Thereafter, Balance	12,301
Total Long-term debt	$ 34,101
2013 Average Rate	3.46%
2014 Average Rate	3.36%
2015 Average Rate	3.41%
2016 Average Rate	3.44%
2017 Average Rate	3.53%
Thereafter Average Rate	2.70%
Average Rate	3.18%

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Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash dividends declared per share	$ 0.60	$ 0.60	$ 0.60
Common stock issued in acquisition, shares	1,483,327
Treasury stock, shares net	117,633	182,507	205,135
Forfeitures of nonstatutory stock options, shares			11,000

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Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Cash and due from banks, interest-bearing amounts	$ 257,116	$ 208,854
Portfolio loans, unearned income	$ 216	$ 715
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	50,000,000,000	50,000,000,000
Common stock, shares issued	31,197,365,000	29,714,038,000
Common stock, shares outstanding	29,732,209,000	28,131,249,000
Treasury stock, shares	1,465,156,000	1,582,789,000

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ALLOWANCE FOR LOAN LOSSES

12 Months Ended

Dec. 31, 2012

ALLOWANCE FOR LOAN LOSSES

NOTE 9. ALLOWANCE FOR LOAN LOSSES

We maintain an ALL at a level determined to be adequate to absorb estimated probable credit losses inherent in the loan portfolio as of the balance sheet date. Refer to Note 1 Summary of Significant Accounting Policies for details of our ALL policy. During the fourth quarter of 2010, we implemented various enhancements to the ALL methodology to better align the calculation with the inherent risk identified within the loan portfolio and align it with regulatory guidance. Changes included consideration of additional loan risk characteristics such as internal risk rating, collateral, and loan-to-value, enhancing the base loss calculation to consider the estimated loss emergence period of each loan segment and expanding the qualitative adjustments to consider additional factors. The enhancements made to the ALL methodology did not materially change the ALL at December 31, 2010.

We develop and document a systematic ALL methodology based on the following portfolio segments: 1) CRE, 2) C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer.

The following are key risks within each portfolio segment:

CRE—Loans secured by commercial purpose real estate, including both owner occupied properties and investment properties for various purposes such as hotels, strip malls and apartments. Operation of the individual projects as well as global cash flows of the debtors are the primary sources of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the collateral type as well as the business prospects of the lessee, if the project is not owner occupied.

C&I—Loans made to operating companies or manufacturers for the purpose of production, operating capacity, accounts receivable, inventory or equipment financing. Cash flow from the operations of the company is the primary source of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the industry of the company. Collateral for these types of loans often do not have sufficient value in a distressed or liquidation scenario to satisfy the outstanding debt.

Commercial Construction—Loans made to finance construction of buildings or other structures, as well as to finance the acquisition and development of raw land for various purposes. While the risk of these loans is generally confined to the construction period, if there are problems, the project may not be complete, and as such, may not provide sufficient cash flow on its own to service the debt or have sufficient value in a liquidation to cover the outstanding principal. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the type of project and the experience and resources of the developer.

Consumer Real Estate—Loans secured by first and second liens such as home equity loans, home equity lines of credit and 1-4 family residences, including purchase money mortgages. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The state of the local housing market can also have a significant impact on this segment because low demand and/or declining home values can limit the ability of borrowers to sell a property and satisfy the debt.

Other Consumer—Loans made to individuals that may be secured by assets other than 1-4 family residences, as well as unsecured loans. This segment includes auto loans, unsecured lines and credit cards. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The value of the collateral, if there is any, is less likely to be a source of repayment due to less certain collateral values.

We further assess risk within each portfolio segment by pooling loans with similar risk characteristics. For the commercial loan classes, the most important indicator of risk is the internally assigned risk rating, including pass, special mention and substandard. Consumer loans are pooled by type of collateral and first or second lien positions for consumer real estate loans. Historical loss rates are applied to these loan pools to determine the general reserve component of the ALL. Management monitors various credit quality indicators for both the commercial and consumer loan portfolios, including delinquency, nonperforming status and changes in risk ratings on a monthly basis. Refer to Note 1 Summary of Significant Accounting Policies for our policy for determining past due status of loans.

The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented:

	December 31, 2012
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,418,934	$	2,230	$	413	$	30,556	$	33,199	$	1,452,133
Commercial and industrial		780,315		4,409		237		6,435		11,081		791,396
Commercial construction		150,823		10,542		—		6,778		17,320		168,143
Home equity		424,485		2,332		865		3,653		6,850		431,335
Residential mortgage		416,364		1,713		1,948		7,278		10,939		427,303
Installment and other consumer		73,334		406		95		40		541		73,875
Consumer construction		2,219		—		—		218		218		2,437
Total	$	3,266,474	$	21,632	$	3,558	$	54,958	$	80,148	$	3,346,622

	December 31, 2011
(in thousands)	Current		30-59 Days Past Due		60-89 Days Past Due		Non- performing		Total Past Due Loans		Total Loans
Commercial real estate	$	1,374,580	$	7,657	$	1,448	$	31,648	$	40,753	$	1,415,333
Commercial and industrial		672,899		3,583		1,701		7,570		12,854		685,753
Commercial construction		182,305		—		—		6,547		6,547		188,852
Home equity		405,578		2,199		691		2,936		5,826		411,404
Residential mortgage		349,214		1,240		1,163		7,229		9,632		358,846
Installment and other consumer		66,675		382		70		4		456		67,131
Consumer construction		2,259		—		—		181		181		2,440
Total	$	3,053,510	$	15,061	$	5,073	$	56,115	$	76,249	$	3,129,759

We continually monitor the commercial loan portfolio through an internal risk rating system. Loan risk ratings are assigned based upon the creditworthiness of the borrower and are reviewed on an ongoing basis according to our internal policies. Loans within the pass rating generally have a lower risk of loss than loans risk rated as special mention and substandard, which generally have an increasing risk of loss.

Our risk ratings are consistent with regulatory guidance and are as follows:

Pass —The loan is currently performing and is of high quality.

Special Mention—A special mention loan has potential weaknesses that warrant management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects or in the strength of our credit position at some future date. Economic and market conditions, beyond the borrower’s control, may in the future necessitate this classification.

Substandard—A substandard loan is not adequately protected by the net worth and/or paying capacity of the borrower or by the collateral pledged, if any. Substandard loans have a well-defined weakness, or weaknesses that jeopardize the liquidation of the debt. These loans are characterized by the distinct possibility that we will sustain some loss if the deficiencies are not corrected.

The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented:

	December 31, 2012
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,265,810		87.2	%	$	718,070		90.7	%	$	118,841		70.7	%	$	2,102,721		87.2	%
Special mention		96,156		6.6	%		42,016		5.3	%		30,748		18.3	%		168,920		7.0	%
Substandard		90,167		6.2	%		31,310		4.0	%		18,554		11.0	%		140,031		5.8	%
Total	$	1,452,133		100.0	%	$	791,396		100.0	%	$	168,143		100.0	%	$	2,411,672		100.0	%

	December 31, 2011
(dollars in thousands)	Commercial Real Estate		% of Total			Commercial and Industrial		% of Total			Commercial Construction		% of Total			Total		% of Total
Pass	$	1,229,005		86.8	%	$	600,895		87.6	%	$	136,270		72.1	%	$	1,966,170		85.9	%
Special mention		84,400		6.0	%		33,135		4.8	%		17,106		9.1	%		134,641		5.9	%
Substandard		101,928		7.2	%		51,723		7.6	%		35,476		18.8	%		189,127		8.2	%
Total	$	1,415,333		100.0	%	$	685,753		100.0	%	$	188,852		100.0	%	$	2,289,938		100.0	%

We monitor the delinquent status of the consumer portfolio on a monthly basis. The risk of loss is generally highest for nonperforming loans.

The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented:

	December 31, 2012
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	427,682	$	420,025	$	73,835	$	2,219	$	923,761
Nonperforming		3,653		7,278		40		218		11,189
Total	$	431,335	$	427,303	$	73,875	$	2,437	$	934,950

	December 31, 2011
(in thousands)	Home Equity		Residential Mortgage		Installment and other consumer		Consumer Construction		Total
Performing	$	408,468	$	351,617	$	67,127	$	2,259	$	829,471
Nonperforming		2,936		7,229		4		181		10,350
Total	$	411,404	$	358,846	$	67,131	$	2,440	$	839,821

We individually evaluate all substandard, doubtful and nonaccrual commercial loans greater than $0.5 million for impairment. Loans are considered to be impaired when based upon current information and events it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. All TDRs are considered to be impaired loans and will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. For all TDRs, regardless of size, as well as all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate.

The following tables present investments in loans considered to be impaired and related information on those impaired loans at the dates and for the periods stated:

	December 31, 2012				Year ended December 31, 2012
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	6,138	$	6,864	$	1,226	$	5,796	$	218
Commercial and industrial		1,864		2,790		1,002		1,826		—
Commercial construction		799		896		3		4,446		—
Consumer real estate		—		—		—		—		—
Other consumer		—		—		—		—		—
Total with a Related Allowance Recorded		8,801		10,550		2,231		12,068		218
Without a related allowance recorded:
Commercial real estate		33,856		45,953		—		41,138		1,112
Commercial and industrial		11,419		12,227		—		11,672		329
Commercial construction		17,713		27,486		—		22,299		571
Consumer real estate		10,827		12,025				20,533		68
Other consumer		25		25		—		6		—
Total without a Related Allowance Recorded		73,840		97,716		—		95,648		2,080
Total:
Commercial real estate		39,994		52,817		1,226		46,934		1,330
Commercial and industrial		13,283		15,017		1,002		13,498		329
Commercial construction		18,512		28,382		3		26,745		571
Consumer real estate		10,827		12,025		—		20,533		68
Other consumer		25		25		—		6		—
Total	$	82,641	$	108,266	$	2,231	$	107,716	$	2,298

	December 31, 2011				Year Ended December 31, 2011
(in thousands)	Recorded Investment		Unpaid Principal Balance		Related Allowance		Average Recorded Investment		Interest Income Recognized
With a related allowance recorded:
Commercial real estate	$	9,049	$	9,276	$	3,487	$	12,045	$	320
Commercial and industrial		4,207		4,207		1,116		3,497		77
Commercial construction		1,975		1,975		942		3,326		4
Consumer real estate		—		—		—		173		—
Total with a Related Allowance Recorded		15,231		15,458		5,545		19,041		401
Without a related allowance recorded:
Commercial real estate		41,058		47,874		—		34,965		1,415
Commercial and industrial		7,784		7,784		—		4,128		132
Commercial construction		24,024		24,375		—		8,856		496
Consumer real estate		5,939		6,545		—		2,617		195
Total without a Related Allowance Recorded		78,805		86,578		—		50,566		2,238
Total:
Commercial real estate		50,107		57,150		3,487		47,010		1,735
Commercial and industrial		11,991		11,991		1,116		7,625		209
Commercial construction		25,999		26,350		942		12,182		500
Consumer real estate		5,939		6,545		—		2,790		195
Total	$	94,036	$	102,036	$	5,545	$	69,607	$	2,639

As of December 31, 2012, $40.0 million of CRE loans comprised 48 percent of the total impaired loans of $82.6 million. These impaired loans are collateralized primarily by commercial real estate properties such as retail or strip malls, office buildings, hotels and various other types of commercial purpose properties. These loans are generally considered collateral dependent and charge-offs are recorded when a confirmed loss exists. Approximately $13.3 million of charge-offs have been recorded relating to these CRE loans over the life of these loans. It is our policy to order appraisals on an annual basis on impaired loans or sooner if facts and circumstances warrant otherwise. As of December 31, 2012, these loans had collateral with an estimated fair value less cost to sell of approximately $55.2 million. We have current appraisals on all but four loans totaling $1.5 million of the $40.0 million impaired CRE loans. These $1.5 million of loans do not have updated appraisals due to bankruptcy proceedings that are awaiting resolution and one loan has a sales agreement in process. Appraisals outdated greater than 16 months are generally discounted an extra 10 percent in order to estimate the impact of aged appraisals, unless management is aware of other facts and circumstances that would imply a different discount should be applied. In determining this discount, management considers the market area of the collateral, the condition of the collateral, and other relevant factors that could impact the collateral value.

The following tables detail activity in the ALL for the years ended December 31:

	2012
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841
Charge-offs		(9,627	)		(5,278	)		(10,521	)		(2,509	)		(1,078	)		(29,013	)
Recoveries		1,259			1,153			891			197			341			3,841
Net (Charge-offs)/ Recoveries		(8,368	)		(4,125	)		(9,630	)		(2,312	)		(737	)		(25,172	)
Provision for loan losses		3,810			610			13,427			4,204			764			22,815
Balance at End of Year	$	25,246		$	7,759		$	7,500		$	5,058		$	921		$	46,484

	2011
(in thousands)	Commercial Real Estate			Commercial and Industrial			Commercial Construction			Consumer Real Estate			Other Consumer			Total Loans
Balance at beginning of year	$	30,425		$	9,777		$	5,904		$	3,962		$	1,319		$	51,387
Charge-offs		(8,824	)		(8,971	)		(1,720	)		(2,617	)		(1,013	)		(23,145	)
Recoveries		780			357			2,463			1,030			360			4,990
Net (Charge-offs)/ Recoveries		(8,044	)		(8,614	)		743			(1,587	)		(653	)		(18,155	)
Provision for loan losses		7,423			10,111			(2,944	)		791			228			15,609
Balance at End of Year	$	29,804		$	11,274		$	3,703		$	3,166		$	894		$	48,841

The following tables present the ALL and recorded investments in loans by category as of December 31:

	2012
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	1,226	$	24,020	$	25,246	$	39,994	$	1,412,139	$	1,452,133
Commercial and industrial		1,002		6,757		7,759		13,283		778,113		791,396
Commercial construction		3		7,497		7,500		18,512		149,631		168,143
Consumer real estate		—		5,058		5,058		10,827		850,248		861,075
Other consumer		—		921		921		25		73,850		73,875
Total	$	2,231	$	44,253	$	46,484	$	82,641	$	3,263,981	$	3,346,622

	2011
	Allowance for Loan Losses						Portfolio Loans
(in thousands)	Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total		Individually Evaluated for Impairment		Collectively Evaluated for Impairment		Total
Commercial real estate	$	3,487	$	26,317	$	29,804	$	50,107	$	1,365,226	$	1,415,333
Commercial and industrial		1,116		10,158		11,274		11,991		673,762		685,753
Commercial construction		942		2,761		3,703		25,999		162,853		188,852
Consumer real estate		—		3,166		3,166		5,939		766,751		772,690
Other consumer		—		894		894		—		67,131		67,131
Total	$	5,545	$	43,296	$	48,841	$	94,036	$	3,035,723	$	3,129,759

XML

Short-Term Borrowings - Composition of Short-Term Borrowings and Interest Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Short-term Debt [Line Items]
Balance	$ 75,000	$ 75,000	$ 40,653
Interest Expense	205	55	210
Securities sold under repurchase agreements, retail [Member]
Short-term Debt [Line Items]
Balance	62,582	30,370	40,653
Interest Expense	82	53	64
Federal Home Loan Bank advances [Member]
Short-term Debt [Line Items]
Balance	75,000	75,000
Interest Expense	$ 123	$ 2	$ 146

XML

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Mainline [Member]	Dec. 31, 2012 Gateway [Member]	Aug. 13, 2012 Gateway [Member]
Goodwill [Line Items]
Acquisition of additional goodwill	$ 10,460,000			$ 6,700,000	$ 3,776,000	$ 3,776,000
Acquisition of core deposits	1,331,000				431,000
Acquisition of wealth management relationships	200,000
Acquisition of insurance contract relationships	600,000
Amortization expense on finite-lived intangible assets	$ 1,709,000	$ 1,737,000	$ 1,946,000

XML

Premises and Equipment - Minimum Annual Rental and Renewal Option Payments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Operating, 2013	$ 2,088
Operating, 2014	2,107
Operating, 2015	2,076
Operating, 2016	2,006
Operating, 2017	1,954
Operating, Thereafter	43,114
Operating, Total	53,345
Capital, 2013	76
Capital ,2014	76
Capital, 2015	76
Capital, 2016	76
Capital, 2017	76
Capital, Thereafter	839
Capital, Total	1,219
2013	2,164
2014	2,183
2015	2,152
2016	2,082
2017	2,030
Thereafter	43,953
Total	$ 54,564

XML

Tax Effects on Other Comprehensive Income - Tax Effects of Components of Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pre-Tax Amount
Change in unrealized gains/losses on securities available-for-sale	$ 4,097	$ 6,702	$ 695
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income	(3,016)	124	(274)
Adjustment to funded status of employee benefit plans	(271)	(18,787)	(606)
Other Comprehensive Income	810	(11,961)	(185)
Change in unrealized gains/losses on securities available-for-sale	(1,434)	(2,346)	(243)
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income	1,055	(43)	96
Adjustment to funded status of employee benefit plans	95	6,576	212
Other Comprehensive Income	(284)	4,187	65
Net of Tax Amount
Change in unrealized gains/losses on securities available-for-sale	2,663	4,356	452
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income	(1,961)	81	(178)
Adjustment to funded status of employee benefit plans	(176)	(12,211)	(394)
Other Comprehensive Income	$ 526	$ (7,774)	$ (120)

XML

Incentive and Restricted Stock Plan and Dividend Reinvestment Plan - Summary of NonStatutory Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Outstanding, Beginning	757,050	930,700	1,100,550
Number of Shares, Granted
Number of Shares, Exercised	0	0	(82,100)
Number of Shares, Forfeited	(81,550)	(173,650)	(87,750)
Number of Shares Outstanding, Ending	675,500	757,050	930,700
Number of shares Exercisable, Ending	675,500	757,050	930,700
Weighted Average Exercise Price, Beginning of year	$ 34.33	$ 32.80	$ 31.85
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Exercised			$ 19.81
Weighted Average Exercise Price, Forfeited	$ 27.29	$ 26.11	$ 33.04
Weighted Average Exercise Price, Ending of Year	$ 35.18	$ 34.33	$ 32.80
Weighted Average Exercise Price, Exercisable at End of Year	$ 35.18	$ 34.33	$ 32.80
Weighted Average Remaining Contractual Term, Outstanding	2 years	2 years 9 months 18 days	3 years 3 months 18 days
Weighted Average Remaining Contractual Term, Exercisable	2 years	2 years 9 months 18 days	3 years 3 months 18 days

XML

Segments - Financial Information of Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting, Asset Reconciling Item [Line Items]
Interest income									$ 156,251	$ 165,079	$ 180,419
Interest expense	4,629	5,025	5,551	5,819	6,192	6,976	7,245	7,320	21,024	27,733	34,573
Net interest income (expense)	38,920	38,820	39,370	39,140	40,259	40,845	41,783	42,192	135,227	137,346	145,846
Provision for loan losses	4,215	2,305	7,023	9,272	2,337	1,535	1,097	10,640	22,815	15,609	29,511
Noninterest income	11,565	12,576	12,525	12,229	11,574	10,424	11,170	11,013	51,912	44,057	47,210
Noninterest expense									122,863	103,908	105,633
Depreciation expense									3,912	4,254	4,259
Intangible amortization									1,709	1,737	1,946
Income tax expense (benefit)	2,400	2,623	1,383	855	4,376	4,681	4,051	1,514	7,261	14,622	14,432
Net Income	9,524	12,595	8,600	3,480	12,256	13,803	14,910	6,295	34,200	47,264	43,480
Community Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Interest income									155,865	164,738	180,319
Interest expense									22,135	27,692	34,692
Net interest income (expense)									133,730	137,046	145,627
Provision for loan losses									22,815	15,609	29,511
Noninterest income									36,422	30,195	32,959
Noninterest expense									97,687	81,180	82,872
Depreciation expense									3,833	4,165	4,163
Intangible amortization									1,600	1,619	1,815
Income tax expense (benefit)									10,207	17,911	17,019
Net Income									34,010	46,757	43,206
Wealth Management [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Interest income									454	307	471
Net interest income (expense)									454	307	471
Noninterest income									9,788	8,328	7,950
Noninterest expense									9,448	7,302	7,525
Depreciation expense									31	32	34
Intangible amortization									57	66	75
Income tax expense (benefit)									352	493	324
Net Income									354	742	463
Insurance [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Interest income									1	1	2
Interest expense										291	293
Net interest income (expense)									1	(290)	(291)
Noninterest income									5,262	5,236	4,968
Noninterest expense									5,415	5,199	4,850
Depreciation expense									48	57	62
Intangible amortization									52	52	56
Income tax expense (benefit)									(88)	(127)	(102)
Net Income									(164)	(235)	(189)
Eliminations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Interest income									(69)	33	(373)
Interest expense									(1,111)	(250)	(412)
Net interest income (expense)									1,042	283	39
Noninterest income									440	298	1,333
Noninterest expense									4,692	4,236	4,181
Income tax expense (benefit)									$ (3,210)	$ (3,655)	$ (2,809)

XML

Income Taxes - Schedule of Significant Components of Temporary Differences with Deferred Tax Assets and Liabilities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2012
Components Of Deferred Tax Assets And Liabilities [Line Items]
Expiration term of tax credit carryforwards	20 years

XML

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2012	Jan. 31, 2013	Jun. 30, 2012
Entity Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Trading Symbol	STBA
Entity Registrant Name	S&T BANCORP INC
Entity Central Index Key	0000719220
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		29,728,005
Entity Public Float			$ 520,833,295

XML

Employee Benefits - Actuarial Weighted Average Assumptions Used in Determining Benefit Obligation (Detail)	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Discount rate	4.00%	4.75%
Rate of compensation increase	3.00%	4.00%

XML

PREMISES AND EQUIPMENT

12 Months Ended

Dec. 31, 2012

PREMISES AND EQUIPMENT

NOTE 10. PREMISES AND EQUIPMENT

The following table is a summary of premises and equipment at December 31:

(in thousands)	2012			2011
Land	$	6,490		$	6,316
Premises		43,434			41,608
Furniture and equipment		24,944			22,941
Leasehold improvements		5,965			4,899
		80,833			75,764
Accumulated depreciation		(42,157	)		(38,009	)
Total	$	38,676		$	37,755

Depreciation expense related to premises and equipment was $3.9 million in 2012 and $4.3 million for both 2011 and 2010.

Certain banking facilities are leased under arrangements expiring at various dates until the year 2054. We account for these leases on a straight-line basis due to escalation clauses. All leases are accounted for as operating leases, except for one capital lease. Rental expense for premises amounted to $2.4 million, $1.9 million and $1.7 million in 2012, 2011 and 2010, respectively. Included in the rental expense for premises are leases entered into with two directors, which totaled $0.2 million for 2012, 2011 and 2010.

Minimum annual rental and renewal option payments for each of the following five years and thereafter are approximately:

(in thousands)	Operating		Capital		Total
2013	$	2,088	$	76	$	2,164
2014		2,107		76		2,183
2015		2,076		76		2,152
2016		2,006		76		2,082
2017		1,954		76		2,030
Thereafter		43,114		839		43,953
Total	$	53,345	$	1,219	$	54,564

XML

Loans and Loans Held For Sale - Summary of Nonperforming Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Nonperforming Assets
Nonaccrual loans	$ 36,018	$ 37,931
Nonaccrual TDRs	18,940	18,184
Total nonperforming loans	54,958	56,115
OREO	911	3,967
Total Nonperforming Assets	$ 55,869	$ 60,082

XML

Premises and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3,912,000	$ 4,254,000	$ 4,259,000
Lease expiration year	Jan. 01, 2054
Rental expense	2,400,000	1,900,000	1,700,000
Rental expense for premises leases with two directors	$ 200,000	$ 200,000	$ 200,000

XML

Consolidated Statements of Net Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
INTEREST INCOME
Loans, including fees	$ 145,181	$ 154,121	$ 169,404
Investment Securities:
Taxable	7,544	8,169	7,685
Tax-exempt	3,121	2,347	2,830
Dividends	405	442	500
Total Interest Income	156,251	165,079	180,419
INTEREST EXPENSE
Deposits	16,796	22,952	28,717
Borrowings and junior subordinated debt securities	4,228	4,781	5,856
Total Interest Expense	21,024	27,733	34,573
NET INTEREST INCOME	135,227	137,346	145,846
Provision for loan losses	22,815	15,609	29,511
Net Interest Income After Provision for Loan Losses	112,412	121,737	116,335
NONINTEREST INCOME
Debit and credit card fees	11,134	10,889	9,954
Service charges on deposit accounts	9,992	9,978	11,178
Wealth management fees	9,808	8,180	7,808
Insurance fees	8,448	8,314	8,312
Securities gains (losses), net	3,016	(124)	274
Mortgage banking	2,878	1,199	3,403
Other	6,636	5,621	6,281
Total Noninterest Income	51,912	44,057	47,210
NONINTEREST EXPENSE
Salaries and employee benefits	60,256	51,078	48,715
Data processing	9,620	6,853	6,145
Net occupancy	7,605	6,943	6,928
Professional services and legal	5,659	5,437	6,889
Furniture and equipment	5,262	4,941	5,054
Marketing	3,302	3,019	2,795
Other taxes	3,200	3,381	3,432
FDIC assessment	2,926	3,570	5,426
Other	25,033	18,686	20,249
Total Noninterest Expense	122,863	103,908	105,633
Income Before Taxes	41,461	61,886	57,912
Provision for income taxes	7,261	14,622	14,432
Net Income	34,200	47,264	43,480
Preferred stock dividends and discount amortization		7,611	6,201
Net Income Available to Common Shareholders	$ 34,200	$ 39,653	$ 37,279
Earnings per common share - basic	$ 1.18	$ 1.41	$ 1.34
Earnings per common share - diluted	$ 1.18	$ 1.41	$ 1.34
Dividends declared per common share	$ 0.60	$ 0.60	$ 0.60

XML

FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2012

FAIR VALUE MEASUREMENTS

NOTE 4. FAIR VALUE MEASUREMENTS

Refer to Note 1 Summary of Significant Accounting Policies under Fair Value Measurements for our accounting policy including details of the valuation methods used to determine the fair values of our assets and liabilities.

The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at December 31, 2012 and 2011. There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	212,066	$	—	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		—		57,896		—		57,896
Mortgage-backed securities of U.S. government corporations and agencies		—		60,781		—		60,781
Obligations of states and political subdivisions		—		112,767		—		112,767
Marketable equity securities		140		8,316		1,130		9,586
Total securities available-for-sale		140		451,826		1,130		453,096
Trading securities held in a Rabbi Trust		2,223		—		—		2,223
Total securities		2,363		451,826		1,130		455,319
Derivative financial assets:
Interest rate swaps		—		23,748		—		23,748
Interest rate lock commitments		—		467		—		467
Total Assets	$	2,363	$	476,041	$	1,130	$	479,534
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,522	$	—	$	23,522
Forward sale contracts		—		48		—		48
Total Liabilities	$	—	$	23,570	$	—	$	23,570

	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Securities available-for-sale:
Obligations of U.S. government corporations and agencies	$	—	$	142,786	$	—	$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		—		65,395		—		65,395
Mortgage-backed securities of U.S. government corporations and agencies		—		48,752		—		48,752
Obligations of states and political subdivisions		—		88,805		—		88,805
Marketable equity securities		2,855		7,316		1,687		11,858
Total securities available-for-sale		2,855		353,054		1,687		357,596
Trading securities held in a Rabbi Trust		1,949		—		—		1,949
Total securities		4,804		353,054		1,687		359,545
Derivative financial assets:
Interest rate swaps		—		23,764		—		23,764
Interest rate lock commitments		—		244		—		244
Total Assets	$	4,804	$	377,062	$	1,687	$	383,553
LIABILITIES
Derivative financial liabilities:
Interest rate swaps	$	—	$	23,639	$	—	$	23,639
Forward sale contracts	$	—	$	95	$	—	$	95
Total Liabilities	$	—	$	23,734	$	—	$	23,734

We classify financial instruments as Level 3 when valuation models are used because significant inputs are not observable in the market. The following tables present the changes in assets measured at fair value on a recurring basis for which we have utilized Level 3 inputs to determine the fair value:

	Years Ended December 31,
(in thousands)	2012			2011
Balance at beginning of year	$	1,687		$	1,588
Total (losses) gains included in other comprehensive income/loss(1)		(350	)		99
Net purchases, sales, issuances and settlements		(207	)		—
Transfers out of Level 3		—			—
Balance at end of year	$	1,130		$	1,687

⁽¹⁾  Changes in estimated fair value of available-for-sale investments are recorded in accumulated other comprehensive income/loss, while gains and losses from sales are recorded in security gains (losses), net in the Consolidated Statements of Net Income.

We may be required to measure certain assets and liabilities on a nonrecurring basis. The following tables present our assets that are measured at estimated fair value on a nonrecurring basis by the fair value hierarchy level at December 31, 2012 and 2011. There were no liabilities measured at estimated fair value on a nonrecurring basis during these periods. Loans held for sale are recorded at the lower of cost or fair value. At December 31, 2012 and 2011, we had no loans held for sale that were recorded at fair value.

	December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	44,059	$	44,059
Other real estate owned		—		—		585		585
Mortgage servicing rights		—		—		2,106		2,106
Total Assets	$	—	$	—	$	46,750	$	46,750
	December 31, 2011
(in thousands)	Level 1		Level 2		Level 3		Total
ASSETS
Impaired Loans	$	—	$	—	$	36,500	$	36,500
Other real estate owned		—		—		3,739		3,739
Mortgage servicing rights		—		—		2,153		2,153
Total Assets	$	—	$	—	$	42,392	$	42,392

The carrying values and fair values of our financial instruments at December 31, 2012 and 2011 are presented in the following tables:

			Fair Value Measurements at December 31, 2012
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	337,711	$	337,711	$	337,711	$	—	$	—
Securities available-for-sale		453,096		453,096		140		451,826		1,130
Loans held for sale		22,499		22,601		—		—		22,601
Portfolio loans		3,346,622		3,347,602		—		—		3,347,602
Federal Home Loan Bank stock, at cost		14,485		14,485		—		—		14,485
Bank owned life insurance		58,619		58,619		—		58,619		—
Trading securities held in a Rabbi Trust		2,223		2,223		2,223		—		—
Mortgage servicing rights		2,106		2,106		—		—		2,106
Interest rate swaps		23,748		23,748		—		23,748		—
Interest rate lock commitments		467		467		—		467		—
LIABILITIES
Deposits	$	3,638,428	$	3,643,683	$	—	$	—	$	3,643,683
Securities sold under repurchase agreements		62,582		62,582		—		—		62,582
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		34,101		36,235		—		—		36,235
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,522		23,522		—		23,522		—
Forward sale contracts		48		48		—		48		—

⁽¹⁾  As reported in the Consolidated Balance Sheets

			Fair Value Measurements at December 31, 2011
(in thousands)	Carrying Value(1)		Total		Level 1		Level 2		Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits	$	270,526	$	270,526	$	270,526	$	—	$	—
Securities available-for-sale		357,596		357,596		2,855		353,054		1,687
Loans held for sale		2,850		2,958		—		—		2,958
Portfolio loans		3,129,759		3,120,352		—		—		3,120,352
Federal Home Loan Bank stock, at cost		18,216		18,216		—		—		18,216
Bank owned life insurance		56,755		56,755		—		56,755		—
Trading securities held in a Rabbi Trust		1,949		1,949		1,949		—		—
Mortgage servicing rights		2,153		2,153		—		—		2,153
Interest rate swaps		23,764		23,764		—		23,764		—
Interest rate lock commitments		244		244		—		244		—
LIABILITIES
Deposits	$	3,335,859	$	3,343,889	$	—	$	—	$	3,343,889
Securities sold under repurchase agreements		30,370		30,370		—		—		30,370
Short-term borrowings		75,000		75,000		—		—		75,000
Long-term borrowings		31,874		34,171		—		—		34,171
Junior subordinated debt securities		90,619		90,619		—		—		90,619
Interest rate swaps		23,639		23,639		—		23,639		—
Forward sale contracts		95		95		—		95		—

⁽¹⁾ As reported in the Consolidated Balance Sheets

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EARNINGS PER SHARE

12 Months Ended

Dec. 31, 2012

EARNINGS PER SHARE

NOTE 3. EARNINGS PER SHARE

The following table reconciles the numerators and denominators of basic EPS with that of diluted EPS:

	Years ended December 31,
(in thousands, except share and per share data)	2012		2011		2010
Numerator for Earnings per Common Share—Basic:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Less: Income allocated to participating shares		126		130		42
Net Income Allocated to Common Shareholders	$	34,074	$	39,523	$	37,237
Numerator for Earnings per Common Share—Diluted:
Net income	$	34,200	$	47,264	$	43,480
Less: Preferred stock dividends and discount amortization		—		7,611		6,201
Net Income Available to Common Shareholders	$	34,200	$	39,653	$	37,279
Denominators:
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Potentially dilutive common shares		32,261		23,169		22,261
Denominator for Treasury Stock Method—Diluted		29,008,880		27,990,150		27,813,406
Weighted Average Common Shares Outstanding—Basic		28,976,619		27,966,981		27,791,145
Add: Average participating shares outstanding		107,274		92,212		33,899
Denominator for Two-Class Method—Diluted		29,083,893		28,059,193		27,825,044
Earnings per common share—basic	$	1.18	$	1.41	$	1.34
Earnings per common share—diluted	$	1.18	$	1.41	$	1.34
Warrants considered anti-dilutive excluded from dilutive potential common shares		517,012		517,012		517,012
Stock options considered anti-dilutive excluded from dilutive potential common shares		747,443		757,580		930,969
Restricted stock considered anti-dilutive excluded from dilutive potential common shares		75,012		69,043		11,638

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Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2012 Segment
Number of reportable segment	3

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SHORT-TERM BORROWINGS

12 Months Ended

Dec. 31, 2012

SHORT-TERM BORROWINGS

NOTE 15. SHORT-TERM BORROWINGS

Short-term borrowings are for terms under one year and were comprised of retail repurchase agreements , or REPOs, and FHLB advances. We define repurchase agreements with our local retail customers as retail REPOs. Securities pledged as collateral under these REPO financing arrangements cannot be sold or repledged by the secured party and are therefore accounted for as a secured borrowing. FHLB advances are for various terms secured by a blanket lien on residential mortgages and other real estate secured loans. The following table represents the composition of short-term borrowings at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Securities sold under repurchase agreements, retail	$	62,582	$	82	$	30,370	$	53	$	40,653	$	64
Federal Home Loan Bank advances		75,000		123		75,000		2		—		146
Total	$	137,582	$	205	$	105,370	$	55	$	40,653	$	210

We had a $5.0 million line of credit with S&T Bank secured by investments of another subsidiary of S&T, which was closed in April 2012.

Information pertaining to REPOs are summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	62,582	$	30,370	$	40,653
Average balance during the year		47,388		41,584		46,489
Average interest rate during the year		0.17%		0.13%		0.14%
Maximum month-end balance during the year	$	62,582	$	42,409	$	52,046
Average interest rate at December 31		0.20%		0.11%		0.07%

Information pertaining to short-term FHLB advances is summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	75,000	$	75,000	$	—
Average balance during the year		50,212		551		32,473
Average interest rate during the year		0.24%		0.32%		0.45%
Maximum month-end balance during the year	$	75,000	$	75,000	$	141,800
Average interest rate at December 31		0.19%		0.18%		—

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GOODWILL AND OTHER INTANGIBLE ASSETS

12 Months Ended

Dec. 31, 2012

GOODWILL AND OTHER INTANGIBLE ASSETS

NOTE 11. GOODWILL AND OTHER INTANGIBLE ASSETS

The following table represents a roll forward of goodwill:

(in thousands)	2012		2011
Balance at beginning of year	$	165,273	$	165,273
Additions		10,460		—
Balance at End of Year	$	175,733	$	165,273

Goodwill represents the excess of the purchase price over the fair value of net assets purchased. Additional goodwill of $10.5 million was recorded during 2012, including $6.7 for our acquisition of Mainline and $3.8 million for our acquisition of Gateway. Refer to Note 2 Business Combinations for further details on these acquisitions. There were no additions to goodwill in 2011.

Goodwill is reviewed for impairment annually with an interim analysis performed when necessary. Based upon our qualitative assessment performed for our annual impairment analysis, we concluded that it is more likely that not that the fair value of the reporting units exceeds the carrying value. In general, the overall macroeconomic conditions and more specifically the economic conditions of the banking industry have been improving recently. Additionally, our overall performance has not significantly deteriorated and we did not identify any other facts and circumstances causing us to conclude that it is more likely than not that the fair value of the reporting units would be less than the carrying value.

The following table shows a summary of intangible assets:

(in thousands)	2012			2011
Gross carrying amount at beginning of year	$	15,070		$	15,070
Additions		1,331			—
Accumulated amortization		(11,051	)		(9,342	)
Balance at End of Year	$	5,350		$	5,728

Intangible assets as of December 31, 2012 consisted of $4.6 million for the acquisition of core deposits, $0.2 million for the acquisition of wealth management relationships and $0.6 million for the acquisition of insurance contract relationships. The additions of $1.3 million includes core deposit intangibles as a result of our acquisitions of Mainline and Gateway. We determined the amount of these identifiable intangible assets as well as those acquired before 2012, based upon independent core deposit, wealth management and insurance contract analyses. Other intangible assets are evaluated for recoverability annually and more frequently if triggering events and changes in circumstances occur. We completed this review in 2012 and 2011 and determined that other intangible assets are not impaired.

Amortization expense on finite-lived intangible assets totaled $1.7 million, $1.7 million and $1.9 million for 2012, 2011 and 2010, respectively. The following is a summary of the expected amortization expense for finite-lived intangibles assets, assuming no new additions, for each of the five years following December 31, 2012:

(in thousands)	Amount
2013	$	1,590
2014		1,129
2015		883
2016		645
2017		500
Total	$	4,747

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Allowance for Loan Losses - Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	$ 934,950	$ 839,821
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	923,761	829,471
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	11,189	10,350
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	431,335	411,404
Home Equity [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	427,682	408,468
Home Equity [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	3,653	2,936
Residential mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	427,303	358,846
Residential mortgage [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	420,025	351,617
Residential mortgage [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	7,278	7,229
Installment and other consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	73,875	67,131
Installment and other consumer [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	73,835	67,127
Installment and other consumer [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	40	4
Consumer construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	2,437	2,440
Consumer construction [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	2,219	2,259
Consumer construction [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment in consumer loan	$ 218	$ 181

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SECURITIES AVAILABLE-FOR-SALE

12 Months Ended

Dec. 31, 2012

SECURITIES AVAILABLE-FOR-SALE

NOTE 7. SECURITIES AVAILABLE-FOR-SALE

The following tables present the amortized cost and fair value of available-for-sale securities for the periods shown:

	December 31, 2012
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	207,229	$	4,890	$	(53	)	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		1,811		—			57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		3,373		—			60,781
Obligations of states and political subdivisions		107,911		4,908		(52	)		112,767
Debt Securities		428,633		14,982		(105	)		443,510
Marketable equity securities		8,502		1,095		(11	)		9,586
Total	$	437,135	$	16,077	$	(116	)	$	453,096

	December 31, 2011
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	138,386	$	4,400	$	—		$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		63,202		2,193		—			65,395
Mortgage-backed securities of U.S. government corporations and agencies		45,289		3,463		—			48,752
Obligations of states and political subdivisions		85,689		3,128		(12	)		88,805
Debt Securities		332,566		13,184		(12	)		345,738
Marketable equity securities		10,152		2,179		(473	)		11,858
Total	$	342,718	$	15,363	$	(485	)	$	357,596

During 2012, there were $3.0 million in gross realized gains, compared to nominal gains in 2011 and $0.4 million in 2010. The $3.0 in gross realized gains relates to the sales of two equity positions during the year as a result of increases in value after merger announcements. There were nominal gross realized losses in 2012 and $0.1 million in gross realized losses in 2011 and 2010, relating to securities available-for-sale.

The following tables present the fair value and the age of gross unrealized losses by investment category for the periods presented:

	December 31, 2012
	Less Than 12 Months					12 Months or More				Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	11,370	$	(53	)	$	—	$	—	$	11,370	$	(53	)
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—		—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—		—		—
Obligations of states and political subdivisions		11,285		(52	)		—		—		11,285		(52	)
Debt Securities		22,655		(105	)		—		—		22,655		(105	)
Marketable equity securities		228		(11	)		—		—		228		(11	)
Total Temporarily Impaired Securities	$	22,883	$	(116	)	$	—	$	—	$	22,883	$	(116	)

	December 31, 2011
	Less Than 12 Months					12 Months or More					Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	—	$	—		$	—	$	—		$	—	$	—
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—			—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—			—		—
Obligations of states and political subdivisions		502		(8	)		414		(4	)		916		(12	)
Debt Securities		502		(8	)		414		(4	)		916		(12	)
Marketable equity securities		5,143		(473	)		—		—			5,143		(473	)
Total Temporarily Impaired Securities	$	5,645	$	(481	)	$	414	$	(4	)	$	6,059	$	(485	)

We do not believe any individual unrealized loss as of December 31, 2012 represents an OTTI. Refer to Note 1 Summary of Significant Accounting Policies for our accounting policy for securities and OTTI.

As of December 31, 2012, the unrealized losses on five debt securities were primarily attributable to changes in interest rates. The unrealized losses on two marketable equity securities as of December 31, 2012 were attributable to temporary declines in the market value of these stocks. We do not intend to sell and it is not likely that we will be required to sell any of the securities, referenced in the table above, in an unrealized loss position before recovery of their amortized cost.

Net unrealized gains of $10.4 million and $9.7 million were included in accumulated other comprehensive loss, net of tax, at December 31, 2012 and 2011, respectively. Gross unrealized gains of $10.5 million and $10.0 million, net of tax, were netted against gross unrealized losses of $0.1 million and $0.3 million, respectively, for these same periods. During 2012 unrealized gains reclassified out of accumulated other comprehensive income into earnings were $3.0 million, while unrealized losses reclassified into earnings to record OTTI were minimal. During 2011, unrealized gains reclassified out of accumulated other comprehensive loss into earnings were minimal, while $0.1 million of unrealized losses were reclassified into earnings to record OTTI.

The amortized cost and fair value of securities available-for-sale at December 31, 2012, by contractual maturity, are included in the table below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

	December 31, 2012
(in thousands)	Amortized Cost		Fair Value
Due in one year or less	$	38,434	$	38,969
Due after one year through five years		130,690		134,192
Due after five years through ten years		64,822		66,507
Due after ten years		81,194		85,165
		315,140		324,833
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		60,781
Debt Securities		428,633		443,510
Marketable equity securities		8,502		9,586
Total	$	437,135	$	453,096

At December 31, 2012 and 2011, securities with carrying values of $307.5 million and $233.9 million, respectively, were pledged to secure repurchase agreements, public funds and trust fund deposits and as collateral for our interest rate swaps.

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OTHER NONINTEREST EXPENSE (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Other Noninterest Expenses

Other noninterest expenses are presented in the table below:

	Years ended December 31,
(in thousands)	2012		2011			2010
Other noninterest expenses:
Joint venture amortization	$	4,199	$	3,302		$	2,573
Other real estate owned		2,166		1,518			1,921
Unfunded loan commitments		1,811		(1,474	)		(1,555	)
Amortization of intangibles		1,709		1,737			1,943
Loan collection fees		430		624			1,770
Other		14,718		12,979			13,597
Total Other Noninterest Expenses	$	25,033	$	18,686		$	20,249

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Long-Term Borrowings - Schedule of Junior Subordinated Debt Securities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Junior Subordinated Debentures [Line Items]
Interest Rate at December 31	3.18%
2006 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Junior Subordinated Debt	$ 25,000
Stated Maturity Date	Dec. 15, 2036
Regulatory Capital	Tier 2
Interest Rate	3 month LIBOR plus 160 bps
Interest Rate at December 31	1.91%
2008 Junior subordinated debt-trust preferred securities [Member]
Junior Subordinated Debentures [Line Items]
Trust Preferred Securities	20,000
Stated Maturity Date	Mar. 15, 2038
First optional redemption date at par	Mar. 15, 2013
Regulatory Capital	Tier 1
Interest Rate	3 month LIBOR plus 350 bps
Interest Rate at December 31	3.81%
2008 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Junior Subordinated Debt	20,000
Stated Maturity Date	Jun. 15, 2018
First optional redemption date at par	Jun. 15, 2013
Regulatory Capital	Tier 2
Interest Rate	3 month LIBOR plus 350 bps
Interest Rate at December 31	3.81%
2008 Junior subordinated debt [Member]
Junior Subordinated Debentures [Line Items]
Junior Subordinated Debt	$ 25,000
Stated Maturity Date	May 30, 2018
First optional redemption date at par	May 30, 2013
Regulatory Capital	Tier 2
Interest Rate	3 month LIBOR plus 250 bps
Interest Rate at December 31	2.81%

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RESTRICTIONS ON CASH AND DUE FROM BANK ACCOUNTS

12 Months Ended

Dec. 31, 2012

RESTRICTIONS ON CASH AND DUE FROM BANK ACCOUNTS

NOTE 5. RESTRICTIONS ON CASH AND DUE FROM BANK ACCOUNTS

The Board of Governors of the Federal Reserve System, or the Federal Reserve, imposes certain reserve requirements on all depository institutions. These reserves are maintained in the form of vault cash or as an interest-bearing balance with the Federal Reserve. During the years ended 2012, 2011 and 2010 the required reserves averaged $36.6 million, $36.6 million and $32.5 million, respectively.

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DIVIDEND AND LOAN RESTRICTIONS

12 Months Ended

Dec. 31, 2012

DIVIDEND AND LOAN RESTRICTIONS

NOTE 6. DIVIDEND AND LOAN RESTRICTIONS

S&T is a legal entity separate and distinct from its banking and other subsidiaries. A substantial portion of our revenues consist of dividend payments we receive from S&T Bank. S&T Bank, in turn, is subject to state laws and regulations that limit the amount of dividends it can pay to us. In addition, both S&T and S&T Bank are subject to various general regulatory policies relating to the payment of dividends, including requirements to maintain adequate capital above regulatory minimums. The Federal Reserve has indicated that banking organizations should generally pay dividends only if (i) the organization’s net income available to common shareholders over the past year has been sufficient to fully fund the dividends and (ii) the prospective rate of earnings retention appears consistent with the organization’s capital needs, asset quality and overall financial condition. Thus, under certain circumstances based upon our financial condition, our ability to declare and pay quarterly dividends may require consultation with the Federal Reserve and may be prohibited by applicable Federal Reserve regulations. If we were to pay a dividend in contravention of Federal Reserve regulations, the Federal Reserve could raise supervisory concerns. We redeemed our Series A Preferred Stock on December 7, 2011, and therefore we are no longer subject to the dividend restriction imposed by participation in the CPP.

Federal law prohibits us from borrowing from S&T Bank unless such loans are collateralized by specific obligations. Further, such loans are limited to 10 percent of S&T Bank’s capital and additional paid-in capital, as defined. In April 2012, we closed a $5.0 million line of credit with S&T Bank that had been secured by investments of another subsidiary of S&T.

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Parent Company Condensed Financial Information - Statements of Net Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Information [Line Items]
Interest expense on long-term debt									$ 1,100	$ 1,100	$ 1,600
Net Income	9,524	12,595	8,600	3,480	12,256	13,803	14,910	6,295	34,200	47,264	43,480
Parent Company [Member]
Condensed Financial Information [Line Items]
Dividends from subsidiaries									35,603	23,029	22,634
Investment income									17	121	86
Interest expense on long-term debt									808	777	782
Other expenses									1,800	1,091	1,648
Income before Equity in Undistributed Net Income of Subsidiaries									33,012	21,282	20,290
Bank subsidiary									1,371	25,590	23,158
Nonbank subsidiaries									(183)	392	32
Net Income									$ 34,200	$ 47,264	$ 43,480

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LOANS AND LOANS HELD FOR SALE

12 Months Ended

Dec. 31, 2012

LOANS AND LOANS HELD FOR SALE

NOTE 8. LOANS AND LOANS HELD FOR SALE

The following table presents the composition of loans:

	December 31,
(in thousands)	2012			2011
Commercial
Commercial real estate	$	1,452,133		$	1,415,333
Commercial and industrial		791,396			685,753
Commercial construction		168,143			188,852
Total Commercial Loans		2,411,672			2,289,938
Consumer
Home equity		431,335			411,404
Residential mortgage		427,303			358,846
Installment and other consumer		73,875			67,131
Consumer construction		2,437			2,440
Total Consumer Loans		934,950			839,821
Total Portfolio Loans		3,346,622			3,129,759
Allowance for loan losses		(46,484	)		(48,841	)
Total Portfolio Loans, net		3,300,138			3,080,918
Loans held for sale		22,499			2,850
Total Loans, Net	$	3,322,637		$	3,083,768

The table above includes loans that were acquired from two bank acquisitions. Approximately $129.5 million of loans were acquired from the Mainline acquisition on March 9, 2012 which consisted of $57.7 million of consumer loans and $71.8 million of commercial loans. Additionally, on August 13, 2012, we acquired Gateway which added $99.1 million of loans, including $74.2 million of commercial and $24.9 million of consumer loans. Additionally, we had $19.3 million in loans held for sale that related to a participation loan that we had not received funds from the participating banks as of December 31, 2012.

We attempt to limit our exposure to credit risk by diversifying our loan portfolio and actively managing concentrations. When concentrations exist in certain segments, we mitigate this risk by monitoring the relevant economic indicators and internal risk rating trends and through stress testing of the loans in these classes. Total commercial loans represent 72 percent and 73 percent of total portfolio loans at December 31, 2012 and December 31, 2011, respectively. Within our commercial portfolio, the CRE and commercial construction portfolios combined comprise 67 percent of total commercial loans and 48 percent of total portfolio loans at December 31, 2012 and 70 percent of total commercial loans and 51 percent of total portfolio loans at December 31, 2011. Further segmentation of the CRE and commercial construction portfolios by industry and collateral type reveal no concentration in excess of nine percent of total loans. The majority of both commercial and consumer loans are made to businesses and individuals in our Western Pennsylvania market, resulting in a geographic concentration. The conditions of the local and regional economies are monitored closely through publicly available data as well as information supplied by our customers. Only the CRE and commercial construction portfolios combined have any significant out-of-state exposure, with 19 percent of the combined portfolio and nine percent of total loans being out-of-state loans at December 31, 2012 and 19 percent of the combined portfolio and 10 percent of total loans being out-of-state loans at December 31, 2011. Management believes underwriting guidelines and ongoing review by credit administration mitigates the concentration risk present in the loan portfolio.

In situations where, for economic or legal reasons related to a borrower’s financial difficulties, we may grant a concession for other than an insignificant period of time to the borrower that would not otherwise be granted, the related loan is classified as a TDR. We strive to identify borrowers in financial difficulty early and work with them to modify to more affordable terms before their loan reaches nonaccrual status. These modified terms generally include extensions of maturity dates at a stated interest rate lower than the current market rate for a new loan with similar risk characteristics, reductions in contractual interest rates, and principal deferment. These modifications are generally for longer term periods that would not be considered insignificant. While unusual, there may be instances of loan principal forgiveness. We may have borrowers classified as TDR wherein their debt obligation has been discharged by a chapter 7 bankruptcy without reaffirmation of debt.

We individually evaluate all substandard commercial loans that experienced a forbearance or change in terms agreement, as well as all substandard consumer and residential mortgage loans that entered into an agreement to modify their existing loan.

All TDRs are considered to be impaired loans and will be reported as impaired loans for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. Further, all impaired loans are reported as nonaccrual loans unless the loan is a TDR that has met the requirements to be returned to accruing status. TDRs can be returned to accruing status if the ultimate collectability of all contractual amounts due, according to the restructured agreement, is not in doubt and there is a period of a minimum of six months of satisfactory payment performance by the borrower either immediately before or after the restructuring. We did not return any TDRs to accruing status during 2012.

The following table summarizes the restructured loans as of the dates presented:

	December 31, 2012						December 31, 2011
(in thousands)	Performing TDRs		Nonperforming TDRs		Total TDRs		Performing TDRs		Nonperforming TDRs		Total TDRs
Commercial real estate	$	14,220	$	9,584	$	23,804	$	22,284	$	10,871	$	33,155
Commercial and industrial		8,270		939		9,209		6,180		—		6,180
Commercial construction		11,734		5,324		17,058		19,682		2,943		22,625
Home equity		4,195		341		4,536		—		—		—
Residential mortgage		3,078		2,752		5,830		1,570		4,370		5,940
Installment and other consumer		24		—		24		—		—		—
Total	$	41,521	$	18,940	$	60,461	$	49,716	$	18,184	$	67,900

The following tables present the restructured loans for the years ending December 31:

	2012
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	704	$	693	$	(11	)
Interest rate reduction		2		1,785		1,768		(17	)
Commercial and industrial
Maturity date extension		4		2,825		2,601		(224	)
Commercial construction
Maturity date extension		6		2,894		1,874		(1,020	)
Home Equity
Discharge of debt		161		4,530		4,530		—
Residential mortgage
Maturity date extension		1		475		439		(36	)
Interest rate reduction		2		67		67		—
Discharge of debt		76		2,349		2,349		—
Installment and other consumer
Discharge of debt		5		25		25		—
Total by Concession Type
Maturity date extension		14		6,898		5,607		(1,291	)
Interest rate reduction		4		1,852		1,835		(17	)
Discharge of debt		242		6,904		6,904		—
Total		260	$	15,654	$	14,346	$	(1,308	)

⁽¹⁾ Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

	2011
(in thousands, except number of loans)	Number of Loans		Pre-Modification Outstanding Recorded Investment(1)		Post-Modification Outstanding Recorded Investment(1)		Total Difference in Recorded Investment
Commercial real estate
Maturity date extension		3	$	3,361	$	3,817	$	456
Interest rate reduction		2		682		604		(78	)
Other		3		2,034		908		(1,126	)
Commercial and industrial
Maturity date extension		6		6,364		6,180		(184	)
Commercial construction
Maturity date extension		12		21,029		20,979		(50	)
Residential mortgage
Maturity date extension		6		5,201		4,825		(376	)
Interest rate reduction		2		336		308		(28	)
Other		1		75		40		(35	)
Total by Concession Type
Maturity date extension		27		35,955		35,801		(154	)
Interest rate reduction		4		1,018		912		(106	)
Other		4		2,109		948		(1,161	)
Total		35	$	39,082	$	37,661	$	(1,421	)

⁽¹⁾  Excludes loans that were paid off or charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

We had $6.9 million of new TDRs related to our consumer loan portfolio for borrowers who had their debt discharged and not reaffirmed through Chapter 7 bankruptcy. These loans are being reported as accruing TDRs as the borrowers are current on their payments and almost all have no history of delinquency.

During 2012, we modified 7 C&I loans totaling $6.6 million, one commercial construction loan totaling $1.2 million and 8 commercial real estate loan totaling $3.6 million for financially troubled borrowers that were not considered to be TDRs. Modifications primarily represented insignificant delays in the timing of payments that were not considered to be concessions or we have been adequately compensated for the concession through principal reductions or additional collateral. As of December 31, 2012 we have no commitments to lend additional funds on any TDRs.

The following table is a summary of TDRs which defaulted (defined as 90 days past due since time of modification) during years ended December 31, 2012 and 2011 that had been restructured within the last twelve months prior to December 31, 2012 and 2011, respectively:

	Defaulted TDRs
	For the Year Ended December 31, 2012				For the Year Ended December 31, 2011
(dollars in thousands)	Number of Defaults		Recorded Investment		Number of Defaults		Recorded Investment
Commercial real estate		—	$	—		2	$	0.9
Total		—	$	—		2	$	0.9

The following table is a summary of nonperforming assets for the years ended December 31:

(in thousands)	2012		2011
Nonperforming Assets
Nonaccrual loans	$	36,018	$	37,931
Nonaccrual TDRs		18,940		18,184
Total nonperforming loans		54,958		56,115
OREO		911		3,967
Total Nonperforming Assets	$	55,869	$	60,082

OREO which is included in other assets in the Consolidated Balance Sheets consists of 13 properties. It is our policy to obtain OREO appraisals on an annual basis.

We have granted loans to certain officers and directors of S&T as well as to certain affiliates of the officers and directors in the ordinary course of business. These loans were made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated persons and did not involve more than normal risk of collectability.

The following table presents a summary of the aggregate amount of loans to any such persons as of December 31:

(in thousands)	2012			2011
Balance at beginning of year	$	31,821		$	34,373
New loans		29,465			23,751
Repayments		(25,211	)		(26,303	)
Balance at End of Year	$	36,075		$	31,821

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Business Combinations - Total Consideration, Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Aug. 13, 2012
Consideration Paid
Cash	$ 19,142
Common stock	28,070
Fair value of previously held equity interest	346
Fair Value of Total Consideration	47,558
Fair Value of Assets Acquired
Cash and cash equivalents	37,781
Securities and other investments	82,892
Loans	228,591
Premises and other equipment	2,775
Core deposit intangible	1,331
Other assets	15,103
Total Assets Acquired	368,473
Fair Value of Liabilities Assumed
Deposits	311,389
Borrowings	16,774
Other liabilities	3,212
Total Liabilities Assumed	331,375
Total Fair Value of Identifiable Net Assets	37,098
Goodwill	10,460
Mainline [Member]
Consideration Paid
Cash	12,904
Common stock	14,786
Fair value of previously held equity interest	74
Fair Value of Total Consideration	27,764
Fair Value of Assets Acquired
Cash and cash equivalents	17,763
Securities and other investments	73,328
Loans	129,501
Premises and other equipment	2,280
Core deposit intangible	900
Other assets	12,438
Total Assets Acquired	236,210
Fair Value of Liabilities Assumed
Deposits	205,989
Borrowings	6,997
Other liabilities	2,144
Total Liabilities Assumed	215,130
Total Fair Value of Identifiable Net Assets	21,080
Goodwill	6,684
Gateway [Member]
Consideration Paid
Cash	6,238	5,200
Common stock	13,284
Fair value of previously held equity interest	272
Fair Value of Total Consideration	19,794
Fair Value of Assets Acquired
Cash and cash equivalents	20,018
Securities and other investments	9,564
Loans	99,090
Premises and other equipment	495
Core deposit intangible	431
Other assets	2,665
Total Assets Acquired	132,263
Fair Value of Liabilities Assumed
Deposits	105,400
Borrowings	9,777
Other liabilities	1,068
Total Liabilities Assumed	116,245
Total Fair Value of Identifiable Net Assets	16,018
Goodwill	$ 3,776	$ 3,776

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Income Taxes - Schedule of Change in Deferred Taxes on Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred tax changes reflected in other comprehensive gain/loss	$ 284	$ (4,186)
Deferred tax changes resulting from purchase accounting adjustments	(5,843)
Deferred tax changes reflected in federal income tax expense (benefit)	$ 1,038	$ 2,448	$ (4,537)

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Allowance for Loan Losses - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Evaluation for Impairment of substandard and commercial loans	$ 500,000
Commercial real estate impaired loans fair value	40,000,000
Commercial real estate loans	82,641,000	94,036,000
Impaired commercial real estate loans that do not have current appraisals	1,500,000
Fair value current appraisal Percent	10.00%
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Commercial real estate impaired loans fair value	40,000,000
Percentage of impaired loans	48.00%
Commercial real estate loans	39,994,000	50,107,000
Charge offs on loans	$ 13,300,000

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Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (Fair Value Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Total securities available-for-sale	$ 453,096	$ 357,596
Trading securities held in a Rabbi Trust	2,223	1,949
Total securities	455,319	359,545
Total Assets	479,534	383,553
LIABILITIES
Total Liabilities	23,570	23,734
Obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	212,066	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	57,896	65,395
Mortgage-backed securities of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	60,781	48,752
Obligations of states and political subdivisions [Member]
ASSETS
Total securities available-for-sale	112,767	88,805
Marketable equity securities [Member]
ASSETS
Total securities available-for-sale	9,586	11,858
Interest rate swaps [Member]
ASSETS
Derivative financial assets	23,748	23,764
LIABILITIES
Derivative financial liabilities	23,522	23,639
Interest rate lock commitments [Member]
ASSETS
Derivative financial assets	467	244
Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities	48	95
Level 1 [Member]
ASSETS
Total securities available-for-sale	140	2,855
Trading securities held in a Rabbi Trust	2,223	1,949
Total securities	2,363	4,804
Total Assets	2,363	4,804
LIABILITIES
Total Liabilities
Level 1 [Member] | Obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 1 [Member] | Collateralized mortgage obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 1 [Member] | Mortgage-backed securities of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 1 [Member] | Obligations of states and political subdivisions [Member]
ASSETS
Total securities available-for-sale
Level 1 [Member] | Marketable equity securities [Member]
ASSETS
Total securities available-for-sale	140	2,855
Level 1 [Member] | Interest rate swaps [Member]
ASSETS
Derivative financial assets
LIABILITIES
Derivative financial liabilities
Level 1 [Member] | Interest rate lock commitments [Member]
ASSETS
Derivative financial assets
Level 1 [Member] | Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities
Level 2 [Member]
ASSETS
Total securities available-for-sale	451,826	353,054
Trading securities held in a Rabbi Trust
Total securities	451,826	353,054
Total Assets	476,041	377,062
LIABILITIES
Total Liabilities	23,570	23,734
Level 2 [Member] | Obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	212,066	142,786
Level 2 [Member] | Collateralized mortgage obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	57,896	65,395
Level 2 [Member] | Mortgage-backed securities of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale	60,781	48,752
Level 2 [Member] | Obligations of states and political subdivisions [Member]
ASSETS
Total securities available-for-sale	112,767	88,805
Level 2 [Member] | Marketable equity securities [Member]
ASSETS
Total securities available-for-sale	8,316	7,316
Level 2 [Member] | Interest rate swaps [Member]
ASSETS
Derivative financial assets	23,748	23,764
LIABILITIES
Derivative financial liabilities	23,522	23,639
Level 2 [Member] | Interest rate lock commitments [Member]
ASSETS
Derivative financial assets	467	244
Level 2 [Member] | Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities	48	95
Level 3 [Member]
ASSETS
Total securities available-for-sale	1,130	1,687
Trading securities held in a Rabbi Trust
Total securities	1,130	1,687
Total Assets	1,130	1,687
LIABILITIES
Total Liabilities
Level 3 [Member] | Obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 3 [Member] | Collateralized mortgage obligations of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 3 [Member] | Mortgage-backed securities of U.S. government corporations and agencies [Member]
ASSETS
Total securities available-for-sale
Level 3 [Member] | Obligations of states and political subdivisions [Member]
ASSETS
Total securities available-for-sale
Level 3 [Member] | Marketable equity securities [Member]
ASSETS
Total securities available-for-sale	1,130	1,687
Level 3 [Member] | Interest rate swaps [Member]
ASSETS
Derivative financial assets
LIABILITIES
Derivative financial liabilities
Level 3 [Member] | Interest rate lock commitments [Member]
ASSETS
Derivative financial assets
Level 3 [Member] | Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities

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Deposits - Scheduled of Maturity of Certificate of Deposit (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Schedule Of Deposits And Borrowings Maturities [Line Items]
2013	$ 643,635
2014	129,963
2015	118,829
2016	53,735
2017	77,336
Thereafter	10,386
Total	$ 1,033,884

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Business Combinations - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2012 Business	Mar. 09, 2012 Mainline [Member]	Dec. 31, 2012 Mainline [Member]	Aug. 13, 2012 Gateway [Member]	Dec. 31, 2012 Gateway [Member]
Business Acquisition [Line Items]
Number of business acquired	2
Business acquisition, percentage of voting interests acquired		100.00%		100.00%
Business acquisition, cash per share offered in exchange of share		$ 69.00		$ 3.08
Business acquisition, shares of S&T offered for exchange with share		3.6316		0.4657
Preferred stock purchased		$ 4,700,000
Contingent liability recorded for IRS proposed 2010 penalty			500,000
Business acquisition, cash paid to former shareholders of Mainline			8,200,000
Fair value of common shares issued			14,800,000	13,300,000
Business acquisition, goodwill calculated	10,460,000		6,684,000	3,776,000	3,776,000
Business acquisition, cash paid to former shareholders	19,142,000		12,904,000	5,200,000	6,238,000
Outstanding equity awards settled				1,000,000
Business acquisition, loans acquired, gross		231,900,000
Business acquisition, Net combined yield and credit mark recognized on loans acquired		3,300,000
One time merger related expense recognized	6,000,000		4,500,000		1,500,000
Legal and professional expenses					600,000
Change of control and severance payments			1,800,000		600,000
Data processing contract termination and conversion cost expenses			2,000,000		300,000
Legal and professional expenses			$ 700,000

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Goodwill and Other Intangible Assets - Roll Forward of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2010
Goodwill [Line Items]
Balance at beginning of year	$ 165,273	$ 165,273
Additions	10,460
Balance at End of Year	$ 175,733	$ 165,273

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Employee Benefits - Estimated Future Benefit Payments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
2013	$ 5,813
2014	5,547
2015	6,601
2016	6,225
2017	6,056
2018-2022	$ 36,212

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OTHER NONINTEREST EXPENSE

12 Months Ended

Dec. 31, 2012

OTHER NONINTEREST EXPENSE

NOTE 26. OTHER NONINTEREST EXPENSE

Other noninterest expenses are presented in the table below:

	Years ended December 31,
(in thousands)	2012		2011			2010
Other noninterest expenses:
Joint venture amortization	$	4,199	$	3,302		$	2,573
Other real estate owned		2,166		1,518			1,921
Unfunded loan commitments		1,811		(1,474	)		(1,555	)
Amortization of intangibles		1,709		1,737			1,943
Loan collection fees		430		624			1,770
Other		14,718		12,979			13,597
Total Other Noninterest Expenses	$	25,033	$	18,686		$	20,249

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Capital Purchase Program - Fair Value of Warrant (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 Y
Contractual term	10 years
Exercise price	$ 31.53
Estimated fair value of company stock	$ 29.14
Expected life	10
Risk-free rate over expected life of the warrant	2.36%
Expected volatility	28.40%
Expected dividend yield	3.85%

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COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Letters of Credit

The following table sets forth the commitments and letters of credit at December 31:

(in thousands)	2012		2011
Commitments to extend credit	$	874,137	$	816,160
Standby letters of credit		95,399		119,576
Total	$	969,536	$	935,736

Future Estimated Payments Related to Data Processing and Communication Charges

The following table sets forth the future estimated payments related to data processing and communication charges for each of the five years following December 31, 2012:

(in thousands)	Total
2013	$	7,388	(1)
2014		7,032
2015		7,172
2016		6,816
2017		708
Total	$	29,116

(1) Included in this amount is $0.6 million related to the Gateway conversion in the first quarter of 2013.

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MORTGAGE SERVICING RIGHTS

12 Months Ended

Dec. 31, 2012

MORTGAGE SERVICING RIGHTS

NOTE 13. MORTGAGE SERVICING RIGHTS

For the years ended December 31, 2012, 2011 and 2010, the 1-4 family mortgage loans that were sold to Federal National Mortgage Association, or FNMA, amounted to $82.9 million, $67.9 million and $109.3 million, respectively. At December 31, 2012, 2011 and 2010 our servicing portfolio totaled $329.2 million, $332.6 million and $318.2 million, respectively.

The following table indicates MSRs and the net carrying values:

(in thousands)	Servicing Rights			Valuation Allowance			Net Carrying Value
Balance at December 31, 2010	$	3,292		$	825		$	2,467
Additions		621			342			279
Amortization		(593	)		—			(593	)
Balance at December 31, 2011	$	3,320		$	1,167		$	2,153
Additions		826			(67	)		893
Amortization		(940	)		—			(940	)
Balance at December 31, 2012	$	3,206		$	1,100		$	2,106

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Income Taxes - Schedule of Income Tax Expense (Benefit) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expense Benefit [Line Items]
Current									$ 6,223	$ 12,174	$ 18,969
Deferred									1,038	2,448	(4,537)
Total	$ 2,400	$ 2,623	$ 1,383	$ 855	$ 4,376	$ 4,681	$ 4,051	$ 1,514	$ 7,261	$ 14,622	$ 14,432

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INCOME TAXES

12 Months Ended

Dec. 31, 2012

INCOME TAXES

NOTE 18. INCOME TAXES

Income tax expense (benefit) for the years ended December 31 are comprised of:

(in thousands)	2012		2011		2010
Current	$	6,223	$	12,174	$	18,969
Deferred		1,038		2,448		(4,537	)
Total	$	7,261	$	14,622	$	14,432

The provision for income taxes differs from the amount computed by applying the statutory federal income tax rate to income before income taxes. We ordinarily generate an annual effective tax rate that is less that the statutory rate of 35 percent primarily due to benefits resulting from tax-exempt interest, excludable dividend income, tax-exempt interest on bank owned life insurance and tax benefits associated with LIHTC from certain partnership investments.

The statutory to effective tax rate reconciliation for the years ended December 31 is as follows:

	2012		2011		2010
Statutory tax rate		35.0 %		35.0 %		35.0 %
Low income housing and federal historic tax credits		(10.5)%		(5.5)%		(3.9)%
Tax-exempt interest		(6.7)%		(4.1)%		(4.8)%
Bank owned life insurance		(1.2)%		(1.2)%		(1.3)%
Acquisition costs		0.5 %		—		—
Dividend exclusion		(0.7)%		(0.6)%		(0.7)%
Other		1.1 %		—		0.6 %
Effective Tax Rate		17.5 %		23.6 %		24.9 %

Income taxes applicable to security gains were $1.1 million in 2012, insignificant in 2011 and $0.1 million in 2010.

Significant components of our temporary differences were as follows at December 31:

(in thousands)	2012			2011
Deferred Tax Liabilities:
Net unrealized holding gains on securities available-for-sale	$	(5,586	)	$	(5,208	)
Prepaid pension		(4,721	)		(5,007	)
Deferred loan income		(969	)		(736	)
Purchase accounting adjustments		(935	)		(3,160	)
Depreciation on premises and equipment		(1,963	)		(1,882	)
Other		(690	)		(701	)
Total Deferred Tax liabilities		(14,864	)		(16,694	)
Deferred Tax Assets:
Allowance for loan losses		16,536			15,593
Tax credit carryforwards (expires in 20 years)		1,430			—
Other employee benefits		2,701			2,148
Low income housing partnerships		2,890			2,608
Net adjustment to funded status of pension		12,899			12,804
Impairment of securities		1,375			2,119
Delinquent interest on nonaccrual loans		1,719			1,187
State net operating loss carryforwards		1,498			1,232
Other		3,157			3,559
Gross Deferred Tax Assets		44,205			41,250
Less: Valuation allowance for Pennsylvania net operating loss carryforwards		(1,498	)		(1,232	)
Total Deferred Tax Assets		42,707			40,018
Net Deferred Tax Asset	$	27,843		$	23,324

We establish a valuation allowance when it is more likely than not that we will not be able to realize the benefit of the deferred tax assets. Except for Pennsylvania net operating loss, or NOL, carryforwards, we have determined that a valuation allowance is unnecessary for the deferred tax assets because it is more likely than not that these assets will be realized through future reversals of existing temporary differences and through future taxable income. Periodically, the valuation allowance is reviewed and adjusted based on management’s assessments of realizable deferred tax assets. Gross deferred tax assets were reduced by a valuation allowance related to Pennsylvania income tax NOLs generated by S&T, as utilization of these losses is not likely. These NOL carryforwards total $15.0 million and will expire in the years 2020-2032.

The period change in deferred taxes on our Consolidated Balance Sheet is comprised of the following at December 31:

(in thousands)	2012			2011
Deferred tax changes reflected in other comprehensive gain/loss	$	284		$	(4,186	)
Deferred tax changes resulting from purchase accounting adjustments		(5,843	)		—
Deferred tax changes reflected in federal income tax expense (benefit)		1,038			2,448

Unrecognized Tax Benefits

A reconciliation of the change in Federal and State gross unrecognized tax benefits, or UTB, for the years ended December 31:

(in thousands)	2012			2011			2010
Balance at beginning of year	$	200		$	242		$	286
Prior period tax positions
Increase		—			—			—
Decrease		—			—			(67	)
Current period tax positions		913			(42	)		23
Reductions for statute of limitations expirations		(135	)		—			—
Balance at End of Year	$	978		$	200		$	242
Amount That Would Affect the Effective Tax Rate if Recognized	$	147		$	197		$	239

We classify interest and penalties as an element of tax expense. We monitor changes in tax statutes and regulations to determine if significant changes will occur over the next 12 months. As of December 31, 2012 no significant changes to UTB are projected, however, tax audit examinations are possible.

We recognized $0.2 million related to interest in 2012 and insignificant amounts in both 2011 and 2010 in the Consolidated Statements of Net Income. Additionally, we recognized a $0.5 million liability for an IRS proposed penalty related to our Mainline acquisition. This amount was recognized as an adjustment to purchase accounting and had no impact on our Consolidated Statement of Net Income.

As of December 31, 2012, all income tax returns filed for the tax years 2009 through 2011 remain subject to examination by the IRS. Currently, our income tax return for the 2010 tax year is under examination by the IRS. We do not expect that the results of this examination will have a material effect on our financial condition or results of operations.

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Goodwill and Other Intangible Assets - Summary of Expected Amortization Expense for Finite-Lived Intangibles Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
2013	$ 1,590
2014	1,129
2015	883
2016	645
2017	500
Total	$ 4,747

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SHORT-TERM BORROWINGS (Tables)

12 Months Ended

Dec. 31, 2012

Composition of Short-Term Borrowings and Interest Expense

The following table represents the composition of short-term borrowings at December 31 and interest expense for the years ended December 31:

	2012				2011				2010
(in thousands)	Balance		Interest Expense		Balance		Interest Expense		Balance		Interest Expense
Securities sold under repurchase agreements, retail	$	62,582	$	82	$	30,370	$	53	$	40,653	$	64
Federal Home Loan Bank advances		75,000		123		75,000		2		—		146
Total	$	137,582	$	205	$	105,370	$	55	$	40,653	$	210

Summary of Information Pertaining to REPOs

Information pertaining to REPOs are summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	62,582	$	30,370	$	40,653
Average balance during the year		47,388		41,584		46,489
Average interest rate during the year		0.17%		0.13%		0.14%
Maximum month-end balance during the year	$	62,582	$	42,409	$	52,046
Average interest rate at December 31		0.20%		0.11%		0.07%

Summary of Information Pertaining to Short-Term FHLB Advances

Information pertaining to short-term FHLB advances is summarized in the table below:

(dollars in thousands)	2012		2011		2010
Balance at December 31	$	75,000	$	75,000	$	—
Average balance during the year		50,212		551		32,473
Average interest rate during the year		0.24%		0.32%		0.45%
Maximum month-end balance during the year	$	75,000	$	75,000	$	141,800
Average interest rate at December 31		0.19%		0.18%		—

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Short-Term Borrowings - Summary of Information Pertaining to REPOs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Short-term Debt [Line Items]
Balance at December 31	$ 75,000	$ 75,000	$ 40,653
REPOs [Member] | Term auction facility [Member] | Federal funds purchased [Member]
Short-term Debt [Line Items]
Balance at December 31	62,582	30,370	40,653
Average balance during the year	47,388	41,584	46,489
Average interest rate during the year	0.17%	0.13%	0.14%
Maximum month-end balance during the year	$ 62,582	$ 42,409	$ 52,046
Average interest rate at December 31	0.20%	0.11%	0.07%

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SECURITIES AVAILABLE-FOR-SALE (Tables)

12 Months Ended

Dec. 31, 2012

Amortized Cost and Fair Value of Available-for-Sale Securities

The following tables present the amortized cost and fair value of available-for-sale securities for the periods shown:

	December 31, 2012
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	207,229	$	4,890	$	(53	)	$	212,066
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		1,811		—			57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		3,373		—			60,781
Obligations of states and political subdivisions		107,911		4,908		(52	)		112,767
Debt Securities		428,633		14,982		(105	)		443,510
Marketable equity securities		8,502		1,095		(11	)		9,586
Total	$	437,135	$	16,077	$	(116	)	$	453,096

	December 31, 2011
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Obligations of U.S. government corporations and agencies	$	138,386	$	4,400	$	—		$	142,786
Collateralized mortgage obligations of U.S. government corporations and agencies		63,202		2,193		—			65,395
Mortgage-backed securities of U.S. government corporations and agencies		45,289		3,463		—			48,752
Obligations of states and political subdivisions		85,689		3,128		(12	)		88,805
Debt Securities		332,566		13,184		(12	)		345,738
Marketable equity securities		10,152		2,179		(473	)		11,858
Total	$	342,718	$	15,363	$	(485	)	$	357,596

Fair Value and Age of Gross Unrealized Losses by Investment Category

The following tables present the fair value and the age of gross unrealized losses by investment category for the periods presented:

	December 31, 2012
	Less Than 12 Months					12 Months or More				Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	11,370	$	(53	)	$	—	$	—	$	11,370	$	(53	)
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—		—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—		—		—
Obligations of states and political subdivisions		11,285		(52	)		—		—		11,285		(52	)
Debt Securities		22,655		(105	)		—		—		22,655		(105	)
Marketable equity securities		228		(11	)		—		—		228		(11	)
Total Temporarily Impaired Securities	$	22,883	$	(116	)	$	—	$	—	$	22,883	$	(116	)

	December 31, 2011
	Less Than 12 Months					12 Months or More					Total
(in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Obligations of U.S. government corporations and agencies	$	—	$	—		$	—	$	—		$	—	$	—
Collateralized mortgage obligations of U.S. government corporations and agencies		—		—			—		—			—		—
Mortgage-backed securities of U.S. government corporations and agencies		—		—			—		—			—		—
Obligations of states and political subdivisions		502		(8	)		414		(4	)		916		(12	)
Debt Securities		502		(8	)		414		(4	)		916		(12	)
Marketable equity securities		5,143		(473	)		—		—			5,143		(473	)
Total Temporarily Impaired Securities	$	5,645	$	(481	)	$	414	$	(4	)	$	6,059	$	(485	)

Amortized Cost and Fair Value of Available-for-Sale Securities

The amortized cost and fair value of securities available-for-sale at December 31, 2012, by contractual maturity, are included in the table below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

	December 31, 2012
(in thousands)	Amortized Cost		Fair Value
Due in one year or less	$	38,434	$	38,969
Due after one year through five years		130,690		134,192
Due after five years through ten years		64,822		66,507
Due after ten years		81,194		85,165
		315,140		324,833
Collateralized mortgage obligations of U.S. government corporations and agencies		56,085		57,896
Mortgage-backed securities of U.S. government corporations and agencies		57,408		60,781
Debt Securities		428,633		443,510
Marketable equity securities		8,502		9,586
Total	$	437,135	$	453,096

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Long-Term Borrowings - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Maturities Of Long Term Debt [Line Items]
Total borrowing	$ 108,900,000	$ 106,600,000
Short-term borrowings	75,000,000	75,000,000
Long-term borrowings	33,900,000	31,600,000
Total loans pledged as collateral	2,000,000,000
Maximum eligible borrowing based on qualifying collateral	787,700,000
Maximum borrowing based on additional collateral is pledged	299,700,000
Interest expense on long-term borrowing	1,100,000	1,100,000	1,600,000
Capital lease	$ 300,000
Percentage of equity owned in STBA Capital Trust 1	100.00%

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Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 34,200	$ 47,264	$ 43,480
Other Comprehensive Income, (Loss) Before Tax and Net of Reclassifications into Net Income:
Change in unrealized gains on securities available-for-sale	4,097	6,702	695
Reclassification adjustment for net (gains) losses on securities available-for-sale included in net income	(3,016)	124	(274)
Adjustment to funded status of employee benefit plans	(271)	(18,787)	(606)
Other Comprehensive Income (Loss), Before Tax and Net of Reclassifications into Net Income	810	(11,961)	(185)
Income tax (expense) benefit related to items of other comprehensive income	(284)	4,187	65
Other Comprehensive Income	526	(7,774)	(120)
Comprehensive Income	$ 34,726	$ 39,490	$ 43,360

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Allowance for Loan Losses - Summary of Allowance for Loan Losses and Recorded Investments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 2,231	$ 5,545
Allowance for Loan Losses, Collectively Evaluated for Impairment	44,253	43,296
Total Allowance for Loan Losses	46,484	48,841	51,387
Portfolio Loans, Individually Evaluated for Impairment	82,641	94,036
Portfolio Loans, Collectively Evaluated for Impairment	3,263,981	3,035,723
Total Portfolio Loans	3,346,622	3,129,759
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	1,226	3,487
Allowance for Loan Losses, Collectively Evaluated for Impairment	24,020	26,317
Total Allowance for Loan Losses	25,246	29,804	30,425
Portfolio Loans, Individually Evaluated for Impairment	39,994	50,107
Portfolio Loans, Collectively Evaluated for Impairment	1,412,139	1,365,226
Total Portfolio Loans	1,452,133	1,415,333
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	1,002	1,116
Allowance for Loan Losses, Collectively Evaluated for Impairment	6,757	10,158
Total Allowance for Loan Losses	7,759	11,274	9,777
Portfolio Loans, Individually Evaluated for Impairment	13,283	11,991
Portfolio Loans, Collectively Evaluated for Impairment	778,113	673,762
Total Portfolio Loans	791,396	685,753
Commercial construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	3	942
Allowance for Loan Losses, Collectively Evaluated for Impairment	7,497	2,761
Total Allowance for Loan Losses	7,500	3,703	5,904
Portfolio Loans, Individually Evaluated for Impairment	18,512	25,999
Portfolio Loans, Collectively Evaluated for Impairment	149,631	162,853
Total Portfolio Loans	168,143	188,852
Consumer real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	5,058	3,166
Total Allowance for Loan Losses	5,058	3,166	3,962
Portfolio Loans, Individually Evaluated for Impairment	10,827	5,939
Portfolio Loans, Collectively Evaluated for Impairment	850,248	766,751
Total Portfolio Loans	861,075	772,690
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	921	894
Total Allowance for Loan Losses	921	894	1,319
Portfolio Loans, Individually Evaluated for Impairment	25
Portfolio Loans, Collectively Evaluated for Impairment	73,850	67,131
Total Portfolio Loans	$ 73,875	$ 67,131

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BUSINESS COMBINATIONS

12 Months Ended

Dec. 31, 2012

BUSINESS COMBINATIONS

NOTE 2. BUSINESS COMBINATIONS

During 2012, we completed two acquisitions, Mainline Bancorp, Inc., or Mainline and Gateway Bank of Pennsylvania, or Gateway. Goodwill was calculated as the excess of the consideration exchanged over the net identifiable assets acquired from each acquisition and will not be deductible for tax purposes. Goodwill from both acquisitions was assigned to our Community Banking segment.

On March 9, 2012, we acquired 100 percent of the voting shares of Mainline, located in Ebensburg, Pennsylvania, which was the holding company and sole shareholder of Mainline National Bank. The acquisition expanded our market share and footprint throughout Cambria and Blair Counties of Western Pennsylvania. Mainline shareholders were entitled to elect to receive for each share of Mainline common stock either $69.00 in cash or 3.6316 shares of S&T common stock. We also purchased Mainline’s preferred stock issued under the U.S. Treasury Capital Purchase Program, or CPP, for $4.7 million on March 9, 2012. The preferred stock was purchased and retired as part of the merger transaction. Purchase accounting guidance allows for a reasonable period of time following an acquisition for the acquirer to obtain the information necessary to complete the accounting for a business combination. This period, known as the measurement period, shall not exceed one year from the acquisition date. The measurement period for the Mainline acquisition ends March 9, 2013. Based on new information received about facts and circumstances that existed as of the acquisition date one measurement period adjustment for $0.5 million was recorded relating to a contingent liability for an IRS proposed penalty for tax year 2010. Cash paid to former Mainline shareholders was $8.2 million and the fair value of common shares issued was $14.8 million. As of December 31, 2012, S&T recognized Goodwill of $6.7 million from the Mainline acquisition.

On August 13, 2012, we acquired 100 percent of the voting shares of Gateway, located in McMurray, Pennsylvania. The acquisition expanded our market share and footprint into Washington and Butler counties in Pennsylvania. Gateway shareholders were entitled to receive $3.08 in cash and 0.4657 shares of S&T common stock in exchange for one share of Gateway common stock. As of December 31, 2012, Gateway was operating as a separate wholly-owned subsidiary of S&T. On February 8, 2013, Gateway Bank was merged into S&T Bank, and their two branches are now fully operational branches of S&T Bank. Cash paid to former Gateway shareholders was $5.2 million and the fair value of common shares issued was $13.3 million. We also settled outstanding equity awards for $1.0 million. As of December 31, 2012, S&T recognized Goodwill of $3.8 million from the Gateway acquisition.

The following table summarizes total consideration paid, assets acquired and liabilities assumed as of December 31, 2012 for both the Mainline and Gateway acquisitions:

(in thousands)	Mainline		Gateway		Combined
Consideration Paid
Cash	$	12,904	$	6,238	$	19,142
Common stock		14,786		13,284		28,070
Fair value of previously held equity interest		74		272		346
Fair Value of Total Consideration	$	27,764	$	19,794	$	47,558
Fair Value of Assets Acquired
Cash and cash equivalents	$	17,763	$	20,018	$	37,781
Securities and other investments		73,328		9,564		82,892
Loans		129,501		99,090		228,591
Premises and other equipment		2,280		495		2,775
Core deposit intangible		900		431		1,331
Other assets		12,438		2,665		15,103
Total Assets Acquired	$	236,210	$	132,263	$	368,473
Fair Value of Liabilities Assumed
Deposits		205,989		105,400		311,389
Borrowings		6,997		9,777		16,774
Other liabilities		2,144		1,068		3,212
Total Liabilities Assumed	$	215,130	$	116,245	$	331,375
Total Fair Value of Identifiable Net Assets		21,080		16,018		37,098
Goodwill	$	6,684	$	3,776	$	10,460

Acquired loans were recorded at fair value with no carryover of the related allowance for loan losses. Determining the fair value of the loans involved estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. Loans acquired with evidence of credit quality deterioration were not significant. We acquired $231.9 million of gross loans and recognized a net combined yield and credit mark of $3.3 million.

Direct costs related to the acquisitions were expensed as incurred. As of December 31, 2012, we recognized a combined total of $6.0 million of one-time merger related expenses. For the Gateway acquisition, we recognized $1.5 million of one-time merger related expenses; consisting primarily of legal, professional and other expenses of $0.6 million, $0.6 million in change in control, severance and other employee costs and $0.3 million in data processing contract termination and conversion costs. For the Mainline acquisition, we recognized $4.5 million of one-time merger related expenses; including $1.8 million in change in control, severance and other employee costs, $2.0 million in data processing contract termination and conversion costs and $0.7 million in legal, professional and other expenses.

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CAPITAL PURCHASE PROGRAM (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value of Warrant

The assumptions used to calculate the fair value of the warrant are summarized below:

Assumption	Value
Contractual term		10 years
Exercise price	$	31.53
Estimated fair value of company stock	$	29.14
Expected life		10 years
Risk-free rate over expected life of the warrant		2.36	%
Expected volatility		28.40	%
Expected dividend yield		3.85	%

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Allowances for Loan Losses - Age Analysis of Past Due Loans Segregated By Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	$ 3,266,474	$ 3,053,510
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	21,632	15,061
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	3,558	5,073
Total nonperforming loans	54,958	56,115
Financing Receivable, Recorded Investment, Past Due, Total	80,148	76,249
Total Portfolio Loans	3,346,622	3,129,759
Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	1,418,934	1,374,580
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	2,230	7,657
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	413	1,448
Total nonperforming loans	30,556	31,648
Financing Receivable, Recorded Investment, Past Due, Total	33,199	40,753
Total Portfolio Loans	1,452,133	1,415,333
Commercial and industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	780,315	672,899
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	4,409	3,583
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	237	1,701
Total nonperforming loans	6,435	7,570
Financing Receivable, Recorded Investment, Past Due, Total	11,081	12,854
Total Portfolio Loans	791,396	685,753
Commercial construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	150,823	182,305
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	10,542
Total nonperforming loans	6,778	6,547
Financing Receivable, Recorded Investment, Past Due, Total	17,320	6,547
Total Portfolio Loans	168,143	188,852
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	424,485	405,578
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	2,332	2,199
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	865	691
Total nonperforming loans	3,653	2,936
Financing Receivable, Recorded Investment, Past Due, Total	6,850	5,826
Total Portfolio Loans	431,335	411,404
Residential mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	416,364	349,214
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	1,713	1,240
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	1,948	1,163
Total nonperforming loans	7,278	7,229
Financing Receivable, Recorded Investment, Past Due, Total	10,939	9,632
Total Portfolio Loans	427,303	358,846
Installment and other consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	73,334	66,675
Financing Receivable, Recorded Investment, 30 to 59 Days Past Due	406	382
Financing Receivable, Recorded Investment, 60 to 89 Days Past Due	95	70
Total nonperforming loans	40	4
Financing Receivable, Recorded Investment, Past Due, Total	541	456
Total Portfolio Loans	73,875	67,131
Consumer construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	2,219	2,259
Total nonperforming loans	218	181
Financing Receivable, Recorded Investment, Past Due, Total	218	181
Total Portfolio Loans	$ 2,437	$ 2,440

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Short-Term Borrowings - Summary of Information Pertaining to Short-Term FHLB Advances (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Short-term Debt [Line Items]
Balance at December 31	$ 75,000	$ 75,000	$ 40,653
Federal Home Loan Bank advances [Member]
Short-term Debt [Line Items]
Balance at December 31	75,000	75,000
Average balance during the year	50,212	551	32,473
Average interest rate during the year	0.24%	0.32%	0.45%
Maximum month-end balance during the year	$ 75,000	$ 75,000	$ 141,800
Average interest rate at December 31	0.19%	0.18%

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Fair Value Measurements - Carrying Values and Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Carrying Value [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	$ 337,711	$ 270,526
Securities available-for-sale	453,096	357,596
Loans held for sale	22,499	2,850
Portfolio loans	3,346,622	3,129,759
Federal Home Loan Bank stock, at cost	14,485	18,216
Bank owned life insurance	58,619	56,755
Trading securities held in a Rabbi Trust	2,223	1,949
Mortgage servicing rights	2,106	2,153
LIABILITIES
Deposits	3,638,428	3,335,859
Securities sold under repurchase agreements	62,582	30,370
Short-term borrowings	75,000	75,000
Long-term borrowings	34,101	31,874
Junior subordinated debt securities	90,619	90,619
Carrying Value [Member] | Interest rate swaps [Member]
ASSETS
Derivative financial assets	23,748	23,764
LIABILITIES
Derivative financial liabilities	23,522	23,639
Carrying Value [Member] | Interest rate lock commitments [Member]
ASSETS
Derivative financial assets	467	244
Carrying Value [Member] | Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities	48	95
Fair Value Measurements [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	337,711	270,526
Securities available-for-sale	453,096	357,596
Loans held for sale	22,601	2,958
Portfolio loans	3,347,602	3,120,352
Federal Home Loan Bank stock, at cost	14,485	18,216
Bank owned life insurance	58,619	56,755
Trading securities held in a Rabbi Trust	2,223	1,949
Mortgage servicing rights	2,106	2,153
LIABILITIES
Deposits	3,643,683	3,343,889
Securities sold under repurchase agreements	62,582	30,370
Short-term borrowings	75,000	75,000
Long-term borrowings	36,235	34,171
Junior subordinated debt securities	90,619	90,619
Fair Value Measurements [Member] | Level 1 [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	337,711	270,526
Securities available-for-sale	140	2,855
Loans held for sale
Portfolio loans
Federal Home Loan Bank stock, at cost
Bank owned life insurance
Trading securities held in a Rabbi Trust	2,223	1,949
Mortgage servicing rights
LIABILITIES
Deposits
Securities sold under repurchase agreements
Short-term borrowings
Long-term borrowings
Junior subordinated debt securities
Fair Value Measurements [Member] | Level 2 [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits
Securities available-for-sale	451,826	353,054
Loans held for sale
Portfolio loans
Federal Home Loan Bank stock, at cost
Bank owned life insurance	58,619	56,755
Trading securities held in a Rabbi Trust
Mortgage servicing rights
LIABILITIES
Deposits
Securities sold under repurchase agreements
Short-term borrowings
Long-term borrowings
Junior subordinated debt securities
Fair Value Measurements [Member] | Level 3 [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits
Securities available-for-sale	1,130	1,687
Loans held for sale	22,601	2,958
Portfolio loans	3,347,602	3,120,352
Federal Home Loan Bank stock, at cost	14,485	18,216
Bank owned life insurance
Trading securities held in a Rabbi Trust
Mortgage servicing rights	2,106	2,153
LIABILITIES
Deposits	3,643,683	3,343,889
Securities sold under repurchase agreements	62,582	30,370
Short-term borrowings	75,000	75,000
Long-term borrowings	36,235	34,171
Junior subordinated debt securities	90,619	90,619
Fair Value Measurements [Member] | Interest rate swaps [Member]
ASSETS
Derivative financial assets	23,748	23,764
LIABILITIES
Derivative financial liabilities	23,522	23,639
Fair Value Measurements [Member] | Interest rate swaps [Member] | Level 1 [Member]
ASSETS
Derivative financial assets
LIABILITIES
Derivative financial liabilities
Fair Value Measurements [Member] | Interest rate swaps [Member] | Level 2 [Member]
ASSETS
Derivative financial assets	23,748	23,764
LIABILITIES
Derivative financial liabilities	23,522	23,639
Fair Value Measurements [Member] | Interest rate swaps [Member] | Level 3 [Member]
ASSETS
Derivative financial assets
LIABILITIES
Derivative financial liabilities
Fair Value Measurements [Member] | Interest rate lock commitments [Member]
ASSETS
Derivative financial assets	467	244
Fair Value Measurements [Member] | Interest rate lock commitments [Member] | Level 1 [Member]
ASSETS
Derivative financial assets
Fair Value Measurements [Member] | Interest rate lock commitments [Member] | Level 2 [Member]
ASSETS
Derivative financial assets	467	244
Fair Value Measurements [Member] | Interest rate lock commitments [Member] | Level 3 [Member]
ASSETS
Derivative financial assets
Fair Value Measurements [Member] | Forward sale contracts [Member]
LIABILITIES
Derivative financial liabilities	48	95
Fair Value Measurements [Member] | Forward sale contracts [Member] | Level 1 [Member]
LIABILITIES
Derivative financial liabilities
Fair Value Measurements [Member] | Forward sale contracts [Member] | Level 2 [Member]
LIABILITIES
Derivative financial liabilities	48	95
Fair Value Measurements [Member] | Forward sale contracts [Member] | Level 3 [Member]
LIABILITIES
Derivative financial liabilities

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TAX EFFECTS ON OTHER COMPREHENSIVE INCOME

12 Months Ended

Dec. 31, 2012

TAX EFFECTS ON OTHER COMPREHENSIVE INCOME

NOTE 19. TAX EFFECTS ON OTHER COMPREHENSIVE INCOME

The following tables present the tax effects of the components of other comprehensive income for the years ended December 31:

(in thousands)	Pre-Tax Amount			Tax (Expense) Benefit			Net of Tax Amount
2012
Change in unrealized gains/losses on securities available-for-sale	$	4,097		$	(1,434	)	$	2,663
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(3,016	)		1,055			(1,961	)
Adjustment to funded status of employee benefit plans		(271	)		95			(176	)
Other Comprehensive Income	$	810		$	(284	)	$	526
2011
Change in unrealized gains/losses on securities available-for-sale	$	6,702		$	(2,346	)	$	4,356
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		124			(43	)		81
Adjustment to funded status of employee benefit plans		(18,787	)		6,576			(12,211	)
Other Comprehensive Income	$	(11,961	)	$	4,187		$	(7,774	)
2010
Change in unrealized gains/losses on securities available-for-sale	$	695		$	(243	)	$	452
Reclassification adjustment for net gains/losses on securities available-for-sale included in net income		(274	)		96			(178	)
Adjustment to funded status of employee benefit plans		(606	)		212			(394	)
Other Comprehensive Income	$	(185	)	$	65		$	(120	)

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Income Taxes - Schedule of Statutory to Effective Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Line Items]
Statutory tax rate	35.00%	35.00%	35.00%
Low income housing and federal historic tax credits	(10.50%)	(5.50%)	(3.90%)
Tax-exempt interest	(6.70%)	(4.10%)	(4.80%)
Bank owned life insurance	(1.20%)	(1.20%)	(1.30%)
Acquisition costs	0.50%
Dividend exclusion	(0.70%)	(0.60%)	(0.70%)
Other	1.10%		0.60%
Effective Tax Rate	17.50%	23.60%	24.90%

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Employee Benefits - Pension Plan Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	$ 81,088
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	8,585
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	23,643
Equity index mutual funds domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,934
Equity index mutual funds international [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	4,218
Domestic individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	39,631
International individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,802
Equity partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,275
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	69,796
Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	22,211
Level 1 [Member] | Equity index mutual funds domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,934
Level 1 [Member] | Equity index mutual funds international [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	4,218
Level 1 [Member] | Domestic individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	39,631
Level 1 [Member] | International individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,802
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	8,585
Level 2 [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	8,585
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	2,707
Level 3 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,432
Level 3 [Member] | Equity partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,275
Fair Value Measurements, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		72,626
Total Assets at Fair Value	479,534	383,553
Fair Value Measurements, Recurring [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		7,440
Fair Value Measurements, Recurring [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		22,872
Fair Value Measurements, Recurring [Member] | Equity index mutual funds domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,580
Fair Value Measurements, Recurring [Member] | Equity index mutual funds international [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		3,437
Fair Value Measurements, Recurring [Member] | Domestic individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		34,600
Fair Value Measurements, Recurring [Member] | International individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,437
Fair Value Measurements, Recurring [Member] | Equity partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,260
Fair Value Measurements, Recurring [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		62,593
Total Assets at Fair Value	2,363	4,804
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		21,539
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | Equity index mutual funds domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,580
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | Equity index mutual funds international [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		3,437
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | Domestic individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		34,600
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | International individual equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,437
Fair Value Measurements, Recurring [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		7,440
Total Assets at Fair Value	476,041	377,062
Fair Value Measurements, Recurring [Member] | Level 2 [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		7,440
Fair Value Measurements, Recurring [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		2,593
Total Assets at Fair Value	1,130	1,687
Fair Value Measurements, Recurring [Member] | Level 3 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		1,333
Fair Value Measurements, Recurring [Member] | Level 3 [Member] | Equity partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value		$ 1,260

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Employee Benefits - Components of Net Periodic Pension Cost and Other Changes In Plan Assets and Benefit (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Components of Net Periodic Pension Cost
Service cost benefits earned during the period	$ 2,788	$ 2,371	$ 2,245
Interest cost on projected benefit obligation	4,358	4,162	4,017
Expected return on plan assets	(5,564)	(5,378)	(4,882)
Amortization of prior service credit	(137)	(7)	(7)
Recognized net actuarial loss	2,474	773	824
Net Periodic Pension Cost	3,919	1,921	2,197
Other Changes in Plan Assets and Benefit Obligation Recognized in Other Comprehensive Loss
Net actuarial loss (gain)	2,477	20,422	1,261
Recognized net actuarial loss	(2,474)	(773)	(824)
Prior service credit	0	(1,513)
Recognized prior service credit	137	7	7
Total (Before Tax Effects)	140	18,143	444
Total Recognized in Net Benefit Cost and Other Comprehensive Gain/Loss (Before Tax Effects)	$ 4,059	$ 20,064	$ 2,641

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Securities Available-For-Sale - Fair Value and Age of Gross Unrealized Losses by Investment Category (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Less Than 12 Months, Fair Value	$ 22,883	$ 5,645
Available-for-sale Securities, Less Than 12 Months, Unrealized Losses	(116)	(481)
Available-for-sale Securities, 12 Months or More, Fair Value		414
Available-for-sale Securities, 12 Months or More, Unrealized Losses		(4)
Available-for-sale Securities, Fair Value, Total	22,883	6,059
Available-for-sale Securities, Unrealized Losses, Total	(116)	(485)
Obligations of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Less Than 12 Months, Fair Value	11,370
Available-for-sale Securities, Less Than 12 Months, Unrealized Losses	(53)
Available-for-sale Securities, Fair Value, Total	11,370
Available-for-sale Securities, Unrealized Losses, Total	(53)
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Less Than 12 Months, Fair Value	11,285	502
Available-for-sale Securities, Less Than 12 Months, Unrealized Losses	(52)	(8)
Available-for-sale Securities, 12 Months or More, Fair Value		414
Available-for-sale Securities, 12 Months or More, Unrealized Losses		(4)
Available-for-sale Securities, Fair Value, Total	11,285	916
Available-for-sale Securities, Unrealized Losses, Total	(52)	(12)
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Less Than 12 Months, Fair Value	22,655	502
Available-for-sale Securities, Less Than 12 Months, Unrealized Losses	(105)	(8)
Available-for-sale Securities, 12 Months or More, Fair Value		414
Available-for-sale Securities, 12 Months or More, Unrealized Losses		(4)
Available-for-sale Securities, Fair Value, Total	22,655	916
Available-for-sale Securities, Unrealized Losses, Total	(105)	(12)
Marketable equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Less Than 12 Months, Fair Value	228	5,143
Available-for-sale Securities, Less Than 12 Months, Unrealized Losses	(11)	(473)
Available-for-sale Securities, Fair Value, Total	228	5,143
Available-for-sale Securities, Unrealized Losses, Total	$ (11)	$ (473)

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BUSINESS COMBINATIONS (Tables)

12 Months Ended

Dec. 31, 2012

Total Consideration, Assets Acquired and Liabilities Assumed

The following table summarizes total consideration paid, assets acquired and liabilities assumed as of December 31, 2012 for both the Mainline and Gateway acquisitions:

(in thousands)	Mainline		Gateway		Combined
Consideration Paid
Cash	$	12,904	$	6,238	$	19,142
Common stock		14,786		13,284		28,070
Fair value of previously held equity interest		74		272		346
Fair Value of Total Consideration	$	27,764	$	19,794	$	47,558
Fair Value of Assets Acquired
Cash and cash equivalents	$	17,763	$	20,018	$	37,781
Securities and other investments		73,328		9,564		82,892
Loans		129,501		99,090		228,591
Premises and other equipment		2,280		495		2,775
Core deposit intangible		900		431		1,331
Other assets		12,438		2,665		15,103
Total Assets Acquired	$	236,210	$	132,263	$	368,473
Fair Value of Liabilities Assumed
Deposits		205,989		105,400		311,389
Borrowings		6,997		9,777		16,774
Other liabilities		2,144		1,068		3,212
Total Liabilities Assumed	$	215,130	$	116,245	$	331,375
Total Fair Value of Identifiable Net Assets		21,080		16,018		37,098
Goodwill	$	6,684	$	3,776	$	10,460

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DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

12 Months Ended

Dec. 31, 2012

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

NOTE 12. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

In the normal course of business, we use derivative instruments and hedging activities as discussed under Derivative Financial Instruments in Note 1 Summary of Significant Accounting Policies.

The following table indicates the amount representing the value of derivative assets and derivative liabilities at December 31:

	Derivatives (included in Other Assets)				Derivatives (included in Other Liabilities)
(in thousands)	2012		2011		2012		2011
Derivatives not Designated as Hedging Instruments
Interest Rate Swap Contracts—Commercial Loans
Fair value	$	23,748	$	23,764	$	23,522	$	23,639
Notional amount		227,532		189,868		227,532		189,868
Collateral posted		—		—		19,595		20,273
Interest Rate Lock Commitments—Mortgage Loans
Fair value		467		244		—		—
Notional amount		14,287		7,093		—		—
Forward Sale Contracts—Mortgage Loans
Fair value		—		—		48		95
Notional amount		—		—		14,100		7,729

The following table indicates the gain or loss recognized in income on derivatives for the year ended December 31:

(in thousands)	2012		2011			2010
Derivatives not Designated as Hedging Instruments
Interest rate swap contracts—commercial loans	$	101	$	(38	)	$	96
Interest rate lock commitments—mortgage loans		223		27			62
Forward sale contracts—mortgage loans		47		(507	)		220
Total Derivative Gain (Loss)	$	371	$	(518	)	$	378

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Deposits - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deposits [Line Items]
Aggregate value of certificate of deposit over $100,000	$ 368.1	$ 357.7