Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of presentation — The accompanying unaudited interim financial statements of WesBanco, Inc. and its consolidated subsidiaries (“WesBanco”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2018. WesBanco’s interim financial statements have been prepared following the significant accounting policies disclosed in Note 1 of the Notes to the Consolidated Financial Statements of its 2018 Annual Report on Form 10-K filed with the Securities and Exchange Commission. In the opinion of management, the accompanying interim financial information reflects all adjustments, including normal recurring adjustments, necessary to present fairly WesBanco’s financial position and results of operations for each of the interim periods presented. Certain prior period amounts have been reclassified to conform to the current period presentation. Such reclassifications had no impact on WesBanco’s net income and stockholders’ equity. Results of operations for interim periods are not necessarily indicative of the results of operations that may be expected for a full year. Recent accounting pronouncements — In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” This ASU specifically aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software and hosting arrangements that include an internal-use software license. The ASU does not affect the accounting for the service element of a hosting arrangement that is a service contract. The guidance is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. WesBanco is currently assessing the impact of ASU 2018-15 on WesBanco’s Consolidated Financial Statements. In August 2018, the FASB issued ASU 2018-14, “Compensation—Retirement Benefits—Defined Benefit Plans—General (Topic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans.” This ASU modifies ASC 715-20 to improve disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The guidance is effective for fiscal years ending after December 15, 2020. Early adoption is permitted. WesBanco is currently assessing the impact of ASU 2018-14 on WesBanco’s Consolidated Financial Statements. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement – Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement.” This ASU modifies the disclosure objective paragraphs of ASC 820 to eliminate (1) “at a minimum” from the phrase “an entity shall disclose at a minimum” and (2) other similar “open ended” disclosure requirements to promote the appropriate exercise of discretion of entities. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in an interim period. WesBanco is currently assessing the impact of ASU 2018-13 on WesBanco’s Consolidated Financial Statements. In September 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326)”, which will require entities to use a new forward-looking “expected loss” model on trade and other receivables, held-to-maturity debt securities, loans and other instruments that generally will result in the earlier recognition of allowances for credit losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses in a manner similar to what they do today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. Entities will have to disclose significantly more information, including information they use to track credit quality by year of origination for most financing receivables. Public business entities must apply the new requirements for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, which for WesBanco will be effective for the fiscal year beginning January 1, 2020. Early adoption is permitted for fiscal years beginning after December 15, 2018. WesBanco formed a cross-functional team to oversee the implementation of this ASU, and has completed an initial data gap assessment, finalized the loan segmentation procedures, and is currently evaluating the various forecasting and modeling assumptions, including qualitative factors, that will be used to estimate the initial current expected credit loss allowance. Substantial progress has been made on the identification and staging of data, development of models, refinement of economic forecasting processes, and documentation of accounting policy decisions. In conjunction with this implementation, WesBanco is reviewing business processes and evaluating potential changes to the control environment. Acquired loans or pools of loans that have experienced more-than-insignificant credit deterioration are deemed to be purchased credit deteriorated (“PCD”) loans, and are grossed-up on day 1 by the initial credit estimate through goodwill as opposed to the provision for credit losses. Acquired loans deemed not to be PCD loans will be adjusted to fair value through goodwill, with an allowance and corresponding provision for credit losses recorded in the first reporting period after acquisition through current period earnings, while the loan mark will accrete through interest income over the life of such loans. At acquisition, WesBanco will consider several factors as indicators that an acquired loan or pool of loans has experienced more-than-insignificant credit deterioration. These factors may include loans 30 days or more past due, loans with an internal risk grade of below average or lower, loans classified as non-accrual by the acquired institution, materiality of the credit and loans that have been previously modified in a troubled debt restructuring. Upon adoption of this standard, acquired loans from prior acquisitions that meet the guidelines under ASC 310-30 will be classified as PCD loans. The accretable portion of the loan mark as of adoption date will continue to accrete into interest income. However, the non-accretable portion of the loan mark will be added to the allowance upon adoption; while any reversals of such mark will flow through the allowance in future periods. The loan mark on ASC 310-20 loans (“the good book”) from acquisitions will continue to accrete through interest income over the life of such loans. WesBanco will perform parallel runs of the new methodology throughout the remainder of 2019 prior to adoption of the ASU. WesBanco currently anticipates that an increase to the allowance for credit losses may be recognized upon adoption to provide for expected credit losses over the estimated life of loan and investment receivables. The magnitude of the increase will depend on economic conditions and trends in the loan and securities portfolios at the time of adoption. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”, which requires entities to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The principal difference from previous guidance is that the lease assets and lease liabilities arising from operating leases were not previously recognized in the balance sheet. Public business entities must apply the new requirements for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. In January 2018, the FASB issued ASU 2018-01, which allows entities the option to apply the provisions of the new lease guidance at the effective date without adjusting the comparative periods presented. In July 2018, the FASB issued ASU 2018-10, which provides narrow-scope improvements to the lease standard and ASU 2018-11, which allows entities to choose an additional transition method, under which an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under this transitional method, the entity shall recognize and measure the leases that exist at the adoption date and the prior comparative periods are not adjusted. WesBanco adopted this ASU as of January 1, 2019 using the transitional method. In addition, WesBanco utilized certain practical expedients including the following - retained the classifications of existing leases, no re-assessment to determine if existing leases have initial direct costs and utilized hindsight when determining the lease term and assessment of impairment in existing leases. WesBanco capitalized $20 million for right-of-use assets and lease liabilities, net of existing straight-line lease liabilities and unfavorable acquired lease liabilities. See additional disclosures in Note 6, “Leases”. In August 2017, the FASB issued ASU 2017-12, “Targeted Improvements to Accounting for Hedging Activities.” The new guidance makes more financial and nonfinancial hedging strategies eligible for hedge accounting. It also amended the presentation and disclosure requirements and changed how companies assess effectiveness. It was intended to more closely align hedge accounting with companies’ risk management strategies, simplify the application of hedge accounting, and increase transparency as to the scope and results of hedging programs. The guidance was effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. Upon adoption, WesBanco reclassified $67.3 million of callable held-to-maturity municipal debt securities to available-for-sale debt securities. In October 2018, the FASB issued ASU 2018-16, “Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes.” This ASU modifies ASC 815 for eligible benchmark interest rates. Due to concerns about the sustainability of the London Interbank Offered Rate (LIBOR), the Federal Reserve initiated an effort to introduce an alternative reference rate in the United States. The Overnight Index Swap (OIS) rate, which is based on SOFR is permitted as a U.S. benchmark interest rate for hedge accounting purposes. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. The adoption of this pronouncement did not have a material impact on WesBanco’s Consolidated Financial Statements.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2019

Summary of Significant Accounting Policies

NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of presentation — The accompanying unaudited interim financial statements of WesBanco, Inc. and its consolidated subsidiaries (“WesBanco”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2018.

WesBanco’s interim financial statements have been prepared following the significant accounting policies disclosed in Note 1 of the Notes to the Consolidated Financial Statements of its 2018 Annual Report on Form 10-K filed with the Securities and Exchange Commission. In the opinion of management, the accompanying interim financial information reflects all adjustments, including normal recurring adjustments, necessary to present fairly WesBanco’s financial position and results of operations for each of the interim periods presented. Certain prior period amounts have been reclassified to conform to the current period presentation. Such reclassifications had no impact on WesBanco’s net income and stockholders’ equity. Results of operations for interim periods are not necessarily indicative of the results of operations that may be expected for a full year.

Recent accounting pronouncements — In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” This ASU specifically aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software and hosting arrangements that include an internal-use software license. The ASU does not affect the accounting for the service element of a hosting arrangement that is a service contract. The guidance is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. WesBanco is currently assessing the impact of ASU 2018-15 on WesBanco’s Consolidated Financial Statements.

In August 2018, the FASB issued ASU 2018-14, “Compensation—Retirement Benefits—Defined Benefit Plans—General (Topic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans.” This ASU modifies ASC 715-20 to improve disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The guidance is effective for fiscal years ending after December 15, 2020. Early adoption is permitted. WesBanco is currently assessing the impact of ASU 2018-14 on WesBanco’s Consolidated Financial Statements.

In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement – Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement.” This ASU modifies the disclosure objective paragraphs of ASC 820 to eliminate (1) “at a minimum” from the phrase “an entity shall disclose at a minimum” and (2) other similar “open ended” disclosure requirements to promote the appropriate exercise of discretion of entities. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in an interim period. WesBanco is currently assessing the impact of ASU 2018-13 on WesBanco’s Consolidated Financial Statements.

In September 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326)”, which will require entities to use a new forward-looking “expected loss” model on trade and other receivables, held-to-maturity debt securities, loans and other instruments that generally will result in the earlier recognition of allowances for credit losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses in a manner similar to what they do today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. Entities will have to disclose significantly more information, including information they use to track credit quality by year of origination for most financing receivables. Public business entities must apply the new requirements for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, which for WesBanco will be effective for the fiscal year beginning January 1, 2020. Early adoption is permitted for fiscal years beginning after December 15, 2018. WesBanco formed a cross-functional team to oversee the implementation of this ASU, and has completed an initial data gap assessment, finalized the loan segmentation procedures, and is currently evaluating the various forecasting and modeling assumptions, including qualitative factors, that will be used to estimate the initial current expected credit loss allowance. Substantial progress has been made on the identification and staging of data, development of models, refinement of economic forecasting processes, and documentation of accounting policy decisions. In conjunction with this implementation, WesBanco is reviewing business processes and evaluating potential changes to the control environment. Acquired loans or pools of loans that have experienced more-than-insignificant credit deterioration are deemed to be purchased credit deteriorated (“PCD”) loans, and are grossed-up on day 1 by the initial credit estimate through goodwill as opposed to the provision for credit losses. Acquired loans deemed not to be PCD loans will be adjusted to fair value through goodwill, with an allowance and corresponding provision for credit losses recorded in the first reporting period after acquisition through current period earnings, while the loan mark will accrete through interest income over the life of such loans. At acquisition, WesBanco will consider several factors as indicators that an acquired loan or pool of loans has experienced more-than-insignificant credit deterioration. These factors may include loans 30 days or more past due, loans with an internal risk grade of below average or lower, loans classified as non-accrual by the acquired institution, materiality of the credit and loans that have been previously modified in a troubled debt restructuring. Upon adoption of this standard, acquired loans from prior acquisitions that meet the guidelines under ASC 310-30 will be classified as PCD loans. The accretable portion of the loan mark as of adoption date will continue to accrete into interest income. However, the non-accretable portion of the loan mark will be added to the allowance upon adoption; while any reversals of such mark will flow through the allowance in future periods. The loan mark on ASC 310-20 loans (“the good book”) from acquisitions will continue to accrete through interest income over the life of such loans. WesBanco will perform parallel runs of the new methodology throughout the remainder of 2019 prior to adoption of the ASU. WesBanco currently anticipates that an increase to the allowance for credit losses may be recognized upon adoption to provide for expected credit losses over the estimated life of loan and investment receivables. The magnitude of the increase will depend on economic conditions and trends in the loan and securities portfolios at the time of adoption.

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”, which requires entities to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The principal difference from previous guidance is that the lease assets and lease liabilities arising from operating leases were not previously recognized in the balance sheet. Public business entities must apply the new requirements for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. In January 2018, the FASB issued ASU 2018-01, which allows entities the option to apply the provisions of the new lease guidance at the effective date without adjusting the comparative periods presented. In July 2018, the FASB issued ASU 2018-10, which provides narrow-scope improvements to the lease standard and ASU 2018-11, which allows entities to choose an additional transition method, under which an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under this transitional method, the entity shall recognize and measure the leases that exist at the adoption date and the prior comparative periods are not adjusted. WesBanco adopted this ASU as of January 1, 2019 using the transitional method. In addition, WesBanco utilized certain practical expedients including the following - retained the classifications of existing leases, no re-assessment to determine if existing leases have initial direct costs and utilized hindsight when determining the lease term and assessment of impairment in existing leases. WesBanco capitalized $20 million for right-of-use assets and lease liabilities, net of existing straight-line lease liabilities and unfavorable acquired lease liabilities. See additional disclosures in Note 6, “Leases”.

In August 2017, the FASB issued ASU 2017-12, “Targeted Improvements to Accounting for Hedging Activities.” The new guidance makes more financial and nonfinancial hedging strategies eligible for hedge accounting. It also amended the presentation and disclosure requirements and changed how companies assess effectiveness. It was intended to more closely align hedge accounting with companies’ risk management strategies, simplify the application of hedge accounting, and increase transparency as to the scope and results of hedging programs. The guidance was effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. Upon adoption, WesBanco reclassified $67.3 million of callable held-to-maturity municipal debt securities to available-for-sale debt securities.

In October 2018, the FASB issued ASU 2018-16, “Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes.” This ASU modifies ASC 815 for eligible benchmark interest rates. Due to concerns about the sustainability of the London Interbank Offered Rate (LIBOR), the Federal Reserve initiated an effort to introduce an alternative reference rate in the United States. The Overnight Index Swap (OIS) rate, which is based on SOFR is permitted as a U.S. benchmark interest rate for hedge accounting purposes. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. For WesBanco, this update was effective for the fiscal year beginning January 1, 2019. The adoption of this pronouncement did not have a material impact on WesBanco’s Consolidated Financial Statements.