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Securities - Additional Information (Detail) (USD $)
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3 Months Ended | 12 Months Ended | ||
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Mar. 31, 2015
Holdings
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Mar. 31, 2014
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Dec. 31, 2014
Holdings
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Dec. 31, 2013
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| Amortized Cost and Fair Value Debt Securities [Abstract] | ||||
| Maximum percentage of equity of one issuer | 10.00%wsbc_MaximumPercentageOfEquityOfOneIssuer | |||
| Number of holdings greater than specified percentage of equity | 0wsbc_NumberOfHoldingsGreaterThanSpecifiedPercentageOfEquity | 0wsbc_NumberOfHoldingsGreaterThanSpecifiedPercentageOfEquity | ||
| Securities with aggregate fair values | $ 1,100,000,000us-gaap_PledgedAssetsNotSeparatelyReportedOtherFinancialInstruments | $ 706,500,000us-gaap_PledgedAssetsNotSeparatelyReportedOtherFinancialInstruments | ||
| Proceeds from sale of available-for-sale securities | 560,676,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities | 3,155,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities | 3,200,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities | |
| Net unrealized gains (losses) on available-for-sale securities included in AOCI | 7,685,000us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax | (3,002,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax | 2,892,000us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax | (6,126,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax |
| Impaired loss relating to securities | 0wsbc_ImpairedLossRelatingToSecurities | |||
| Federal home loan bank stock, Total | $ 20,900,000us-gaap_FederalHomeLoanBankStock | $ 11,600,000us-gaap_FederalHomeLoanBankStock | ||
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- Definition
Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The carrying amount, as of the date of the latest financial statement presented, of other assets which are owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Impaired loss relating to securities. No definition available.
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- Definition
The maximum percentage of shareholders' equity of any one issuer other than the U.S. government and its agencies. No definition available.
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- Definition
Number of holdings greater than specified percentage of equity. No definition available.
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