FHLB and Other Short-Term Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank Advances By Branch Of FHLB Bank And Other Borrowings [Line Items]
Borrowings	$ 549,003,000	$ 1,415,615,000
Weighted-average interest rate	2.05%	2.27%
FHLB stock owned by WesBanco pledged as collateral on these advances	$ 34,000,000.0	$ 66,800,000
Remaining maximum borrowing capacity	4,100,000,000	3,200,000,000
Other short-term borrowings	241,950,000	282,362,000
Securities sold under agreements to repurchase	242,000,000.0	274,900,000
Federal funds purchased	$ 0	$ 7,500,000
Federal funds purchased interest rate		1.55%
Securities Sold under Agreements to Repurchase [Member]
Federal Home Loan Bank Advances By Branch Of FHLB Bank And Other Borrowings [Line Items]
Securities sold under agreements to repurchase, weighted average interest rate	0.60%	2.10%
Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Federal Home Loan Bank Advances By Branch Of FHLB Bank And Other Borrowings [Line Items]
Revolving line of credit, maximum aggregate unsecured borrowings	$ 30,000,000.0
Revolving line of credit, outstanding balance	$ 0	$ 0
Initiation date of revolving credit facility	Aug. 31, 2020

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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The calculated weighted average interest rate for Federal Home Loan Bank advances outstanding as of the Balance Sheet date.

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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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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).

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Date the credit facility first became available, in CCYY-MM-DD format.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowings classified as other, maturing within one year or the normal operating cycle, if longer.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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Federal Home Loan Bank advances by branch of FHLB bank and other borrowings.

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