Loans and the Allowance for Credit Losses - Additional Information (Detail)			3 Months Ended	12 Months Ended
	Jan. 01, 2020 USD ($)	Nov. 22, 2019 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) Contract Loan	Dec. 31, 2020 USD ($) Contract	Dec. 31, 2019 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Net deferred fee loan income (costs)				$ (3,300,000)	$ 6,200,000
Un-accreted discount on purchased loans from acquisitions				25,900,000	39,400,000
Recognition on retained earnings				$ 62,477,000	101,960,000	$ 11,065,000
Percentage of national unemployment projection				4.70%
Expected average percentage of national unemployment in future				4.40%
Calculation period of reversion				1 year
Reserve on accrued interest related to CARES Act				$ 100,000
Accrued interest receivable for loans				46,800,000
Accrued interest receivable for loans related to CARES Act				22,000,000.0
Aggregate amount of residential real estate, home equity and consumer loans classified as substandard				30,200,000	27,700,000
Internally assigned loan grades to residential real estate, home equity and consumer loans				7,400,000	4,100,000
Unfunded commercial loan commitments				$ 21,700,000	$ 28,700,000
Number of restructured contracts greater than $1 million | Contract				0	0
Threshold for TDR				$ 1,000,000.0	$ 1,000,000.0
Accruing and non accrual TDR permitted interest-only payment period				6 months
Unfunded commitments to debtors for nonperforming loans				$ 100,000	900,000
Number of loans modified | Loan				3,553
Total loan amount modified CARES Act				$ 2,200,000,000
Loan amount remaining in deferral period CARES Act				$ 51,800,000
Description of deferred payments to customers impacted by the COVID-19 pandemic				Wesbanco originally offered three to six months of deferred payments to commercial and retail customers impacted by the COVID-19 pandemic depending on the type of loan and the industry for commercial loans. In the fourth quarter of 2020, Wesbanco offered up to an additional twelve months of deferred payments to certain commercial loan customers, predominantly in the hospitality industry, based on specific criteria related to the borrower, the underlying property and the potential for guarantors / co-borrowers.
Other real estate owned					504,000
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recognition on retained earnings				$ 2,708,000	9,065,000	1,400,000
Other real estate owned				0	100,000
Foreclosure proceedings in process on residential real estate loans				4,000,000.0	1,800,000
Foreclosure proceedings temporarily suspended on real estate loans				800,000	2,300,000
ASU 2016-13 [Member]
Financing Receivable, Recorded Investment [Line Items]
Adjustment for loan credit losses	$ 6,700,000
Revision of Prior Period, Accounting Standards Update, Adjustment [Member] | ASU 2016-13 [Member]
Financing Receivable, Recorded Investment [Line Items]
Recognition on retained earnings	41,400,000				41,442,000
Revision of Prior Period, Accounting Standards Update, Adjustment [Member] | ASU 2016-13 [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recognition on retained earnings					5,630,000
Old Line Bancshares, Inc. [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income		$ 2,570,000,000.0
Preliminary fair value of acquired loans		2,514,061,000
Book Value of 310-20 loans		2,544,400,000
Fair market value adjustment of acquired retained loans		28,900,000
Loans acquired with deteriorated credit quality		25,600,000		13,600,000
Loans acquired with deteriorated credit quality, fair value		18,700,000
Loans acquired with deteriorated credit quality outstanding customer balance				13,800,000
Acquired impaired loans allowances for credit losses	$ 6,100,000			3,700,000
Acquired loans, sold book value			$ 56,600,000
Acquired loans, sold			$ 36,400,000
Old Line Bancshares, Inc. [Member] | Cost Recovery Method [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans acquired with deteriorated credit quality, fair value		$ 4,000,000.0
Old Line Bancshares, Inc. [Member] | Nonperforming Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans acquired with deteriorated credit quality outstanding customer balance				1,100,000
SBA Payroll Protection Program [Member]
Financing Receivable, Recorded Investment [Line Items]
Net deferred fee loan income (costs)				6,100,000	13,800,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recognition on retained earnings				10,749,000	3,918,000	$ 2,714,000
Commercial and Industrial [Member] | Maximum [Member]
Financing Receivable, Recorded Investment [Line Items]
Annual sales of borrowers				$ 100,000,000
Commercial and Industrial [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member] | ASU 2016-13 [Member]
Financing Receivable, Recorded Investment [Line Items]
Recognition on retained earnings					$ 22,357,000