Regulatory Matters - Summary of Risk-Based Capital Amounts and Ratios (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Percentage of risk-weighted assets in bank holding companies in Tier 1	4.00%
Tier 1 capital to risk-weighted assets, minimum value	6.00%
Total capital to risk-weighted assets, minimum value	8.00%
Common equity tier 1, minimum value	4.50%
Tier 1 leverage, well capitalized	5.00%
Tier 1 capital to risk-weighted assets, well capitalized	8.00%
Total capital to risk-weighted assets, well capitalized	10.00%
Common equity tier 1, well capitalized	6.50%
Tier 1 leverage, amount	$ 1,617,413,000	$ 1,441,738,000
Tier 1 capital to risk-weighted assets, amount	1,617,413,000	1,441,738,000
Total capital to risk-weighted assets, amount	1,931,414,000	1,691,764,000
Common equity tier 1, amount	$ 1,472,929,000	$ 1,441,738,000
Tier 1 leverage, ratio	10.51%	11.30%
Tier 1 capital to risk-weighted assets, ratio	14.72%	12.89%
Total capital to risk-weighted assets, ratio	17.58%	15.12%
Common equity tier 1, ratio	13.40%	12.89%
Wesbanco Bank, Inc [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Percentage of risk-weighted assets in bank holding companies in Tier 1	4.00%
Tier 1 capital to risk-weighted assets, minimum value	6.00%
Total capital to risk-weighted assets, minimum value	8.00%
Common equity tier 1, minimum value	4.50%
Tier 1 leverage, well capitalized	5.00%
Tier 1 capital to risk-weighted assets, well capitalized	8.00%
Total capital to risk-weighted assets, well capitalized	10.00%
Common equity tier 1, well capitalized	6.50%
Tier 1 leverage, amount	$ 1,536,609,000	$ 1,419,968,000
Tier 1 capital to risk-weighted assets, amount	1,536,609,000	1,419,968,000
Total capital to risk-weighted assets, amount	1,685,610,000	1,498,494,000
Common equity tier 1, amount	$ 1,536,609,000	$ 1,419,968,000
Tier 1 leverage, ratio	10.00%	11.12%
Tier 1 capital to risk-weighted assets, ratio	14.04%	12.74%
Total capital to risk-weighted assets, ratio	15.40%	13.44%
Common equity tier 1, ratio	14.04%	12.74%
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, amount	$ 615,814,000	$ 510,306,000
Tier 1 capital to risk-weighted assets, amount	659,372,000	671,314,000
Total capital to risk-weighted assets, amount	879,162,000	895,086,000
Common equity tier 1, amount	494,529,000	503,486,000
Minimum [Member] | Wesbanco Bank, Inc [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, amount	614,792,000	510,591,000
Tier 1 capital to risk-weighted assets, amount	656,732,000	668,951,000
Total capital to risk-weighted assets, amount	875,643,000	891,935,000
Common equity tier 1, amount	$ 492,549,000	$ 501,713,000