Regulatory Matters - Summary of Risk-Based Capital Amounts and Ratios (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Percentage of risk-weighted assets in bank holding companies in Tier 1	4.00%
Common equity tier 1, minimum value	4.50%
Tier 1 capital to risk-weighted assets, minimum value	6.00%
Total capital to risk-weighted assets, minimum value	8.00%
Tier 1 leverage, well capitalized	5.00%
Common equity tier 1, well capitalized	6.50%
Tier 1 capital to risk-weighted assets, well capitalized	8.00%
Total capital to risk-weighted assets, well capitalized	10.00%
Tier 1 leverage, amount	$ 1,441,738,000	$ 1,258,605,000
Common equity tier 1, amount	1,441,738,000	1,096,105,000
Tier 1 capital to risk-weighted assets, amount	1,441,738,000	1,258,605,000
Total capital to risk-weighted assets, amount	$ 1,691,764,000	$ 1,333,503,000
Tier 1 leverage, ratio	11.30%	10.74%
Common equity tier 1, ratio	12.89%	13.14%
Tier 1 capital to risk-weighted assets, ratio	12.89%	15.09%
Total capital to risk-weighted assets, ratio	15.12%	15.99%
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%
Common equity tier 1, minimum value	4.50%
Tier 1 capital to risk-weighted assets, minimum value	6.00%
Total capital to risk-weighted assets, minimum value	8.00%
Tier 1 leverage, well capitalized	5.00%
Common equity tier 1, well capitalized	6.50%
Tier 1 capital to risk-weighted assets, well capitalized	8.00%
Total capital to risk-weighted assets, well capitalized	10.00%
Tier 1 leverage, amount	$ 1,419,968,000	$ 1,108,600,000
Common equity tier 1, amount	1,419,968,000	1,108,600,000
Tier 1 capital to risk-weighted assets, amount	1,419,968,000	1,108,600,000
Total capital to risk-weighted assets, amount	$ 1,498,494,000	$ 1,183,498,000
Tier 1 leverage, ratio	11.12%	9.48%
Common equity tier 1, ratio	12.74%	13.30%
Tier 1 capital to risk-weighted assets, ratio	12.74%	13.30%
Total capital to risk-weighted assets, ratio	13.44%	14.20%
Minimum [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 leverage, amount	$ 510,306,000	$ 468,824,000
Common equity tier 1, amount	503,486,000	375,254,000
Tier 1 capital to risk-weighted assets, amount	671,314,000	500,338,000
Total capital to risk-weighted assets, amount	895,086,000	667,118,000
Minimum [Member] | Wesbanco Bank, Inc [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, amount	510,591,000	467,939,000
Common equity tier 1, amount	501,713,000	375,117,000
Tier 1 capital to risk-weighted assets, amount	668,951,000	500,156,000
Total capital to risk-weighted assets, amount	$ 891,935,000	$ 666,874,000