Regulatory Matters - Summary of Risk-Based Capital Amounts and Ratios (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
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	$ 901,873,000	$ 751,748,000
Common equity tier 1, amount	773,306,000	656,911,000
Tier 1 capital to risk-weighted assets, amount	901,873,000	751,748,000
Total capital to risk-weighted assets, amount	$ 971,762,000	$ 794,643,000
Tier 1 leverage, ratio	9.81%	9.38%
Common equity tier 1, ratio	11.28%	11.66%
Tier 1 capital to risk-weighted assets, ratio	13.16%	13.35%
Total capital to risk-weighted assets, ratio	14.18%	14.11%
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	$ 827,173,000	$ 701,384,000
Common equity tier 1, amount	827,173,000	701,384,000
Tier 1 capital to risk-weighted assets, amount	827,173,000	701,384,000
Total capital to risk-weighted assets, amount	$ 896,598,000	$ 743,923,000
Tier 1 leverage, ratio	9.02%	8.77%
Common equity tier 1, ratio	12.10%	12.49%
Tier 1 capital to risk-weighted assets, ratio	12.10%	12.49%
Total capital to risk-weighted assets, ratio	13.11%	13.24%
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, amount	$ 367,843,000	$ 320,575,000
Common equity tier 1, amount	308,462,000	253,418,000
Tier 1 capital to risk-weighted assets, amount	411,283,000	337,891,000
Total capital to risk-weighted assets, amount	548,378,000	450,521,000
Minimum [Member] | WesBanco Bank Inc [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, amount	366,903,000	320,020,000
Common equity tier 1, amount	307,728,000	252,793,000
Tier 1 capital to risk-weighted assets, amount	410,305,000	337,057,000
Total capital to risk-weighted assets, amount	$ 547,073,000	$ 449,409,000