Subordinated Debentures Subordinated Debentures, Additional Information (Details) $ in Millions |
Mar. 31, 2022
USD ($)
|
---|---|
First Commonwealth Capital Trust II [Member] | |
Debt Instrument [Line Items] | |
Debt Issuance Costs, Gross | $ 0.6 |
First Commonwealth Bank 2028 [Member] | |
Debt Instrument [Line Items] | |
Subordinated Debt Par Amount | 50.0 |
Debt Issuance Costs, Gross | 0.9 |
First Commonwealth Bank 2033 [Member] | |
Debt Instrument [Line Items] | |
Subordinated Debt Par Amount | 50.0 |
Debt Issuance Costs, Gross | 1.1 |
First Commonwealth Capital Trust III [Member] | |
Debt Instrument [Line Items] | |
Debt Issuance Costs, Gross | $ 0.5 |