Receivables, Loans, Notes Receivable, and Others (Policies)	6 Months Ended
Jun. 30, 2025
Receivables [Abstract]
Nonperforming Loans Policy	Nonaccrual loans. Loans are classified as nonaccrual when, in the opinion of management, collection of principal or interest is doubtful or when principal or interest payments are 90 days or more past due. Generally, loans are classified as nonaccrual due to the continued failure to adhere to contractual payment terms by the borrower, coupled with other pertinent factors. When a loan is classified as nonaccrual, the accrual of interest income is discontinued and previously accrued but unpaid interest is reversed. Any payments received while a loan is on nonaccrual status are applied as a reduction to the carrying value of the loan. A loan classified as nonaccrual may return to accrual status if none of the principal and interest is due and unpaid, and the Bank expects repayment of the remaining contractual principal and interest. First Financial individually reviews all nonaccrual loan relationships greater than $250,000 to determine if a reserve is required based on the borrower’s overall financial condition, resources and payment record, support from guarantors and the realizable value of any collateral. These reserves are based on discounted cash flows using the loan's initial effective interest rate or the fair value of the collateral for certain collateral dependent loans.
us-gaap_LoansAndLeasesReceivablePastDueStatusPolicy	Delinquency. Loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement remains unpaid after the date of the scheduled payment.
Financing Receivable, Modifications, Policy	FDM might result when a borrower is in financial distress, and may be in the form of principal forgiveness, an interest rate reduction, a term extension or an other-than-insignificant payment delay. In some cases, the Company might provide multiple types of modifications for a single loan. One type of modification, such as payment delay, may be granted initially, however, if the borrower continues to experience financial difficulty, another modification, such as term extension and/or interest rate reduction might be granted. Loans included in the "combination" column in the table that follows have more than one modification made to the same loan within the current reporting period. Additionally, modifications with a term extension or interest rate reduction are intended to reduce the borrower’s monthly payment, while modifications with a payment delay, which typically allow borrowers to make monthly payments or interest only payments for a period of time, are structured to cure the payment defaults by making delinquent payments due at maturity. Payment deferrals may be up to one year and have minimal financial impact since the deferred payments are paid at maturity.

Receivables, Loans, Notes Receivable, and Others (Policies)

6 Months Ended

Jun. 30, 2025

Nonaccrual loans. Loans are classified as nonaccrual when, in the opinion of management, collection of principal or interest is doubtful or when principal or interest payments are 90 days or more past due. Generally, loans are classified as nonaccrual due to the continued failure to adhere to contractual payment terms by the borrower, coupled with other pertinent factors. When a loan is classified as nonaccrual, the accrual of interest income is discontinued and previously accrued but unpaid interest is reversed. Any payments received while a loan is on nonaccrual status are applied as a reduction to the carrying value of the loan. A loan classified as nonaccrual may return to accrual status if none of the principal and interest is due and unpaid, and the Bank expects repayment of the remaining contractual principal and interest.

First Financial individually reviews all nonaccrual loan relationships greater than $250,000 to determine if a reserve is required based on the borrower’s overall financial condition, resources and payment record, support from guarantors and the realizable value of any collateral. These reserves are based on discounted cash flows using the loan's initial effective interest rate or the fair value of the collateral for certain collateral dependent loans.

us-gaap_LoansAndLeasesReceivablePastDueStatusPolicy

Delinquency. Loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement remains unpaid after the date of the scheduled payment.

Financing Receivable, Modifications, Policy

FDM might result when a borrower is in financial distress, and may be in the form of principal forgiveness, an interest rate reduction, a term extension or an other-than-insignificant payment delay. In some cases, the Company might provide multiple types of modifications for a single loan. One type of modification, such as payment delay, may be granted initially, however, if the borrower continues to experience financial difficulty, another modification, such as term extension and/or interest rate reduction might be granted. Loans included in the "combination" column in the table that

follows have more than one modification made to the same loan within the current reporting period. Additionally, modifications with a term extension or interest rate reduction are intended to reduce the borrower’s monthly payment, while modifications with a payment delay, which typically allow borrowers to make monthly payments or interest only payments for a period of time, are structured to cure the payment defaults by making delinquent payments due at maturity. Payment deferrals may be up to one year and have minimal financial impact since the deferred payments are paid at maturity.