Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2021
Policy Text Block [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards Not Yet Effective or Not Yet Adopted In July 2021, the FASB updated the Codification and amended ASC Topic 842, “Leases,” to require lessors to classify leases as operating leases if they have variable lease payments that do not depend on an index or rate and would have selling losses if they were classified as sales-type or direct financing leases. When a lease is classified as operating, the lessor does not recognize a net investment in the lease, does not derecognize the underlying asset, and, therefore, does not recognize a selling profit or loss. The leased asset continues to be subject to the measurement and impairment requirements under other applicable GAAP before and after the lease transaction. For public business entities, the amendment will be effective for annual reporting periods beginning after December 15, 2021, including interim periods within those fiscal years. Early adoption is permitted. The Corporation does not expect that the amendments of this update will have a material effect on its consolidated financial statements.
Nonaccrual and Past Due Loans [Policy Text Block]	Effective April 1, 2021, the Corporation updated its policies regarding the timing of recognition of auto loans and small personal loans charge-offs. The update requires the Corporation to charge-off auto loans, finance leases, and small personal loans, or portions of such loans, classified as “loss” when the loan becomes 120 days or more past due. Under the previous policy, the Corporation reserved the portion of auto loans and finance leases deemed “loss” once they were 120 days delinquent and charged-off an auto loan to their net realizable value when the collateral deficiency was deemed uncollectible (i.e., when foreclosure/repossession is probable) or when the loan was 365 days past due. For small personal loans, the Corporation previously reserved loans that were classified as “loss” when they were 120 days delinquent and charged-off a loan when the loan became 180 days past due. The policy update is supported by the fact that the majority of consumer loans that become 120 days or more delinquent will ultimately go to foreclosure or the borrower has demonstrated an inability or lack of willingness to meet their obligation of making timely payments to cure the delinquency. At the time we implemented the update to the charge-off policy in the second quarter of 2021, the amount of loans determined to be classified as “loss” amounted to $4.1 million, which was charged-off during the quarter. Approximately $1.1 million of such charge-off exceeded existing reserves at the time the Corporation implemented the policy update. This update to the policy did not have an impact on the approach we use to estimate the ACL for auto loans, finance leases, or small personal loans.
Troubled Debt Restructuring [Policy Text Block]	The Corporation’s loss mitigation programs for residential mortgage and consumer loans can provide for one or a combination of the following: movement of interest past due to the end of the loan; extension of the loan term; deferral of principal payments; and reduction of interest rates either permanently or for a period of up to six years (increasing back in step-up rates). Additionally, in certain cases, the restructuring may provide for the forgiveness of contractually-due principal or interest. Uncollected interest is added to the principal at the end of the loan term at the time of the restructuring and not recognized as income until collected or when the loan is paid off. These programs are available only to those borrowers who have defaulted, or are likely to default, permanently on their loans and would lose their homes in a foreclosure action absent some lender concession. Nevertheless, if the Corporation is not reasonably assured that the borrower will comply with its contractual commitment, the property is foreclosed. Prior to permanently modifying a loan, the Corporation may enter into trial modifications with certain borrowers. Trial modifications generally represent a six-month period during which the borrower makes monthly payments under the anticipated modified payment terms prior to a formal modification. Upon successful completion of a trial modification, the Corporation and the borrower enter into a permanent modification. TDR loans that are participating in or that have been offered a binding trial modification are classified as TDRs when the trial offer is made and continue to be classified as TDRs regardless of whether the borrower enters into a permanent modification. As of September 30, 2021, the Corporation included as TDRs $0.3 million of residential mortgage loans that were participating in or had been offered a trial modification. For the commercial real estate, commercial and industrial, and construction loan portfolios, at the time of a restructuring, the Corporation determines, on a loan-by-loan basis, whether a concession was granted for economic or legal reasons related to the borrower’s financial difficulty. Concessions granted for loans in these portfolios could include: reductions in interest rates to rates that are considered below market; extension of repayment schedules and maturity dates beyond the original contractual terms; waivers of borrower covenants; forgiveness of principal or interest; or other contractual changes that are considered to be concessions. The Corporation mitigates loan defaults for these loan portfolios through its collection function. The function’s objective is to minimize both early stage delinquencies and losses upon default of loans in these portfolios. In the case of the commercial and industrial, commercial mortgage, and construction loan portfolios, the Corporation’s Special Asset Group (“SAG”) focuses on strategies for the accelerated reduction of non-performing assets through note sales, short sales, loss mitigation programs, and sales of OREO. In addition, the Corporation extends, renews, and restructures loans with satisfactory credit profiles. Many commercial loan facilities are structured as lines of credit, which generally have one-year terms and, therefore, require annual renewals. Other facilities may be restructured or extended from time to time based upon changes in the borrower’s business needs, use of funds, and timing of completion of projects, and other factors. If the borrower is not deemed to have financial difficulties, extensions, renewals, and restructurings are done in the normal course of business and not considered to be concessions, and the loans continue to be recorded as performing.

Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2021

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Issued Accounting Standards Not Yet Effective or Not Yet Adopted

In July 2021, the FASB updated the Codification and amended ASC Topic 842, “Leases,” to require lessors to classify leases as operating leases if they have variable lease payments that do not depend on an index or rate and would have selling losses if they were classified as sales-type or direct financing leases. When a lease is classified as operating, the lessor does not recognize a net investment in the lease, does not derecognize the underlying asset, and, therefore, does not recognize a selling profit or loss. The leased asset continues to be subject to the measurement and impairment requirements under other applicable GAAP before and after the lease transaction. For public business entities, the amendment will be effective for annual reporting periods beginning after December 15, 2021, including interim periods within those fiscal years. Early adoption is permitted. The Corporation does not expect that the amendments of this update will have a material effect on its consolidated financial statements.

Nonaccrual and Past Due Loans [Policy Text Block]

Effective April 1, 2021, the Corporation updated its policies regarding the timing of recognition of auto loans and small personal loans charge-offs. The update requires the Corporation to charge-off auto loans, finance leases, and small personal loans, or portions of such loans, classified as “loss” when the loan becomes 120 days or more past due. Under the previous policy, the Corporation reserved the portion of auto loans and finance leases deemed “loss” once they were 120 days delinquent and charged-off an auto loan to their net realizable value when the collateral deficiency was deemed uncollectible (i.e., when foreclosure/repossession is probable) or when the loan was 365 days past due. For small personal loans, the Corporation previously reserved loans that were classified as “loss” when they were 120 days delinquent and charged-off a loan when the loan became 180 days past due. The policy update is supported by the fact that the majority of consumer loans that become 120 days or more delinquent will ultimately go to foreclosure or the borrower has demonstrated an inability or lack of willingness to meet their obligation of making timely payments to cure the delinquency.

At the time we implemented the update to the charge-off policy in the second quarter of 2021, the amount of loans determined to be classified as “loss” amounted to $4.1 million, which was charged-off during the quarter. Approximately $1.1 million of such charge-off exceeded existing reserves at the time the Corporation implemented the policy update. This update to the policy did not have an impact on the approach we use to estimate the ACL for auto loans, finance leases, or small personal loans.

Troubled Debt Restructuring [Policy Text Block]

The Corporation’s loss mitigation programs for residential mortgage and consumer loans can provide for one or a combination of the following: movement of interest past due to the end of the loan; extension of the loan term; deferral of principal payments; and reduction of interest rates either permanently or for a period of up to six years (increasing back in step-up rates). Additionally, in certain cases, the restructuring may provide for the forgiveness of contractually-due principal or interest. Uncollected interest is added to the principal at the end of the loan term at the time of the restructuring and not recognized as income until collected or when the loan is paid off. These programs are available only to those borrowers who have defaulted, or are likely to default, permanently on their loans and would lose their homes in a foreclosure action absent some lender concession. Nevertheless, if the Corporation is not reasonably assured that the borrower will comply with its contractual commitment, the property is foreclosed.

Prior to permanently modifying a loan, the Corporation may enter into trial modifications with certain borrowers. Trial modifications generally represent a six-month period during which the borrower makes monthly payments under the anticipated modified payment terms prior to a formal modification. Upon successful completion of a trial modification, the Corporation and the borrower enter into a permanent modification. TDR loans that are participating in or that have been offered a binding trial modification are classified as TDRs when the trial offer is made and continue to be classified as TDRs regardless of whether the borrower enters into a permanent modification. As of September 30, 2021, the Corporation included as TDRs $0.3 million of residential mortgage loans that were participating in or had been offered a trial modification.

For the commercial real estate, commercial and industrial, and construction loan portfolios, at the time of a restructuring, the Corporation determines, on a loan-by-loan basis, whether a concession was granted for economic or legal reasons related to the borrower’s financial difficulty. Concessions granted for loans in these portfolios could include: reductions in interest rates to rates that are considered below market; extension of repayment schedules and maturity dates beyond the original contractual terms; waivers of borrower covenants; forgiveness of principal or interest; or other contractual changes that are considered to be concessions. The Corporation mitigates loan defaults for these loan portfolios through its collection function. The function’s objective is to minimize both early stage delinquencies and losses upon default of loans in these portfolios. In the case of the commercial and industrial, commercial mortgage, and construction loan portfolios, the Corporation’s Special Asset Group (“SAG”) focuses on strategies for the accelerated reduction of non-performing assets through note sales, short sales, loss mitigation programs, and sales of OREO.

In addition, the Corporation extends, renews, and restructures loans with satisfactory credit profiles. Many commercial loan facilities are structured as lines of credit, which generally have one-year terms and, therefore, require annual renewals. Other facilities may be restructured or extended from time to time based upon changes in the borrower’s business needs, use of funds, and timing of completion of projects, and other factors. If the borrower is not deemed to have financial difficulties, extensions, renewals, and restructurings are done in the normal course of business and not considered to be concessions, and the loans continue to be recorded as performing.