Contingencies and Other Disclosures	12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Other Disclosures	Contingencies and Other Disclosures Contingencies Contingent Liabilities Overview Contingent liabilities arise in the ordinary course of business. Often they are related to lawsuits, arbitration, mediation, and other forms of litigation. Various litigation matters currently are threatened or pending against FHN and its subsidiaries. Also, FHN at times receives requests for information, subpoenas, or other inquiries from federal, state, and local regulators, from other government authorities, and from other parties concerning various matters relating to FHN’s current or former businesses. Certain matters of that sort are pending at most times, and FHN generally cooperates when those matters arise. Pending and threatened litigation matters sometimes are settled by the parties, and sometimes pending matters are resolved in court or before an arbitrator or are withdrawn. Regardless of the manner of resolution, frequently the most significant changes in status of a matter occur over a short time period, often following a lengthy period of little substantive activity. In view of the inherent difficulty of predicting the outcome of these matters, particularly where the claimants seek very large or indeterminate damages, or where the cases present novel legal theories or involve a large number of parties, or where claims or other actions may be possible but have not been brought, FHN cannot reasonably determine what the eventual outcome of the matters will be, what the timing of the ultimate resolution of these matters may be, or what the eventual loss or impact related to each matter may be. FHN establishes a loss contingency liability for a litigation matter when loss is both probable and reasonably estimable as prescribed by applicable financial accounting guidance. If loss for a matter is probable and a range of possible loss outcomes is the best estimate available, accounting guidance requires a liability to be established at the low end of the range. Based on current knowledge, and after consultation with counsel, management is of the opinion that loss contingencies related to threatened or pending litigation matters should not have a material adverse effect on the consolidated financial condition of FHN, but may be material to FHN’s operating results for any particular reporting period depending, in part, on the results from that period. Material Loss Contingency Matters As used in this Note, except for matters that are reported as having been substantially settled or otherwise substantially resolved, FHN's “material loss contingency matters” generally fall into at least one of the following categories: (i) FHN has determined material loss to be probable and has established a material loss liability in accordance with applicable financial accounting guidance; (ii) FHN has determined material loss to be probable but is not reasonably able to estimate an amount or range of material loss liability; or (iii) FHN has determined that material loss is not probable but is reasonably possible, and the amount or range of that reasonably possible material loss is estimable. As defined in applicable accounting guidance, loss is reasonably possible if there is more than a remote chance of a material loss outcome for FHN. FHN provides contingencies note disclosures for certain pending or threatened litigation matters each quarter, including all matters mentioned in categories (i) or (ii) and, occasionally, certain matters mentioned in category (iii). In all litigation matters discussed in this Note, unless settled or otherwise resolved, FHN believes it has meritorious defenses and intends to pursue those defenses vigorously. FHN reassesses the liability for litigation matters each quarter as the matters progress. At December 31, 2025, the aggregate amount of liabilities established for all such loss contingency matters was $1 million. In each material litigation-related loss contingency matter, except as otherwise noted, there is more than a remote chance that any of the following outcomes will occur: the plaintiff will substantially prevail; the defense will substantially prevail; the plaintiff will prevail in part; or the matter will be settled by the parties. At December 31, 2025, FHN estimates that for all material litigation-related loss contingency matters, estimable reasonably possible losses in future periods in excess of currently established liabilities could aggregate in a range from zero to less than $1 million. As a result of the general uncertainties discussed above and the specific uncertainties discussed for the matters mentioned below, it is possible that the ultimate future loss experienced by FHN for any particular matter may materially exceed the amount, if any, of currently established liability for that matter. Other Disclosures Indemnification Agreements and Guarantees In the ordinary course of business, FHN enters into indemnification agreements for legal proceedings against its directors and officers and standard representations and warranties for underwriting agreements, merger and acquisition agreements, loan sales, contractual commitments, and various other business transactions or arrangements. The extent of FHN’s obligations under these agreements depends upon the occurrence of future events; therefore, it is not possible to estimate a maximum potential amount of payouts that could be required by such agreements.

Contingencies

Contingent Liabilities Overview

Contingent liabilities arise in the ordinary course of business. Often they are related to lawsuits, arbitration, mediation, and other forms of litigation. Various litigation matters currently are threatened or pending against FHN and its subsidiaries. Also, FHN at times receives requests for information, subpoenas, or other inquiries from federal, state, and local regulators, from other government authorities, and from other parties concerning various matters relating to FHN’s current or former businesses. Certain matters of that sort are pending at most times, and FHN generally cooperates when those matters arise. Pending and threatened litigation matters sometimes are settled by the parties, and sometimes pending matters are resolved in court or before an arbitrator or are withdrawn. Regardless of the manner of resolution, frequently the most significant changes in status of a matter occur over a short time period, often following a lengthy period of little substantive activity. In view of the inherent difficulty of predicting the outcome of these matters, particularly where the claimants seek very large or indeterminate damages, or where the cases present novel legal theories or involve a large number of parties, or where claims or other actions may be possible but have not been brought, FHN cannot reasonably determine what the eventual outcome of the matters will be, what the timing of the ultimate resolution of these matters may be, or what the eventual loss or impact related to each matter may be. FHN establishes a loss contingency liability for a litigation matter when loss is both probable and reasonably estimable as prescribed by applicable financial accounting guidance. If loss for a matter is probable and a range of possible loss outcomes is the best estimate available, accounting guidance requires a liability to be established at the low end of the range.

Based on current knowledge, and after consultation with counsel, management is of the opinion that loss contingencies related to threatened or pending litigation matters should not have a material adverse effect on the consolidated financial condition of FHN, but may be material to FHN’s operating results for any particular reporting period depending, in part, on the results from that period.

Material Loss Contingency Matters

As used in this Note, except for matters that are reported as having been substantially settled or otherwise substantially resolved, FHN's “material loss contingency matters” generally fall into at least one of the following categories: (i) FHN has determined material loss to be probable and has established a material loss liability in accordance with applicable financial accounting guidance;

(ii) FHN has determined material loss to be probable but is not reasonably able to estimate an amount or range of material loss liability; or (iii) FHN has determined that material loss is not probable but is reasonably possible, and the amount or range of that reasonably possible material loss is estimable. As defined in applicable accounting guidance, loss is reasonably possible if there is more than a remote chance of a material loss outcome for FHN. FHN provides contingencies note disclosures for certain pending or threatened litigation matters each quarter, including all matters mentioned in categories (i) or (ii) and, occasionally, certain matters mentioned in category (iii). In all litigation matters discussed in this Note, unless settled or otherwise resolved, FHN believes it has meritorious defenses and intends to pursue those defenses vigorously.

FHN reassesses the liability for litigation matters each quarter as the matters progress. At December 31, 2025, the aggregate amount of liabilities established for all such loss contingency matters was $1 million.

In each material litigation-related loss contingency matter, except as otherwise noted, there is more than a remote chance that any of the following outcomes will occur: the plaintiff will substantially prevail; the defense will substantially prevail; the plaintiff will prevail in part; or the matter will be settled by the parties. At December 31, 2025, FHN estimates that for all material litigation-related loss contingency matters, estimable reasonably possible losses in future periods in excess of currently established liabilities could aggregate in a range from zero to less than $1 million.

As a result of the general uncertainties discussed above and the specific uncertainties discussed for the matters mentioned below, it is possible that the ultimate future loss experienced by FHN for any particular matter may materially exceed the amount, if any, of currently established liability for that matter.

Other Disclosures

Indemnification Agreements and Guarantees

In the ordinary course of business, FHN enters into indemnification agreements for legal proceedings against its directors and officers and standard representations and warranties for underwriting agreements, merger and acquisition agreements, loan sales, contractual commitments, and various other business transactions or arrangements.

The extent of FHN’s obligations under these agreements depends upon the occurrence of future events; therefore, it is not possible to estimate a maximum potential amount of payouts that could be required by such agreements.