Basis of Presentation and Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Accounting Standards Adopted

Summary of Accounting Changes

The following table describes updates to accounting standards issued by the Financial Accounting Standards Board ("FASB") that have been adopted by FHN during the current year and the effects of adoption on FHN's financial statements.

ACCOUNTING STANDARDS ADOPTED SINCE JANUARY 1, 2026

Standard	Summary of Guidance	Effects on Financial Statements
ASU 2025-08 Purchased Loans Issued November 2025	•Amends the guidance in ASC 326 on the accounting for certain purchased loans. •Requires entities to account for acquired loans (excluding credit cards) that meet certain criteria at acquisition (purchased seasoned loans) by recognizing them at their purchase price plus an allowance for expected credit losses (gross-up approach) which eliminates the credit mark double-count that was previously recognized for all non-PCD loans. Purchased seasoned loans are defined as either: (1) non-PCD loans that are obtained in a business combination, or (2) non-PCD loans that (a) are obtained in an asset acquisition or upon consolidation of a variable interest entity that is not a business and (b) are acquired more than 90 days after their origination date by a transferee that was not involved in their origination. •Introduces an accounting policy election related to the subsequent measurement of expected credit losses for entities that use a method other than a discounted cash flow analysis to estimate credit losses on purchased seasoned loans. If this accounting policy is elected, entities can use the amortized cost basis of the asset to subsequently measure their credit loss allowance which facilitates pooling of purchased seasoned loans with originated loans for the determination of ACL post-acquisition.	•Effective for fiscal years beginning after December 15, 2026, including interim periods within those fiscal years. •Early adoption is permitted. •Required to be applied prospectively to loans that are acquired on or after the initial application date. •FHN early adopted ASU 2025-08 beginning January 1, 2026. Since ASU 2025-08 only affects prospective loan acquisitions, there was no effect of adoption on FHN's consolidated financial statements.

ASU 2025-09 Hedge Accounting Improvements Issued November 2025 •Amends the guidance in ASC 815 to more closely align hedge accounting with the economics of an entity’s risk management activities. •Expands the hedged risks permitted to be aggregated in a group of individual forecasted transactions for cash flow hedges and increases the variable price components eligible to be designated as the hedged risk in the forecasted purchase or sale of nonfinancial assets. •Eliminates the requirement to apply the net written option test when certain compound derivatives are used in interest rate hedges. •Simplifies the application of hedge accounting for entities hedging forecasted interest payments on choose-your-rate debt instruments and addresses application issues related to “dual hedges,” where a foreign-currency-denominated debt instrument is designated as a hedging instrument and a hedged item. •Effective for fiscal years beginning after December 15, 2026, including interim periods within those fiscal years. •Early adoption is permitted. •Required to be applied prospectively for all hedging relationships. •Entities may elect to adopt the amendments in ASU 2025-09 for hedging relationships that exist as of the date of adoption. •FHN early adopted ASU 2025-09 beginning January 1, 2026. There were no effects on FHN's existing accounting hedges as a result of adoption.