Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Securities available-for-sale and financial instruments	$ 284	$ 296
Loan valuations and loss reserves	152	107
Employee benefits	119	128
Lease liability	82	85
Depreciation and amortization	54	37
Accrued expenses	20	21
Federal loss carryforwards	29	32
State loss carryforwards	3	3
Other	25	28
Gross deferred tax assets	768	737
Deferred tax liabilities:
Leasing	363	316
ROU lease asset	73	76
Other intangible assets	71	75
Prepaid expenses	23	20
Equity investments	2	31
Other	9	4
Gross deferred tax liabilities	541	522
Net deferred tax assets	$ 227	$ 215

Deferred Tax Assets, Lease Liability

No definition available.

Name:	fhn_DeferredTaxAssetsLeaseLiability
Namespace Prefix:	fhn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from the provision for loan losses, which can only be deducted for tax purposes when actual loan losses are known, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken. Also includes losses associated with the repurchase obligations and other loss reserves.

+ References

No definition available.