Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Loan valuations and loss reserves	$ 107	$ 108
Employee benefits	128	93
Accrued expenses	21	22
Depreciation and amortization	37	24
Lease liability	85	91
Federal loss carryforwards	32	34
State loss carryforwards	3	2
Securities available-for-sale and financial instruments	296	355
Other	28	32
Gross deferred tax assets	737	761
Deferred tax liabilities:
Equity investments	31	3
Other intangible assets	75	80
Prepaid expenses	20	17
ROU lease asset	76	82
Leasing	316	265
Other	4	1
Gross deferred tax liabilities	522	448
Net deferred tax assets	$ 215	$ 313

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.