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

Amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for assets, including financial assets, excluding goodwill, with a finite life.

No definition available.

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

Amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for assets, including financial assets, excluding goodwill, with a finite life.

No definition available.

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

Amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for assets, including financial assets, excluding goodwill, with a finite life.

No definition available.

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

Amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for assets, including financial assets, excluding goodwill, with a finite life.

No definition available.

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

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.