Employer investment in qualified defined contribution plan.

No definition available.

Name:	fhn_EmployerInvestmentInQualifiedDefinedContributionPlan
Namespace Prefix:	fhn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Age in which estimates of social security benefits received will be incorporated for purpose of determining pension benefits.

+ References

No definition available.

+ Details

Name:	fhn_EstimatedSocialSecurityBenefitsAge
Namespace Prefix:	fhn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cash or cash equivalents contributed by the entity to fund its pension plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

Name:	us-gaap_PensionContributions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Pension, Savings, And Other Employee Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended		12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012 Non Qualified Plans [Member]	Dec. 31, 2013 Non Qualified Plans [Member]	Dec. 31, 2013 Savings Plan [Member]	Dec. 31, 2012 Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated social security benefits age	65 years 0 months
Contributions to non-qualified plans		$ 7.3		$ 1.7	$ 1.5
Employer investment in qualified defined contribution plan				100.00%	50.00%
Maximum percent of employee pre-tax contributions that may be matched by the Company				6.00%	6.00%
Benefit payments in 2013			$ 6.2