XML 83 R67.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Pension, Savings, And Other Employee Benefits (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2017 | Sep. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |
Estimated social security benefits age | 65 years |  |  |  |
Contributions to qualified plans | $ 0 | $ 165,000 | $ 0 |  |
Non-Qualified Plans [Member] |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |
Contributions to qualified plans |  |  |  |  | $ 5,100
Expected pension contribution |  |  |  | $ 5,000 |
Savings Plan [Member] |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |
Employer investment in qualified defined contribution plan | 100.00% |  | 100.00% |  |
Maximum percent of employee pre-tax contributions that may be matched by the Company | 6.00% |  | 6.00% |  |

X
- Definition Employer investment in qualified defined contribution plan. + References No definition available. + Details
Name: | fhn_EmployerInvestmentInQualifiedDefinedContributionPlan
Namespace Prefix: | fhn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- 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: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. + 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 (g) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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

X
- 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=66902209&loc=d3e3536-108585 + Details
Name: | us-gaap_PensionContributions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | fhn_DefinedBenefitPlansandOtherPostretirementBenefitPlansAxis=fhn_NonQualifiedPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fhn_DefinedBenefitPlansandOtherPostretirementBenefitPlansAxis=fhn_SavingsPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |