XML 91 R64.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Acquisitions and Divestitures - Merger and Integration Expenses (Details) - IBERIABANK (IBKC) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020
Business Acquisition [Line Items] |  |
Merger and integration expense | $ 187 | $ 155
Personnel expense |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 56 | 66
Impairment of long-lived assets |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 34 | 6
Legal and professional fees |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 21 | 39
Contract employment and outsourcing |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 12 | 1
Advertising and public relations |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 10 | 0
Contribution expense |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | 0 | 20
Other expense |  |
Business Acquisition [Line Items] |  |
Merger and integration expense | $ 54 | $ 23

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs. + References No definition available. + Details
Name: | us-gaap_BusinessCombinationIntegrationRelatedCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fhn_IBERIABANKCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_EmployeeCompensationIncentivesAndBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_ImpairmentOfLongLivedAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_ProfessionalFeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_ContractEmploymentAndOutsourcingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_AdvertisingAndPublicRelationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_CharitableContributionExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fhn_AllOtherExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |