XML 101 R90.htm IDEA: XBRL DOCUMENT
v3.19.2

Variable Interest Entities - Summary of the Impact of Qualifying LIHTC Investments (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Low income housing tax credits |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Amortization of qualifying LIHTC investments | $ 4,287 | $ 2,191 | $ 8,285 | $ 4,547
Affordable Housing Tax Credits and Other Tax Benefits | (3,522) | (2,560) | (7,151) | (5,097)
Other tax benefits related to qualifying LIHTC investments |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Affordable Housing Tax Credits and Other Tax Benefits | $ (1,609) | $ (894) | $ (3,219) | $ (1,584)

X
- Definition Amount of affordable housing tax credits and other tax benefits recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 740 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=116633289&loc=SL49122993-202985 + Details
Name: | us-gaap_AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of amortization expense of investment in qualified affordable housing projects. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 740 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=116633289&loc=SL49122993-202985 + Details
Name: | us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=fhn_LowIncomeHousingTaxCreditsMemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=fhn_OtherTaxBenefitsRelatedToQualifyingLihtcInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |