XML 40 R87.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Premises, Equipment, and Leases - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Property, Plant and Equipment [Abstract] |  |
Impairment losses | $ 26.9 | $ 3.9
Impairment recoveries |  | 1.5
Gain/(loss) on sale of properties, before applicable income taxes | 2.3 | $ 4.3
Undiscounted amount of leases that have not yet commenced | $ 2.6 |

X
- Definition Impairment Recoveries On Properties Disposed Of + References No definition available. + Details
Name: | fhn_ImpairmentRecoveriesOnPropertiesDisposedOf
Namespace Prefix: | fhn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Lessee, Operating Lease, Lease Not yet Commenced, Future Undiscounted Amount + References No definition available. + Details
Name: | fhn_LesseeOperatingLeaseLeaseNotyetCommencedFutureUndiscountedAmount
Namespace Prefix: | fhn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the amount of gain (loss) on sale of properties during the reporting period gross of the applicable income taxes realized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 974 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-15.(a)(1)(ii) -URI http://asc.fasb.org/extlink&oid=6875705&loc=d3e641549-123027 + Details
Name: | us-gaap_GainLossOnSaleOfPropertiesBeforeApplicableIncomeTaxes
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration