Derivatives (Derivatives Associated With Capital Markets Trading Activities) (Details) (USD $) In Thousands	Jun. 30, 2011	Jun. 30, 2010
Customer Interest Rate Contracts [Member]
Notional	$ 1,458,306	$ 1,679,157
Assets	72,576	82,406
Liabilities	1,537	4,687
Offsetting Upstream Interest Rate Contracts [Member]
Notional	1,458,306	1,679,157
Assets	1,537	4,687
Liabilities	72,576	82,406
Forwards and Futures Purchased [Member]
Notional, Forwards and Futures	3,397,605	3,637,263
Assets, Forwards and Futures	5,318	692
Liabilities, Forwards and Futures	1,785	5,496
Forwards and Futures Sold [Member]
Notional, Forwards and Futures	3,771,659	3,944,878
Assets, Forwards and Futures	1,228	6,030
Liabilities, Forwards and Futures	$ 8,413	$ 2,823

Fair value as of the balance sheet date of forwards and futures derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

Name:	fhn_ForwardsAndFuturesDerivativeAssetsAtFairValue
Namespace Prefix:	fhn
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of forwards and futures derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ Details

Name:	fhn_ForwardsAndFuturesDerivativeLiabilitiesAtFairValue
Namespace Prefix:	fhn
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Notional Amount Of Forwards And Futures

+ Details

Name:	fhn_NotionalAmountOfForwardsAndFutures
Namespace Prefix:	fhn
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

+ Details

Name:	us-gaap_InterestRateDerivativeAssetsAtFairValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

+ Details

Name:	us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate notional amount of interest rate derivatives, which relates to the currency amount specified in the interest rate derivative instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

+ Details

Name:	us-gaap_NotionalAmountOfInterestRateDerivatives
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant