Loan Sales and Securitizations (Schedule of Principal Amount of Delinquent Loans, and Net Credit Losses) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal amount of loans securitized and sold	$ 5,800,000,000		$ 8,000,000,000
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal Amount of Residential Real Estate Loans	15,094,508,000	[1],[2],[3]	18,128,275,000	[1],[2],[3]
Net Credit Losses	440,234,000	[2]	536,418,000	[2]
Principal Amount90 Days Or More Past Due Or Nonaccrual [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal Amount of Residential Real Estate Loans	700,000,000		800,000,000
Principal Amount90 Days Or More Past Due Or Nonaccrual [Member] | Government National Mortgage Association Certificates And Obligations G N M A [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal Amount of Residential Real Estate Loans	$ 36,600,000		$ 42,200,000

[1] On December 31, 2012 and 2011, includes $.7 billion and $.8 billion, respectively, where the principal amount is 90 days or more past due or nonaccrual. Included in these amounts are $36.6 million and $42.2 million of GNMA guaranteed mortgages on December 31, 2012 and 2011, respectively.

[2] No delinquency or net credit loss data is provided for the loans transferred to FNMA or FHLMC because these agencies retain credit risk. See Note 18 - Contingencies and Other Disclosures for discussion related to repurchase obligations for loans transferred to GSEs or private investors.

[3] Amounts represent real estate residential loans in FHN’s portfolio, held-for-sale, and loans that have been transferred in proprietary securitizations and whole loan sales in which FHN has a retained interest other than servicing rights. Also includes $5.8 billion and $8.0 billion of loans transferred to GSEs with any type of retained interest on December 31, 2012 and 2011, respectively.