Fair Value Of Assets And Liabilities (Schedule Of Unobservable Inputs Utilized In Determining The Fair Value Of Level 3 Recurring And Non-Recurring Measurements) (Details) (USD $)														9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2012 Fair Value Inputs Level3 [Member]		Sep. 30, 2011 Fair Value Inputs Level3 [Member]		Sep. 30, 2012 Interest Only Strip [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]		Sep. 30, 2012 Recent Purchase Offers [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Recent Capitalization Transactions [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Interest Only Strip [Member]		Sep. 30, 2012 Discounted Cash Flow [Member] Interest Only Strip [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Mortgage Servicing Rights [Member]		Sep. 30, 2012 Discounted Cash Flow [Member] Mortgage Servicing Rights [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Short Term Debt [Member]		Sep. 30, 2012 Discounted Cash Flow [Member] Short Term Debt [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Discounted Cash Flow [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Appraisals From Comparable Properties [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Appraisals From Comparable Properties [Member] Real Estate Acquired By Foreclosure [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Appraisals From Comparable Properties [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Other Collateral Valuations [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Recent Purchase Offers [Member] Zero Percent To Ten Percent Discount [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Recent Capitalization Transactions [Member] Zero Percent To Ten Percent Discount [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Six Percent To Ten Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Two Percent To Four Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Fifteen Percent To Twenty Five Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Fifty Percent To Sixty Percent Of Original Upb [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Zero Percent To Fifteen Percent Of Adjustment To Yield [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Nine Months To Eighteen Months [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Discounted Cash Flow [Member] Ten Percent To Fifty Percent [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Appraisals From Comparable Properties [Member] Five Percent To Fifteen Percent Of Appraisal [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Appraisals From Comparable Properties [Member] Zero Percent To Ten Percent Of Appraisal [Member] Real Estate Acquired By Foreclosure [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Appraisals From Comparable Properties [Member] Zero Percent To Twenty Five Percent Of Appraisal [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Other Collateral Valuations [Member] Twenty Percent To Fifty Percent Of Gross Value [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Maximum [Member] Other Collateral Valuations [Member] Zero Percent To Twenty Five Percent Of Reported Value [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Recent Purchase Offers [Member] Zero Percent To Ten Percent Discount [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Recent Capitalization Transactions [Member] Zero Percent To Ten Percent Discount [Member] Venture Capital Funds [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Six Percent To Ten Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Two Percent To Four Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Fifteen Percent To Twenty Five Percent Values Utilized [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Fifty Percent To Sixty Percent Of Original Upb [Member] Loans Held For Sale [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Zero Percent To Fifteen Percent Of Adjustment To Yield [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Nine Months To Eighteen Months [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Discounted Cash Flow [Member] Ten Percent To Fifty Percent [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Appraisals From Comparable Properties [Member] Five Percent To Fifteen Percent Of Appraisal [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Appraisals From Comparable Properties [Member] Zero Percent To Ten Percent Of Appraisal [Member] Real Estate Acquired By Foreclosure [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Appraisals From Comparable Properties [Member] Zero Percent To Twenty Five Percent Of Appraisal [Member] Other Assets Tax Credit Investments [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Other Collateral Valuations [Member] Twenty Percent To Fifty Percent Of Gross Value [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]	Sep. 30, 2012 Minimum [Member] Other Collateral Valuations [Member] Zero Percent To Twenty Five Percent Of Reported Value [Member] Loans Net Of Unearned Income [Member] Fair Value Inputs Level3 [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Trading securities									$ 13,739,000
Total MSR recognized by FHN	120,537,000	144,069,000	150,803,000	207,319,000	120,537,000		150,803,000
Other short-term borrowings	11,585,000		15,814,000		11,585,000		15,814,000
Other Liabilities, Fair Value Disclosure	225,084,000		264,904,000		2,340,000		3,656,000				2,340,000
Loans, net of unearned income					128,626,000	[1]
Loans held-for-sale - mortgage					227,106,000
Real estate acquired by foreclosure, nonrecurring measurements					50,589,000	[2],[3]	80,055,000	[2]
Available-for-sale Securities, Fair Value Disclosure	2,926,153,000		3,129,587,000		14,702,000		21,045,000			9,000,000
Other assets	357,326,000		409,173,000		0		0					76,822,000	[4]
Valuation Techniques														Recent purchase offers	Recent capitalization transactions			Discounted cash flow	Discounted cash flow			Discounted cash flow			Discounted cash flow	Discounted cash flow	Discounted cash flow	Appraisals from comparable properties	Appraisals from comparable properties	Appraisals from comparable properties	Other collateral valuations
Prepayment Speed																																			10.00%															6.00%
Loss severity trends																																						60.00%															50.00%
Delinquency adjustment factor																																					25.00%															15.00%
Credit spreads																																				4.00%															2.00%
Adjustment for preferences in equity tranches																																10.00%	10.00%														0.00%	0.00%
Visa covered litigation resolution amount																																		$ 5,000,000,000															$ 4,400,000,000
Probability of resolution scenarios																																									50.00%															10.00%
Time until resolution																																								1 year 6 months															9 months
Adjustment for value changes since appraisal																																										15.00%	10.00%														5.00%	0.00%
Borrowing base certificates																																													50.00%															20.00%
Financial statements/auction values																																														25.00%															0.00%
Adjustments to current sales yields for specific properties																																							15.00%															0.00%
Marketability adjustments for specific properties																																												25.00%															0.00%
Fair Value Measurements Significant Assumptions																(a)	[5]			(a)	[5]		(b)	[6]

[1] Represents carrying value of loans for which adjustments are based on the appraised value of the collateral. Write-downs on these loans are recognized as part of provision.

[2] Represents the fair value and related losses of foreclosed properties that were measured subsequent to their initial classification as foreclosed assets. Balance excludes foreclosed real estate related to government insured mortgages.

[3] Represents the fair value of foreclosed properties that were measured subsequent to their initial classification as foreclosed assets. Balance excludes foreclosed real estate related to government insured mortgages.

[4] Represents tax credit investments.

[5] The unobservable inputs for Interest-only trading securities and MSR are discussed in Note 12 – Loan Sales and Securitizations.

[6] The inputs and associated ranges for Other short-term borrowings mirror those of the related MSR.