Earnings Per Share (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income from continuing operations attributable to FHN	$ 30,962	$ 39,288
Effect of dilutive securities	1,842,000	4,382,000
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options, weighted average exercise price	$ 23.96	$ 26.70
Shares excluded from computation of earnings per share	9,900,000	10,500,000
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of earnings per share		100,000