Earnings Per Share (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income from continuing operations attributable to FHN	$ (125,261)	$ 16,321	$ (94,299)	$ 55,609
Effect of dilutive securities		1,467,000		2,457,000
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options, weighted average exercise price	$ 21.54	$ 24.44	$ 22.26	$ 26.12
Shares excluded from computation of earnings per share	10,500,000	10,800,000	10,600,000	10,200,000
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of earnings per share	3,400,000	400,000	3,500,000	200,000