Consolidated Statements of Changes in Equity - USD ($) $ in Millions		Total	Series G	Preferred Stock	Common Stock	Common Stock Series G	Capital Surplus	Capital Surplus Series G	Retained Earnings	Accumulated Other Comprehensive Income (Loss)		Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2020				26,250,000
Beginning balance (in shares) at Dec. 31, 2020					555,031,000
Beginning balance at Dec. 31, 2020		$ 8,307		$ 470	$ 347		$ 5,074		$ 2,261	$ (140)	[1]	$ 295
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		1,010							999			11
Other comprehensive income (loss)		(148)								(148)	[1]
Cash dividends declared:
Preferred stock		(32)							(32)
Preferred stock		(37)
Common stock		(332)							(332)
Preferred stock issuance (in shares)				1,500,000
Preferred stock issuance		145		$ 145
Call of preferred stock (in shares)				(1,000,000)
Call of preferred stock		(100)		$ (95)					(5)
Common stock repurchased (in shares)	[2]				(25,063,000)
Common stock repurchased	[2]	(416)			$ (16)		(400)
Common stock issued for:
Stock options and restricted stock awards (in shares)					3,609,000
Stock options exercised and restricted stock awards		28			$ 2		26
Preferred stock conversion to common stock		0
Stock-based compensation expense		43					43
Dividends declared - noncontrolling interest of subsidiary preferred stock		(11)										(11)
Ending balance (in shares) at Dec. 31, 2021				26,750,000
Ending balance (in shares) at Dec. 31, 2021					533,577,000
Ending balance at Dec. 31, 2021		$ 8,494		$ 520	$ 333		4,743		2,891	(288)	[1]	295
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]		Accounting Standards Update 2022-02
Net income		$ 912							900			12
Other comprehensive income (loss)		(1,080)								(1,080)	[1]
Cash dividends declared:
Preferred stock		(32)							(32)
Common stock		(329)							(329)
Preferred stock issuance (in shares)				4,936,000
Preferred stock issuance		494		$ 494
Common stock repurchased (in shares)					(577,000)
Common stock repurchased		(12)					(12)
Common stock issued for:
Stock options and restricted stock awards (in shares)					4,101,000
Stock options exercised and restricted stock awards		37			$ 3		34
Preferred stock conversion to common stock		0
Stock-based compensation expense		75					75
Dividends declared - noncontrolling interest of subsidiary preferred stock		(12)										(12)
Ending balance (in shares) at Dec. 31, 2022				31,686,000
Ending balance (in shares) at Dec. 31, 2022					537,101,000
Ending balance at Dec. 31, 2022		8,547		$ 1,014	$ 336		4,840		3,430	(1,368)	[1]	295
Ending balance (Accounting Standards Update 2022-02) at Dec. 31, 2022		4							4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		916							897			19
Other comprehensive income (loss)		180								180
Cash dividends declared:
Preferred stock		(32)							(32)
Common stock		(335)							(335)
Call of preferred stock (in shares)				(4,936,000)
Call of preferred stock		(494)		$ (494)
Common stock repurchased (in shares)					(807,000)
Common stock repurchased		(10)			$ (1)		(9)
Common stock issued for:
Stock options and restricted stock awards (in shares)					2,802,000
Stock options exercised and restricted stock awards		5					5
Series G preferred stock conversion (in shares)						19,743,000
Preferred stock conversion to common stock		493	$ 493			$ 12		$ 481
Stock-based compensation expense		36			$ 2		34
Dividends declared - noncontrolling interest of subsidiary preferred stock		$ (19)										(19)
Ending balance (in shares) at Dec. 31, 2023		26,750	0	26,750,000
Ending balance (in shares) at Dec. 31, 2023					558,839,000
Ending balance at Dec. 31, 2023		$ 9,291		$ 520	$ 349		$ 5,351		$ 3,964	$ (1,188)	[1]	$ 295

[1] Due to the nature of the preferred stock issued by FHN and its subsidiaries, all components of other comprehensive income (loss) have been attributed solely to FHN as the controlling interest holder.

[2] 2021 includes $401 million repurchased under share repurchase programs.