Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Series L Preferred Stock	Huntington Shareholders’ Equity	Huntington Shareholders’ Equity Common Stock	Huntington Shareholders’ Equity Series L Preferred Stock	Preferred Stock	Preferred Stock Series L Preferred Stock	Common Stock	Common Stock Common Stock	Capital Surplus	Capital Surplus Common Stock	Treasury Stock	AOCI	Retained Earnings	Retained Earnings Series L Preferred Stock	Non-controlling Interest
Balance, beginning of period at Dec. 31, 2024	$ 19,782			$ 19,740			$ 1,989		$ 15		$ 15,484		$ (86)	$ (2,866)	$ 5,204		$ 42
Balance, beginning of period, common stock (in shares) at Dec. 31, 2024									1,460,620,000
Balance, beginning of period, treasury stock (in shares) at Dec. 31, 2024													(6,984,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	531			527											527		4
Other comprehensive income (loss), net of tax	433			433										433
Cash dividends declared:
Common	(230)			(230)											(230)
Preferred	(27)			(27)											(27)
Recognition of the fair value of share-based compensation	21			21							21
Other share-based compensation activity (in shares)									3,356,000
Other share-based compensation activity	(26)			(26)							(26)
Other	2			(4)									$ (4)				6
Other (in shares)													(180,000)
Balance, end of period at Mar. 31, 2025	20,486			20,434			1,989		$ 15		15,479		$ (90)	(2,433)	5,474		52
Balance, end of period, common stock (in shares) at Mar. 31, 2025									1,463,976,000
Balance, end of period, treasury stock (in shares) at Mar. 31, 2025													(7,164,000)
Balance, beginning of period at Dec. 31, 2025	$ 24,379			24,342			2,731		$ 16		17,244		$ (92)	(1,908)	6,351		37
Balance, beginning of period, common stock (in shares) at Dec. 31, 2025	1,567,732,506								1,574,920,000
Balance, beginning of period, treasury stock (in shares) at Dec. 31, 2025	(7,187,541)												(7,188,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 527			523											523		4
Other comprehensive income (loss), net of tax	(151)			(151)										(151)
Cadence acquisition:
Issuance of stock, acquisition (in shares)										461,548,000
Issuance of stock, acquisition		$ 8,068	$ 150		$ 8,068	$ 150		$ 150		$ 4		$ 8,064
Conversion of equity awards	117			117							117
Repurchases of common stock (in shares)									(8,953,000)
Repurchases of common stock	(150)			(150)							(150)
Cash dividends declared:
Common	(318)			(318)											(318)
Preferred	(41)			(41)											(41)	$ (2)
Recognition of the fair value of share-based compensation	45			45							45
Other share-based compensation activity (in shares)									6,885,000
Other share-based compensation activity	(49)			(49)							(49)
Other	4			(1)							2		$ (3)				5
Other (in shares)													(81,000)
Balance, end of period at Mar. 31, 2026	$ 32,581			$ 32,535			$ 2,881		$ 20		$ 25,273		$ (95)	$ (2,059)	$ 6,515		$ 46
Balance, end of period, common stock (in shares) at Mar. 31, 2026	2,027,130,587								2,034,400,000
Balance, end of period, treasury stock (in shares) at Mar. 31, 2026	(7,269,138)												(7,269,000)