Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Huntington Shareholders’ Equity	Preferred Stock	Common Stock	Capital Surplus	Treasury Stock	AOCI	Retained Earnings	Non-controlling Interest
Balance, beginning of period at Dec. 31, 2023	$ 19,398	$ 19,353	$ 2,394	$ 15	$ 15,389	$ (91)	$ (2,676)	$ 4,322	$ 45
Balance, beginning of period, common stock (in shares) at Dec. 31, 2023				1,455,723,000
Balance, beginning of period, treasury stock (in shares) at Dec. 31, 2023						(7,403,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,426	1,410						1,410	16
Net Income	1,410
Other comprehensive income (loss), net of tax	572	572					572
Income attributable to non-controlling interest	16
Other comprehensive income, net of tax	572
Cash dividends declared:
Common	(687)	(687)						(687)
Preferred	(107)	(107)						(107)
Recognition of the fair value of share-based compensation	81	81			81
Other share-based compensation activity (in shares)				4,263,000
Other share-based compensation activity	(18)	(18)		$ 0	(15)			(3)
Other	(13)	2			0	$ 2			(15)
Other (in shares)						229,000
Balance, end of period at Sep. 30, 2024	20,652	20,606	2,394	$ 15	15,455	$ (89)	(2,104)	4,935	46
Balance, end of period, common stock (in shares) at Sep. 30, 2024				1,459,986,000
Balance, end of period, treasury stock (in shares) at Sep. 30, 2024						(7,174,000)
Balance, beginning of period at Jun. 30, 2024	19,563	19,515	2,394	$ 15	15,425	$ (90)	(2,911)	4,682	48
Balance, beginning of period, common stock (in shares) at Jun. 30, 2024				1,459,756,000
Balance, beginning of period, treasury stock (in shares) at Jun. 30, 2024						(7,323,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	522	517						517	5
Net Income	517
Other comprehensive income (loss), net of tax	807	807					807
Income attributable to non-controlling interest	5
Other comprehensive income, net of tax	807
Cash dividends declared:
Common	(229)	(229)						(229)
Preferred	(36)	(36)						(36)
Recognition of the fair value of share-based compensation	28	28			28
Other share-based compensation activity (in shares)				230,000
Other share-based compensation activity	3	3		$ 0	2			1
Other	(6)	1				$ 1			(7)
Other (in shares)						149,000
Balance, end of period at Sep. 30, 2024	20,652	20,606	2,394	$ 15	15,455	$ (89)	(2,104)	4,935	46
Balance, end of period, common stock (in shares) at Sep. 30, 2024				1,459,986,000
Balance, end of period, treasury stock (in shares) at Sep. 30, 2024						(7,174,000)
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	1,453,635,809			1,460,620,000
Balance, beginning of period, treasury stock (in shares) at Dec. 31, 2024	(6,984,102)					(6,984,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 1,706	1,692						1,692	14
Net Income	1,692
Other comprehensive income (loss), net of tax	795	795					795
Income attributable to non-controlling interest	14
Other comprehensive income, net of tax	795
Net proceeds from issuance of Series K preferred stock	741	741	741
Cash dividends declared:
Common	(690)	(690)						(690)
Preferred	(81)	(81)						(81)
Recognition of the fair value of share-based compensation	84	84			84
Other share-based compensation activity (in shares)				5,678,000
Other share-based compensation activity	(35)	(35)		$ 0	(33)			(2)
Other	(16)	2	1		2	$ (1)			(18)
Other (in shares)						76,000
Balance, end of period at Sep. 30, 2025	$ 22,286	22,248	2,731	$ 15	15,537	$ (87)	(2,071)	6,123	38
Balance, end of period, common stock (in shares) at Sep. 30, 2025	1,459,390,757			1,466,298,000
Balance, end of period, treasury stock (in shares) at Sep. 30, 2025	(6,907,525)					(6,908,000)
Balance, beginning of period at Jun. 30, 2025	$ 20,970	20,928	1,989	$ 15	15,506	$ (87)	(2,246)	5,751	42
Balance, beginning of period, common stock (in shares) at Jun. 30, 2025				1,465,773,000
Balance, beginning of period, treasury stock (in shares) at Jun. 30, 2025						(6,973,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	633	629						629
Net Income	629
Other comprehensive income (loss), net of tax	175	175					175
Income attributable to non-controlling interest	4
Other comprehensive income, net of tax	175
Net proceeds from issuance of Series K preferred stock	741	741	741
Cash dividends declared:
Common	(230)	(230)						(230)
Preferred	(27)	(27)						(27)
Recognition of the fair value of share-based compensation	31	31			31
Other share-based compensation activity (in shares)				525,000
Other share-based compensation activity	0	0		$ 0	0
Other	(7)	1	1		0	$ 0			(8)
Other (in shares)						65,000
Balance, end of period at Sep. 30, 2025	$ 22,286	$ 22,248	$ 2,731	$ 15	$ 15,537	$ (87)	$ (2,071)	$ 6,123	$ 38
Balance, end of period, common stock (in shares) at Sep. 30, 2025	1,459,390,757			1,466,298,000
Balance, end of period, treasury stock (in shares) at Sep. 30, 2025	(6,907,525)					(6,908,000)