Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
INTEREST INCOME
Loans		$ 1,476	$ 837
Loans held for sale		13	12
Securities available for sale		194	173
Held-to-maturity securities		74	46
Trading account assets		12	6
Short-term investments		42	4
Other investments		13	2
Total interest income		1,824	1,080
INTEREST EXPENSE
Deposits		350	14
Federal funds purchased and securities sold under repurchase agreements		22	0
Bank notes and other short-term borrowings		78	3
Long-term debt		275	49
Total interest expense		725	66
NET INTEREST INCOME		1,099	1,014
Provision for credit losses		139	83
Net interest income after provision for credit losses		960	931
NONINTEREST INCOME
Trust and investment services income		128	136
Investment banking and debt placement fees		145	163
Cards and payments income		81	80
Service charges on deposit accounts		67	91
Corporate services income		76	91
Commercial mortgage servicing fees		46	36
Corporate-owned life insurance income		29	31
Consumer mortgage income		11	21
Operating lease income and other leasing gains		25	32
Other income		0	(5)
Total noninterest income		608	676
NONINTEREST EXPENSE
Personnel		701	630
Net occupancy		70	73
Computer processing		92	77
Business services and professional fees		45	53
Equipment		22	23
Operating lease expense		20	28
Marketing		21	28
Other expense		205	158
Total noninterest expense		1,176	1,070
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		392	537
Income taxes		81	90
INCOME (LOSS) FROM CONTINUING OPERATIONS		311	447
Income (loss) from discontinued operations		1	1
NET INCOME (LOSS)		312	448
Less: Net income (loss) attributable to noncontrolling interests		0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		312	448
Income (loss) from continuing operations attributable to Key common shareholders		275	420
Net income (loss) attributable to Key common shareholders		$ 276	$ 421
Per Common Share:
Income (loss) from continuing operations attributable to Key common shareholders (in usd per share)		$ 0.30	$ 0.45
Income (loss) from discontinued operations, net of taxes (in usd per share)		0	0
Net income (loss) attributable to Key common shareholders (in usd per share)	[1]	0.30	0.46
Per Common Share — assuming dilution:
Income (loss) from continuing operations attributable to Key common shareholders (in usd per share)		0.30	0.45
Income (loss) from discontinued operations, net of taxes (in usd per share)		0	0
Net income (loss) attributable to Key common shareholders (in usd per share)	[1]	$ 0.30	$ 0.45
Weighted-average Common Shares outstanding (in shares)		926,490	922,941
Effect of Common Share options and other stock awards (in shares)		7,314	10,692
Weighted-average Common Shares and potential Common Shares outstanding (in shares)	[2]	933,804	933,634

[1] EPS may not foot due to rounding.

[2] Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable.