KeyCorp (KEY) 10-K 22 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 17, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Entity File Number	1-11302
Entity Registrant Name	KeyCorp
Entity Incorporation, State or Country Code	OH
Entity Tax Identification Number	34-6542451
Entity Address, Address Line One	127 Public Square,
Entity Address, City or Town	Cleveland,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44114-1306
City Area Code	216
Local Phone Number	689-3000
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 11,887,028,662
Entity Common Stock, Shares Outstanding		968,815,152
Documents Incorporated by Reference	Certain specifically designated portions of KeyCorp’s definitive Proxy Statement for its 2021 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000091576
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Common Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Shares, $1 par value
Trading Symbol	KEY
Security Exchange Name	NYSE
Series E Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Perpetual Non-Cumulative Preferred Stock, Series E)
Trading Symbol	KEY PrI
Security Exchange Name	NYSE
Series F Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Cumulative Preferred Stock, Series F)
Trading Symbol	KEY PrJ
Security Exchange Name	NYSE
Series G Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Cumulative Preferred Stock, Series G)
Trading Symbol	KEY PrK
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks		$ 1,091	$ 732
Short-term investments		16,194	1,272
Trading account assets		735	1,040
Securities available for sale		27,556	21,843
Held-to-maturity securities (fair value: $8,023 and $10,116)		7,595	10,067
Other investments		621	605
Loans, net of unearned income of $449 and $630		101,185	94,646
Allowance for loan and lease losses		(1,626)	(900)
Net loans		99,559	93,746
Loans held for sale	[1]	1,583	1,334
Premises and equipment		753	814
Goodwill		2,664	2,664
Other intangible assets		188	253
Corporate-owned life insurance		4,286	4,233
Accrued income and other assets		6,812	5,494
Discontinued assets		699	891
Total assets		170,336	144,988
Deposits in domestic offices:
NOW and money market deposit accounts		80,427	66,714
Savings deposits		5,913	4,651
Certificates of deposit ($100,000 or more)		2,733	6,598
Other time deposits		3,010	5,054
Total interest-bearing deposits		92,083	83,017
Noninterest-bearing deposits		43,199	28,853
Total deposits		135,282	111,870
Federal funds purchased and securities sold under repurchase agreements		220	387
Bank notes and other short-term borrowings		759	705
Accrued expense and other liabilities		2,385	2,540
Long-term debt		13,709	12,448
Total liabilities		152,355	127,950
EQUITY
Preferred stock		1,900	1,900
Common Shares, $1 par value; authorized 2,100,000,000 and 2,100,000,000 shares; issued 1,256,702,081 and 1,256,702,081 shares		1,257	1,257
Capital surplus		6,281	6,295
Retained earnings		12,751	12,469
Treasury stock, at cost (280,928,782 and 279,513,530 shares)		(4,946)	(4,909)
Accumulated other comprehensive income (loss)		738	26
Key shareholders’ equity		17,981	17,038
Noncontrolling interests		0	0
Total equity		17,981	17,038
Total liabilities and equity		$ 170,336	$ 144,988
[1]	Total loans held for sale include Real estate — residential mortgage loans held for sale at fair value of $264 million at December 31, 2020, and $140 million at December 31, 2019

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value	$ 8,023,000,000	$ 10,116,000,000
Unearned income on loans	449,000,000	630,000,000
Certificate of deposit ($100,000 or more)	$ 100,000	$ 100,000
Common shares, par value (in dollars per share)	$ 1	$ 1
Common shares, shares authorized (in shares)	2,100,000,000	2,100,000,000
Common shares, shares issued (in shares)	1,256,702,081	1,256,702,081
Treasury stock (in shares)	280,928,782	279,513,530
Residential Mortgage [Member]
Loans held for sale	$ 264,000,000	$ 140,000,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INTEREST INCOME
Loans		$ 3,866	$ 4,267	$ 4,023
Loans held for sale		69	63	66
Securities available for sale		484	537	409
Held-to-maturity securities		222	262	284
Trading account assets		20	32	29
Short-term investments		18	61	46
Other investments		6	13	21
Total interest income		4,685	5,235	4,878
INTEREST EXPENSE
Deposits		347	853	517
Federal funds purchased and securities sold under repurchase agreements		6	2	11
Bank notes and other short-term borrowings		12	17	21
Long-term debt		286	454	420
Total interest expense		651	1,326	969
NET INTEREST INCOME		4,034	3,909	3,909
Provision for credit losses		1,021	445	246
Net interest income after provision for credit losses		3,013	3,464	3,663
NONINTEREST INCOME
Trust and investment services income		507	475	499
Investment banking and debt placement fees		661	630	650
Service charges on deposit accounts		311	337	349
Operating lease income and other leasing gains		167	162	89
Corporate services income		228	236	233
Cards and payments income		368	275	270
Corporate-owned life insurance income		139	136	137
Consumer mortgage income		176	63	43
Commercial mortgage servicing fees		80	77	69
Other income	[1]	15	68	176
Total noninterest income		2,652	2,459	2,515
NONINTEREST EXPENSE
Personnel		2,336	2,250	2,309
Net occupancy		298	293	308
Computer processing		232	214	210
Business services and professional fees		196	186	184
Equipment		100	100	105
Operating lease expense		138	123	120
Marketing		97	96	102
FDIC assessment		32	31	72
Intangible asset amortization		65	89	99
OREO expense, net		8	13	6
Other expense		607	506	460
Total noninterest expense		4,109	3,901	3,975
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		1,556	2,022	2,203
Income taxes		227	314	344
INCOME (LOSS) FROM CONTINUING OPERATIONS		1,329	1,708	1,859
Income (loss) from discontinued operations		14	9	7
NET INCOME (LOSS)		1,343	1,717	1,866
Less: Net income (loss) attributable to noncontrolling interests		0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,343	1,717	1,866
Income (loss) from continuing operations attributable to Key common shareholders		1,223	1,611	1,793
Net income (loss) attributable to Key common shareholders		$ 1,237	$ 1,620	$ 1,800
Per Common Share:
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		$ 1.26	$ 1.62	$ 1.72
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0.01
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.28	1.63	1.73
Per Common Share — assuming dilution:
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		1.26	1.61	1.70
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0.01
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.27	1.62	1.71
Cash dividends declared per common share (in dollars per share)		$ 0.74	$ 0.710	$ 0.565
Weighted-average common shares outstanding (in shares)		967,783	992,091	1,040,890
Effect of convertible preferred stock (in shares)		0	0	0
Effect of common share options and other stock awards (in shares)		7,024	10,163	13,792
Weighted-average common shares and potential common shares outstanding (in shares)	[3]	974,807	1,002,254	1,054,682
[1]	Net securities gains (losses) totaled $4 million for the year ended December 31, 2020, $20 million for the year ended December 31, 2019, and less than $1 million for the year ended December 31, 2018. For 2020, 2019, and 2018, we did not have any impairment losses related to securities.
[2]	EPS may not foot due to rounding.
[3]	Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable.

Consolidated Statements of In_2

Consolidated Statements of Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net securities gains (losses) (less than for 2018)	$ 4,000,000	$ 20,000,000	$ 0
Impairment recognized in earnings	0	0	0
Other Noninterest Income [Member]
Net securities gains (losses) (less than for 2018)	$ 4,000,000	$ 20,000,000	$ 1,000,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,343	$ 1,717	$ 1,866
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on securities available for sale, net of income taxes of $(143), $(151), and $(19)	452	488	(62)
Net unrealized gains (losses) on derivative financial instruments, net of income taxes of $(72), $(93), and $11	226	300	36
Foreign currency translation adjustments, net of income taxes of $0, $(4), and $11	0	14	(23)
Net pension and postretirement benefit costs, net of income taxes of $(9), $(13), and $3	34	42	10
Total other comprehensive income (loss), net of tax	712	844	(39)
Comprehensive income (loss)	2,055	2,561	1,827
Less: Comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income (loss) attributable to Key	$ 2,055	$ 2,561	$ 1,827

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on securities available for sale, tax	$ (143)	$ (151)	$ (19)
Net unrealized gains (losses) on derivative instruments, tax	(72)	(93)	11
Foreign currency translation adjustments, tax	0	(4)	11
Net pension and postretirement benefit costs, tax	$ (9)	$ (13)	$ 3

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Series D Preferred Stock [Member]	Series E Preferred Stock [Member]	Series F Preferred Stock [Member]	Series G Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member]Series F Preferred Stock [Member]	Common Stock [Member]	Capital Surplus [Member]	Capital Surplus [Member]Series F Preferred Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series D Preferred Stock [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]Series F Preferred Stock [Member]	Retained Earnings [Member]Series G Preferred Stock [Member]	Treasury Stock, at Cost [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]Retained Earnings [Member]
Beginning Balance, Preferred Shares (in shares) at Dec. 31, 2017						521,000
Beginning Balance, Common Shares (in shares) at Dec. 31, 2017								1,069,084,000
Beginning Balance at Dec. 31, 2017						$ 1,025		$ 1,257	$ 6,335		$ 10,335					$ (3,150)	$ (779)	$ 2	$ (2)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other reclassification of AOCI											13
Net income (loss)	$ 1,866										1,866
Other comprehensive income (loss)	$ (39)																(39)
Deferred compensation									21
Dividends, Cash [Abstract]
Cash dividends declared on common shares											(590)
Cash dividends declared on preferred stock												$ (26)	$ (31)	$ (9)
Issuance of Preferred Stock (in shares)							425,000
Issuance of Preferred Stock							$ 425			$ (13)
Open market Common Share repurchases (in shares)								(54,006,000)
Open market Common Share repurchases																(1,098)
Employee equity compensation program Common Share repurchases (in shares)								(2,286,000)
Employee equity compensation program Common Share repurchases																(47)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)								6,711,000
Common shares reissued (returned) for stock options and other employee benefit plans									(12)							114
Net contribution from (distribution to) noncontrolling interests																		(1)
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2018						946,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2018								1,019,503,000
Ending Balance at Dec. 31, 2018						$ 1,450		$ 1,257	6,331		11,556					(4,181)	(818)	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Net income (loss)	$ 1,717										1,717							0
Other comprehensive income (loss)	844																844
Deferred compensation									9
Dividends, Cash [Abstract]
Cash dividends declared on common shares											(707)
Cash dividends declared on preferred stock												(26)	(31)	(24)	$ (16)
Issuance of Preferred Stock (in shares)							450,000
Issuance of Preferred Stock							$ 450			$ (15)
Open market Common Share repurchases (in shares)								(48,347,000)
Open market Common Share repurchases																(835)
Employee equity compensation program Common Share repurchases (in shares)								(1,901,000)
Employee equity compensation program Common Share repurchases									(2)							(33)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)								7,934,000
Common shares reissued (returned) for stock options and other employee benefit plans									(28)							140
Net contribution from (distribution to) noncontrolling interests																		(1)
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2019						1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2019								977,189,000
Ending Balance at Dec. 31, 2019	17,038					$ 1,900		$ 1,257	6,295		12,469					(4,909)	26	0	(230)	[2]
Beginning Balance, Preferred Shares (in shares) at Dec. 31, 2018						946,000
Beginning Balance, Common Shares (in shares) at Dec. 31, 2018								1,019,503,000
Beginning Balance at Dec. 31, 2018						$ 1,450		$ 1,257	6,331		11,556					(4,181)	(818)	1
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2020		21,000	500,000	425,000	450,000	1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2020								975,773,000
Ending Balance at Dec. 31, 2020	17,981					$ 1,900		$ 1,257	6,281		12,751					(4,946)	738	0
Beginning Balance, Preferred Shares (in shares) at Dec. 31, 2019						1,396,000
Beginning Balance, Common Shares (in shares) at Dec. 31, 2019								977,189,000
Beginning Balance at Dec. 31, 2019	17,038					$ 1,900		$ 1,257	6,295		12,469					(4,909)	26	0	$ (230)	[2]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other reclassification of AOCI											(3)
Net income (loss)	1,343										1,344							0
Other comprehensive income (loss)	712																712
Deferred compensation									4
Dividends, Cash [Abstract]
Cash dividends declared on common shares											(723)
Cash dividends declared on preferred stock												$ (26)	$ (31)	$ (24)	$ (25)
Open market Common Share repurchases (in shares)								(7,151,000)
Open market Common Share repurchases																(134)
Employee equity compensation program Common Share repurchases (in shares)								(1,823,000)
Employee equity compensation program Common Share repurchases									(18)							(36)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)								7,558,000
Common shares reissued (returned) for stock options and other employee benefit plans									0							133
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2020		21,000	500,000	425,000	450,000	1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2020								975,773,000
Ending Balance at Dec. 31, 2020	$ 17,981					$ 1,900		$ 1,257	$ 6,281		$ 12,751					$ (4,946)	$ 738	$ 0
[1]	Includes the impact of implementing ASU 2014-09, ASU 2016-01, and ASU 2017-12.
[2]	Includes the impact of implementing ASU 2016-13. See Notes to Consolidated Financial Statements.

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash dividends declared per common share (in dollars per share)	$ 0.74	$ 0.710	$ 0.565
Series D Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	50	50	50
Series E Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	1.531252	1.531252	1.531252
Series F Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	1.4125	1.4125	$ 0.529688
Series G Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	$ 1.406252	$ 0.882813

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net income (loss)	$ 1,343	$ 1,717	$ 1,866
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for credit losses	1,021	445	246
Depreciation and amortization expense, net	111	241	382
Accretion of acquired loans	28	50	86
Increase in cash surrender value of corporate-owned life insurance	(119)	(121)	(117)
Stock-based compensation expense	101	96	99
FDIC reimbursement (payments), net of FDIC expense	0	0	(10)
Deferred income taxes (benefit)	(191)	53	98
Proceeds from sales of loans held for sale	14,076	11,980	14,019
Originations of loans held for sale, net of repayments	(13,856)	(11,704)	(13,948)
Net losses (gains) from sale of loans held for sale	(233)	(188)	(183)
Net losses (gains) and writedown on OREO	0	7	0
Net losses (gains) on leased equipment	(21)	(17)	41
Net losses (gains) on sales of fixed assets	5	(2)	9
Net securities losses (gains)	(4)	(20)	0
Net decrease (increase) in trading account assets	305	(191)	(13)
Gain on sale of KIBS	0	0	(83)
Other operating activities, net	(893)	560	14
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	1,673	2,906	2,506
INVESTING ACTIVITIES
Cash received (used) in acquisitions, net of cash acquired	0	(185)	0
Proceeds from sale of KIBS	0	0	124
Net decrease (increase) in short-term investments, excluding acquisitions	(14,922)	1,290	1,885
Purchases of securities available for sale	(15,619)	(5,714)	(4,594)
Proceeds from sales of securities available for sale	583	362	0
Proceeds from prepayments and maturities of securities available for sale	9,923	3,586	3,197
Proceeds from prepayments and maturities of held-to-maturity securities	2,493	1,477	1,558
Purchases of held-to-maturity securities	(17)	(22)	(1,242)
Purchases of other investments	(134)	(52)	(28)
Proceeds from sales of other investments	101	60	62
Proceeds from prepayments and maturities of other investments	15	56	40
Net decrease (increase) in loans, excluding acquisitions, sales, and transfers	(7,358)	(6,190)	(3,700)
Proceeds from sales of portfolio loans	211	399	204
Proceeds from corporate-owned life insurance	66	59	78
Purchases of premises, equipment, and software	(63)	(85)	(99)
Proceeds from sales of premises and equipment	0	18	2
Proceeds from sales of OREO	0	23	31
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(24,721)	(4,918)	(2,482)
FINANCING ACTIVITIES
Net increase (decrease) in deposits, excluding acquisitions	23,412	4,561	2,074
Net increase (decrease) in short-term borrowings	(113)		(148)
Net increase (decrease) in short-term borrowings		229
Net proceeds from issuance of long-term debt	3,607	2,129	2,306
Payments on long-term debt	(2,508)	(3,634)	(2,880)
Issuance of preferred shares	0	435	412
Repurchase of Common Shares	(134)	(835)	(1,098)
Employee equity compensation program Common Share repurchases	(36)	(33)	(47)
Net proceeds from reissuance of Common Shares	8	18	20
Cash dividends paid	(829)	(804)	(656)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	23,407	2,066	(17)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	359	54	7
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	732	678	671
CASH AND DUE FROM BANKS AT END OF YEAR	1,091	732	678
Additional disclosures relative to cash flows:
Interest paid	731	1,251	892
Income taxes paid (refunded)	241	18	12
Noncash items:
Reduction of secured borrowing and related collateral	7	5	20
Loans transferred to portfolio from held for sale	75	157	24
Loans transferred to held for sale from portfolio	310	468	(33)
Loans transferred to other real estate owned	96	29	25
CMBS risk retentions	40	59	16
ABS risk retentions	$ 19	$ 12	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Organization We are one of the nation’s largest bank-based financial services companies, providing deposit, lending, cash management, and investment services to individuals and small and medium-sized businesses through our subsidiary, KeyBank. We also provide a broad range of sophisticated corporate and investment banking products, such as merger and acquisition advice, public and private debt and equity, syndications, and derivatives to middle market companies in selected industries throughout the United States through our subsidiary, KBCM. As of December 31, 2020, KeyBank operated 1,073 full-service retail banking branches and 1,386 ATMs in 15 states, as well as additional offices, online and mobile banking capabilities, and a telephone banking call center. Additional information pertaining to our two major business segments, Consumer Bank and Commercial Bank, is included in Note 25 (“Business Segment Reporting”). Use of Estimates Our accounting policies conform to GAAP and prevailing practices within the financial services industry. We must make certain estimates and judgments when determining the amounts presented in our consolidated financial statements and the related notes. If these estimates prove to be inaccurate, actual results could differ from those reported. Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of KeyCorp and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Some previously reported amounts have been reclassified to conform to current reporting practices. The consolidated financial statements also include the accounts of any voting rights entities in which we have a controlling financial interest and certain VIEs. In accordance with the applicable accounting guidance for consolidations, we consolidate a VIE if we have the power to direct activities of the VIE that most significantly impact the entity’s economic performance and the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. See Note 13 (“Variable Interest Entities”) for information on our involvement with VIEs. We use the equity method to account for unconsolidated investments in voting rights entities or VIEs if we have significant influence over the entity’s operating and financing decisions (usually defined as a voting or economic interest of 20% to 50%, but not controlling). Unconsolidated investments in voting rights entities or VIEs in which we have a voting or economic interest of less than 20% generally are carried at fair value or a cost measurement alternative. In preparing these financial statements, subsequent events were evaluated through the time the financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users or filed with the SEC. Cash and Cash Equivalents Cash and due from banks are considered “cash and cash equivalents” for financial reporting purposes. We do not consider cash on deposit with the Federal Reserve to be restricted. Loans Loans held in portfolio, which management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are carried at the principal amount outstanding, net of unearned income, including net deferred loan fees and costs and unamortized premiums and discounts. We defer certain nonrefundable loan origination and commitment fees, and the direct costs of originating or acquiring loans. The net deferred amount is amortized over the estimated lives of the related loans as an adjustment to the yield. Accrued interest on loans is included in "other assets" on the balance sheet and is excluded from the calculation of the allowance for credit losses due to our charge-off policy to reverse accrued interest on nonperforming loans against interest income in a timely manner. Certain loans that received a payment deferral or forbearance under a COVID-19 hardship relief program have not been classified as nonperforming loans and continue to accrue and recognize interest income during the period of the deferral. We, therefore, recognize an allowance for credit losses for accrued interest receivable amounts that result from deferred payments under a COVID-19 hardship relief program because those amounts would not be considered to be written off in a timely manner. As of December 31, 2020, the allowance for credit losses on accrued interest receivable was immaterial. Sales-type leases are carried at the aggregate of the lease receivable, estimated unguaranteed residual values, and deferred initial direct fees and costs if certain criteria are met. Direct financing leases are carried at the aggregate of the lease receivable, estimated unguaranteed residual values, and deferred initial direct fees and costs, less unearned income. Unearned income on direct financing leases is amortized over the lease terms using a method approximating the interest method that produces a constant rate of return. Deferred initial direct fees and costs for both sales-type and direct financing leases are amortized over the lease terms as an adjustment to the yield. Expected credit losses on net investments in leases, including any unguaranteed residual asset, are included in the ALLL. Net gains or losses on sales of lease residuals are included in “other income” or “other expense” on the income statement. Additional information pertaining to the value of lease residuals is provided in Note 10 (“Leases”). Loans Held for Sale Loans held for sale generally include certain residential and commercial mortgage loans, other commercial loans, and student loans. Loans are initially classified as held for sale when they are individually identified as being available for immediate sale and a formal plan exists to sell them. Loans held for sale are recorded at either fair value, if elected, or the lower of cost or fair value. Fair value is determined based on available market data for similar assets. When a loan is originated as held-for-sale, origination fees and costs are deferred but not amortized. Upon sale of the loans, deferred origination fees and costs are recognized as part of the calculated gain or loss on sale. Our commercial loans (including commercial mortgage and non-mortgage loans) and student loans, which we originated and intend to sell, are carried at the lower of aggregate cost or fair value. Subsequent declines in fair value for loans held for sale are recognized as a charge to “other income” on the income statement. Consumer real estate - residential mortgages loans have been elected to be carried at fair value. Subsequent increases and decreases in fair value for loans elected to be measured at fair value are recorded to “consumer mortgage income” on the income statement. Additional information regarding fair value measurements associated with our loans held for sale is provided in Note 6 (“Fair Value Measurements”). We may transfer certain loans to held for sale at the lower of cost or fair value. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a reduction in the ALLL. When a loan is transferred into the held for sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold. We may also transfer loans from held for sale to the loan portfolio held for investment. If a loan held for sale for which fair value accounting was elected is transferred to held for investment, it will continue to be accounted for at fair value in the loan portfolio. Nonperforming Loans Nonperforming loans are loans for which we do not accrue interest income, and include commercial and consumer loans and leases, as well as current year TDRs and nonaccruing TDR loans from prior years. Nonperforming loans do not include loans held for sale. Once a loan is designated nonaccrual, the interest accrued but not collected is reversed against interest income, and payments subsequently received are applied to principal until qualifying for return to accrual. We generally classify commercial loans as nonperforming and stop accruing interest (i.e., designate the loan “nonaccrual”) when the borrower’s principal or interest payment is 90 days past due unless the loan is well-secured and in the process of collection. Commercial loans are also placed on nonaccrual status when payment is not past due but we have serious doubts about the borrower’s ability to comply with existing repayment terms. Once a loan is designated nonaccrual (and as a result assessed for impairment), the interest accrued but not collected is generally charged against the ALLL, and payments subsequently received are applied to principal. Commercial loans are typically charged off in full or charged down to the fair value of the underlying collateral when the borrower’s payment is 180 days past due. We classify consumer loans as nonperforming and stop accruing interest when the borrower’s payment is 120 days past due, unless the loan is well-secured and in the process of collection. Any second lien home equity loan with an associated first lien that is 120 days or more past due or in foreclosure, or for which the first mortgage delinquency timeframe is unknown, is reported as a nonperforming loan. Secured loans that are discharged through Chapter 7 bankruptcy and not formally re-affirmed are designated as nonperforming and TDRs. Our charge-off policy for most consumer loans takes effect when payments are 120 days past due. Home equity and residential mortgage loans generally are charged down to net realizable value when payment is 180 days past due. Credit card loans and similar unsecured products continue to accrue interest until the account is charged off at 180 days past due. Commercial and consumer loans may be returned to accrual status if we are reasonably assured that all contractually due principal and interest are collectible and the borrower has demonstrated a sustained period (generally six months) of repayment performance under the contracted terms of the loan and applicable regulation. Purchased Loans Purchased performing loans that do not have evidence of deterioration in credit quality at acquisition are recorded at fair value at the acquisition date. Any premium or discount associated with purchased performing loans is recognized as interest income based on the effective yield method of amortization for term loans or the straight-line method of amortization for revolving loans. The methods utilized to estimate the required ALLL for purchased performing loans is similar to originated loans. Purchased loans that have experienced a more-than-insignificant deterioration in credit quality since origination are deemed PCD loans. PCD loans are initially recorded at fair value along with an allowance for credit losses determined using the same methodology as originated loans. The sum of the loan's purchase price and allowance for credit losses becomes its initial amortized cost basis. The difference between the initial amortized cost basis and the par value of the loan is a noncredit discount or premium, which is amortized into interest income over the life of the loan. Subsequent changes to the allowance for credit losses are recorded through provision for credit losses. Allowance for Loan and Lease Losses We estimate the ALLL using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. The ALLL is measured on a collective (pool) basis when similar risk characteristics exist. Our portfolio segments include commercial and consumer. Each of these two segments comprises multiple loan classes. Classes are characterized by similarities in initial measurement, risk attributes, and the manner in which we monitor and assess credit risk. The commercial segment is composed of commercial and industrial, commercial real estate, and commercial lease financing loan classes. The consumer lending segment is composed of residential mortgage, home equity, consumer direct, credit card, student lending and consumer indirect loan classes. The ALLL represents our current estimate of lifetime credit losses inherent in our loan portfolio at the balance sheet date. In determining the ALLL, we estimate expected future losses for the loan's entire contractual term adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications. The ALLL is the sum of three components: (i) asset specific/ individual loan reserves; (ii) quantitative (formulaic or pooled) reserves; and (iii) qualitative (judgmental) reserves. Asset Specific / Individual Component Loans that do not share risk characteristics are evaluated on an individual basis. Loans evaluated individually are not included in the collective evaluation. We have elected to apply the practical expedient to measure expected credit losses of a collateral dependent asset using the fair value of the collateral, less any costs to sell, when foreclosure is not probable, when repayment of the loan is expected to be provided substantially through the operation or sale of the collateral, and the borrower is experiencing financial difficulty. Individual reserves are determined as follows: • For commercial non-accruing loans greater than or equal to a defined dollar threshold, individual reserves are determined based on an analysis of the present value of the loan's expected future cash flows or the fair value of the collateral less costs to sell. • For commercial non-accruing loans below the defined dollar threshold, an established LGD percentage is multiplied by the loan balance and the results are aggregated for purposes of measuring specific reserve impairment. • The population of individually assessed consumer loans includes loans deemed collateral dependent, in addition to all TDRs. The expected loss for these loans is estimated based on the present value of the loan's expected future cash flows, except in instances where the loan is collateral dependent, in which case the loan is written down based on the collateral's fair market value less costs to sell. Quantitative Component We use a non-DCF factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller loan portfolios. • PD: This component model is used to estimate the likelihood that a borrower will cease making payments as agreed. The major contributors to this are the borrower credit attributes and macro-economic trends. The objective of the PD model is to produce default likelihood forecasts based on the observed loan-level information and projected paths of macroeconomic variables. • LGD: This component model is used to estimate the loss on a loan once a loan is in default. • EAD: Estimates the loan balance at the time the borrower stops making payments. For all term loans, an amortization based formulaic approach is used for account level EAD estimates. We calculate EAD using a portfolio specific method in each of our revolving product portfolios. For line products that are unconditionally cancellable, the balances will either use a paydown curve or be held flat through the life of the loan. Qualitative Component The ALLL also includes identified qualitative factors related to idiosyncratic risk factors, changes in current economic conditions that may not be reflected in quantitatively derived results, and other relevant factors to ensure the ALLL reflects our best estimate of current expected credit losses. While our reserve methodologies strive to reflect all relevant risk factors, there continues to be uncertainty associated with, but not limited to, potential imprecision in the estimation process due to the inherent time lag of obtaining information and normal variations between estimates and actual outcomes. We provide additional reserves that are designed to provide coverage for losses attributable to such risks. The ALLL also includes factors that may not be directly measured in the determination of individual or collective reserves. Such qualitative factors may include: • The nature and volume of the institution’s financial assets; • The existence, growth, and effect of any concentrations of credit; • The volume and severity of past due financial assets, the volume of nonaccrual assets, and the volume and severity of adversely classified or graded assets; • The value of the underlying collateral for loans that are not collateral dependent; • The institution’s lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries; • The quality of the institution’s credit review function; • The experience, ability, and depth of the institution’s lending, investment, collection, and other relevant management and staff; • The effect of other external factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters; and • Actual and expected changes in international, national, regional, and local economic and business conditions and developments in which the institution operates that affect the collectability of financial assets. Liability for Credit Losses on Lending-Related Commitments The liability for credit losses on lending-related commitments, such as letters of credit and unfunded loan commitments, is included in “accrued expense and other liabilities” on the balance sheet. Expected credit losses are estimated over the contractual period in which we are exposed to credit risk via a contractual obligation unless that obligation is unconditionally cancellable by us. The liability for credit losses on lending-related commitments is adjusted as a provision for credit losses. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated useful life. Consistent with our estimation process on our loan and lease portfolio, we use a non-DCF factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller portfolios. Allowance for Credit Losses on Other Financial Assets The allowance for credit losses on other financial assets, such as other receivables and servicing advances, is determined based on historical loss information and other available indicators. If such information does not indicate any expected credit losses, Key may estimate the allowance for credit losses on other financial assets to be zero or close to zero. As of December 31, 2020, the allowance for credit losses on other financial assets was immaterial. Fair Value Measurements Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market. Therefore, fair value represents an exit price at the measurement date. We value our assets and liabilities based on the principal or most advantageous market where each would be sold (in the case of assets) or transferred (in the case of liabilities). In the absence of observable market transactions, we consider liquidity valuation adjustments to reflect the uncertainty in pricing the instruments. Valuation inputs can be observable or unobservable. Observable inputs are assumptions based on market data obtained from an independent source. Unobservable inputs are assumptions based on our own information or assessment of assumptions used by other market participants in pricing the asset or liability. Our unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy that gives the highest ranking to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for Level 2 assets and liabilities are based on one or a combination of the following factors: (i) quoted market prices for similar assets or liabilities; (ii) observable inputs, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy ascribed to a fair value measurement in its entirety is based on the lowest level input that is significant to the measurement. Assets and liabilities may transfer between levels based on the observable and unobservable inputs used at the valuation date. Assets and liabilities are recorded at fair value on a recurring or nonrecurring basis. Nonrecurring fair value adjustments are typically recorded as a result of the application of lower of cost or fair value accounting; or impairment. At a minimum, we conduct our valuations quarterly. Additional information regarding fair value measurements and disclosures is provided in Note 6 (“Fair Value Measurements”). Short-Term Investments Short-term investments consist of segregated, interest-bearing deposits due from banks, the Federal Reserve, and certain non-U.S. banks as well as reverse repurchase agreements and United States Treasury Bills with an original maturity of three months or less. Trading Account Assets Trading account assets are debt and equity securities, as well as commercial loans, that we purchase and hold but intend to sell in the near term. These assets are reported at fair value. Realized and unrealized gains and losses on trading account assets are reported in “other income” on the income statement. Securities Securities available for sale. Debt securities that we intend to hold for an indefinite period of time but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs, or other factors are classified as available-for-sale and reported at fair value. Realized gains and losses resulting from sales of securities using the specific identification method, are included in “other income” on the income statement. Unrealized holding gains are recorded through other comprehensive income. Unrealized losses in fair value below the amortized cost basis are assessed to determine whether the impairment gets recorded through other comprehensive income or through earnings using a valuation allowance. For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either of these criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value in “other income” on the income statement. For debt securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized costs, the nature of the security, the underlying collateral, and the financial condition of the issuers, among other factors. If this assessment indicates a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for available-for-sale securities is recorded for the credit loss, limited by the amount that the fair value is less than the amortized costs basis. Any impairment that has not been recorded through an allowance for available-for-sale securities is recognized in other comprehensive income. Changes in the allowance available-for-sale are recorded as provision for (or reversal of) credit loss. Losses are charged against the allowance for available-for-sale securities when management believes the uncollectibility of an available-for-sale security is confirmed or when either criteria regarding intent or requirement to sell is met. “Other securities” held in the available-for-sale portfolio consist of convertible preferred stock of privately held companies. For additional information, refer to Note 7 (“Securities”). Held-to-maturity securities. Debt securities that we have the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost and adjusted for amortization of premiums and accretion of discounts using the interest method. This method produces a constant rate of return on the adjusted carrying amount. The held-to-maturity portfolio is classified by the following major security types: agency residential collateralized mortgage obligations, agency residential mortgage-backed securities, agency commercial mortgage-backed securities, asset backed securities, and other. “Other securities” held in the held-to-maturity portfolio consist of foreign bonds and capital securities. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type. The estimate of expected losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. We do not measure expected credit losses on held-to-maturity securities in which historical credit loss information adjusted for current conditions and reasonable and supportable forecasts results in an expectation that nonpayment of the amortized cost basis is zero. All of our mortgage-backed securities are issued by U.S. government-sponsored enterprises or GNMA, are highly rated by major rating agencies and have a long history of no credit losses. Other securities are comprised of State of Israel bonds denominated and paid in U.S. dollars. Israel bonds have a long history of no credit losses. Additionally, as of December 31, 2020, the State of Israel's credit rating remains "stable" among Fitch, Moody's, and S&P (A+, A1, AA-). Other Investments Other investments include equity and mezzanine instruments as well as other types of investments that generally are carried at the alternative cost method. The alternative cost method results in these investments being recorded at cost, less any impairment, plus or minus changes resulting from observable market transactions. Adjustments are included in “other income” on the income statement. Derivatives and Hedging All derivatives are recognized on the balance sheet at fair value in “accrued income and other assets” or “accrued expense and other liabilities.” The net increase or decrease in derivatives is included in “other operating activities, net” within the statement of cash flows. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedge relationship, and on the type of hedge relationship. For derivatives that are not in a hedge relationship, any gain or loss, as well as any premium paid or received, is recognized immediately in earnings in “corporate services income” or “other income” on the income statement, depending whether the derivative is for customer accommodation or risk management, respectively. A derivative that is designated and qualifies as a hedging instrument must be designated as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Changes in the fair value of a hedging instrument are reflected in the same income statement line as the earnings effect of the change in fair value of the hedged item attributable to the hedged risk. A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities, and commitments caused by changes in interest rates or other economic factors. The change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time as a change in fair value of the hedged item attributable to the hedged risk. A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The gain or loss on a cash flow hedge is recorded as a component of AOCI on the balance sheet and reclassified to earnings in the same period in which the hedged transaction affects earnings (e.g., when we incur variable-rate interest on debt, earn variable-rate interest on loans, or sell commercial real estate loans). A net investment hedge is used to hedge the exposure of changes in the carrying value of investments as a result of changes in the related foreign exchange rates. The gain or loss on a net investment hedge is recorded as a component of AOCI on the balance sheet when the terms of the derivative match the notional and currency risk being hedged. The amount in AOCI is reclassified into income when the hedged transaction affects earnings (e.g., when we dispose or liquidate a foreign subsidiary). Hedge “effectiveness” is determined by the extent to which changes in the fair value of a derivative instrument offset changes in the fair value, cash flows, or carrying value attributable to the risk being hedged. If the relationship between the change in the fair value of the derivative instrument and the change in the hedged item falls within a range considered to be the industry norm, the hedge is considered “highly effective” and qualifies for hedge accounting. A hedge is “ineffective” if the relationship between the changes falls outside the acceptable range. In that case, hedge accounting is discontinued on a prospective basis. Hedge effectiveness is tested at least quarterly. We take into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets on the balance sheet and contracts with positive fair values included in derivative liabilities. Derivative assets and derivative liabilities are recorded within “accrued income and other assets” and “accrued expense and other liabilities,” respectively. Additional information regarding the accounting for derivatives is provided in Note 8 (“Derivatives and Hedging Activities”). Loan Sales and Securitizations We sell and at times may securitize loans and other financial assets. We recognize the sale and securitization of loans or other financial assets when the transferred assets are legally isolated from our creditors and the appropriate accounting criteria are met. When we securitize loans or other financial assets, we may retain a portion of the securities issued, including senior interests, subordinated interests, interest-only strips, servicing rights, and other interests, all of which are considered retained interests in the transferred assets. The interests are initially measured at fair value which is based on independent third party market prices or market prices for similar assets. If market prices are not available, fair value is estimated based on the present value of expected future cash flows using assumptions as to discount rates, interest rates, prepayment speeds, and credit losses. Loans sold or securitized are removed from the balance sheet and a net gain or loss is recognized in “other income” at the time of sale. Gains or losses recognized depend on the fair value of the loans sold and the retained interests at the date of sale. Servicing Assets We service commercial real estate and residential mortgage loans. Servicing assets and liabilities purchased or retained are initially measured at fair value and are recorded as a component of “accrued income and other assets” on the balance sheet. When no ready market value (such as quoted market prices, or prices based on sales or purchases of similar assets) is available to determine the fair value of servicing assets, fair value is determined by calculating the present value of future cash flows associated with servicing t

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Common Share	2. Earnings Per Common Share Basic earnings per share is the amount of earnings (adjusted for dividends declared on our preferred stock) available to each Common Share outstanding during the reporting periods. Diluted earnings per share is the amount of earnings available to each Common Share outstanding during the reporting periods adjusted to include the effects of potentially dilutive Common Shares. Potentially dilutive Common Shares include stock options and other stock-based awards. Potentially dilutive Common Shares are excluded from the computation of diluted earnings per share in the periods where the effect would be antidilutive. Our basic and diluted earnings per Common Share are calculated as follows: Year ended December 31, dollars in millions, except per share amounts 2020 2019 2018 EARNINGS Income (loss) from continuing operations $ 1,329 $ 1,708 $ 1,859 Less: Net income (loss) attributable to noncontrolling interests — — — Income (loss) from continuing operations attributable to Key 1,329 1,708 1,859 Less: Dividends on preferred stock 106 97 66 Income (loss) from continuing operations attributable to Key common shareholders 1,223 1,611 1,793 Income (loss) from discontinued operations, net of taxes 14 9 7 Net income (loss) attributable to Key common shareholders $ 1,237 $ 1,620 $ 1,800 WEIGHTED-AVERAGE COMMON SHARES Weighted-average Common Shares outstanding (000) 967,783 992,091 1,040,890 Effect of common share options and other stock awards 7,024 10,163 13,792 Weighted-average common shares and potential Common Shares outstanding (000) (a) 974,807 1,002,254 1,054,682 EARNINGS PER COMMON SHARE Income (loss) from continuing operations attributable to Key common shareholders $ 1.26 $ 1.62 $ 1.72 Income (loss) from discontinued operations, net of taxes .01 .01 .01 Net income (loss) attributable to Key common shareholders (b) 1.28 1.63 1.73 Income (loss) from continuing operations attributable to Key common shareholders — assuming dilution 1.26 1.61 1.70 Income (loss) from discontinued operations, net of taxes .01 .01 .01 Net income (loss) attributable to Key common shareholders — assuming dilution (b) 1.27 1.62 1.71 (a) Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable. (b) EPS may not foot due to rounding.

Restrictions on Cash, Dividends

Restrictions on Cash, Dividends and Lending Activities	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Restrictions on Cash, Dividends, and Lending Activities	3. Restrictions on Cash, Dividends, and Lending Activities Federal law requires a depository institution to maintain a prescribed amount of cash or deposit reserve balances with its Federal Reserve Bank. KeyBank maintained average reserve balances aggregating $97 million in 2020 to fulfill these requirements while they were in effect. As announced on March 15, 2020, the Federal Reserve Board reduced reserve requirement ratios to zero percent effective March 26, 2020. This action eliminated reserve requirements for all depository institutions. Capital distributions from KeyBank and other subsidiaries are our principal source of cash flows for paying dividends on our common and preferred shares, servicing our debt, and financing corporate operations. Federal banking law limits the amount of capital distributions that a bank can make to its holding company without prior regulatory approval. A national bank’s dividend-paying capacity is affected by several factors, including net profits (as defined by statute) for the previous two calendar years and for the current year, up to the date the dividend is declared. During 2020, KeyBank paid $1.3 billion in dividends to KeyCorp. At January 1, 2021, KeyBank had regulatory capacity to pay $720 million in dividends to KeyCorp without prior regulatory approval. At December 31, 2020, KeyCorp held $3.8 billion in cash and short-term investments, which can be used to pay dividends to shareholders, service debt, and finance corporate operations.

Loan Portfolio

Loan Portfolio	12 Months Ended
	Dec. 31, 2020
Financing Receivable, before Allowance for Credit Loss [Abstract]
Loan Portfolio	4. Loan Portfolio Loan Portfolio by Portfolio Segment and Class of Financing Receivable (a) December 31, in millions 2020 2019 Commercial and industrial (a) $ 52,907 $ 48,295 Commercial real estate: Commercial mortgage 12,687 13,491 Construction 1,987 1,558 Total commercial real estate loans 14,674 15,049 Commercial lease financing (b) 4,399 4,688 Total commercial loans 71,980 68,032 Residential — prime loans: Real estate — residential mortgage 9,298 7,023 Home equity loans 9,360 10,274 Total residential — prime loans 18,658 17,297 Consumer direct loans 4,714 3,513 Credit cards 989 1,130 Consumer indirect loans 4,844 4,674 Total consumer loans 29,205 26,614 Total loans (c) $ 101,185 $ 94,646 (a) Accrued interest of $241 million and $244 million at December 31, 2020, and December 31, 2019, respectively, is presented in "Accrued income and other assets" on the Consolidated Balance Sheets and is excluded from the amortized cost basis disclosed in this table. (b) Loan balances include $127 million and $144 million of commercial credit card balances at December 31, 2020, and December 31, 2019, respectively. (c) Commercial lease financing includes receivables of $23 million and $15 million held as collateral for a secured borrowing at December 31, 2020, and December 31, 2019, respectively. Principal reductions are based on the cash payments received from these related receivables. Additional information pertaining to this secured borrowing is included in Note 20 (“Long-Term Debt”). (d) Total loans exclude loans in the amount of $710 million at December 31, 2020, and $865 million at December 31, 2019, related to the discontinued operations of the education lending business.

Asset Quality

Asset Quality	12 Months Ended
	Dec. 31, 2020
Credit Loss [Abstract]
Asset Quality	5. Asset Quality ALLL We estimate the appropriate level of the ALLL on at least a quarterly basis. The methodology is described in Note 1 ("Basis of Presentation and Accounting Policies") under the heading "Allowance for Loan and Lease Losses" of this report. The ALLL at December 31, 2020, represents our current estimate of lifetime credit losses inherent in the loan portfolio at that date. The changes in the ALLL by loan category for the periods indicated are as follows: Twelve months ended December 31, 2020: in millions December 31, 2019 Impact of ASC 326 Adoption January 1, 2020 Provision Charge-offs Recoveries December 31, 2020 Commercial and Industrial $ 551 $ (141) $ 410 $ 585 $ (351) $ 34 $ 678 Commercial real estate: Real estate — commercial mortgage 143 16 159 184 (19) 3 327 Real estate — construction 22 (7) 15 32 — — 47 Total commercial real estate loans 165 9 174 216 (19) 3 374 Commercial lease financing 35 8 43 38 (35) 1 47 Total commercial loans 751 (124) 627 839 (405) 38 1,099 Real estate — residential mortgage 7 77 84 19 (2) 1 102 Home equity loans 31 147 178 (3) (11) 7 171 Consumer direct loans 34 63 97 61 (37) 7 128 Credit cards 47 35 82 36 (39) 8 87 Consumer indirect loans 30 6 36 13 (28) 18 39 Total consumer loans 149 328 477 126 (117) 41 527 Total ALLL — continuing operations 900 204 1,104 965 (a) (522) 79 1,626 Discontinued operations 10 31 41 (5) (5) 5 36 Total ALLL — including discontinued operations $ 910 $ 235 $ 1,145 $ 960 $ (527) $ 84 $ 1,662 (a) Excludes a provision for losses on lending-related commitments of $56 million. Twelve months ended December 31, 2019 : in millions December 31, 2018 Provision Charge-offs Recoveries December 31, 2019 Commercial and Industrial $ 532 $ 311 $ (319) $ 27 $ 551 Commercial real estate: Real estate — commercial mortgage 142 7 (8) 2 143 Real estate — construction 33 (6) (5) — 22 Total commercial real estate loans 175 1 (13) 2 165 Commercial lease financing 36 20 (26) 5 35 Total commercial loans 743 332 (358) 34 751 Real estate — residential mortgage 7 1 (3) 2 7 Home equity loans 35 7 (19) 8 31 Consumer direct loans 30 38 (41) 7 34 Credit cards 48 36 (44) 7 47 Consumer indirect loans 20 27 (34) 17 30 Total consumer loans 140 109 (141) 41 149 Total ALLL — continuing operations 883 441 (a) (b) (499) (b) 75 900 Discontinued operations 14 3 (12) 5 10 Total ALLL — including discontinued operations $ 897 $ 444 $ (511) $ 80 $ 910 (a) Excludes a provision for losses on lending-related commitments of $4 million. (b) Includes the realization of a $139 million loss related to a previously disclosed fraud incident. Twelve months ended December 31, 2018 in millions December 31, 2017 Provision Charge-offs Recoveries December 31, 2018 Commercial and industrial $ 529 $ 125 $ (159) $ 37 $ 532 Real estate — commercial mortgage 133 27 (21) 3 142 Real estate — construction 30 1 — 2 33 Commercial lease financing 43 (2) (10) 5 36 Total commercial loans 735 151 (190) 47 743 Real estate — residential mortgage 7 1 (3) 2 7 Home equity loans 43 2 (21) 11 35 Consumer direct loans 28 31 (36) 7 30 Credit cards 44 41 (44) 7 48 Consumer indirect loans 20 14 (30) 16 20 Total consumer loans 142 89 (134) 43 140 Total ALLL — continuing operations 877 240 (a) (324) 90 883 Discontinued operations 16 8 (15) 5 14 Total ALLL — including discontinued operations $ 893 $ 248 $ (339) $ 95 $ 897 (a) Excludes a provision for losses on lending-related commitments of $6 million. As described in Note 1 ("Basis of Presentation and Accounting Policies"), we estimate the ALLL using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. In our estimation of expected credit losses, we use a two year reasonable and supportable period across all products. Following this two year period in which supportable forecasts can be generated, for all modeled loan portfolios, we revert expected credit losses to a level that is consistent with our historical information by reverting the macroeconomic variables (model inputs) to their long run average. We revert to historical loss rates for less complex estimation methods for smaller portfolios. A 20 year fixed length look back period is used to calculate the long run average of the macroeconomic variables. A four quarter reversion period is used where the macroeconomic variables linearly revert to their long run average following the two year reasonable and supportable period. We develop our reasonable and supportable forecasts using relevant data including, but not limited to, changes in economic output, unemployment rates, property values, and other factors associated with the credit losses on financial assets. Some macroeconomic variables apply to all portfolio segments, while others are more portfolio specific. The following table discloses key macroeconomic variables for each loan portfolio. Segment Portfolio Key Macroeconomic Variables (a) Commercial Commercial and industrial BBB corporate bond rate (spread), GDP, industrial production, and unemployment rate Commercial real estate BBB corporate bond rate (spread), property and real estate price indices, and unemployment rate Commercial lease financing BBB corporate bond rate (spread), GDP, and unemployment rate Consumer Real estate — residential mortgage GDP, home price index, unemployment rate, and 30 year mortgage rate Home equity Home price index, unemployment rate, and 30 year mortgage rate Consumer direct Unemployment rate and U.S. household income Consumer indirect New vehicle sales, Manheim used vehicle value index, and unemployment rate Credit cards Unemployment rate and U.S. household income Discontinued operations Unemployment rate (a) Variables include all transformations and interactions with other risk drivers. Additionally, variables may have varying impacts at different points in the economic cycle. In addition to macroeconomic drivers, portfolio attributes such as remaining term, outstanding balance, risk ratings, FICO, LTV, and delinquency also drive ALLL changes. Our ALLL models were designed to capture the correlation between economic and portfolio changes. As such, evaluating shifts in individual portfolio attributes and macroeconomic variables in isolation may not be indicative of past or future performance. Economic Outlook As of December 31, 2020, the COVID-19 pandemic has continued to create economic stress and uncertainty in the U.S. and globally. We utilized the Moody’s November 2020 Consensus forecast to estimate our expected credit losses as of December 31, 2020. This forecast considered the global economic impact from the ongoing pandemic, as well as the potential United States' fiscal response. We considered all available information at year end, including the December 2020 fiscal stimulus package and the rollout of the COVID vaccines and determined the forecast to be a reasonable view of the outlook for the global economy. The baseline scenario reflects moderate economic growth over the next two years in markets in which we operate. U.S. GDP continues to rebound from the unprecedented decline in the second quarter of 2020 with a 3% annualized growth rate forecast for the fourth quarter of 2020. GDP continues to grow throughout 2021, returning to pre-pandemic levels by the fourth quarter of 2021. The national unemployment rate forecast is 7.2% in the fourth quarter of 2020, declining to 6.3% by the fourth quarter of 2021. To the extent we identify credit risk considerations that are not captured by the third-party economic forecast, we address the risk through management’s qualitative adjustments to the ALLL. As a result of the unprecedented economic uncertainty caused by the COVID-19 pandemic, our future loss estimates may vary considerably from our December 31, 2020, assumptions. Commercial Loan Portfolio The ALLL from continuing operations for the commercial segment decreased by $124 million, or 16.5%, from December 31, 2019 to January 1, 2020, with the adoption of ASU 2016-13, Financial Instruments - Credit Losses (ASC 326). The commercial ALLL increased by $472 million, or 75.3%, from January 1, 2020, through December 31, 2020, driven by updated economic forecasts that capture deterioration triggered by the global COVID-19 pandemic . The primary changes to the economic forecast included higher unemployment and decreased GDP and commercial real estate price indices, which contributed to the ALLL increase for the overall commercial segment. Negative risk rating migration and increased criticized assets during the year also contributed to increases in ALLL levels for the commercial segment. As of December 31, 2020, we concluded that no ALLL is necessary for $6.7 billion in outstanding PPP loans as they are 100% guaranteed by the SBA. Consumer Loan Portfolio The ALLL from continuing operations for the consumer segment increased by $328 million, or 220%, from December 31, 2019 to January 1, 2020, with the adoption of ASU 2016-13, Financial Instruments - Credit Losses (ASC 326). The consumer ALLL increased $50 million, or 10.5%, from January 1, 2020 through December 31, 2020, largely driven by updated economic forecasts that capture deterioration triggered by the global COVID-19 pandemic. The most meaningful economic forecast change contributing to the increase in reserves since January 1, 2020 is deterioration in the unemployment rate outlook, which impacts all consumer segments. As it relates to the changes in the ALLL due to portfolio factors, shifts are largely driven by attrition activity, targeted portfolio growth and overall strong credit performance. The ALLL results reflect incremental credit risk considerations as a result of the economic stress and related borrower assistance programs, which are addressed through qualitative adjustments. Credit Risk Profile The prevalent risk characteristic for both commercial and consumer loans is the risk of loss arising from an obligor’s inability or failure to meet contractual payment or performance terms. Evaluation of this risk is stratified and monitored by the loan risk rating grades assigned for the commercial loan portfolios and the refreshed FICO score assigned for the consumer loan portfolios. The internal risk grades assigned to loans follow our definitions of Pass and Criticized, which are consistent with published definitions of regulatory risk classifications. Loans with a pass rating represent those loans not classified on our rating scale for problem credits, as minimal credit risk has been identified. Criticized loans are those loans that either have a potential weakness deserving management's close attention or have a well-defined weakness that may put full collection of contractual cash flows at risk. Borrower FICO scores provide information about the credit quality of our consumer loan portfolio as they provide an indication as to the likelihood that a debtor will repay its debts. The scores are obtained from a nationally recognized consumer rating agency and are presented in the tables below at the dates indicated. Most extensions of credit are subject to loan scoring. Loan grades are assigned at the time of origination, verified by credit risk management, and periodically re-evaluated thereafter. This risk rating methodology blends our judgment with quantitative modeling. Commercial loans generally are assigned two internal risk ratings. The first rating reflects the probability that the borrower will default on an obligation; the second rating reflects expected recovery rates on the credit facility. Default probability is determined based on, among other factors, the financial strength of the borrower, an assessment of the borrower’s management, the borrower’s competitive position within its industry sector, and our view of industry risk in the context of the general economic outlook. Types of exposure, transaction structure, and collateral, including credit risk mitigants, affect the expected recovery assessment. Commercial Credit Exposure Credit Risk Profile by Creditworthiness Category and Vintage (a) As of December 31, 2020 Term Loans Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Amortized Cost Basis by Origination Year and Internal Risk Rating in millions 2020 2019 2018 2017 2016 Prior Total Commercial and Industrial Risk Rating: Pass $ 13,100 $ 5,487 $ 4,040 $ 2,617 $ 1,967 $ 2,709 $ 19,832 $ 118 $ 49,870 Criticized (Accruing) 66 198 174 236 150 279 1,527 22 2,652 Criticized (Nonaccruing) 8 27 71 28 17 7 226 1 385 Total commercial and industrial 13,174 5,712 4,285 2,881 2,134 2,995 21,585 141 52,907 Real estate — commercial mortgage Risk Rating: Pass 1,591 2,937 1,737 867 765 3,027 885 43 11,852 Criticized (Accruing) 12 142 81 145 72 255 22 2 731 Criticized (Nonaccruing) — 1 4 4 2 88 5 — 104 Total real estate — commercial mortgage 1,603 3,080 1,822 1,016 839 3,370 912 45 12,687 Real estate — construction Risk Rating: Pass 367 764 510 188 27 22 31 5 1,914 Criticized (Accruing) — 14 38 18 — 2 1 — 73 Criticized (Nonaccruing) — — — — — — — — Total real estate — construction 367 778 548 206 27 24 32 5 1,987 Commercial lease financing Risk Rating: Pass 1,076 1,050 534 504 228 901 — — 4,293 Criticized (Accruing) 10 35 15 26 7 4 — — 97 Criticized (Nonaccruing) — 2 2 2 2 1 — — 9 Total commercial lease financing 1,086 1,087 551 532 237 906 — 4,399 Total commercial loans $ 16,230 $ 10,657 $ 7,206 $ 4,635 $ 3,237 $ 7,295 $ 22,529 $ 191 $ 71,980 (a) Accrued interest of $140 million, presented in Other Assets on the Consolidated Balance Sheets, was excluded from the amortized cost basis disclosed in this table. Consumer Credit Exposure Credit Risk Profile by FICO Score and Vintage (a) As of December 31, 2020 Term Loans Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Amortized Cost Basis by Origination Year and FICO Score in millions 2020 2019 2018 2017 2016 Prior Total Real estate — residential mortgage FICO Score: 750 and above $ 3,595 $ 1,620 $ 194 $ 254 $ 537 $ 1,211 — — $ 7,411 660 to 749 710 284 76 48 100 332 — — 1,550 Less than 660 16 28 21 10 26 170 — — 271 No Score 1 2 2 7 2 52 — — 66 Total real estate — residential mortgage 4,322 1,934 293 319 665 1,765 — — 9,298 Home equity loans FICO Score: 750 and above 1,043 404 168 202 190 839 $ 2,689 $ 590 6,125 660 to 749 385 198 82 77 69 253 1,237 206 2,507 Less than 660 27 30 18 20 20 113 426 61 715 No Score 2 2 1 — — 2 5 1 13 Total home equity loans 1,457 634 269 299 279 1,207 4,357 858 9,360 Consumer direct loans FICO Score: 750 and above 1,840 883 115 32 16 57 119 — 3,062 660 to 749 479 268 80 22 14 33 254 1 1,151 Less than 660 23 37 21 8 5 10 81 — 185 No Score 65 35 21 21 10 11 153 — 316 Total consumer direct loans 2,407 1,223 237 83 45 111 607 1 4,714 Credit cards FICO Score: 750 and above — — — — — — 488 — 488 660 to 749 — — — — — — 407 — 407 Less than 660 — — — — — — 93 — 93 No Score — — — — — — 1 — 1 Total credit cards — — — — — — 989 — 989 Consumer indirect loans FICO Score: 750 and above 1,092 924 369 188 69 66 — — 2,708 660 to 749 653 558 232 97 36 47 — — 1,623 Less than 660 143 163 99 54 25 28 — — 512 No Score 1 — — — — — — — 1 Total consumer indirect loans 1,889 1,645 700 339 130 141 — — 4,844 Total consumer loans $ 10,075 $ 5,436 $ 1,499 $ 1,040 $ 1,119 $ 3,224 $ 5,953 $ 859 $ 29,205 (a) Accrued interest of $101 million, presented in Other Assets on the Consolidated Balance Sheets, was excluded from the amortized cost basis disclosed in this table. Nonperforming and Past Due Loans Our policies for determining past due loans, placing loans on nonaccrual, applying payments on nonaccrual loans, and resuming accrual of interest for our commercial and consumer loan portfolios are disclosed in Note 1 (”Basis of Presentation and Accounting Policies”) and Note 1 (“Summary of Significant Accounting Policies”) under the heading “Nonperforming Loans”. Under the CARES Act as well as banking regulator interagency guidance, certain loan modifications to borrowers experiencing financial distress as a result of the economic impacts created by the COVID-19 pandemic may not be required to be reported as past due and nonperforming. For COVID-19 related loan modifications which occurred from March 1, 2020, through December 31, 2020, and met the loan modification criteria under either the CARES Act or the criteria specified by the regulatory agencies, we have elected to re-age to current status all commercial loans and consumer loans that are not secured by real-estate and freeze the delinquency status of consumer real estate secured loans as of the modification or forbearance grant date. At December 31, 2020, the portfolio loans and leases that have received a payment deferral or forbearance as part of our COVID-19 hardship relief programs totaled $575 million, of which $506 million of loan modifications and forbearances made under the criteria of either the CARES Act, banking regulator interagency guidance, or short-term forbearance policies were not reported as nonperforming. The following aging analysis of past due and current loans as of December 31, 2020, and December 31, 2019, provides further information regarding Key’s credit exposure. Aging Analysis of Loan Portfolio (a) December 31, 2020 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans (c) Total Past Due and Non-performing Loans (c) Total Loans (d) in millions LOAN TYPE Commercial and industrial $ 52,396 $ 36 $ 50 $ 40 $ 385 $ 511 $ 52,907 Commercial real estate: Commercial mortgage 12,548 9 5 21 104 139 12,687 Construction 1,986 — — 1 — 1 1,987 Total commercial real estate loans 14,534 9 5 22 104 140 14,674 Commercial lease financing 4,369 21 1 — 8 30 4,399 Total commercial loans $ 71,299 $ 66 $ 56 $ 62 $ 497 $ 681 $ 71,980 Real estate — residential mortgage $ 9,173 $ 11 $ 3 $ 1 $ 110 $ 125 $ 9,298 Home equity loans 9,143 34 20 9 154 217 9,360 Consumer direct loans 4,694 7 4 4 5 20 4,714 Credit cards 972 5 3 7 2 17 989 Consumer indirect loans 4,792 25 7 3 17 52 4,844 Total consumer loans $ 28,774 $ 82 $ 37 $ 24 $ 288 $ 431 $ 29,205 Total loans $ 100,073 $ 148 $ 93 $ 86 $ 785 $ 1,112 $ 101,185 (a) Amounts in table represent amortized cost and exclude loans held for sale. (b) Accrued interest of $241 million presented in “other assets” on the Consolidated Balance Sheets is excluded from the amortized cost basis disclosed in this table. (c) PCI loans meeting nonperforming criteria were historically excluded from Key's nonperforming disclosures. As a result of CECL implementation on January 1, 2020, PCI loans became PCD loans. PCD loans that met the definition of nonperforming are now included in nonperforming disclosures. (d) Net of unearned income, net of deferred fees and costs, and unamortized discounts and premiums. December 31, 2019 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans in millions LOAN TYPE Commercial and industrial $ 47,768 $ 110 $ 52 $ 53 $ 264 $ 479 48 $ 48,295 Commercial real estate: Commercial mortgage 13,258 8 5 13 83 109 124 13,491 Construction 1,551 3 — 1 2 6 1 1,558 Total commercial real estate loans 14,809 11 5 14 85 115 125 15,049 Commercial lease financing 4,647 22 11 2 6 41 — 4,688 Total commercial loans $ 67,224 $ 143 $ 68 $ 69 $ 355 $ 635 173 $ 68,032 Real estate — residential mortgage $ 6,705 $ 7 $ 5 $ 1 $ 48 $ 61 $ 257 $ 7,023 Home equity loans 10,071 30 10 5 145 190 13 10,274 Consumer direct loans 3,484 10 5 7 4 26 3 3,513 Credit cards 1,104 6 5 12 3 26 — 1,130 Consumer indirect loans 4,609 32 8 3 22 65 — 4,674 Total consumer loans $ 25,973 $ 85 $ 33 $ 28 $ 222 $ 368 $ 273 $ 26,614 Total loans $ 93,197 $ 228 $ 101 $ 97 $ 577 $ 1,003 $ 446 $ 94,646 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the principal amount of the loan increased or decreased by net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude PCI, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans. At December 31, 2020, the carrying amount of our commercial nonperforming loans outstanding represented 70% of their original contractual amount owed, total nonperforming loans outstanding represented 76% of their original contractual amount owed, and nonperforming assets in total were carried at 83% of their original contractual amount owed. Nonperforming loans reduced expected interest income by $27 million, $31 million, and $30 million for each of the twelve months ended December 31, 2020, December 31, 2019, and December 31, 2018, respectively. The amortized cost basis of nonperforming loans on nonaccrual status for which there is no related allowance for credit losses was $379 million at December 31, 2020. Collateral-dependent Financial Assets We classify financial assets as collateral-dependent when our borrower is experiencing financial difficulty, and we expect repayment to be provided substantially through the operation or sale of the collateral. Our commercial loans have collateral that includes cash, accounts receivable, inventory, commercial machinery, commercial properties, commercial real estate construction projects, and stock or ownership interests in the borrowing entity. When appropriate we also consider the enterprise value of the borrower as a repayment source for collateral-dependent loans. Our consumer loans have collateral that includes residential real estate, automobiles, boats, and RVs. There were no significant changes in the extent to which collateral secures our collateral-dependent financial assets during 2020. TDRs We classify loan modifications as TDRs when a borrower is experiencing financial difficulties and we have granted a concession without commensurate financial, structural, or legal consideration. Our loan modifications are handled on a case-by-case basis and are negotiated to achieve mutually agreeable terms that maximize loan collectability and meet the borrower’s financial needs. Under the CARES Act as well as banking regulator interagency guidance, certain loan modifications to borrowers experiencing financial distress as a result of the economic impacts created by the COVID-19 pandemic may not be required to be treated as TDRs under U.S. GAAP. We elected to suspend TDR accounting for $506 million of COVID-19 related loan modifications as of December 31, 2020, as such loan modifications met the criteria under either the CARES Act, banking regulator interagency guidance or are a short-term forbearance. Commitments outstanding to lend additional funds to borrowers whose loan terms have been modified in TDRs were $1 million and $4 million at December 31, 2020, and December 31, 2019, respectively. The consumer TDR other concession category in the table below primarily includes those borrowers’ debts that are discharged through Chapter 7 bankruptcy and have not been formally re-affirmed. At December 31, 2020, and December 31, 2019, the recorded investment of consumer residential mortgage loans in the process of foreclosure was approximately $92 million and $97 million, respectively. The following table shows the post-modification outstanding recorded investment by concession type for our commercial and consumer accruing and nonaccruing TDRs that occurred during the periods indicated: December 31, in millions 2020 2019 Commercial loans: Extension of Maturity Date $ 5 $ 11 Payment or Covenant Modification/Deferment 59 11 Bankruptcy Plan Modification — — Increase in new commitment or new money — 8 Total $ 64 $ 30 Consumer loans: Interest rate reduction $ 41 $ 14 Other 21 29 Total $ 62 $ 43 Total TDRs $ 126 $ 73 The following table summarizes the change in the post-modification outstanding recorded investment of our accruing and nonaccruing TDRs during the periods indicated: December 31, in millions 2020 2019 Balance at beginning of the period $ 347 $ 399 Additions 173 112 Payments (95) (145) Charge-offs (62) (19) Balance at end of period $ 363 $ 347 A further breakdown of TDRs included in nonperforming loans by loan category for the periods indicated are as follows: December 31, 2020 December 31, 2019 Number of Loans Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number Pre-modification Post-modification dollars in millions LOAN TYPE Nonperforming: Commercial and industrial 66 $ 136 $ 92 51 $ 72 $ 53 Commercial real estate: Real estate — commercial mortgage 7 62 50 6 64 58 Total commercial real estate loans 7 62 50 6 64 58 Total commercial loans 73 198 142 57 136 111 Real estate — residential mortgage 258 35 34 181 13 11 Home equity loans 630 41 37 713 42 41 Consumer direct loans 212 3 3 172 2 2 Credit cards 356 2 2 368 2 2 Consumer indirect loans 861 15 11 1,131 19 16 Total consumer loans 2,317 96 87 2,565 78 72 Total nonperforming TDRs 2,390 294 229 2,622 214 183 Prior-year accruing: (a) Commercial and industrial 3 5 — 6 30 25 Commercial real estate: Real estate — commercial mortgage — — — 1 — — Total commercial loans 3 5 — 7 30 25 Real estate — residential mortgage 485 37 31 493 37 31 Home equity loans 1,781 106 83 1,751 104 84 Consumer direct loans 163 4 3 139 4 3 Credit cards 536 3 1 486 3 1 Consumer indirect loans 775 29 16 714 33 20 Total consumer loans 3,740 179 134 3,583 181 139 Total prior-year accruing TDRs 3,743 184 134 3,590 211 164 Total TDRs 6,133 $ 478 $ 363 6,212 $ 425 $ 347 (a) All TDRs that were restructured prior to January 1, 2020, and January 1, 2019, are fully accruing. Commercial loan TDRs are considered defaulted when principal and interest payments are 90 days past due. Consumer loan TDRs are considered defaulted when principal and interest payments are more than 60 days past due. During 2020, there were seven commercial loan TDRs and 212 consumer loan TDRs with a combined recorded investment of $10 million that experienced payment defaults after modifications resulting in TDR status during 2019. During 2019, there were no commercial loan TDRs and 356 consumer loan TDRs with a combined recorded investment of $8 million that experienced payment defaults after modifications resulting in TDR status during 2018. Liability for Credit Losses on Off Balance Sheet Exposures The liability for credit losses inherent in unfunded lending-related commitments, such as letters of credit and unfunded loan commitments, and certain financial guarantees is included in “accrued expense and other liabilities” on the balance sheet and is assessed a reserve under CECL. Changes in the liability for credit losses on off balance sheet exposures are summarized as follows: Twelve Months Ended December 31, in millions 2020 2019 Balance at the end of the prior period $ 68 $ 64 Liability for credit losses on contingent guarantees at the end of the prior period 7 — Cumulative effect from change in accounting principle (a), (b) 66 — Balance at beginning of period 141 64 Provision (credit) for losses on off balance sheet exposures 56 4 Balance at end of period $ 197 $ 68 (a) The cumulative effect from change in accounting principle relates to the January 1, 2020, adoption of ASU 2016-13. (b) Excludes $4 million related to the provision for other financial assets.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements In accordance with GAAP, Key measures certain assets and liabilities at fair value. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in our principal market. Additional information regarding our accounting policies for determining fair value is provided in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Fair Value Measurements.” Assets and Liabilities Measured at Fair Value on a Recurring Basis The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2020, and December 31, 2019. December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total in millions ASSETS MEASURED ON A RECURRING BASIS Trading account assets: U.S. Treasury, agencies and corporations — $ 633 — $ 633 — $ 843 — $ 843 States and political subdivisions — 24 — 24 — 30 — 30 Other mortgage-backed securities — 47 — 47 — 78 — 78 Other securities — 13 — 13 — 44 — 44 Total trading account securities — 717 — 717 — 995 — 995 Commercial loans — 18 — 18 — 45 — 45 Total trading account assets — 735 — 735 — 1,040 — 1,040 Securities available for sale: U.S. Treasury, agencies and corporations — 1,000 — 1,000 — 334 — 334 States and political subdivisions — — — — — 4 — 4 Agency residential collateralized mortgage obligations — 14,273 — 14,273 — 12,783 — 12,783 Agency residential mortgage-backed securities — 2,164 — 2,164 — 1,714 — 1,714 Agency commercial mortgage-backed securities — 10,106 — 10,106 — 6,997 — 6,997 Other securities — — $ 13 13 — — $ 11 11 Total securities available for sale — 27,543 13 27,556 — 21,832 11 21,843 Other investments: Principal investments: Direct — — 1 1 — — 1 1 Indirect (measured at NAV) (a) — — — 53 — — — 68 Total principal investments — — 1 54 — — 1 69 Equity investments: Direct — — 13 13 — — 12 12 Direct (measured at NAV) (a) — — — 7 — — — 1 Indirect (measured at NAV) (a) — — — 7 — — — 8 Total equity investments — — 13 27 — — 12 21 Total other investments — — 14 81 — — 13 90 Loans, net of unearned income (residential) — — 11 11 — — 4 4 Loans held for sale (residential) — 264 — 264 — 140 — 140 Derivative assets: Interest rate — 1,528 56 1,584 — 941 22 963 Foreign exchange $ 78 31 — 109 $ 49 $ 18 $ — $ 67 Commodity — 424 2 426 — 208 — 208 Credit — — 1 1 — — 1 1 Other — 26 32 58 — 9 5 14 Derivative assets 78 2,009 91 2,178 49 1,176 28 1,253 Netting adjustments (b) — — — (380) — — — (473) Total derivative assets 78 2,009 91 1,798 49 1,176 28 780 Total assets on a recurring basis at fair value $ 78 $ 30,551 $ 129 $ 30,445 $ 49 $ 24,188 $ 56 $ 23,897 LIABILITIES MEASURED ON A RECURRING BASIS Bank notes and other short-term borrowings: Short positions $ 256 $ 503 — $ 759 $ 19 $ 686 — $ 705 Derivative liabilities: Interest rate — 288 — 288 — 253 — 253 Foreign exchange 72 31 — 103 43 17 — 60 Commodity — 408 — 408 — 200 — 200 Credit — — $ 11 11 — 1 $ 9 10 Other — 16 — 16 — 10 — 10 Derivative liabilities 72 743 11 826 43 481 9 533 Netting adjustments (b) — — — (675) — — — (335) Total derivative liabilities 72 743 11 151 43 481 9 198 Total liabilities on a recurring basis at fair value $ 328 $ 1,246 $ 11 $ 910 $ 62 $ 1,167 $ 9 $ 903 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (b) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The net basis takes into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Total derivative assets and liabilities include these netting adjustments. Qualitative Disclosures of Valuation Techniques The following table describes the valuation techniques and significant inputs used to measure the classes of assets and liabilities reported at fair value on a recurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Securities (includes trading account assets securities available for sale, and U.S. Treasury Bills classified as short-term investments) Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities. This includes exchange-traded equity securities. Fair value of level 2 securities is determined by: • Pricing models (either by a third party pricing service or internally). Inputs include: yields, benchmark securities, bids, offers, actual trade data (i.e., spreads, credit ratings, and interest rates) for comparable assets, spread tables, matrices, high-grade scales, and option-adjusted spreads. • Observable market prices of similar securities. Fair value of level 3 securities is determined by: • Internally developed valuation techniques, principally discounted cash flow methods (income approach). • Revenue multiples of comparable public companies (market approach). For level 3 securities, increases (decreases) in the discount rate and marketability discount used in the discounted cash flow models would have resulted in lower (higher) fair value measurements. Higher volatility factors would have further magnified changes in fair value. The valuations provided by the third-party pricing service are based on observable market inputs, which include benchmark yields, reported trades, issuer spreads, benchmark securities, bids, offers, and reference data obtained from market research publications. Inputs used by the third-party pricing service in valuing CMOs and other mortgage-backed securities also include new issue data, monthly payment information, whole loan collateral performance, and “To Be Announced” prices. In valuations of securities issued by state and political subdivisions, inputs used by the third-party pricing service also include material event notices. We regularly validate the pricing methodologies of valuations derived from a third-party pricing service to ensure the fair value determination is consistent with applicable accounting guidance and that our assets are properly classified in the fair value hierarchy. To perform this validation, we: • review documentation received from our third-party pricing service regarding the inputs used in its valuations and determine a level assessment for each category of securities; • substantiate actual inputs used for a sample of securities by comparing the actual inputs used by our third-party pricing service to comparable inputs for similar securities; and • substantiate the fair values determined for a sample of securities by comparing the fair values provided by our third-party pricing service to prices from other independent sources for the same and similar securities. We analyze variances and conduct additional research with our third-party pricing service and take appropriate steps based on our findings. Level 1, 2, and 3 (primarily Level 2) Commercial loans (trading account assets) Fair value is based on: • Observable market price spreads for similar loans. Valuations reflect prices within the bid-ask spread that are most representative of fair value. Level 2 Principal investments (direct) Direct principal investments consist of equity and debt instruments of private companies made by our principal investing entities. Fair value is determined using: • Operating performance and market multiples of comparable businesses • Other unique facts and circumstances related to each individual investment Direct principal investments are accounted for as investment companies in accordance with the applicable accounting guidance, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. We are in the process of winding down our direct principal investment portfolio. As of December 31, 2020, the balance is less than $1 million. Level 3 Asset/liability class Valuation technique Valuation hierarchy classification(s) Principal investments (indirect) Indirect principal investments include primary and secondary investments in private equity funds engaged mainly in venture- and growth-oriented investing. These investments do not have readily determinable fair values and qualify for the practical expedient to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership interest in partners’ capital to which a proportionate share of net assets is attributed). Indirect principal investments are also accounted for as investment companies, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. Under the provisions of the Volcker Rule, we are required to dispose or conform our indirect investments to the requirements of the statute by no later than July 21, 2022. As of December 31, 2020, we have not committed to a plan to sell these investments. Therefore, these investments continue to be valued using the net asset value per share methodology. NAV The following table presents the fair value of our direct and indirect principal investments and related unfunded commitments at December 31, 2020, as well as financial support provided for the years ended December 31, 2020, and December 31, 2019. Financial support provided Year ended December 31, December 31, 2020 2020 2019 in millions Fair Value Unfunded Commitments Funded Commitments Funded Other Funded Commitments Funded Other INVESTMENT TYPE Direct investments $ 1 — — — — $ — Indirect investments (a) 53 $ 16 $ 2 — $ 2 — Total $ 54 $ 16 $ 2 — $ 2 $ — (a) Our indirect investments consist of buyout funds, venture capital funds, and fund of funds. These investments are generally not redeemable. Instead, distributions are received through the liquidation of the underlying investments of the fund. An investment in any one of these funds typically can be sold only with the approval of the fund’s general partners. At December 31, 2020, no significant liquidation of the underlying investments has been communicated to Key. The purpose of funding our capital commitments to these investments is to allow the funds to make additional follow-on investments and pay fund expenses until the fund dissolves. We, and all other investors in the fund, are obligated to fund the full amount of our respective capital commitments to the fund based on our and their respective ownership percentages, as noted in the applicable Limited Partnership Agreement. Asset/liability class Valuation technique Valuation hierarchy classification(s) Other direct equity investments Fair value is determined using: • Discounted cash flows • Operating performance and market/exit multiples of comparable businesses • Other unique facts and circumstances related to each individual investment For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. Level 2 investments reflect the price of recent investments, which is deemed representative of fair value. Level 2 and 3 Other direct and indirect equity investments (NAV) Certain direct investments do not have readily determinable fair values and qualify for the practical expedient in the accounting guidance that allows us to estimate fair value based upon net asset value per share. NAV Asset/liability class Valuation technique Valuation hierarchy classification(s) Loans held for sale and held for investment (residential) Residential mortgage loans held for sale are accounted for at fair value. Fair values are based on: • Quoted market prices, where available • Prices for other traded mortgage loans with similar characteristics • Purchase commitments and bid information received from market participants Prices are adjusted as necessary to include: • The embedded servicing value in the loans • The specific characteristics of certain loans that are priced based on the pricing of similar loans. (These adjustments represent unobservable inputs to the valuation but are not considered significant given the relative insensitivity of the value to changes in these inputs to the fair value of the loans.) Residential loans held for investment: Certain residential loans held for sale contain salability exceptions that make them unable to be sold into the performing loan sales market. Loans in this category are transferred to the held to maturity loan portfolio and are included in “Loans, net of unearned income” on the balance sheet. This type of loan is classified as level 3 in the valuation hierarchy as transaction details regarding sales of this type of loan are often unavailable. Fair value is based upon: • Unobservable bid information from brokers and investors Higher (lower) unobservable bid information would have resulted in higher (lower) fair value measurements. Level 1, 2 and 3 (primarily level 2) Derivatives Exchange-traded derivatives are valued using quoted prices in active markets and, therefore, are classified as Level 1 instruments. The majority of our derivative positions are Level 2 and are valued using internally developed models based on market convention and observable market inputs. These derivative contracts include interest rate swaps, certain options, floors, cross currency swaps, credit default swaps, and forward mortgage loan sale commitments. Significant inputs used in the valuation models include: • LIBOR, SOFR and OIS curves, index pricing curves, foreign currency curves • Volatility surfaces (a three-dimensional graph of implied volatility against strike price and maturity) We have customized derivative instruments and risk participations that are classified as Level 3 instruments. These derivative positions are valued using internally developed models, with inputs consisting of available market data, including: • Credit spreads and interest rates The unobservable internally derived assumptions include: • Loss given default • Internal risk assessments of customers The fair value represents an estimate of the amount that the risk participation counterparty would need to pay/receive as of the measurement date based on the probability of customer default on the swap transaction and the fair value of the underlying customer swap. Therefore, for sold risk participation agreements, a higher loss probability and a lower credit rating would negatively affect the fair value of the risk participations and a lower loss probability and higher credit rating would positively affect the fair value of the risk participations. (For purchased risk participation agreements, higher loss probabilities and lower credit ratings would positively affect the fair value.) Level 1, 2, and 3 (primarily level 2) Asset/liability class Valuation technique Valuation hierarchy classification(s) Derivatives (continued) We use interest rate lock commitments for our residential mortgage business, which are classified as Level 3 instruments. The significant components of the valuation model include: • Interest rates observable in the market • Investor supplied prices for similar securities • The probability of the loan closing (i.e. the "pull-through" amount, a significant unobservable input). Increases (decreases) in the probability of the loan closing would have resulted in higher (lower) fair value measurements. Valuation of residential mortgage forward sale commitments utilizes observable market prices of comparable commitments and mortgage securities (Level 2). The fair values of our derivatives include a credit valuation adjustment related to both counterparty and our own creditworthiness. The credit component considers master netting and collateral agreements and is determined by the individual counterparty based on potential future exposures, expected recovery rates, and market-implied probabilities of default. Level 1, 2, and 3 (primarily level 2) Liability for short positions This includes fixed income securities held by our broker dealer in its trading inventory. Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities Fair value of level 2 securities is determined by: • Observable market prices of similar securities • Market activity, spreads, credit ratings and interest rates for each security type Level 1 and 2 We also make liquidity valuation adjustments to the fair value of certain assets to reflect the uncertainty in the pricing and trading of the instruments when we are unable to observe recent market transactions for identical or similar instruments. Liquidity valuation adjustments are based on the following factors: • the amount of time since the last relevant valuation; • whether there is an actual trade or relevant external quote available at the measurement date; and • volatility associated with the primary pricing components. Changes in Level 3 Fair Value Measurements The following table shows the change in the fair values of our Level 3 financial instruments measured at fair value on a recurring basis for the years ended December 31, 2020, and December 31, 2019. in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 Transfers out of Level 3 End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2020 Securities available for sale Other securities $ 11 $ 2 — — — — — — — $ 13 — Other investments Principal investments Direct 1 — — — — — — — — 1 — Equity investments Direct 12 — $ 1 (c) — — — — — — 13 $ 1 Loans held for sale (residential) — — — — $ (10) — $ 10 — — — — Loans held for investment (residential) 4 — — — (2) — 9 — — 11 — Derivative instruments (b) Interest rate 22 — 19 (d) $ 17 (10) — — $ 99 (e) $ (91) (e) 56 — Credit (8) — (2) (d) 1 (1) — — — — (10) — Other (a) 5 — 7 — — — 20 — — 32 — in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 Transfers out of Level 3 End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2019 Securities available for sale Other securities $ 20 15 — — — — — — $ (24) $ 11 — Other investments Principal investments Direct 1 — — — — — — — — 1 — Equity investments Direct 7 — $ 4 (c) — — — — $ 1 — 12 $ 4 Loans held for sale (residential) — — — — $ (1) — $ 1 — — — — Loans held for investment (residential) 3 — — — — — 1 — — 4 — Derivative instruments (b) Interest rate 5 — 3 (d) $ 2 (1) — — 21 (e) (8) (e) 22 — Credit — — (8) (d) — — $ — — — — (8) — Other (a) 3 — — — — — $ 2 — — 5 — (a) Amounts represent Level 3 interest rate lock commitments. (b) Amounts represent Level 3 derivative assets less Level 3 derivative liabilities. (c) Realized and unrealized gains and losses on principal investments are reported in “other income” on the income statement. Realized and unrealized losses on equity investments are reported in “other income” on the income statement. (d) Realized and unrealized gains and losses on derivative instruments are reported in “corporate services income” and “other income” on the income statement. (e) Certain derivatives previously classified as Level 2 were transferred to Level 3 because Level 3 unobservable inputs became significant. Certain derivatives previously classified as Level 3 were transferred to Level 2 because Level 3 unobservable inputs became less significant. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis in accordance with GAAP. The adjustments to fair value generally result from the application of accounting guidance that requires assets and liabilities to be recorded at the lower of cost or fair value, or assessed for impairment. There were no liabilities measured at fair value on a nonrecurring basis at December 31, 2020, and December 31, 2019. The following table presents our assets measured at fair value on a nonrecurring basis at December 31, 2020, and December 31, 2019: December 31, 2020 December 31, 2019 in millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS MEASURED ON A NONRECURRING BASIS Impaired loans and leases — — $ 108 $ 108 — — $ 76 $ 76 Accrued income and other assets — $ — 56 56 — 118 51 169 Total assets on a nonrecurring basis at fair value — $ — $ 164 $ 164 — 118 $ 127 $ 245 Qualitative Disclosures of Valuation Techniques The following table describes the valuation techniques and significant inputs used to measure the significant classes of assets and liabilities reported at fair value on a nonrecurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Collateral-dependent loans When a loan is collateral-dependent, the fair value of the loan is determined based on the fair value of the underlying collateral. Level 3 Commercial loans and student loans held for sale Through a quarterly analysis of our loan portfolios held for sale, which include both performing and nonperforming commercial loans and student loans, we determine any adjustments necessary to record the portfolios at the lower of cost or fair value in accordance with GAAP. Valuation inputs include: • Non-binding bids for the respective loans or similar loans • Recent sales transactions • Internal models that emulate recent securitizations Level 2 and 3 Direct financing leases and operating lease assets held for sale Valuations of direct financing leases and operating lease assets held for sale are performed using an internal model that relies on market data, including: • Swap rates and bond ratings • Our own assumptions about the exit market for the leases • Details about the individual leases in the portfolio Leases for which we receive a current nonbinding bid, and for which the sale is considered probable, may be classified as Level 2. Valuations of lease and operating lease assets held for sale that employ our own assumptions are classified as Level 3 assets. The inputs based on our own assumptions include changes in the value of leased items and internal credit ratings. Level 2 and 3 OREO, other repossessed personal properties, and right-of-use assets (a) OREO, other repossessed properties, and right-of-use assets are valued based on: • Appraisals and third-party price opinions, less estimated selling costs Generally, we classify these assets as Level 3, but OREO and other repossessed properties for which we receive binding purchase agreements are classified as Level 2. Returned lease inventory is valued based on market data for similar assets and is classified as Level 2. Level 2 and 3 LIHTC, HTC, and NMTC investments (a) Valuation of LIHTC, HTC and NMTC involves measuring the present value of future tax benefits and comparing that value against the current carrying value of the investment. Expected future tax benefits are discounted to their present value using discounted cash flow modeling that incorporates an appropriate risk premium. LIHTC and HTC investments are impaired when it is more likely than not that the carrying amount of the investment will not be realized. Level 3 Other equity investments We have other investments in equity securities that do not have readily determinable fair values and do not qualify for the practical expedient to measure the investment using a net asset value per share. We have elected to measure these securities at cost less impairment plus or minus adjustments due to observable orderly transactions. Impairment is recorded when there is evidence that the expected fair value of the investment has declined to below the recorded cost. At each reporting period, we assess if these investments continue to qualify for this measurement alternative. At December 31, 2020, and December 31, 2019, the carrying amount of equity investments recorded under this method was $171 million and $134 million, respectively. No impairment was recorded for the year ended December 31, 2020. Level 3 Mortgage Servicing Rights (a) Refer to Note 9. Mortgage Servicing Assets Level 3 (a) Asset classes included in “Accrued income and other assets” on the Consolidated Balance Sheets Quantitative Information about Level 3 Fair Value Measurements The range and weighted-average of the significant unobservable inputs used to fair value our material Level 3 recurring and nonrecurring assets at December 31, 2020, and December 31, 2019, along with the valuation techniques used, are shown in the following table: Level 3 Asset (Liability) Valuation Technique Significant Range (Weighted-Average) (b), (c) dollars in millions December 31, 2020 December 31, 2019 December 31, 2020 December 31, 2019 Recurring Securities available-for-sale: Other securities $ 13 $ 11 Discounted cash flows Discount rate N/A (15.09%) N/A (16.10%) Marketability discount N/A (30.00%) N/A (30.00%) Volatility factor N/A (44.00%) N/A (43.00%) Other investments: (a) Equity investments Direct 13 12 Discounted cash flows Discount rate 13.90 - 17.04% (15.47%) 13.91 - 17.24% (15.61%) Marketability discount N/A (30.00%) N/A (30.00%) Volatility factor N/A (52.00%) N/A (47.00%) Loans, net of unearned income (residential) 11 4 Market comparable pricing Comparability factor 64.50%-99.04% (94.17%) 79.00 - 98.00% (91.05%) Derivative instruments: Interest rate 56 22 Discounted cash flows Probability of default .02 - 100% (7.90%) .02 - 100% (5.40%) Internal risk rating 1 - 19 (9.675) 1 - 19 (9.168) Loss given default 0 - 1 (.483) 0 - 1 (.492) Credit (assets) 1 1 Discounted cash flows Probability of default .02 - 100% (4.70%) .02 - 100% (4.2%) Internal risk rating 1 - 19 (10.478) 1 - 19 (10.13) Loss given default 0 - 1 (.490) 0 - 1 (.498) Credit (liabilities) (11) (9) Discounted cash flows Probability of default .02 - 100% (15.45%) .02 - 100% (12.24%) Internal risk rating 1 - 19 (8.555) 1 - 19 (8.058) Loss given default 0 - 1 (.431) 0 - 1 (.411) Other (d) 32 5 Discounted cash flows Loan closing rates 36.95 - 99.68% (77.51%) 37.71 - 99.69% (79.33%) Nonrecurring Impaired loans 108 76 Fair value of underlying collateral Discount rate 0 - 100.00% (36.00%) 0 - 60.00% (10.00%) Accrued income and other assets: (e) OREO 16 5 Appraised value Appraised value N/M N/M (a) Principal investments, direct is excluded from this table as the balance at December 31, 2020, is insignificant (less than $1 million). (a) The weighted average of significant unobservable inputs is calculated using a weighting relative to fair value. (b) For significant unobservable inputs with no range, a single figure is reported to denote the single quantitative factor used. (c) Amounts represent interest rate lock commitments. (d) Excludes $40 million and $46 million pertaining to mortgage servicing assets measured at fair value as of December 31, 2020, and December 31, 2019, respectively. Refer to Note 9 (“Mortgage Servicing Assets”) for significant unobservable inputs pertaining to these assets. Fair Value Disclosures of Financial Instruments The levels in the fair value hierarchy ascribed to our financial instruments and the related carrying amounts at December 31, 2020, and December 31, 2019, are shown in the following table. December 31, 2020 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 735 — $ 735 — — — $ 735 Other investments (b) 621 — — $ 555 $ 66 — 621 Loans, net of unearned income (residential) (d) 11 — — 11 — — 11 Loans held for sale (residential) (b) 264 — 264 — — — 264 Derivative assets - trading (b) 1,676 $ 78 1,939 91 — $ (433) (f) 1,675 Fair value - OCI Securities available for sale (b) 27,556 — 27,543 13 — — 27,556 Derivative assets - hedging (b) (g) 123 — 70 — — 53 (f) 123 Amortized cost Held-to-maturity securities (c) 7,595 — 8,023 — — — 8,023 Loans, net of unearned income (d) 99,548 — — 98,946 — — 98,946 Loans held for sale (b) 1,319 — — 1,319 — — 1,319 Other Cash and short-term investments (a) 17,285 17,285 — — — — 17,285 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) 154 72 746 11 — (675) (f) 154 Fair value - OCI Derivative liabilities - hedging (b) (g) (3) — (3) — — — (f) (3) Amortized cost Time deposits (e) 5,743 — 5,765 — — — 5,765 Short-term borrowings (a) 979 256 723 — — — 979 Long-term debt (e) 13,709 13,925 734 — — — 14,659 Other Deposits with no stated maturity (a) 129,539 — 129,539 — — — 129,539 December 31, 2019 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 1,040 — $ 1,040 — — — $ 1,040 Other investments (b) 605 — — $ 528 $ 77 — 605 Loans, net of unearned income (residential) (d) 4 — — 4 — — 4 Loans held for sale (residential) (b) 140 — 140 — — — 140 Derivative assets - trading (b) 715 $ 49 985 28 — $ (347) (f) 715 Fair value - OCI Securities available for sale (b) 21,843 — 21,832 11 — — 21,843 Derivative assets - hedging (b) (g) 65 — 191 — — (126) (f) 65 Amortized cost Held-to-maturity securities (c) 10,067 — 10,116 — — — 10,116 Loans, net of unearned income (d) 93,742 — — 92,641 — — 92,641 Loans held for sale (b) 1,194 — — 1,194 — — 1,194 Other Cash and short-term investments (a) 2,004 2,004 — — — — 2,004 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) 194 43 461 9 — (319) (f) 194 Fair value - OCI Derivative liabilities - hedging (b) (g) 4 — 20 — — (16) (f) 4 Amortized cost Time deposits (e) 11,652 — 11,752 — — — 11,752 Short-term borrowings (a) 1,092 19 1,073 — — — 1,092 Long-term debt (e) 12,448 12,694 $ 249 — — — 12,943 Other Deposits with no stated maturity (a) 100,218 — 100,218 — — — 100,218 Valuation Methods and Assumptions (a) Fair value equals or approximates carrying amount. The fair value of deposits with no stated maturity does not take into consideration the value ascribed to core deposit intangibles. (b) Information pertaining to our methodology for measuring the fair values of these assets and liabilities is included in the sections entitled “Qualitative Disclosures of Valuation Techniques” and “Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis” in this Note. Investments accounted for under the cost method (or cost less impairment adjusted for observable price changes for certain equity investments) are classified as Level 3 assets. These investments are not actively traded in an open market as sales for these types of investments are rare. The carrying amount of the investments carried at cost are adjusted for declines in value if they are considered to be other-than-temporary (or due to observable orderly transactions of the same issuer for equity investments eligible for the cost less impairment measurement alternative). These adjustments are included in “other income” on the income statement. (c) Fair values of held-to-maturity securities are determined by using models that are based on security-specific details, as well as relevant industry and economic factors. The most significant of these inputs are quoted market prices, interest rate spreads on relevant benchmark securities, and certain prepayment assumptions. We review the valuations derived from the models to ensure that they are reasonable and consistent with the values placed on similar securities traded in the secondary markets. (d) The fair value of loans is based on the present value of the expected cash flows. The projected cash flows are based on the contractual terms of the loans, adjusted for prepayments and use of a discount rate based on the relative risk of the cash flows, taking into account the loan type, maturity of the loan, liquidity risk, servicing costs, and a required return on debt and capital. In addition, an inc

Securities

Securities	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Securities	7. Securities The amortized cost, unrealized gains and losses, and approximate fair value of our securities available for sale and held-to-maturity securities are presented in the following tables. Gross unrealized gains and losses represent the difference between the amortized cost and the fair value of securities on the balance sheet as of the dates indicated. Accordingly, the amount of these gains and losses may change in the future as market conditions change. 2020 2019 December 31, in millions Amortized Cost (a) Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE U.S. Treasury, Agencies, and Corporations $ 1,000 — — $ 1,000 $ 334 — $ — $ 334 States and political subdivisions — — — — 4 — — 4 Agency residential collateralized mortgage obligations 14,001 $ 297 $ 25 14,273 12,772 $ 82 71 12,783 Agency residential mortgage-backed securities 2,094 70 — 2,164 1,677 41 4 1,714 Agency commercial mortgage-backed securities 9,707 432 33 10,106 6,898 139 40 6,997 Other securities 8 5 — 13 7 4 — 11 Total securities available for sale $ 26,810 $ 804 $ 58 $ 27,556 $ 21,692 $ 266 $ 115 $ 21,843 HELD-TO-MATURITY SECURITIES Agency residential collateralized mortgage obligations $ 3,775 $ 124 $ — $ 3,899 $ 5,692 $ 23 $ 49 $ 5,666 Agency residential mortgage-backed securities 271 14 — 285 409 6 — 415 Agency commercial mortgage-backed securities 3,515 290 — 3,805 3,940 78 9 4,009 Asset-backed securities 19 — — 19 11 — — 11 Other securities 15 — — 15 15 — — 15 Total held-to-maturity securities $ 7,595 $ 428 $ — $ 8,023 $ 10,067 $ 107 $ 58 $ 10,116 (a) Amortized cost amounts exclude accrued interest receivable which is recorded within “other assets” on the balance sheet. At December 31, 2020 accrued interest receivable on available for sale securities and held-to-maturity securities totaled $42 million and $15 million, respectively. The following table summarizes available for sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of December 31, 2020, and December 31, 2019: Duration of Unrealized Loss Position Less than 12 Months 12 Months or Longer Total in millions Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses December 31, 2020 Securities available for sale: Agency residential collateralized mortgage obligations $ 2,110 $ 25 $ — $ — $ 2,110 $ 25 Agency residential mortgage-backed securities 6 — (a) $ 5 — (a) 11 — Agency commercial mortgage-backed securities 2,709 33 — — 2,709 33 Held-to-maturity securities: Agency residential collateralized mortgage obligations — — 24 — (a) 24 — Other securities 5 — (a) — — 5 — Total securities in an unrealized loss position $ 4,830 $ 58 $ 29 $ — $ 4,859 $ 58 December 31, 2019 Securities available for sale: U.S. Treasury, agencies, and corporations $ 30 — (b) $ 30 — (b) $ 60 — Agency residential collateralized mortgage obligations 3,432 $ 20 3,221 $ 51 6,653 $ 71 Agency residential mortgage-backed securities 33 — (b) 629 4 662 4 Agency commercial mortgage-backed securities 1,541 17 1,213 23 2,754 40 Held-to-maturity securities: Agency residential collateralized mortgage obligations 1,626 14 2,289 35 3,915 49 Agency residential mortgage-backed securities 56 — (b) — — 56 — Agency commercial mortgage-backed securities 518 9 — — 518 9 Asset-backed securities 11 — (b) — — 11 — Other securities 3 — (b) — — 3 — Total securities in an unrealized loss position $ 7,250 $ 60 $ 7,382 $ 113 $ 14,632 $ 173 (a) At December 31, 2020, gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for other securities held-to-maturity with a loss duration of less than 12 months. At December 31, 2020, gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration greater than 12 months or longer and less than $1 million. for agency residential mortgage-backed securities held to maturity. (b) At December 31, 2019, gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations and agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for agency residential mortgage-backed securities, asset-backed securities, and other securities held-to-maturity with a loss duration of less than 12 months. At December 31, 2019, gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations securities available for sale with a loss duration greater than 12 months or longer. Based on our evaluation at December 31, 2020, under the new impairment model, an allowance for credit losses has not been recorded nor have unrealized losses been recognized into income. The issuers of the securities are of high credit quality and have a long history of no credit losses, management does not intend to sell and it is likely that management will not be required to sell the securities prior to their anticipated recovery, and the decline in fair value is largely attributed to changes in interest rates and other market conditions. The issuers continue to make timely principal and interest payments. At December 31, 2020, securities available-for-sale and held-to-maturity securities totaling $13.6 billion were pledged to secure securities sold under repurchase agreements, to secure public and trust deposits, to facilitate access to secured funding, and for other purposes required or permitted by law. The following table shows securities by remaining maturity. CMOs and other mortgage-backed securities in the available-for-sale and held-to-maturity portfolios are presented based on their expected average lives. The remaining securities, in both the available-for-sale and held-to-maturity portfolios, are presented based on their remaining contractual maturity. Actual maturities may differ from expected or contractual maturities since borrowers have the right to prepay obligations with or without prepayment penalties. Securities Held-to-Maturity December 31, 2020 Amortized Cost Fair Value Amortized Cost Fair Value in millions Due in one year or less $ 1,889 $ 1,896 $ 77 $ 78 Due after one through five years 15,410 15,891 4,941 5,150 Due after five through ten years 6,686 6,964 2,577 2,795 Due after ten years 2,825 2,805 — — Total $ 26,810 $ 27,556 $ 7,595 $ 8,023

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	8. Derivatives and Hedging Activities We are a party to various derivative instruments, mainly through our subsidiary, KeyBank. The primary derivatives that we use are interest rate swaps, caps, floors, forwards and futures; foreign exchange contracts; commodity derivatives; and credit derivatives. These instruments help us manage exposure to interest rate risk, mitigate the credit risk inherent in our loan portfolio, hedge against changes in foreign currency exchange rates, and meet client financing and hedging needs. As further discussed in this note: • interest rate risk is the risk that the EVE or net interest income will be adversely affected by fluctuations in interest rates; • credit risk is the risk of loss arising from an obligor’s inability or failure to meet contractual payment or performance terms; and • foreign exchange risk is the risk that an exchange rate will adversely affect the fair value of a financial instrument. At December 31, 2020, after taking into account the effects of bilateral collateral and master netting agreements, we ha d $123 million of derivative assets and $3 million of derivative liabilities that relate to contracts entered into for hedging purposes. As of the same date, after taking into account the effects of bilateral collateral and master netting agreements and a reserve for potential future losses, we had derivative assets of $1.7 billion and derivative liabilities of $153 million that were not designated as hedging instruments. These positions are primarily comprised of derivative contracts entered into for client accommodation purposes. Additional information regarding our accounting policies for derivatives is provided in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Derivatives and Hedging.” Derivatives Designated in Hedge Relationships Net interest income and the EVE change in response to changes in the mix of assets, liabilities, and off-balance sheet instruments and the associated interest rates tied to each instrument. In addition, differences in the repricing and maturity characteristics of interest-earning assets and interest-bearing liabilities cause net interest income and the EVE to fluctuate. We utilize derivatives that have been designated as part of a hedge relationship in accordance with the applicable accounting guidance to manage net interest income and EVE to within our stated risk tolerances. The primary derivative instruments used to manage interest rate risk are interest rate swaps. We designate certain “receive fixed/pay variable” interest rate swaps as fair value hedges. These contracts convert certain fixed-rate long-term debt into variable-rate obligations, thereby modifying our exposure to changes in interest rates. As a result, we receive fixed-rate interest payments in exchange for making variable-rate payments over the lives of the contracts without exchanging the notional amounts. Similarly, we designate certain “receive fixed/pay variable” interest rate swaps as cash flow hedges. These contracts effectively convert certain floating-rate loans into fixed-rate loans to reduce the potential adverse effect of interest rate decreases on future interest income. Again, we receive fixed-rate interest payments in exchange for making variable-rate payments over the lives of the contracts without exchanging the notional amounts. We designate interest rate floors as cash flow hedges. Interest rate floors also reduce the potential adverse effect of interest rate decreases on future interest income. We receive interest payments when the strike price specified in the contracts falls below a reference rate in exchange for an upfront premium. We designate certain “pay fixed/receive variable” interest rate swaps as cash flow hedges. These swaps convert certain floating-rate debt into fixed-rate debt. We also use these swaps to manage the interest rate risk associated with anticipated sales of certain commercial real estate loans and certain student loans originated through our Laurel Road digital lending business. The swaps protect against the possible short-term decline in the value of the loans that could result from changes in interest rates between the time they are originated and the time they are sold. We use foreign currency forward transactions to hedge the foreign currency exposure of our net investment in various foreign equipment finance entities. These entities are denominated in a non-U.S. currency. These swaps are designated as net investment hedges to mitigate the exposure of measuring the net investment at the spot foreign exchange rate. Our last remaining net investment hedge was discontinued in the fourth quarter of 2019 in connection with the liquidation of the net assets of KEF’s Canadian subsidiary. Derivatives Not Designated in Hedge Relationships We may enter into interest rate swap contracts to manage economic risks but do not designate the instruments in hedge relationships. Excluding contracts addressing customer exposures, the amount of derivatives hedging risks on an economic basis at December 31, 2020, was not significant. Like other financial services institutions, we originate loans and extend credit, both of which expose us to credit risk. We actively manage our overall loan portfolio and the associated credit risk in a manner consistent with asset quality objectives and concentration risk tolerances to mitigate portfolio credit risk. Purchasing credit protection through default swaps enables us to transfer to a third party a portion of the credit risk associated with a particular extension of credit, including situations where there is a forecasted sale of loans. We purchase credit default swaps to reduce the credit risk associated with the debt securities held in our trading portfolio. We also enter into derivative contracts for other purposes, including: • interest rate swap, cap, and floor contracts entered into generally to accommodate the needs of commercial loan clients; • energy and base metal swap and option contracts entered into to accommodate the needs of clients; • foreign exchange forward and option contracts entered into primarily to accommodate the needs of clients; and • futures contracts and positions with third parties that are intended to offset or mitigate the interest rate or market risk related to client positions discussed above. Fair Values, Volume of Activity, and Gain/Loss Information Related to Derivative Instruments The following table summarizes the fair values of our derivative instruments on a gross and net basis as of December 31, 2020, and December 31, 2019. The change in the notional amounts of these derivatives by type from December 31, 2019, to December 31, 2020, indicates the volume of our derivative transaction activity during 2020. The notional amounts are not affected by bilateral collateral and master netting agreements. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Where master netting agreements are not in effect or are not enforceable under bankruptcy laws, we do not adjust those derivative assets and liabilities with counterparties. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. Our derivative instruments are included in “accrued income and other assets” or “accrued expenses and other liabilities” on the balance sheet, as indicated in the following table: December 31, 2020 December 31, 2019 Fair Value (a) Fair Value in millions Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate $ 36,135 $ 70 $ (3) $ 39,208 $ 191 $ 20 Total 36,135 70 (3) 39,208 191 20 Derivatives not designated as hedging instruments: Interest rate 78,424 1,514 291 71,209 772 233 Foreign exchange 6,385 109 103 6,572 67 60 Commodity 9,702 426 408 5,324 208 200 Credit 423 1 11 427 1 10 Other (b) 4,951 58 16 3,337 14 10 Total 99,885 2,108 829 86,869 1,062 513 Netting adjustments (c) — (380) (675) — (473) (335) Net derivatives in the balance sheet 136,020 1,798 151 126,077 780 198 Other collateral (d) — (2) (11) — (2) (42) Net derivative amounts $ 136,020 $ 1,796 $ 140 $ 126,077 $ 778 $ 156 (a) We take into account bilateral collateral and master netting agreement that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets and contracts with positive fair values included in derivative liabilities. (b) Other derivatives include interest rate lock commitments and forward sale commitments related to our residential mortgage banking activities, forward purchase and sales contracts consisting of contractual commitments associated with “to be announced” securities and when issued securities. (c) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. (d) Other collateral represents the amount that cannot be used to offset our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The other collateral consists of securities and is exchanged under bilateral collateral and master netting agreements that allow us to offset the net derivative position with the related collateral. The application of the other collateral cannot reduce the net derivative position below zero. Therefore, excess other collateral, if any, is not reflected above. Fair value hedges. During the year ended December 31, 2020, we did not exclude any portion of these hedging instruments from the assessment of hedge effectiveness. The following tables summarize the amounts that were recorded on the balance sheet as of December 31, 2020 and December 31, 2019, related to cumulative basis adjustments for fair value hedges. December 31, 2020 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment Interest rate contracts Long-term debt (b) $ 8,182 $ 416 Interest rate contracts Securities available for sale (c) 2,080 (21) December 31, 2019 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment Interest rate contracts Long-term debt (b) $ 8,408 $ 240 (a) The carrying amount represents the portion of the asset or liability designated as the hedged item. (b) Basis adjustments related to de-designated hedges that no longer qualify as fair value hedges reduced the hedge accounting basis adjustment by $8 million and $9 million at December 31, 2020 and December 31, 2019, respectively. (c) These amounts are designated as fair value hedges under the last-of-layer method. The carrying amount represents the amortized costs basis of the prepayable financial assets used to designate hedging relationships in which the hedged item is the last layer expected to be remaining at the end of the hedging relationship. At December 31, 2020, the amortized cost of the closed portfolios used in these hedging relationships was $2.5 billion Cash flow hedges. During the year ended December 31, 2020, we did not exclude any portion of these hedging instruments from the assessment of hedge effectiveness. Considering the interest rates, yield curves, and notional amounts as of December 31, 2020, we would expect to reclassify an estim ated $232 million of after-tax net losses on derivative instruments from AOCI to income during the next 12 months for our cash flow hedges. In addition, we expect to reclassify approximately $73 million of pre-tax net losses related to terminated cash flow hedges from AOCI to income during the next 12 months. As of December 31, 2020, the maximum length of time over which we hedge forecasted transactions is 11 years. The following tables summarize the effect of fair value and cash flow hedge accounting on the income statement for the years ended December 31, 2020, December 31, 2019, and December 31, 2018. Location and amount of net gains (losses) recognized in income on fair value and cash flow hedging relationships (a) in millions Interest expense – long-term debt Interest income – loans Investment banking and debt placement fees Interest expense – deposits Other income Twelve months ended December 31, 2020 Total amounts presented in the consolidated statement of income $ (286) $ 3,866 $ 661 $ (347) $ 15 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (177) — — — — Recognized on derivatives designated as hedging instruments 305 — — — — Net income (expense) recognized on fair value hedges 128 — — — — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (4) 319 — — — Net income (expense) recognized on cash flow hedges $ (4) $ 319 $ — — — Twelve months ended December 31, 2019 Total amounts presented in the consolidated statement of income $ (454) $ 4,267 $ 630 $ (853) $ 68 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (247) — — (1) — Recognized on derivatives designated as hedging instruments 231 — — — — Net income (expense) recognized on fair value hedges (16) — — $ (1) $ — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (1) 15 — — — Foreign exchange contracts — — — — 32 Net income (expense) recognized on cash flow hedges $ (1) $ 15 $ — — $ 32 Twelve months ended December 31, 2018 Total amounts presented in the consolidated statement of income $ (420) $ 4,023 $ 650 $ (517) $ 176 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (5) — — 1 — Recognized on derivatives designated as hedging instruments (12) — — — — Net income (expense) recognized on fair value hedges (17) — — 1 $ — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (2) (68) 2 — 31 Net income (expense) recognized on cash flow hedges $ (2) $ (68) $ 2 — 31 Net investment hedges. We previously entered into foreign currency forward contracts to hedge our exposure to changes in the carrying value of our investments in foreign subsidiaries as a result of changes in the related foreign exchange rates. In December 2019, our last remaining net investment hedge was discontinued in connection with the substantial liquidation of the net assets of KEF’s Canadian subsidiary. The discontinuance of this hedge relationship resulted in reclassification from AOCI into other income of pre-tax gains of $25 million related to cumulative changes in the fair value of the net investment hedge. The gain was offset by the reclassification of $11 million from AOCI into other income related to the pre-tax foreign currency translation adjustment loss on the net investment balance. The following table summarizes the pre-tax net gains (losses) on our cash flow and net investment hedges for the years ended December 31, 2020, December 31, 2019, and December 31, 2018, and where they are recorded on the income statement. The table includes net gains (losses) recognized in OCI during the period and net gains (losses) reclassified from AOCI into income during the current period. in millions Net Gains (Losses) Income Statement Location of Net Gains (Losses) Net Gains (Losses) Reclassified From OCI Into Income (a) Net Gains (Losses) Recognized in Other Income (a) Twelve months ended December 31, 2020 Cash Flow Hedges Interest rate $ 628 Interest income — Loans $ 319 $ — Interest rate (5) Interest expense — Long-term debt (4) — Interest rate (9) Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts — Other Income — — Total $ 614 $ 315 $ — Twelve months ended December 31, 2019 Cash Flow Hedges Interest rate $ 442 Interest income — Loans $ 15 $ — Interest rate (1) Interest expense — Long-term debt (1) — Interest rate 3 Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (4) Other Income 32 — Total $ 440 $ 46 $ — Twelve months ended December 31, 2018 Cash Flow Hedges Interest rate $ (13) Interest income — Loans $ (68) $ — Interest rate 2 Interest expense — Long-term debt (2) — Interest rate 1 Investment banking and debt placement fees 2 — Net Investment Hedges Foreign exchange contracts 19 Other Income 31 — Total $ 9 $ (37) $ — Nonhedging instruments. The following table summarizes the pre-tax net gains (losses) on our derivatives that are not designated as hedging instruments for the years ended December 31, 2020, December 31, 2019, and December 31, 2018, and where they are recorded on the income statement. 2020 2019 2018 Year ended December 31, in millions Corporate Consumer Mortgage Income Other Total Corporate Consumer Mortgage Income Other Total Corporate Consumer Mortgage Income Other Total NET GAINS (LOSSES) Interest rate $ 32 — $ (10) $ 22 $ 46 — $ (2) $ 44 $ 38 — $ (1) $ 37 Foreign exchange 41 — — 41 45 — — 45 42 — — 42 Commodity 19 — — 19 6 — — 6 8 — — 8 Credit (4) — (29) (33) (6) — (36) (42) 2 — (30) (28) Other — $ 19 19 38 — $ 2 — 2 — $ (1) 12 11 Total net gains (losses) $ 88 $ 19 $ (20) $ 87 $ 91 $ 2 $ (38) $ 55 $ 90 $ (1) $ (19) $ 70 Counterparty Credit Risk We use several means to mitigate and manage exposure to credit risk on derivative contracts. We enter into bilateral collateral and master netting agreements that provide for the net settlement of all contracts with a single counterparty in the event of default. Additionally, we monitor counterparty credit risk exposure on each contract to determine appropriate limits on our total credit exposure across all product types. We review our collateral positions on a daily basis and exchange collateral with our counterparties in accordance with standard ISDA documentation, central clearing rules, and other related agreements. We hold collateral in the form of cash and highly rated securities issued by the U.S. Treasury, government-sponsored enterprises, or GNMA. Cash collateral netted against derivative assets on the balance sheet totaled $63 million at December 31, 2020, and $207 million at December 31, 2019. The cash collateral netted against derivative liabilities totaled $232 million at December 31, 2020, and $69 million at December 31, 2019. The following table summarizes the fair value of our derivative assets by type at the dates indicated. These assets represent our gross exposure to potential loss after taking into account the effects of bilateral collateral and master netting agreements and other means used to mitigate risk. December 31, in millions 2020 2019 Interest rate $ 1,448 $ 848 Foreign exchange 52 30 Commodity 178 95 Credit (1) — Other 58 14 Derivative assets before collateral 1,735 987 Add (Less): Related collateral 63 (207) Total derivative assets $ 1,798 $ 780 We enter into derivative transactions with two primary groups: broker-dealers and banks, and clients. Since these groups have different economic characteristics, we have different methods for managing counterparty credit exposure and credit risk. We enter into transactions with broker-dealers and banks for various risk management purposes. These types of transactions are primarily high dollar volume. We enter into bilateral collateral and master netting agreements with these counterparties. We clear certain types of derivative transactions with these counterparties, whereby central clearing organizations become the counterparties to our derivative contracts. In addition, we enter into derivative contracts through swap execution facilities. Swap clearing and swap execution facilities reduce our exposure to counterparty credit risk. At December 31, 2020, we had gross exposure of $250 million to broker-dealers and banks. We had net exposure of $245 million after the application of master netting agreements and cash collateral, where such qualifying agreements exist. We had net exposure of $243 million after considering $3 million of additional collateral held in the form of securities. We enter into transactions using master netting agreements with clients to accommodate their business needs. In most cases, we mitigate our credit exposure by cross-collateralizing these transactions to the underlying loan collateral. For transactions that are not clearable, we mitigate our market risk by buying and selling U.S. Treasuries and Eurodollar futures or entering into offsetting positions. Due to the cross-collateralization to the underlying loan, we typically do not exchange cash or marketable securities collateral in connection with these transactions. To address the risk of default associated with t hese contracts, we have established a CVA reserve (included in “accrued income and other assets”) in the amount of $49 million at December 31, 2020. The CVA is calculated from potential future exposures, expected recovery rates, and market-implied probabilities of default. At December 31, 2020, we had gross exposure of $1.7 billion to client counterparties and other entities that are not broker-dealers or banks for derivatives that have associated master netting agreements. We had net exposure of $1.6 billion on our derivatives with these counterparties after the application of master netting agreements, collateral, and the related reserve. Credit Derivatives We are a buyer and, under limited circumstances, may be a seller of credit protection through the credit derivative market. We purchase credit derivatives to manage the credit risk associated with specific commercial lending and swap obligations as well as exposures to debt securities. Our credit derivative portfolio was in a net liability position of $9 million as of both December 31, 2020, and December 31, 2019. Our credit derivative portfolio may consist of the following: • Single-name credit default swap : A bilateral contract whereby the seller agrees, for a premium, to provide protection against the credit risk of a specific entity (the “reference entity”) in connection with a specific debt obligation. The protected credit risk is related to adverse credit events, such as bankruptcy, failure to make payments, and acceleration or restructuring of obligations, identified in the credit derivative contract. • Traded credit default swap index: Represents a position on a basket or portfolio of reference entities. • Risk participation agreement: A transaction in which the lead participant has a swap agreement with a customer. The lead participant (purchaser of protection) then enters into a risk participation agreement with a counterparty (seller of protection), under which the counterparty receives a fee to accept a portion of the lead participant’s credit risk. If the customer defaults on the swap contract, the counterparty to the risk participation agreement must reimburse the lead participant for the counterparty’s percentage of the positive fair value of the customer swap as of the default date. If the customer swap has a negative fair value, the counterparty has no reimbursement requirements. If the customer defaults on the swap contract and the seller fulfills its payment obligations under the risk participation agreement, the seller is entitled to a pro rata share of the lead participant’s claims against the customer under the terms of the swap agreement. The following table provides information on the types of credit derivatives sold by us and held on the balance sheet at December 31, 2020, and December 31, 2019. The notional amount represents the amount that the seller could be required to pay. The payment/performance risk shown in the table represents a weighted average of the default probabilities for all reference entities in the respective portfolios. These default probabilities are implied from observed credit indices in the credit default swap market, which are mapped to reference entities based on Key’s internal risk rating. 2020 2019 December 31, dollars in millions Notional Average Payment / Notional Average Payment / Other $ 227 12.76 19.53 % $ 134 14.30 14.56 % Total credit derivatives sold $ 227 — — $ 134 — — Credit Risk Contingent Features We have entered into certain derivative contracts that require us to post collateral to the counterparties when these contracts are in a net liability position. The amount of collateral to be posted is based on the amount of the net liability and thresholds generally related to our long-term senior unsecured credit ratings with Moody’s and S&P. Collateral requirements also are based on minimum transfer amounts, which are specific to each Credit Support Annex (a component of the ISDA Master Agreement) that we have signed with the counterparties. In a limited number of instances, counterparties have the right to terminate their ISDA Master Agreements with us if our ratings fall below a certain level, usually investment-grade level (i.e., “Baa3” for Moody’s and “BBB-” for S&P). At December 31, 2020, KeyBank’s rating w as “A3” with Moody’s and “A-” with S&P, and KeyCorp’s rating was “Baa1” with Moody’s and “BBB+” with S&P. As of December 31, 2020, the aggregate fair value of all derivative contracts with credit risk contingent features (i.e., those containi ng collateral posting or termination provisions based on our ratings) held by KeyBank that were in a net liability position totale d $44 million, which includes $111 million in derivative assets and $156 million in derivative liabilities. We had $30 million in c ash and securities collateral posted to cover those positions as of December 31, 2020. There were no derivative contracts with credit risk contingent features held by KeyCorp at December 31, 2020. The following table summarizes the additional cash and securities collateral that KeyBank would have been required to deliver under the ISDA Master Agreements had the credit risk contingent features been triggered for the derivative contracts in a net liability position as of December 31, 2020, and December 31, 2019. The additional collateral amounts were calculated based on scenarios under which KeyBank’s ratings are downgraded one, two, or three ratings as of December 31, 2020, and December 31, 2019, and take into account all collateral already posted. A similar calculation was performed for KeyCorp, and no additional collateral would have been required at December 31, 2020, or December 31, 2019. December 31, in millions 2020 2019 Moody’s S&P Moody’s S&P KeyBank’s long-term senior unsecured credit ratings A3 A- A3 A- One rating downgrade $ 1 $ 1 $ 1 $ 1 Two rating downgrades 1 1 1 1 Three rating downgrades 1 1 1 1 KeyBank’s long-term senior unsecured credit rating was four ratings above noninvestment grade at Moody’s and S&P as of December 31, 2020, and December 31, 2019. If KeyBank’s ratings had been downgraded below investment grade as of December 31, 2020, and December 31, 2019, payments of up to $2 million and $3 million, respectively, would have been required to either terminate the contracts or post additional collateral for those contracts in a net liability position, taking into account all collateral already posted. If KeyCorp’s ratings had been downgraded below investment grade as of December 31, 2020, and December 31, 2019, no payments would h ave

Mortgage Servicing Assets

Mortgage Servicing Assets	12 Months Ended
	Dec. 31, 2020
Servicing Asset [Abstract]
Mortgage Servicing Assets	9. Mortgage Servicing Assets We originate and periodically sell commercial and residential mortgage loans but continue to service those loans for the buyers. We also may purchase the right to service commercial mortgage loans for other lenders. We record a servicing asset if we purchase or retain the right to service loans in exchange for servicing fees that exceed the going market servicing rate and are considered more than adequate compensation for servicing. Additional information pertaining to the accounting for mortgage and other servicing assets is included in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Servicing Assets.” Commercial Changes in the carrying amount of commercial mortgage servicing assets are summarized as follows: Year ended December 31, in millions 2020 2019 Balance at beginning of period $ 539 $ 502 Servicing retained from loan sales 138 108 Purchases 33 47 Amortization (117) (115) Temporary impairments (15) (3) Balance at end of period $ 578 $ 539 Fair value at end of period $ 668 $ 665 The fair value of commercial mortgage servicing assets is determined by calculating the present value of future cash flows associated with servicing the commercial mortgage loans. This calculation uses a number of assumptions that are based on current market conditions. The range and weighted-average of the significant unobservable inputs used to fair value our commercial mortgage servicing assets at December 31, 2020, and December 31, 2019, along with the valuation techniques, are shown in the following table: dollars in millions December 31, 2020 December 31, 2019 Valuation Technique Significant Unobservable Input Range Weighted-Average Range Weighted-Average Discounted cash flow Expected defaults 1.01 2.00 % 1.18 % 1.00 2.00 % 1.13 % Residual cash flows discount rate 7.48 10.62 % 9.22 % 7.00 11.44 % 9.32 % Escrow earn rate 0.92 1.14 % 1.04 % 1.44 2.32 % 2.03 % Loan assumption rate 0.00 1.77 % 1.43 % 0.01 3.37 % 1.37 % If these economic assumptions change or prove incorrect, the fair value of commercial mortgage servicing assets may also change. Expected credit losses, escrow earn rates, and discount rates are critical to the valuation of commercial mortgage servicing assets. Estimates of these assumptions are based on how a market participant would view the respective rates and reflect historical data associated with the commercial mortgage loans, industry trends, and other considerations. Actual rates may differ from those estimated due to changes in a variety of economic factors. A decrease in the value assigned to the escrow earn rates would cause a decrease in the fair value of our commercial mortgage servicing assets. An increase in the assumed default rates of commercial mortgage loans or an increase in the assigned discount rates would cause a decrease in the fair value of our commercial mortgage servicing assets. Prepayment activity on commercial serviced loans does not significantly impact the valuation of our commercial mortgage servicing assets. Unlike residential mortgages, commercial mortgages experience significantly lower prepayments due to certain contractual restrictions impacting the borrower’s ability to prepay the mortgage. The amortization of commercial mortgage servicing assets for each period, as shown in the table at the beginning of this note, is recorded as a reduction to contractual fee income. The contractual fee income from servicing commercial mortgage loans totaled $214 million for the year ended December 31, 2020, $196 million for the year ended December 31, 2019, and $171 million for the year ended December 31, 2018. This fee income was partially offset by $117 million of amortization for the year ended December 31, 2020, $115 million for the year ended December 31, 2019, and $102 million for the year ended December 31, 2018. Both the contractual fee income and the amortization are recorded, net, in “commercial mortgage servicing fees” on the income statement. Residential Changes in the carrying amount of residential mortgage servicing assets are summarized as follows: in millions 2020 2019 Balance at beginning of period $ 46 37 Servicing retained from loan sales 36 $ 15 Purchases — — Amortization (14) (6) Temporary impairments $ (10) $ — Balance at end of period $ 58 $ 46 Fair value at end of period $ 60 $ 50 The fair value of residential mortgage servicing assets is determined by calculating the present value of future cash flows associated with servicing the residential mortgage loans. This calculation uses a number of assumptions that are based on current market conditions. The range and weighted-average of the significant unobservable inputs used to fair value our residential mortgage servicing assets at December 31, 2020, along with the valuation techniques, are shown in the following table: December 31, 2020 December 31, 2019 Valuation Technique Significant Unobservable Input Range Weighted-Average Range Weighted-Average Discounted cash flow Prepayment speed 12.39 54.27 % 17.09 % 10.38 61.51 % 12.95 % Discount rate 7.51 8.63 % 7.55 % 7.5 8.50 % 7.52 % Servicing cost $62.00 $5,125 $75.37 $62 $4,375 $68.73 If these economic assumptions change or prove incorrect, the fair value of residential mortgage servicing assets may also change. Prepayment speed, discount rates, and servicing cost are critical to the valuation of residential mortgage servicing assets. Estimates of these assumptions are based on how a market participant would view the respective rates and reflect historical data associated with the residential mortgage loans, industry trends, and other considerations. Actual rates may differ from those estimated due to changes in a variety of economic factors. An increase in the prepayment speed would cause a decrease in the fair value of our residential mortgage servicing assets. An increase in the assigned discount rates and servicing cost assumptions would cause a decrease in the fair value of our residential mortgage servicing assets. The amortization of residential mortgage servicing assets for December 31, 2020, as shown in the table above, is recorded as a reduction to contractual fee income. The contractual fee income from servicing residential mortgage loans totaled $34 million for the year ended December 31, 2020, $21 million for the year ended December 31, 2019, and $14 million for the year ended December 31, 2018. This fee income was offset by $14 million of amortization for the year ended December 31, 2020, $6 million for the year ended December 31, 2019, and $4 million for the year ended December 31, 2018. Both the contractual fee income and the amortization are recorded, net, in “consumer mortgage income” on the income statement.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	10. Leases As a lessee, we enter into leases of land, buildings, and equipment. Our real estate leases primarily relate to bank branches and office space. The leases of equipment principally relate to technology assets for data processing and data storage. As a lessor, we primarily provide financing through our equipment leasing business. Lessee Our leases are classified as either operating or financing and have remaining terms ranging from 1 to 20 years with the exception of certain ground leases that have terms over 30 years. For leases with initial terms greater than one year, a lease liability, measured as the present value of unpaid lease payments, and a corresponding right-of-use asset for the right to use the leased properties are reported on the balance sheet. Lease payments are discounted using Key’s incremental borrowing rate, consistent with what Key would pay to borrow on a collateralized basis over a term similar to each lease. Leases with an initial term of less than one year are not recorded on the balance sheet. The related expense is recognized on a straight-line basis over the lease term. Certain leases contain options to extend the lease term for up to five years. Some leases give us the option to terminate, for a penalty or at the lessor's discretion. Leases with variable payments are primarily based on adjustments for inflation over the term of the lease based on a contractually defined index. Certain ATM leases include variable payments based on volume of transactions. Operating lease expense is recognized in "net occupancy" and "equipment" on the income statement. The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019. (b) During the third quarter of 2019, we entered into a sale leaseback transaction related to one branch which resulted in total proceeds of $16 million. Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13 Information pertaining to the lease term and weighted-average discount rate is summarized as follows: December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 % Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722 Lessor Equipment Leasing Leases may have fixed or floating rate terms. Variable payments are based on an index or other specified rate and are included in rental payments. Certain leases contain an option to extend the lease term or the option to terminate at the discretion of the lessee. Under certain conditions, lease agreements may also contain the option for a lessee to purchase the underlying asset. Interest income from sales-type and direct financing leases is recognized in "interest income — loans" on the statement of income. Income related to operating leases is recognized in “operating lease income and other leasing gains” on the income statement. The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295 Equipment leasing receivables relate to sales-type and direct financing leases. The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969 The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Effective January 1, 2019, as a result of the implementation of ASU 2016-02, Key assesses net investments in leases, including residual values, for impairment and recognizes any impairment losses in accordance with the impairment guidanc e for financial instruments. The carrying amount of residual assets covered by residual value guarantees at December 31, 2020, and December 31, 2019, was $269 million and $289 million, respectively. At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570 At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581
Leases	10. Leases As a lessee, we enter into leases of land, buildings, and equipment. Our real estate leases primarily relate to bank branches and office space. The leases of equipment principally relate to technology assets for data processing and data storage. As a lessor, we primarily provide financing through our equipment leasing business. Lessee Our leases are classified as either operating or financing and have remaining terms ranging from 1 to 20 years with the exception of certain ground leases that have terms over 30 years. For leases with initial terms greater than one year, a lease liability, measured as the present value of unpaid lease payments, and a corresponding right-of-use asset for the right to use the leased properties are reported on the balance sheet. Lease payments are discounted using Key’s incremental borrowing rate, consistent with what Key would pay to borrow on a collateralized basis over a term similar to each lease. Leases with an initial term of less than one year are not recorded on the balance sheet. The related expense is recognized on a straight-line basis over the lease term. Certain leases contain options to extend the lease term for up to five years. Some leases give us the option to terminate, for a penalty or at the lessor's discretion. Leases with variable payments are primarily based on adjustments for inflation over the term of the lease based on a contractually defined index. Certain ATM leases include variable payments based on volume of transactions. Operating lease expense is recognized in "net occupancy" and "equipment" on the income statement. The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019. (b) During the third quarter of 2019, we entered into a sale leaseback transaction related to one branch which resulted in total proceeds of $16 million. Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13 Information pertaining to the lease term and weighted-average discount rate is summarized as follows: December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 % Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722 Lessor Equipment Leasing Leases may have fixed or floating rate terms. Variable payments are based on an index or other specified rate and are included in rental payments. Certain leases contain an option to extend the lease term or the option to terminate at the discretion of the lessee. Under certain conditions, lease agreements may also contain the option for a lessee to purchase the underlying asset. Interest income from sales-type and direct financing leases is recognized in "interest income — loans" on the statement of income. Income related to operating leases is recognized in “operating lease income and other leasing gains” on the income statement. The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295 Equipment leasing receivables relate to sales-type and direct financing leases. The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969 The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Effective January 1, 2019, as a result of the implementation of ASU 2016-02, Key assesses net investments in leases, including residual values, for impairment and recognizes any impairment losses in accordance with the impairment guidanc e for financial instruments. The carrying amount of residual assets covered by residual value guarantees at December 31, 2020, and December 31, 2019, was $269 million and $289 million, respectively. At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570 At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581
Leases	10. Leases As a lessee, we enter into leases of land, buildings, and equipment. Our real estate leases primarily relate to bank branches and office space. The leases of equipment principally relate to technology assets for data processing and data storage. As a lessor, we primarily provide financing through our equipment leasing business. Lessee Our leases are classified as either operating or financing and have remaining terms ranging from 1 to 20 years with the exception of certain ground leases that have terms over 30 years. For leases with initial terms greater than one year, a lease liability, measured as the present value of unpaid lease payments, and a corresponding right-of-use asset for the right to use the leased properties are reported on the balance sheet. Lease payments are discounted using Key’s incremental borrowing rate, consistent with what Key would pay to borrow on a collateralized basis over a term similar to each lease. Leases with an initial term of less than one year are not recorded on the balance sheet. The related expense is recognized on a straight-line basis over the lease term. Certain leases contain options to extend the lease term for up to five years. Some leases give us the option to terminate, for a penalty or at the lessor's discretion. Leases with variable payments are primarily based on adjustments for inflation over the term of the lease based on a contractually defined index. Certain ATM leases include variable payments based on volume of transactions. Operating lease expense is recognized in "net occupancy" and "equipment" on the income statement. The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019. (b) During the third quarter of 2019, we entered into a sale leaseback transaction related to one branch which resulted in total proceeds of $16 million. Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13 Information pertaining to the lease term and weighted-average discount rate is summarized as follows: December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 % Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722 Lessor Equipment Leasing Leases may have fixed or floating rate terms. Variable payments are based on an index or other specified rate and are included in rental payments. Certain leases contain an option to extend the lease term or the option to terminate at the discretion of the lessee. Under certain conditions, lease agreements may also contain the option for a lessee to purchase the underlying asset. Interest income from sales-type and direct financing leases is recognized in "interest income — loans" on the statement of income. Income related to operating leases is recognized in “operating lease income and other leasing gains” on the income statement. The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295 Equipment leasing receivables relate to sales-type and direct financing leases. The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969 The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Effective January 1, 2019, as a result of the implementation of ASU 2016-02, Key assesses net investments in leases, including residual values, for impairment and recognizes any impairment losses in accordance with the impairment guidanc e for financial instruments. The carrying amount of residual assets covered by residual value guarantees at December 31, 2020, and December 31, 2019, was $269 million and $289 million, respectively. At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570 At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581
Leases	10. Leases As a lessee, we enter into leases of land, buildings, and equipment. Our real estate leases primarily relate to bank branches and office space. The leases of equipment principally relate to technology assets for data processing and data storage. As a lessor, we primarily provide financing through our equipment leasing business. Lessee Our leases are classified as either operating or financing and have remaining terms ranging from 1 to 20 years with the exception of certain ground leases that have terms over 30 years. For leases with initial terms greater than one year, a lease liability, measured as the present value of unpaid lease payments, and a corresponding right-of-use asset for the right to use the leased properties are reported on the balance sheet. Lease payments are discounted using Key’s incremental borrowing rate, consistent with what Key would pay to borrow on a collateralized basis over a term similar to each lease. Leases with an initial term of less than one year are not recorded on the balance sheet. The related expense is recognized on a straight-line basis over the lease term. Certain leases contain options to extend the lease term for up to five years. Some leases give us the option to terminate, for a penalty or at the lessor's discretion. Leases with variable payments are primarily based on adjustments for inflation over the term of the lease based on a contractually defined index. Certain ATM leases include variable payments based on volume of transactions. Operating lease expense is recognized in "net occupancy" and "equipment" on the income statement. The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019. (b) During the third quarter of 2019, we entered into a sale leaseback transaction related to one branch which resulted in total proceeds of $16 million. Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13 Information pertaining to the lease term and weighted-average discount rate is summarized as follows: December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 % Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722 Lessor Equipment Leasing Leases may have fixed or floating rate terms. Variable payments are based on an index or other specified rate and are included in rental payments. Certain leases contain an option to extend the lease term or the option to terminate at the discretion of the lessee. Under certain conditions, lease agreements may also contain the option for a lessee to purchase the underlying asset. Interest income from sales-type and direct financing leases is recognized in "interest income — loans" on the statement of income. Income related to operating leases is recognized in “operating lease income and other leasing gains” on the income statement. The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295 Equipment leasing receivables relate to sales-type and direct financing leases. The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969 The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Effective January 1, 2019, as a result of the implementation of ASU 2016-02, Key assesses net investments in leases, including residual values, for impairment and recognizes any impairment losses in accordance with the impairment guidanc e for financial instruments. The carrying amount of residual assets covered by residual value guarantees at December 31, 2020, and December 31, 2019, was $269 million and $289 million, respectively. At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570 At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581
Leases	10. Leases As a lessee, we enter into leases of land, buildings, and equipment. Our real estate leases primarily relate to bank branches and office space. The leases of equipment principally relate to technology assets for data processing and data storage. As a lessor, we primarily provide financing through our equipment leasing business. Lessee Our leases are classified as either operating or financing and have remaining terms ranging from 1 to 20 years with the exception of certain ground leases that have terms over 30 years. For leases with initial terms greater than one year, a lease liability, measured as the present value of unpaid lease payments, and a corresponding right-of-use asset for the right to use the leased properties are reported on the balance sheet. Lease payments are discounted using Key’s incremental borrowing rate, consistent with what Key would pay to borrow on a collateralized basis over a term similar to each lease. Leases with an initial term of less than one year are not recorded on the balance sheet. The related expense is recognized on a straight-line basis over the lease term. Certain leases contain options to extend the lease term for up to five years. Some leases give us the option to terminate, for a penalty or at the lessor's discretion. Leases with variable payments are primarily based on adjustments for inflation over the term of the lease based on a contractually defined index. Certain ATM leases include variable payments based on volume of transactions. Operating lease expense is recognized in "net occupancy" and "equipment" on the income statement. The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019. (b) During the third quarter of 2019, we entered into a sale leaseback transaction related to one branch which resulted in total proceeds of $16 million. Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13 Information pertaining to the lease term and weighted-average discount rate is summarized as follows: December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 % Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722 Lessor Equipment Leasing Leases may have fixed or floating rate terms. Variable payments are based on an index or other specified rate and are included in rental payments. Certain leases contain an option to extend the lease term or the option to terminate at the discretion of the lessee. Under certain conditions, lease agreements may also contain the option for a lessee to purchase the underlying asset. Interest income from sales-type and direct financing leases is recognized in "interest income — loans" on the statement of income. Income related to operating leases is recognized in “operating lease income and other leasing gains” on the income statement. The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295 Equipment leasing receivables relate to sales-type and direct financing leases. The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969 The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Effective January 1, 2019, as a result of the implementation of ASU 2016-02, Key assesses net investments in leases, including residual values, for impairment and recognizes any impairment losses in accordance with the impairment guidanc e for financial instruments. The carrying amount of residual assets covered by residual value guarantees at December 31, 2020, and December 31, 2019, was $269 million and $289 million, respectively. At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570 At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Premises and Equipment	11. Premises and Equipment Premises and Equipment Premises and equipment at December 31, 2020, and December 31, 2019, consisted of the following: December 31, dollars in millions Useful life (in years) 2020 2019 Land Indefinite $ 126 $ 128 Buildings and improvements 15-40 722 729 Leasehold improvements 1-15 631 620 Furniture and equipment 2-15 843 872 Capitalized building leases 1-14 (a) 28 28 Construction in process N/A 44 48 Total premises and equipment 2,394 2,425 Less: Accumulated depreciation and amortization (1,641) (1,611) Premises and equipment, net $ 753 $ 814 (a) Capitalized building and equipment leases are amortized over the lesser of the useful life of asset or lease term. Depreciation and amortization expense related to premises and equipment for the years ended December 31, 2020, December 31, 2019, and December 31, 2018 was $115 million, $118 million, and $131 million, respectively. This includes amortization of assets under capital leases. Software Eligible costs related to computer software developed or obtained for internal use that add functionality, improve efficiency or extend the useful life of a system are capitalized. Amortization of capitalized software begins when it is ready for its intended use, which is after all substantial testing is completed. Capitalized costs are amortized using the straight-line or accelerated method over its useful life. Balances are included in “Accrued income and other assets”. Key had capitalized software assets, including internally-developed and purchased software and costs associated with certain cloud computing arrangements of $385 million and $910 million and related accumulated amortization of $183 million and $756 million as of December 31, 2020 and December 31, 2019, respectively. This includes in-

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	12. Goodwill and Other Intangible Assets Our annual goodwill impairment testing is performed as of October 1 each year, or more frequently as events occur or circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. Additional information pertaining to our accounting policy for goodwill and other intangible assets is summarized in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Goodwill and Other Intangible Assets.” During 2020, there was deterioration in the market and disruption resulting from the COVID-19 pandemic, which impacted Key’s market capitalization. We conducted a quantitative interim impairment test as of September 30, 2020, and concluded goodwill was not impaired. As a result of that interim test, we determined that the estimated fair value of the Consumer Bank reporting unit was 11% greater than its carrying amount, the estimated fair value of the Commercial Bank reporting unit was 17% greater than its carrying amount and the estimated fair value of the Institutional Bank reporting unit, which is aggregated in the Commercial Bank reporting segment, was 11% greater than its carrying amount. The fair values of each reporting unit were estimated using a combination of income and market approaches. The income approach utilized discounted cash flow projections for each reporting unit. The market approach consisted primarily of public company metrics but also considered recent transactions in the financial services industry. The carrying amounts of Key’s reporting units represent the average equity based on risk-weighted regulatory capital for goodwill impairment testing and management reporting purposes. For our annual test, we conducted a qualitative analysis as of October 1, 2020, and concluded goodwill was not impaired. We reviewed and evaluated various qualitative factors such as financial and stock performance, market capitalization, internal forecasts and economic indicators. We will continue to monitor for impairment as appropriate. During 2019, Key performed a quantitative annual test but it was not necessary to perform further reviews of goodwill in interim periods. Changes in the carrying amount of goodwill by reporting segment are presented in the following table: in millions Consumer Bank Commercial Bank Total BALANCE AT DECEMBER 31, 2018 $ 2,102 $ 414 $ 2,516 Reallocation of goodwill (498) 498 — Laurel Road acquisition 148 — 148 BALANCE AT DECEMBER 31, 2019 1,752 912 2,664 BALANCE AT DECEMBER 31, 2020 $ 1,752 $ 912 $ 2,664 Additional information regarding the Laurel Road acquisition is provided in Note 15 (“Acquisitions, Divestiture, and Discontinued Operations”). Additional information regarding the above reallocation of goodwill is provided in Note 25 (“Business Segment Reporting”). As of December 31, 2020, we expect goodwill in the amount of $517 million to be deductible for tax purposes in future periods. There were no accumulated impairment losses related to any of Key’s reporting units at December 31, 2020, December 31, 2019, and December 31, 2018. The following table shows the gross carrying amount and the accumulated amortization of intangible assets subject to amortization: 2020 2019 December 31, in millions Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible assets subject to amortization: Core deposit intangibles $ 355 $ 236 $ 355 $ 193 PCCR intangibles 16 12 152 145 Other intangible assets 105 40 115 31 Total $ 476 $ 288 $ 622 $ 369 The following table presents estimated intangible asset amortization expense for the next five years. Estimated in millions 2021 2022 2023 2024 2025 Intangible asset amortization expense $ 62 $ 57 $ 51 $ 28 $ 19

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities	13. Variable Interest Entities A VIE is a partnership, limited liability company, trust, or other legal entity that meets any one of the following criteria: • The entity does not have sufficient equity to conduct its activities without additional subordinated financial support from another party. • The entity’s investors lack the power to direct the activities that most significantly impact the entity’s economic performance. • The entity’s equity at risk holders do not have the obligation to absorb losses or the right to receive residual returns. • The voting rights of some investors are not proportional to their economic interests in the entity, and substantially all of the entity’s activities involve, or are conducted on behalf of, investors with disproportionately few voting rights. Our significant VIEs are summarized below. We define a “significant interest” in a VIE as a subordinated interest that exposes us to a significant portion, but not the majority, of the VIE’s expected losses or residual returns, even though we do not have the power to direct the activities that most significantly impact the entity’s economic performance. LIHTC investments. Through KCDC, we have made investments directly and indirectly in LIHTC operating partnerships formed by third parties. As a limited partner in these operating partnerships, we are allocated tax credits and deductions associated with the underlying properties. We have determined that we are not the primary beneficiary of these investments because the general partners have the power to direct the activities that most significantly influence the economic performance of their respective partnerships and have the obligation to absorb expected losses and the right to receive residual returns. As we are not the primary beneficiary of these investments, we do not consolidate them. Our maximum exposure to loss in connection with these partnerships consists of our unamortized investment balance plus any unfunded equity commitments and tax credits claimed but subject to recapture. We had $1.4 billion and $1.5 billion of investments in LIHTC operating partnerships at December 31, 2020, and December 31, 2019, respectively. These investments are recorded in “accrued income and other assets” on our balance sheet. We do not have any loss reserves recorded related to these investments because we believe the likelihood of any loss is remote. For all legally binding unfunded equity commitments, we increase our recognized investment and recognize a liability. As of December 31, 2020, and December 31, 2019, we had liabilities of $484 million and $546 million, respectively, related to investments in qualified affordable housing projects, which are recorded in “accrued expense and other liabilities” on our balance sheet. We continue to invest in these LIHTC operating partnerships. The assets and liabilities presented in the table below convey the size of KCDC’s direct and indirect investments at December 31, 2020, and December 31, 2019. As these investments represent unconsolidated VIEs, the assets and liabilities of the investments themselves are not recorded on our balance sheet. Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2020 LIHTC investments $ 6,914 $ 2,765 $ 1,823 December 31, 2019 LIHTC investments $ 6,405 $ 2,526 $ 1,846 We amortize our LIHTC investments over the period that we expect to receive the tax benefits. In 2020, we recognized $195 million of amortization and $177 million of tax credits associated with these investments within “income taxes” on our income statement. In 2019, we recognized $187 million of amortization and $184 million of tax credits associated with these investments within “income taxes” on our income statement. Principal investments. Through our principal investing entity, KCC, we have made investments in private equity funds engaged in venture- and growth-oriented investing. As a limited partner to these funds, KCC records these investments at fair value and receives distributions from the funds in accordance with the funds’ partnership agreements. We are not the primary beneficiary of these investments as we do not hold the power to direct the activities that most significantly affect the funds’ economic performance. Such power rests with the funds’ general partners. In addition, we neither have the obligation to absorb the funds’ expected losses nor the right to receive their residual returns. Our voting rights are also disproportionate to our economic interests, and substantially all of the funds’ activities are conducted on behalf of investors with disproportionately few voting rights. Because we are not the primary beneficiary of these investments, we do not consolidate them. Our maximum exposure to loss associated with indirect principal investments consists of the investments’ fair value plus any unfunded equity commitments. The fair value of our indirect principal investments totaled $53 million and $68 million at December 31, 2020, and December 31, 2019, respectively. These investments are recorded in “other investments” on our balance sheet. Additional information on indirect principal investments is provided in Note 6 (“Fair Value Measurements”). The table below reflects the size of the private equity funds in which KCC was invested as well as our maximum exposure to loss in connection with these investments at December 31, 2020. Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2020 Indirect investments $ 10,899 $ 168 $ 69 December 31, 2019 Indirect investments $ 12,954 $ 205 $ 89 Through our principal investing entities, we have formed and funded operating entities that provide management and other related services to our investment company funds, which directly invest in portfolio companies. In return for providing services to our direct investment funds, these entities’ receive a minority equity interest in the funds. This minority equity ownership is recorded at fair value on the entities’ financial statements. Additional information on our direct principal investments is provided in Note 6 (“Fair Value Measurements”). While other equity investors manage the daily operations of these entities, we retain the power, through voting rights, to direct the activities of the entities that most significantly impact their economic performance. In addition, we have the obligation to absorb losses and the right to receive residual returns that could potentially be significant to these entities. As a result, we have determined that we are the primary beneficiary of these funds and have consolidated them since formation. The entities had no liabilities at December 31, 2020, and December 31, 2019, and other equity investors have no recourse to our general credit. Other unconsolidated VIEs. We are involved with other various entities in the normal course of business which we have determined to be VIEs. We have determined that we are not the primary beneficiary of these VIEs because we do not have the power to direct the activities that most significantly impact their economic performance. Our assets associated with these unconsolidated VIEs totaled $351 million at December 31, 2020, and $282 million at December 31, 2019. These assets are recorded in “accrued income and other assets,” “other investments,”

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes Income taxes included in the income statement are summarized below. We file a consolidated federal income tax return. Year ended December 31, in millions 2020 2019 2018 Currently payable: Federal $ 336 $ 241 $ 184 State 83 20 62 Total currently payable 419 261 246 Deferred: Federal (156) 34 117 State (36) 19 (19) Total deferred (192) 53 98 Total income tax (benefit) expense (a) $ 227 $ 314 $ 344 (a) There was income tax (benefit) expense on securities transactions of $1 million in 2020, a $5 million in 2019 and no income tax (benefit) expense on securities transactions 2018. Income tax expense excludes equity- and gross receipts-based taxes, which are assessed in lieu of an income tax in certain states in which we operate. These non-income taxes, which are recorded in “noninterest expense” on the income statement, totaled $30 million in 2020, $23 million in 2019, and $15 million in 2018. On December 22, 2017, the TCJ Act was signed into law. This comprehensive tax legislation provided for significant changes to the U.S. Internal Revenue Code of 1986, as amended, that impacted corporate taxation requirements such as the reduction in the federal corporate income tax rate from 35% to 21% effective January 1, 2018. During 2018, we completed and filed our 2017 federal income tax return and management finalized its assessment of the initial impact of the TCJ Act, recorded in 2017, and related regulatory guidance. As a result, our income tax provision was increased by $7 million. Significant components of our deferred tax assets and liabilities included in “accrued expense and other liabilities” on the balance sheet, are as follows: December 31, in millions 2020 2019 Allowance for loan and lease losses $ 443 $ 236 Employee benefits 166 164 Federal net operating losses and credits 7 81 Fair value adjustments — 21 Non-tax accruals 76 61 Operating lease liabilities (a) 174 178 State net operating losses and credits 1 1 Other 297 245 Gross deferred tax assets 1,164 987 Less: Valuation Allowance — — Total deferred tax assets 1,164 987 Leasing transactions 556 628 Net unrealized securities gains 340 117 Operating lease right-of-use assets (a) 153 156 Other 215 175 Total deferred tax liabilities 1,264 1,076 Net deferred tax assets (liabilities) (b) $ (100) $ (89) (a) A separate deferred tax asset and liability is recognized for each operating lease item resulting from the adoption of ASC 842 in 2019. (b) From continuing operations. We conduct quarterly assessments of all available evidence to determine the amount of deferred tax assets that are more-likely-than-not to be realized, and therefore recorded. The available evidence used in connection with these assessments includes taxable income in prior periods, projected future taxable income, potential tax-planning strategies, and projected future reversals of deferred tax items. These assessments involve a degree of subjectivity and may undergo significant change. Based on these criteria, we have no recorded valuation allowances at December 31, 2020. At December 31, 2020, we had federal net operating loss carryforwards of $26 million and federal credit carryforwards of $1 million. The federal net operating loss carryforwards are from prior acquisitions by First Niagara and are subject to annual limitations under the tax code and, if not utilized, will expire in the years beginning 2027. The federal credit carryforward consists of general business credits which expire in 2037, under the Internal Revenue Code. We currently expect to fully utilize these losses and credits. We had state net operating loss carryforwards of $30 million, resulting in a net state deferred tax asset of $1 million. The following table shows how our total income tax expense (benefit) and the resulting effective tax rate were derived: Year ended December 31, dollars in millions 2020 2019 2018 Amount Rate Amount Rate Amount Rate Income (loss) before income taxes times 21% statutory federal tax rate $ 327 21.0 % $ 425 21.0 % $ 463 21.0 % Amortization of tax-advantaged investments 150 9.7 132 6.5 127 5.8 Foreign tax adjustments — — — — 2 .1 Tax-exempt interest income (28) (1.8) (30) (1.5) (30) (1.4) Corporate-owned life insurance income (29) (1.9) (29) (1.4) (29) (1.3) State income tax, net of federal tax benefit 37 2.4 31 1.5 34 1.5 Tax credits (218) (14.0) (231) (11.4) (234) (10.6) Tax Cuts and Jobs Act — — — — 7 .3 Other (12) (.8) 16 .9 4 .2 Total income tax expense (benefit) $ 227 14.6 % $ 314 15.6 % $ 344 15.6 % Liability for Unrecognized Tax Benefits The change in our liability for unrecognized tax benefits is as follows: Year ended December 31, 2020 2019 Balance at beginning of year $ 19 $ 35 Increase for other tax positions of prior years 40 2 Decrease for payments and settlements — — Decrease related to tax positions taken in prior years (1) (18) Balance at end of year $ 58 $ 19 Each quarter, we review the amount of unrecognized tax benefits recorded in accordance with the applicable accounting guidance. Any adjustment to unrecognized tax benefits is recorded in income tax expense. The amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate was $58 million at December 31, 2020, and $19 million at December 31, 2019. It is reasonably possible that the balance of unrecognized tax benefits could decrease in the next twelve months due to examinations by various tax authorities or the expiration of statutes of limitations. As permitted under the applicable accounting guidance, it is our policy to record interest and penalties related to unrecognized tax benefits in income tax expense. We recorded net interest benefit of $0.2 million, $0.9 million, and $0.7 million in 2020, 2019, and 2018, respectively. We did not recover any state tax penalties in 2020, 2019, or 2018. At December 31, 2020, we had an accrued interest payable of $3 million, compared to $2 million at December 31, 2019. There was no liability for accrued state tax penalties at December 31, 2020, and December 31, 2019. At December 31, 2020 there were no unrecognized tax benefits presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward, compared to $15.9 million at December 31, 2019. We file federal income tax returns, as well as returns in various state and foreign jurisdictions. We are subject to income tax examination by the IRS for the tax years 2016 and forward. Currently, we are not under IRS audit for any tax years. We are not subject to income tax examinations by other tax authorities for years prior to 2013. Pre-1988 Bank Reserves acquired in a business combination

Acquisitions, Divestiture, and

Acquisitions, Divestiture, and Discontinued Operations	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions, Divestiture, and Discontinued Operations	15. Acquisitions, Divestiture, and Discontinued Operations Acquisitions Laurel Road Digital Lending Business. On April 3, 2019, KeyBank acquired Laurel Road's digital lending business from Laurel Road Bank. Laurel Road Bank's three bank branches located in southeast Connecticut were not part of this transaction. Through the acquisition, KeyBank expects to enhance its digital capabilities with state-of-the-art, customer-centric technology and to leverage Laurel Road's proven ability to attract and serve professional millennial clients. The acquisition is accounted for as a business combination. As a result of the acquisition, we recognized identifiable intangible assets with a fair value of $37 million and goodwill of $148 million. The valuation of the acquired assets and liabilities of Laurel Road was final at June 30, 2020. Discontinued operations Discontinued operations includes our government-guaranteed and private education lending business. At December 31, 2020, and December 31, 2019, approximately $710 million and $865 million, respectively, of education loans are included in discontinued assets on the consolidated balance sheets. Net interest income after provision for credit losses for this business is not material and is included in income (loss) from discontinued operations, net of taxes on the consolidated statements of income.

Securities Financing Activities

Securities Financing Activities	12 Months Ended
	Dec. 31, 2020
Brokers and Dealers [Abstract]
Securities Financing Activities	16. Securities Financing Activities The following table summarizes our securities financing agreements at December 31, 2020, and December 31, 2019: December 31, 2020 December 31, 2019 in millions Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Offsetting of financial assets: Reverse repurchase agreements $ 6 $ (6) — — $ 5 $ (5) — — Securities borrowed 500 — $ (500) — — — — — Total $ 506 $ (6) $ (500) — $ 5 $ (5) — — Offsetting of financial liabilities: Repurchase agreements (c) $ 220 $ (6) $ (214) — $ 187 $ (7) $ (180) — Total $ 220 $ (6) $ (214) — $ 187 $ (7) $ (180) — (a) Netting adjustments take into account the impact of master netting agreements that allow us to settle with a single counterparty on a net basis. (b) These adjustments take into account the impact of bilateral collateral agreements that allow us to offset the net positions with the related collateral. The application of collateral cannot reduce the net position below zero. Therefore, excess collateral, if any, is not reflected above. (c) Repurchase agreements are collateralized by mortgaged-backed agency securities and are contracted on an overnight or continuous basis. As of December 31, 2020, the carrying amount of assets pledged as collateral against repurchase agreements totaled $232 million. Assets pledged as collateral are reported in “available for sale” and “held-to-maturity” securities on our balance sheet. At December 31, 2020, the liabilities associated with collateral pledged were solely comprised of customer sweep financing activity and had a carrying value of $214 million. The collateral pledged under customer sweep repurchase agreements is posted to a third-party custodian and cannot be sold or repledged by the secured party. The risk related to a decline in the market value of collateral pledged is minimal given the collateral's high credit quality and the overnight duration of the repurchase agreements.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	17. Stock-Based Compensation We maintain several stock-based compensation plans, which are described below. Total compensation expense for these plans was $101 million for 2020, $96 million for 2019, and $99 million for 2018. The total income tax benefit recognized in the income statement for these plans was $24 million for 2020, $23 million for 2019, and $23 million for 2018. Our compensation plans allow us to grant stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, or other awards which may be denominated or payable in or valued by reference to our Common Shares or other factors, discounted stock purchases, and deferred compensation to eligible employees and directors. At December 31, 2020, we had 47,287,594 Common Shares available for future grant under our compensation plans. In accordance with a resolution adopted by the Compensation and Organization Committee of KeyCorp’s Board of Directors, we may not grant options to purchase Common Shares, restricted stock or other shares under any long-term compensation plan in an aggregate amount that exceeds 6% of our outstanding Common Shares in any rolling three-year period. Stock Options Stock options granted to employees generally become exercisable at the rate of 25% per year. No option granted by KeyCorp will be exercisable less than one year after, or expire later than ten years from, the grant date. The exercise price is the closing price of our Common Shares on the grant date (or the prior business day if the grant date is not a business day). We determine the fair value of options granted using the Black-Scholes option-pricing model. This model was originally developed to determine the fair value of exchange-traded equity options, which (unlike employee stock options) have no vesting period or transferability restrictions. Because of these differences, the Black-Scholes model does not precisely value an employee stock option, but it is commonly used for this purpose. The model assumes that the estimated fair value of an option is amortized as compensation expense over the option’s vesting period. The Black-Scholes model requires several assumptions, which we developed and update based on historical trends and current market observations. Our determination of the fair value of options is only as accurate as the underlying assumptions. The assumptions pertaining to options issued during 2020, 2019, and 2018 are shown in the following table. Year ended December 31, 2020 2019 2018 Average option life 6.5 years 6.5 years 6.5 years Future dividend yield 3.90 % 3.88 % 2.28 % Historical share price volatility .267 .266 .282 Weighted-average risk-free interest rate 1.3 % 2.5 % 2.8 % In 2019, shareholders approved the 2019 Equity Compensation Plan, under which 71,600,000 shares may be issued as equity awards. The Compensation and Organization Committee has authority to approve all stock option grants but may delegate some of its authority to grant awards from time to time. The committee has delegated to our Chief Executive Officer the authority to grant equity awards, including stock options, to any employee who is not designated an “officer” for purposes of Section 16 of the Exchange Act. No more than 3,000,000 Common Shares may be issued under this authority. The following table summarizes activity, pricing and other information for our stock options for the year ended December 31, 2020: Number of Options Weighted-Average Exercise Price Per Option Weighted-Average Remaining Life Aggregate Intrinsic Value (a) Outstanding at December 31, 2019 6,685,808 $ 13.32 5.2 years $ 47 Granted 549,170 19.03 Exercised (821,916) 10.37 Lapsed or canceled (40,378) 15.25 Outstanding at December 31, 2020 6,372,684 $ 14.18 4.6 21 Expected to vest 1,426,063 18.75 7.1 — Exercisable at December 31, 2020 4,867,838 $ 12.77 3.8 $ 21 (a) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of the option. The weighted-average grant-date fair value of options was $2.96 for options granted during 2020, $3.07 for options granted during 2019, and $5.12 for options granted during 2018. Stock option exercises numbered 821,916 in 2020, 2,039,208 in 2019, and 1,960,444 in 2018. The aggregate intrinsic value of exercised options was $5 million for 2020, $18 million for 2019, and $21 million for 2018. As of December 31, 2020, unrecognized compensation cost related to nonvested options under the plans totaled $1 million. We expect to recognize this cost over a weighted-average period of 2.5 years. Cash received from options exercised was $8 million, $18 million, and $20 million in 2020, 2019, and 2018, respectively. The actual tax benefit realized for the tax deductions from options exercised totaled less than $1 million for 2020 and $1 million for both 2019 and 2018. Long-Term Incentive Compensation Program Our Long-Term Incentive Compensation Program (the “Program”) rewards senior executives and other employees critical to our long-term financial success. Awards are granted annually in a variety of forms: • deferred cash payments that generally vest and are payable at the rate of 25% per year; • time-lapsed (service condition) restricted stock units payable in stock, which generally vest at the rate of 25% per year; • performance units payable in stock, which vest at the end of the three-year performance cycle and will not vest unless Key attains defined performance levels and the service condition is met; and • performance units payable in cash, which vest at the end of the three-year performance cycle and will not vest unless Key attains defined performance levels and the service condition is met. During 2020, the total of performance units vested that were payable in stock and cash numbered 421,352 and 654,108, respectively. The total fair value of the performance units vested during 2020 that were payable in stock and cash was $8 million and $13 million, respectively. During 2019, the performance units vested that were payable in stock and cash numbered 855,233 and 1,139,582, respectively. The total fair value of the performance units vested during 2019 that were payable in stock and cash was $9 million and $20 million, respectively. The following table summarizes activity and pricing information for the nonvested shares in the Program for the year ended December 31, 2020. Vesting Contingent on Service Conditions Vesting Contingent on Performance and Service Conditions - Payable in Stock Vesting Contingent on Performance and Service Conditions - Payable in Cash Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Weighted- Outstanding at December 31, 2019 10,296,394 $ 17.73 491,189 $ 18.87 $ 3,899,884 $ 20.37 Granted 5,796,992 19.40 (10,666) 18.98 1,651,519 16.16 Vested (4,203,663) 16.33 (421,352) 18.96 (654,108) 19.46 Forfeited (373,353) 19.16 — — (117,256) 13.16 Outstanding at December 31, 2020 11,516,370 $ 19.01 59,171 $ 18.20 $ 4,780,039 $ 16.23 The compensation cost of time-lapsed and performance-based restricted stock or unit awards granted under the Program is calculated using the closing trading price of our Common Shares on the grant date (or the prior business day if the grant date is not a business day). Unlike time-lapsed and performance-based restricted stock or units, we do not pay dividends during the vesting period for performance shares or units that may become payable in excess of targeted performance. The weighted-average grant-date fair value of awards granted under the Program was $18.68 during 2020, $18.25 during 2019, and $19.28 during 2018. As of December 31, 2020, unrecognized compensation cost related to nonvested shares under the Program totaled $88 million. We expect to recognize this cost over a weighted-average period of 2.3 years. The total fair value of shares vested was $89 million in 2020, $89 million in 2019, and $93 million in 2018. Deferred Compensation and Other Restricted Stock Awards Our deferred compensation arrangements include voluntary and mandatory deferral programs for Common Shares awarded to certain employees and directors. Mandatory deferred incentive awards vest at the rate of 25% per year beginning one year after the deferral date. Deferrals under the voluntary programs are immediately vested. We also may grant, upon approval by the Compensation and Organization Committee (or our Chief Executive Officer with respect to their delegated authority), other time-lapsed restricted stock or unit awards under various programs to recognize outstanding performance. The following table summarizes activity and pricing information for the nonvested shares granted under our deferred compensation plans and these other restricted stock or unit award programs for the year ended December 31, 2020. Number of Nonvested Shares Weighted-Average Grant-Date Fair Value Outstanding at December 31, 2019 3,037,964 $ 17.67 Granted 691,377 16.22 Dividend equivalents 11 13.91 Vested (1,048,864) 17.18 Forfeited (108,401) 18.20 Outstanding at December 31, 2020 2,572,087 $ 17.46 The weighted-average grant-date fair value of awards granted was $16.22 during 2020, $17.57 during 2019, and $20.77 during 2018. As of December 31, 2020, unrecognized compensation cost related to nonvested shares granted under our deferred compensation plans and the other restricted stock or unit award programs totaled $13 million. We expect to recognize this cost over a weighted-average period of 3.9 years. The total fair value of shares vested was $18 million in 2020, $19 million in 2019, and $22 million in 2018. Dividend equivalents presented in the preceding table represent the value of dividends accumulated during the vesting period. Discounted Stock Purchase Plan Our Discounted Stock Purchase Plan provides employees the opportunity to purchase our Common Shares at a 10% discount through payroll deductions or cash payments. Purchases are limited to $10,000 in any month and $50,000 in any calendar year, and are immediately vested. To accommodate employee purchases, we issue treasury shares on or around the fifteenth day of the month following the month employee payments are received. We issued 500,508 Common Shares at a weighted-average cost to employees of $11.76 during 2020, 327,243 Common Shares at a weighted-average cost to employees of $15.73 during 2019, and 327,435 Common Shares at a weighted-average cost to employees of $17.48 during 2018. Information pertaining to our method of accounting for stock-based compensation is included in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Stock-Based Compensation.”

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Benefits	18. Employee Benefits Pension Plans Key maintains a cash balance pension plan and other defined benefit plans. These plans are frozen and closed to new employees. We continue to credit participants’ existing account balances for interest until they receive their plan benefits. Plans provide benefits based upon length of service and compensation levels. Key utilizes its fiscal year-end as the measurement date for its pension and other postretirement employee benefit plans. Actuarial gains and losses are deferred and amortized over the future service periods of active employees. We determine the expected return on plan assets using a calculated market-related value of plan assets. Gain or loss amounts in AOCI are only amortized to the extent that they exceed 10% of the greater of the market-related value or the projected benefit obligation. Pre-tax AOCI not yet recognized as net pension cost was $427 million at December 31, 2020, and $471 million at December 31, 2019, consisting entirely of net unrecognized losses. During 2020, 2019, and 2018, we recognized a settlement loss for lump sum payments made under certain pension plans. In accordance with the applicable accounting guidance for defined benefit plans, we performed a remeasurement of the affected plans in conjunction with the settlement and recognized the settlement loss as reflected in the following table. The components of net pension cost and the amount recognized in OCI for all funded and unfunded plans are as follows: Year ended December 31, in millions 2020 2019 2018 Interest cost on PBO $ 34 $ 46 $ 41 Expected return on plan assets (38) (48) (53) Amortization of losses 17 13 17 Settlement loss 9 18 17 Net pension cost $ 22 $ 29 $ 22 Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ (18) $ (8) $ 20 Amortization of gains (26) (31) (33) Total recognized in comprehensive income $ (44) $ (39) $ (13) Total recognized in net pension cost and comprehensive income $ (22) $ (10) $ 9 The information related to our pension plans presented in the following tables is based on current actuarial reports using measurement dates of December 31, 2020, and December 31, 2019. The following table summarizes changes in the PBO related to our pension plans. Actuarial losses in 2020 were primarily a result of the decrease in discount rate, offset by a gain from the decrease in interest crediting rates. Year ended December 31, in millions 2020 2019 PBO at beginning of year $ 1,233 $ 1,201 Interest cost 34 46 Actuarial losses (gains) 66 91 Benefit payments (85) (105) PBO at end of year $ 1,248 $ 1,233 The following table summarizes changes in the FVA. Year ended December 31, in millions 2020 2019 FVA at beginning of year $ 1,102 $ 1,046 Actual return on plan assets 123 147 Employer contributions 13 14 Benefit payments (85) (105) FVA at end of year $ 1,153 $ 1,102 The following table summarizes the funded status of the pension plans, which equals the amounts recognized in the balance sheets at December 31, 2020, and December 31, 2019. December 31, in millions 2020 2019 Funded status (a) $ (95) $ (131) Net prepaid pension cost recognized consists of: Noncurrent assets $ 81 48 Current liabilities (14) $ (14) Noncurrent liabilities (162) (165) Net prepaid pension cost recognized (b) $ (95) $ (131) (a) The shortage of the FVA under the PBO. (b) Represents the accrued benefit liability of the pension plans. At December 31, 2020, our primary qualified cash balance pension plan was sufficiently funded under the requirements of ERISA. Consequently, we are not required to make a minimum contribution to that plan in 2021. We also do not expect to make any significant discretionary contributions during 2021. At December 31, 2020, we expect to pay the benefits from all funded and unfunded pension plans as follows: 2021 — $92 million; 2022— $91 million; 2023 — $89 million; 2024 — $87 million; 2025 — $84 million and $371 million in the aggregate from 2026 through 2030. The ABO for all of our pension plans was $1.2 billion at December 31, 2020, and $1.2 billion at December 31, 2019. As indicated in the table below, collectively our plans had an ABO in excess of plan assets as follows: December 31, 2020 2019 in millions Cash Balance Pension Plan Other Defined Benefit Plans Cash Balance Pension Plan Other Defined Benefit Plans PBO $ 1,072 $ 176 $ 1,054 $ 179 ABO 1,072 176 1,054 179 Fair value of plan assets 1,153 — 1,102 — To determine the actuarial present value of benefit obligations, we assumed the following weighted-average rates. December 31, 2020 2019 Discount rate 2.05 % 2.89 % Compensation increase rate N/A N/A Weighted-average interest crediting rate 1.65 % 2.39 % To determine net pension cost, we assumed the following weighted-average rates. Year ended December 31, 2020 2019 2018 Discount rate 2.89 % 4.00 % 3.25 % Compensation increase rate N/A N/A N/A Expected return on plan assets 3.75 4.50 4.75 We estimate that we will recognize $15 million in net pension cost for 2021, compared to net pension cost of $22 million in 2020 and $29 million for 2019. We estimate that a 25 basis point increase or decrease in the expected return on plan assets would change our net pension cost for 2021 by approximately $3 million. Pension cost also is affected by an assumed discount rate. We estimate that a 25 basis point change in the assumed discount rate would change net pension cost for 2021 by approximately $2 million. The expected return on plan assets is determined by considering a number of factors, the most significant of which are: • Our expectations for returns on plan assets over the long term, weighted for the investment mix of the assets. These expectations consider, among other factors, historical capital market returns of equity, fixed income, convertible, and other securities, and forecasted returns that are modeled under various economic scenarios. • Historical returns on our plan assets. Based on an annual reassessment of current and expected future capital market returns, our expected return on plan assets was 3.75% for 2020, 4.5% for 2019 and 4.75% for 2018. We deemed a rate of 2.75% to be appropriate in estimating 2020 pension cost. The investment objectives of the pension fund are developed to reflect the characteristics of the plan, such as pension formulas, cash lump sum distribution features, and the liability profiles of the plan’s participants. An executive oversight committee reviews the plan’s investment performance at least quarterly, and compares performance against appropriate market indices. The pension fund’s investment objectives are to balance total return objectives with a continued management of plan liabilities, and to minimize the mismatch between assets and liabilities. These objectives are being implemented through liability driven investing and the adoption of a de-risking glide path. The following table shows the asset target allocations prescribed by the pension fund’s investment policies based on the plan’s funded status at December 31, 2020. Target Allocation Asset Class 2020 Equity securities: U.S. 4 % International 2 Fixed income securities 87 Real assets 4 Other assets 3 Total 100 % Equity securities include common stocks of domestic and foreign companies, as well as foreign company stocks traded as American Depositary Shares on U.S. stock exchanges. Debt securities include investments in domestic- and foreign-issued corporate bonds, U.S. government and agency bonds, international government bonds, and mutual funds. Real assets include an investment in a diversified real asset strategy separate account designed to provide exposure to the three core real assets: Treasury Inflation-Protected Securities, commodities, and real estate. Other assets include investments in a multi-strategy investment fund and a limited partnership. Although the pension funds’ investment policies conditionally permit the use of derivative contracts, we have not entered into any such contracts, and we do not expect to employ such contracts in the future. The valuation methodologies used to measure the fair value of pension plan assets vary depending on the type of asset, as described below. For an explanation of the fair value hierarchy, see Note 1 (“Summary of Significant Accounting Policies”) under the heading “Fair Value Measurements.” Equity securities. Equity securities traded on securities exchanges are valued at the closing price on the exchange or system where the security is principally traded. These securities are classified as Level 1 since quoted prices for identical securities in active markets are available. Debt securities. Substantially all debt securities are investment grade and include domestic- and foreign-issued corporate bonds and U.S. government and agency bonds. These securities are valued using evaluated prices based on observable inputs, such as dealer quotes, available trade information, spreads, bids and offers, prepayment speeds, U.S. Treasury curves, and interest rate movements. Debt securities are classified as Level 2. Mutual funds. Exchange-traded mutual funds listed or traded on securities exchanges are valued at the closing price on the exchange or system where the security is principally traded. These securities are classified as Level 1 because quoted prices for identical securities in active markets are available. Collective investment funds. Investments in collective investment funds are valued using the net asset value practical expedient and are not classified within the fair value hierarchy. Fair value is determined based on Key’s proportionate share of total net assets in the fund. Insurance investment contracts and pooled separate accounts. Deposits under insurance investment contracts and pooled separate accounts with insurance companies do not have readily determinable fair values and are valued using a methodology that is consistent with accounting guidance that allows the plan to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership in partners’ capital to which a proportionate share of net assets is attributed); thus, these investments are not classified within the fair value hierarchy. Other assets. Other assets include an investment in a multi-strategy investment fund and an investment in a limited partnership. These investments do not have readily determinable fair values and are valued using a methodology consistent with accounting guidance that allows the plan to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership in partners’ capital to which a proportionate share of net assets is attributed); thus, these investments are not classified within the fair value hierarchy. The following tables show the fair values of our pension plan assets by asset class at December 31, 2020, and December 31, 2019. December 31, 2020 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. $ 9 — — $ 9 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 171 — 171 Corporate bonds — International — 79 — 79 Government and agency bonds — U.S. — 165 — 165 Government bonds — International — 2 — 2 State and municipal bonds — 27 — 27 Mutual funds: Equity — International 2 — — 2 Collective investment funds (measured at NAV) (a) — — — 636 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 17 Other assets (measured at NAV) (a) — — — 42 Total net assets at fair value $ 14 $ 444 — $ 1,153 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2019 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. 8 — — 8 Common — International — — — — Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 155 — 155 Corporate bonds — International — 72 — 72 Government and agency bonds — U.S. — 190 — 190 Government bonds — International — 2 — 2 State and municipal bonds — 27 — 27 Mutual funds: Equity — International 2 — — 2 Collective investment funds (measured at NAV) (a) — — — 584 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 16 Other assets (measured at NAV) (a) — — — 43 Total net assets at fair value $ 13 $ 446 — $ 1,102 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. Other Postretirement Benefit Plans We sponsor a retiree healthcare plan in which all employees age 55 with five years of service (or employees age 50 with 15 years of service who are terminated under conditions that entitle them to a severance benefit) are eligible to participate. Participant contributions are adjusted annually. Key may provide a subsidy toward the cost of coverage for certain employees hired before 2001 with a minimum of 15 years of service at the time of termination. We use a separate VEBA trust to fund the retiree healthcare plan. The components of pre-tax AOCI not yet recognized as net postretirement benefit cost are shown below. December 31, in millions 2020 2019 Net unrecognized losses (gains) $ (10) $ (10) Net unrecognized prior service credit (15) (17) Total unrecognized AOCI $ (25) $ (27) The components of net postretirement benefit cost and the amount recognized in OCI for all funded and unfunded plans are as follows: December 31, in millions 2020 2019 2018 Service cost of benefits earned $ — $ 1 $ 1 Interest cost on APBO 2 2 2 Expected return on plan assets (2) (2) (2) Amortization of prior service credit (1) — (1) Amortization of gains — (1) (1) Net postretirement benefit (1) — (1) Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 1 $ 1 $ 1 Amortization of prior service credit — 1 1 Amortization of losses — — — Total recognized in comprehensive income $ 1 $ 2 $ 2 Total recognized in net postretirement benefit cost and comprehensive income $ — $ 2 $ 1 The information related to our postretirement benefit plans presented in the following tables is based on current actuarial reports using measurement dates of December 31, 2020, and December 31, 2019. The following table summarizes changes in the APBO. Actuarial losses are a result of asset performance. Year ended December 31, in millions 2020 2019 APBO at beginning of year $ 52 $ 63 Service cost — 1 Interest cost 2 2 Plan participants’ contributions 1 1 Actuarial losses (gains) 8 10 Benefit payments (11) (8) Plan amendments — (17) APBO at end of year $ 52 $ 52 The following table summarizes changes in FVA. Year ended December 31, in millions 2020 2019 FVA at beginning of year $ 52 $ 47 Employer contributions — — Plan participants’ contributions 1 1 Benefit payments (11) (8) Actual return on plan assets 10 12 FVA at end of year $ 52 $ 52 The postretirement plans were fully funded at December 31, 2020, and December 31, 2019. Therefore, no liabilities were recognized on our balance sheet. There are no regulations that require contributions to the VEBA trust that funds our retiree healthcare plan, so there is no minimum funding requirement. We are permitted to make discretionary contributions to the VEBA trust, subject to certain IRS restrictions and limitations. We anticipate that our discretionary contributions in 2021, if any, will be minimal. At December 31, 2020, we expect to pay the benefits from other postretirement plans as follows: 2021 — $6 million; 2022 — $6 million; 2023 — $5 million; 2024 — $5 million; 2025 — $5 million; and $23 million in the aggregate from 2026 through 2030. To determine the APBO, we assumed discount rates of 4.0% at December 31, 2020, and 4.5% at December 31, 2019. To determine net postretirement benefit cost, we assumed the following weighted-average rates. Year ended December 31, 2020 2019 2018 Discount rate 4.50 % 4.50 % 3.50 % Expected return on plan assets 4.50 4.50 4.50 The realized net investment income for the postretirement healthcare plan VEBA trust is subject to federal income taxes, which are reflected in the weighted-average expected return on plan assets shown above. Assumed healthcare cost trend rates do not have a material impact on net postretirement benefit cost or obligations since the postretirement plan has cost-sharing provisions and benefit limitations. We do not expect to recognize a credit or an expense in net postretirement benefit cost for 2021. We recognized a credit of less than $1 million in 2020 and 2019. We estimate the expected returns on plan assets for the VEBA trust much the same way we estimate returns on our pension funds. The primary investment objectives of the VEBA trust are to obtain a market rate of return, take into consideration the safety and/or risk of the investment, and to diversify the portfolio in order to satisfy the trust’s anticipated liquidity requirements. The following table shows the asset target allocations prescribed by the trust’s investment policy. Target Allocation Asset Class 2020 Equity securities 80 % Fixed income securities 20 Cash equivalents — Total 100 % Investments consist of mutual funds and collective investment funds that invest in underlying assets in accordance with the target asset allocations shown above. Exchange-traded mutual funds are valued using quoted prices and, therefore, are classified as Level 1. Investments in collective investment funds are valued using the Net Asset Value practical expedient and are not classified within the fair value hierarchy. The following tables show the fair values of our postretirement plan assets by asset class at December 31, 2020, and December 31, 2019. December 31, 2020 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 21 — — $ 21 Equity — International 9 — — 9 Fixed income — U.S. 7 — — 7 Collective investment funds: Equity — U.S. (a) — — — 14 Other assets (measured at NAV) (a) — — — 1 Total net assets at fair value $ 37 — — $ 52 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2019 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 22 — — $ 22 Equity — International 9 — — 9 Fixed income — U.S. 7 — — 7 Fixed income — International — — — — Collective investment funds: Equity — U.S. (a) — $ — — 12 Other assets (measured at NAV) — — — 2 Total net assets at fair value $ 38 $ — — $ 52 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. The Medicare Prescription Drug, Improvement and Modernization Act of 2003 introduced a prescription drug benefit under Medicare and prescribes a federal subsidy to sponsors of retiree healthcare benefit plans that offer prescription drug coverage that is “actuarially equivalent” to the benefits under Medicare Part D. Based on our application of the relevant regulatory formula, we determined that the prescription drug coverage related to our retiree healthcare benefit plan is not actuarially equivalent to the Medicare benefit for the vast majority of retirees. For the years ended December 31, 2020, and December 31, 2019, we did not receive federal subsidies. Employee 401(k) Savings Plan A substantial number of our employees are covered under a savings plan that is qualified under Section 401(k) of the Internal Revenue Code. The plan permits employees to contribute from 1% to 100% of eligible compensation, with up to 6% being eligible for matching contributions. The plan also permits us to provide a discretionary annual profit sharing contribution to eligible employees who have at least one year of service. We accrued a 1% contribution for 2020 and made contributions of 1% and 2% for 2019 and 2018, respectively, on eligible compensation for employees eligible on the last business day of the respective plan years. We also maintain a deferred savings plan that provides certain employees with benefits they otherwise would not have been eligible to receive under the qualified plan once their compensation for the plan year reached the IRS contribution limits. Total expense associated with the above plans was $103 million in 2020, $98 million in 2019, and $106 million in 2018.

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Short-Term Borrowings	19. Short-Term Borrowings Selected financial information pertaining to the components of our short-term borrowings is as follows: December 31, dollars in millions 2020 2019 2018 FEDERAL FUNDS PURCHASED Balance at year end $ — 200 $ — Average during the year 455 $ 61 537 Maximum month-end balance 2,285 1,000 3,197 Weighted-average rate during the year (a) 1.24 % 2.12 % 1.68 % Weighted-average rate at December 31 (a) — 1.56 — SECURITIES SOLD UNDER REPURCHASE AGREEMENTS Balance at year end $ 220 $ 187 $ 319 Average during the year 215 203 391 Maximum month-end balance 267 283 614 Weighted-average rate during the year (a) .11 % .22 % .09 % Weighted-average rate at December 31 (a) .04 .09 .09 OTHER SHORT-TERM BORROWINGS Balance at year end $ 759 $ 705 $ 544 Average during the year 1,452 730 915 Maximum month-end balance 4,606 847 1,133 Weighted-average rate during the year (a) 0.85 % 2.31 % 2.34 % Weighted-average rate at December 31 (a) .60 1.99 2.92 (a) Rates exclude the effects of interest rate swaps and caps, which modify the repricing characteristics of certain short-term borrowings. For more information about such financial instruments, see Note 8 (“Derivatives and Hedging Activities”). As described below and in Note 20 (“Long-Term Debt”), KeyCorp and KeyBank have a number of programs and facilities that support our short-term financing needs. Certain subsidiaries maintain credit facilities with third parties, which provide alternative sources of funding. KeyCorp is the guarantor of some of the third-party facilities. Short-term credit facilities. We maintain cash on deposit in our Federal Reserve account, which has reduced our need to obtain funds through various short-term unsecured money market products. This account, which was maintained at $15.4 billion at December 31, 2020, and the unpledged securities in our investment portfolio provide a buffer to address unexpected short-term liquidity needs. We also have secured borrowing facilities at the FHLB and the Federal Reserve Bank of Cleveland to satisfy short-term liquidity requirements. As of December 31, 2020, our unused secured borrowing capacity was $22.6 billion at the Federal Reserve Bank of Cleveland and $8.4 billion at the FHLB.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	20. Long-Term Debt The following table presents the components of our long-term debt, net of unamortized discounts and adjustments related to hedging with derivative financial instruments. We use interest rate swaps and caps, which modify the repricing characteristics of certain long-term debt, to manage interest rate risk. For more information about such financial instruments, see Note 8 (“Derivatives and Hedging Activities”). December 31, dollars in millions 2020 2019 Senior medium-term notes due through 2021 (a) $ 3,962 $ 4,111 3.136% Subordinated notes due 2028 (b) 162 162 6.875% Subordinated notes due 2029 (b) 115 109 7.75% Subordinated notes due 2029 (b) 149 141 7.25% Subordinated notes due 2021 (c) 311 324 Other subordinated notes (b)(d) 74 71 Total parent company 4,773 4,918 Senior medium-term notes due through 2039 (e) 6,718 5,874 3.18% Senior remarketable notes due 2027 (f) 232 222 3.40% Subordinated notes due 2026 (g) 625 589 6.95% Subordinated notes due 2028 (g) 299 299 3.90% Subordinated notes due 2029 (g) 398 371 Secured borrowing due through 2025 (h) 19 15 Federal Home Loan Bank advances due through 2038 (i) 608 121 Investment Fund Financing due through 2052 (j) 21 26 Key Govt Finance, Inc. Other Long Term Debt-ASR 4 — Obligations under Capital Leases due through 2032 (k) 12 13 Total subsidiaries 8,936 7,530 Total long-term debt $ 13,709 $ 12,448 (a) Senior medium-term notes had a weighted-average interest rate of 3.7025% at December 31, 2020, and 3.7815% at December 31, 2019. These notes had fixed interest rates at December 31, 2020, and December 31, 2019. These notes may not be redeemed prior to their maturity dates. (b) See Note 21 (“Trust Preferred Securities Issued by Unconsolidated Subsidiaries”) for a description of these notes. (c) The First Niagara subordinated debt had a weighted-average interest rate of 7.25% at December 31, 2020, and a weighted-average interest rate of 7.25% at December 31, 2019. These notes may not be redeemed prior to their maturity dates. (d) The First Niagara variable rate trust preferred securities had a weighted-average interest rate of 1.72% at December 31, 2020, and 3.42% at December 31, 2019. These notes may be redeemed prior to their maturity dates. (e) Senior medium-term notes had weighted-average interest rates of 2.516% at December 31, 2020, and 2.595% at December 31, 2019. These notes are a combination of fixed and floating rates. These notes may not be redeemed prior to their maturity dates. (f) The remarketable senior medium-term notes had a weighted-average interest rate of 3.18% at December 31, 2020, and 3.18% at December 31, 2019. These notes had fixed interest rates at December 31, 2017, and December 31, 2018. These notes may not be redeemed prior to their maturity dates. (g) These notes are all obligations of KeyBank and may not be redeemed prior to their maturity dates. (h) The secured borrowing had weighted-average interest rates of 4.445% at December 31, 2020, and 4.445% at December 31, 2019. This borrowing is collateralized by commercial lease financing receivables, and principal reductions are based on the cash payments received from the related receivables. Additional information pertaining to these commercial lease financing receivables is included in Note 4 (“Loan Portfolio”). (i) Long-term advances from the Federal Home Loan Bank had a weighted-average interest rate of 1.15% at December 31, 2020, and 3.506% at December 31, 2019. These advances, which had fixed interest rates, were secured by real estate loans and securities totaling $607 million at December 31, 2020, and $121 million at December 31, 2019. (j) Investment Fund Financing had a weighted-average interest rate of 1.77% at December 31, 2020, and 1.63% at December 31, 2019. (k) These are capital leases acquired in the First Niagara merger with a maturity range from March 2021 through October 2032 At December 31, 2020, scheduled principal payments on long-term debt were as follows: in millions Parent Subsidiaries Total 2021 $ 1,315 $ 1,272 $ 2,587 2022 — 2,403 2,403 2023 — 1,231 1,231 2024 — 1,101 1,101 2025 562 772 1,334 All subsequent years 2,896 2,157 5,053 As described below, KeyBank and KeyCorp have a number of programs that support our long-term financing needs. Global bank note program. On September 28, 2018, KeyBank updated its Bank Note Program authorizing the issuance of up to $20 billion of notes. Under the program, KeyBank is authorized to issue notes with original maturities of seven days or more for senior notes or five years or more for subordinated notes. Notes will be denominated in U.S. dollars. Amounts outstanding under the program and any prior bank note programs are classified as “long-term debt” on the balance sheet. In 2019, KeyBank issued the following notes under the 2018 Bank Note Program: on February 1, 2019, $600 million of 3.300% Senior Bank Notes due February 1, 2022, and $400 million of Floating Rate Senior Bank Notes due February 1, 2022; and on March 13, 2019, $350 million of 3.900% Subordinated Bank Notes due April 13, 2029. In 2020, KeyBank issued the following notes under the 2018 Bank Note Program: on March 10, 2020, $700 million of 1.25% Senior Bank Notes due March 10, 2023; and on December 16, 2020, $750 million Fixed-to-Floating Rate Senior Bank Notes due January 3, 2024 and $350 million Floating Rate Senior Bank Notes due January 3, 2024. As of December 31, 2020, $3.2 billion of notes had been issued under the 2018 Bank Note Program, and $16.8 billion remained available for issuance. KeyCorp shelf registration, including Medium-Term Note Program . On June 9, 2020 KeyCorp updated its shelf registration statement on file with the SEC under rules that allow companies to register various types of debt and equity securities without limitations on the aggregate amounts available for issuance. KeyCorp also maintains a Medium-Term Note Program that permits KeyCorp to issue notes with original maturities of nine months or more. In 2019, KeyCorp issued the following notes under the program: On September 11, 2019, $750 million of 2.550% Senior Notes due October 1, 2029. On February 6, 2020, KeyCorp issued $800 million of 2.25% Senior Notes due April 6, 2027, under the Medium-Term Note Program. At December 31, 2020, KeyCorp had authorized and available for issuance up to $5.0 billion of additional debt securities under the Medium-Term Note Program. Issuances of capital securities or preferred stock by KeyCorp must be approved by the Board and cannot be objected to by the Federal Reserve.

Trust Preferred Securities Issu

Trust Preferred Securities Issued by Unconsolidated Subsidiaries	12 Months Ended
	Dec. 31, 2020
Banking and Thrift, Other Disclosures [Abstract]
Trust Preferred Securities Issued by Unconsolidated Subsidiaries	21. Trust Preferred Securities Issued by Unconsolidated Subsidiaries We own the outstanding common stock of business trusts formed by us that issued corporation-obligated mandatorily redeemable trust preferred securities. The trusts used the proceeds from the issuance of their trust preferred securities and common stock to buy debentures issued by KeyCorp. These debentures are the trusts’ only assets; the interest payments from the debentures finance the distributions paid on the mandatorily redeemable trust preferred securities. The outstanding common stock of these business trusts is recorded in “other investments” on our balance sheet. We unconditionally guarantee the following payments or distributions on behalf of the trusts: • required distributions on the trust preferred securities; • the redemption price when a capital security is redeemed; and • the amounts due if a trust is liquidated or terminated. The Regulatory Capital Rules require us to treat our mandatorily redeemable trust preferred securities as Tier 2 capital. The trust preferred securities, common stock, and related debentures are summarized as follows: dollars in millions Trust Preferred Securities, Net of Discount (a) Common Stock Principal Amount of Debentures, Net of Discount (b) Interest Rate of Trust Preferred Securities and (c) Maturity of Trust Preferred Securities and Debentures December 31, 2020 KeyCorp Capital I $ 156 $ 6 $ 162 0.965 % 2028 KeyCorp Capital II 110 4 114 6.875 2029 KeyCorp Capital III 145 4 149 7.750 2029 HNC Statutory Trust III 20 1 21 1.605 2035 Willow Grove Statutory Trust I 19 1 20 1.527 2036 HNC Statutory Trust IV 17 1 18 1.494 2037 Westbank Capital Trust II 8 — 8 2.429 2034 Westbank Capital Trust III 8 — 8 2.429 2034 Total $ 483 $ 17 $ 500 4.464 % — December 31, 2019 $ 466 $ 17 $ 483 5.214 % — (a) The trust preferred securities must be redeemed when the related debentures mature, or earlier if provided in the governing indenture. Each issue of trust preferred securities carries an interest rate identical to that of the related debenture. Certain trust preferred securities include debt issuance costs and basis adjustments related to fair value hedges totaling $70 million at December 31, 2020, and $57 million at December 31, 2019. See Note 8 (“Derivatives and Hedging Activities”) for an explanation of fair value hedges. (b) We have the right to redeem these debentures. If the debentures purchased by KeyCorp Capital I, HNC Statutory Trust III, Willow Grove Statutory Trust I, HNC Statutory Trust IV, Westbank Capital Trust II, or Westbank Capital Trust III are redeemed before they mature, the redemption price will be the principal amount, plus any accrued but unpaid interest. If the debentures purchased by KeyCorp Capital II or KeyCorp Capital III are redeemed before they mature, the redemption price will be the greater of: (i) the principal amount, plus any accrued but unpaid interest, or (ii) the sum of the present values of principal and interest payments discounted at the Treasury Rate (as defined in the applicable indenture), plus 20 basis points for KeyCorp Capital II or 25 basis points for KeyCorp Capital III or 50 basis points in the case of redemption upon either a tax or a capital treatment event for either KeyCorp Capital II or KeyCorp Capital III, plus any accrued but unpaid interest. The principal amount of certain debentures includes debt issuance costs and basis adjustments related to fair value hedges totaling $70 million at December 31, 2020, and $57 million at December 31, 2019. See Note 8 for an explanation of fair value hedges. The principal amount of debentures, net of discounts, is included in “long-term debt” on the balance sheet. (c) The interest rates for the trust preferred securities issued by KeyCorp Capital II and KeyCorp Capital III are fixed. The trust preferred securities issued by KeyCorp Capital I have a floating interest rate, equal to three-month LIBOR plus 74 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust III have a floating interest rate, equal to three-month LIBOR plus 140 basis points, that reprices quarterly. The trust preferred securities issued by Willow Grove Statutory Trust I have a floating interest rate, equal to three-month LIBOR plus 131 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust IV have a floating interest rate, equal to three-month LIBOR plus 128 basis points, that reprices quarterly. The trust preferred securities issued by Westbank Capital Trust II and Westbank Capital Trust III each have a floating interest rate, equal to three-month LIBOR plus 219 basis points, that reprices quarterly. The total interest rates are weighted-average rates.

Commitments, Contingent Liabili

Commitments, Contingent Liabilities and Guarantees	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingent Liabilities and Guarantees	22. Commitments, Contingent Liabilities, and Guarantees Commitments to Extend Credit or Funding Loan commitments provide for financing on predetermined terms as long as the client continues to meet specified criteria. These agreements generally carry variable rates of interest and have fixed expiration dates or termination clauses. We typically charge a fee for our loan commitments. Since a commitment may expire without resulting in a loan, our aggregate outstanding commitments may significantly exceed our eventual cash outlay. Loan commitments involve credit risk not reflected on our balance sheet. We mitigate exposure to credit risk with internal controls that guide how we review and approve applications for credit, establish credit limits and, when necessary, demand collateral. In particular, we evaluate the creditworthiness of each prospective borrower on a case-by-case basis and, when appropriate, adjust the allowance for credit losses on lending-related commitments. Additional information pertaining to this allowance is included in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Liability for Credit Losses on Lending-Related Commitments,” and in Note 5 (“Asset Quality”). We also provide financial support to private equity investments, including existing direct portfolio companies and indirect private equity funds, to satisfy unfunded commitments. These unfunded commitments are not recorded on our balance sheet. Additional information on principal investing commitments is provided in Note 6 (“Fair Value Measurements”). Other unfunded equity investment commitments at December 31, 2020, and December 31, 2019, related to tax credit investments and were primarily attributable to LIHTC investments. Unfunded tax credit investment commitments are recorded on our balance sheet in “other liabilities.” Additional information on LIHTC commitments is provided in Note 13 (“Variable Interest Entities”). The following table shows the remaining contractual amount of each class of commitment related to extending credit or funding principal investments as of December 31, 2020, and December 31, 2019. For loan commitments and commercial letters of credit, this amount represents our maximum possible accounting loss on the unused commitment if the borrower were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan. December 31, in millions 2020 2019 Loan commitments: Commercial and other $ 47,792 $ 45,323 Commercial real estate and construction 2,365 2,961 Home equity 9,299 9,945 Credit cards 6,685 6,560 Total loan commitments 66,141 64,789 Commercial letters of credit 74 91 Purchase card commitments 708 729 Principal investing commitments 16 21 Tax credit investment commitments 487 547 Total loan and other commitments $ 67,426 $ 66,177 Legal Proceedings Litigation. From time to time, in the ordinary course of business, we and our subsidiaries are subject to various litigation, investigations, and administrative proceedings. Private, civil litigations may range from individual actions involving a single plaintiff to putative class action lawsuits with potentially thousands of class members. Investigations may involve both formal and informal proceedings, by both government agencies and self-regulatory bodies. These matters may involve claims for substantial monetary relief. At times, these matters may present novel claims or legal theories. Due to the complex nature of these various other matters, it may be years before some matters are resolved. While it is impossible to ascertain the ultimate resolution or range of financial liability, based on information presently known to us, we do not believe there is any matter to which we are a party, or involving any of our properties that, individually or in the aggregate, would reasonably be expected to have a material adverse effect on our financial condition. We continually monitor and reassess the potential materiality of these litigation matters. We note, however, that in light of the inherent uncertainty in legal proceedings there can be no assurance that the ultimate resolution will not exceed established reserves. As a result, the outcome of a particular matter, or a combination of matters, may be material to our results of operations for a particular period, depending upon the size of the loss or our income for that particular period. Guarantees We are a guarantor in various agreements with third parties. The following table shows the types of guarantees that we had outstanding at December 31, 2020. Information pertaining to the basis for determining the liabilities recorded in connection with these guarantees is included in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Contingencies and Guarantees.” December 31, 2020 Maximum Potential Undiscounted Future Payments Liability Recorded in millions Financial guarantees: Standby letters of credit $ 3,231 $ 71 Recourse agreement with FNMA 5,811 23 Residential mortgage reserve 2,471 10 Written put options (a) 3,631 54 Total $ 15,144 $ 158 (a) The maximum potential undiscounted future payments represent notional amounts of derivatives qualifying as guarantees. We determine the payment/performance risk associated with each type of guarantee described below based on the probability that we could be required to make the maximum potential undiscounted future payments shown in the preceding table. We use a scale of low (0% to 30% probability of payment), moderate (greater than 30% to 70% probability of payment), or high (greater than 70% probability of payment) to assess the payment/performance risk, and have determined that the payment/performance risk associated with each type of guarantee outstanding at December 31, 2020, is low. Standby letters of credit. KeyBank issues standby letters of credit to address clients’ financing needs. These instruments obligate us to pay a specified third party when a client fails to repay an outstanding loan or debt instrument or fails to perform some contractual nonfinancial obligation. Any amounts drawn under standby letters of credit are treated as loans to the client; they bear interest (generally at variable rates) and pose the same credit risk to us as a loan. At December 31, 2020, our standby letters of credit had a remaining weighted-average life of 1.7 years, with remaining actual lives ranging from less than 1 year to as many as 13.9 years. Recourse agreement with FNMA. At December 31, 2020, the outstanding commercial mortgage loans in this program had a weighted-average remaining term of 7.9 years, and the unpaid principal balance outstanding of loans sold by us as a participant was $19.3 billion. The maximum potential amount of undiscounted future payments that we could be required to make under this program, as shown in the preceding table, is equal to approximately 30% of the principal balance of loans outstanding at December 31, 2020. FNMA delegates responsibility for originating, underwriting, and servicing mortgages, and we assume a limited portion of the risk of loss during the remaining term on each commercial mortgage loan that we sell to FNMA. We maintain a reserve for such potential losses in an amount that we believe approximates the fair value of our liability in addition to the expected credit loss for the guarantee as described in Note 5 (“Asset Quality”). Residential Mortgage Banking. We often originate and sell residential mortgage loans and retain the servicing rights. Our loan sales activity is generally conducted through loan sales in a secondary market sponsored by FNMA and FHLMC and through the issuance of GNMA mortgage backed securities. Subsequent to the sale of mortgage loans, we do not typically retain any interest in the underlying loans except through our relationship as the servicer of the loans. As is customary in the mortgage banking industry, we, or banks we have acquired, have made certain representations and warranties related to the sale of residential mortgage loans (including loans sold with servicing rights released) and to the performance of our obligations as servicer. The breach of any such representations or warranties could result in losses for us. Our maximum exposure to loss is equal to the outstanding principal balance of the sold loans; however, any loss would be reduced by any payments received on the loans or through the sale of collateral. At December 31, 2020, the unpaid principal balance outstanding of loans sold by us was $8.2 billion. The maximum potential amount of undiscounted future payments that we could be required to make under this program, as shown in the preceding table, is equal to approximately 30% of the principal balance of loans outstanding at December 31, 2020. Our liability for estimated repurchase obligations on loans sold, which is included in other liabilities on our balance sheet, was $10 million at December 31, 2020. Written put options. In the ordinary course of business, we “write” put options for clients that wish to mitigate their exposure to changes in interest rates and commodity prices. At December 31, 2020, our written put options had an average life of three years. These instruments are considered to be guarantees, as we are required to make payments to the counterparty (the client) based on changes in an underlying variable that is related to an asset, a liability, or an equity security that the client holds. We are obligated to pay the client if the applicable benchmark interest rate or commodity price is above or below a specified level (known as the “strike rate”). These written put options are accounted for as derivatives at fair value, as further discussed in Note 8 (“Derivatives and Hedging Activities”). We mitigate our potential future payment obligations by entering into offsetting positions with third parties. Written put options where the counterparty is a broker-dealer or bank are accounted for as derivatives at fair value but are not considered guarantees since these counterparties typically do not hold the underlying instruments. In addition, we are a purchaser and seller of credit derivatives, which are further discussed in Note 8. Other Off-Balance Sheet Risk Other off-balance sheet risk stems from financial instruments that do not meet the definition of a guarantee as specified in the applicable accounting guidance, and from other relationships. Indemnifications provided in the ordinary course of business. We provide certain indemnifications, primarily through representations and warranties in contracts that we execute in the ordinary course of business in connection with loan and lease sales and other ongoing activities, as well as in connection with purchases and sales of businesses. We maintain reserves, when appropriate, with respect to liability that reasonably could arise as a result of these indemnities. Intercompany guarantees. KeyCorp, KeyBank, and certain of our affiliates are parties to various guarantees that facilitate the ongoing business activities of other affiliates. These business activities encompass issuing debt, assuming certain lease and insurance obligations, purchasing or issuing investments and securities, and engaging in certain leasing transactions involving clients.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income	23. Accumulated Other Comprehensive Income Our changes in AOCI for the years ended December 31, 2020, and December 31, 2019, are as follows: in millions Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on derivative financial instruments Foreign currency translation adjustment Net pension and postretirement benefit costs Total Balance at December 31, 2018 $ (373) $ (50) $ (14) $ (381) $ (818) Other comprehensive income before reclassification, net of income taxes 503 335 3 19 860 Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (15) (35) 11 23 (16) Net current-period other comprehensive income, net of income taxes 488 300 14 42 844 Balance at December 31, 2019 $ 115 $ 250 $ — $ (339) $ 26 Other comprehensive income before reclassification, net of income taxes 455 466 — 15 936 Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (3) (240) — 19 (224) Net current-period other comprehensive income, net of income taxes 452 226 — 34 712 Balance at December 31, 2020 $ 567 $ 476 $ — $ (305) $ 738 (a) See table below for details about these reclassifications. Our reclassifications out of AOCI for the years ended December 31, 2020, and December 31, 2019, are as follows: Twelve months ended December 31, Affected Line Item in the Statement Where Net Income is Presented in millions 2020 2019 Unrealized gains (losses) on available for sale securities Realized gains $ 4 20 Other income 4 20 Income (loss) from continuing operations before income taxes 1 5 Income taxes $ 3 15 Income (loss) from continuing operations Unrealized gains (losses) on derivative financial instruments Interest rate $ 319 $ 15 Interest income — Loans Interest rate (4) (1) Interest expense — Long-term debt Foreign exchange contracts — 32 Other income 315 46 Income (loss) from continuing operations before income taxes 75 11 Income taxes $ 240 $ 35 Income (loss) from continuing operations Foreign currency translation adjustment — (14) Other income — (14) Income (loss) from continuing operations before income taxes — (3) Income taxes — (11) Income (loss) from continuing operations Net pension and postretirement benefit costs Amortization of losses $ (17) $ (13) Other expense Settlement loss (9) (18) Other expense Amortization of prior service credit 1 — Other expense (25) (31) Income (loss) from continuing operations before income taxes (6) (8) Income taxes $ (19) $ (23) Income (loss) from continuing operations

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Shareholders' Equity	24. Shareholders' Equity Comprehensive Capital Plan In January 2021, the Board of Directors authorized the repurchase of up to $900 million of our Common Shares, effective through the third quarter of 2021. Under our previous authorization pursuant to our 2019 capital plan, we completed $152 million of Common Share repurchases in the first quarter of 2020, including $117 million of Common Share repurchases in the open market and $35 million of Common Share repurchases related to employee equity compensation programs. These repurchases were completed prior to our announcement to temporarily suspend share repurchase activity on March 17, 2020, in response to the COVID-19 pandemic. We repurchased a total of $489 million of common shares pursuant to the 2019 capital plan, dating back to the third quarter of 2019. Consistent with our capital plan, the Board declared a quarterly dividend of $.185 per Common Share for each quarter of 2020. These quarterly dividend payments brought our annual dividend to $.74 per Common Share for 2020. Preferred Stock The following table summarizes our preferred stock at December 31, 2020: Preferred stock series Amount outstanding (in millions) Shares authorized and outstanding Par value Liquidation preference Ownership interest per depositary share Liquidation preference per depositary share 2020 dividends paid per depositary share Fixed-to-Floating Rate Perpetual Noncumulative Series D $ 525 21,000 $ 1 $ 25,000 1/25th $ 1,000 $ 12.50 Fixed-to-Floating Rate Perpetual Noncumulative Series E 500 500,000 1 1,000 1/40th 25 .382813 Fixed Rate Perpetual Noncumulative Series F 425 425,000 1 1,000 1/40th 25 .353125 Fixed Rate Perpetual Noncumulative Series G 450 450,000 1 1,000 1/40th 25 .351563 Capital Adequacy KeyCorp and KeyBank (consolidated) must meet specific capital requirements imposed by federal banking regulators. Sanctions for failure to meet applicable capital requirements may include regulatory enforcement actions that restrict dividend payments, require the adoption of remedial measures to increase capital, terminate FDIC deposit insurance, and mandate the appointment of a conservator or receiver in severe cases. In addition, failure to maintain a “well capitalized” status affects how regulators evaluate applications for certain endeavors, including acquisitions, continuation and expansion of existing activities, and commencement of new activities, and could make clients and potential investors less confident. As of December 31, 2020, KeyCorp and KeyBank (consolidated) met all regulatory capital requirements. KeyBank (consolidated) qualified for the “well capitalized” prompt corrective action capital category at December 31, 2020, because its capital and leverage ratios exceeded the prescribed threshold ratios for that capital category and it was not subject to any written agreement, order, or directive to meet and maintain a specific capital level for any capital measure. Since that date, we believe there has been no change in condition or event that has occurred that would cause the capital category for KeyBank (consolidated) to change. BHCs are not assigned to any of the five prompt corrective action capital categories applicable to insured depository institutions. If, however, those categories applied to BHCs, we believe that KeyCorp would satisfy the criteria for a “well capitalized” institution at December 31, 2020, and since that date, we believe there has been no change in condition or event that has occurred that would cause such capital category to change. Because the regulatory capital categories under the prompt corrective action regulations serve a limited supervisory function, investors should not use them as a representation of the overall financial condition or prospects of KeyBank or KeyCorp. At December 31, 2020, Key and KeyBank (consolidated) had regulatory capital in excess of all current minimum risk-based capital (including all adjustments for market risk) and leverage ratio requirements as shown in the following table. Actual To Meet Minimum To Qualify as Well dollars in millions Amount Ratio Amount Ratio Amount Ratio December 31, 2020 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 17,976 13.40 % $ 10,736 8.00 % N/A N/A KeyBank (consolidated) 17,195 13.09 10,511 8.00 $ 13,139 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 14,907 11.11 % $ 8,052 6.00 % N/A N/A KeyBank (consolidated) 14,539 11.07 7,884 6.00 $ 10,511 8.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 14,907 8.94 % $ 6,671 4.00 % N/A N/A KeyBank (consolidated) 14,539 8.80 6,605 4.00 $ 8,256 5.00 % December 31, 2019 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 16,731 12.79 % $ 10,469 8.00 % N/A N/A KeyBank (consolidated) 16,313 12.69 10,287 8.00 $ 12,858 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 14,207 10.86 % $ 7,852 6.00 % N/A N/A KeyBank (consolidated) 14,091 10.96 7,715 6.00 $ 7,715 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 14,207 9.87 % $ 5,756 4.00 % N/A N/A KeyBank (consolidated) 14,091 9.91 5,688 4.00 $ 7,110 5.00 %

Business Segment Reporting

Business Segment Reporting	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Business Segment Reporting	25. Business Segment Reporting Key previously reported its results of operations through two reportable business segments, Key Community Bank and Key Corporate Bank. In the first quarter of 2019, Key underwent a company-wide organizational change, resulting in the realignment of its businesses into two reportable business segments, Consumer Bank and Commercial Bank, with the remaining operations that do not meet the criteria for disclosure as a separate reportable business recorded in Other. The new business segment structure aligns with how management reviews performance and makes decisions by client, segment and business unit. Prior period information was restated to conform to the new business segment structure. Additionally, goodwill was reallocated to the new segments on a relative fair value basis. On March 31, 2019, the Consumer Bank was allocated goodwill in the amount of $1.6 billion and the Commercial Bank was allocated goodwill in the amount of $912 million. The following is a description of the segments and their primary businesses at December 31, 2020. Consumer Bank The Consumer Bank serves individuals and small businesses throughout our 15-state branch footprint by offering a variety of deposit and investment products, personal finance and financial wellness services, lending, mortgage and home equity, student loan refinancing, credit card, treasury services, and business advisory services. In addition, wealth management and investment services are offered to assist institutional, non-profit, and high-net-worth clients with their banking, trust, portfolio management, charitable giving, and related needs. Commercial Bank The Commercial Bank is an aggregation of our Institutional and Commercial operating segments. The Commercial operating segment is a full-service corporate bank focused principally on serving the needs of middle market clients in seven industry sectors: consumer, energy, healthcare, industrial, public sector, real estate, and technology. The Commercial operating segment is also a significant servicer of commercial mortgage loans and a significant special servicer of CMBS. The Institutional operating segment delivers a broad suite of banking and capital markets products to its clients, including syndicated finance, debt and equity capital markets, commercial payments, equipment finance, commercial mortgage banking, derivatives, foreign exchange, financial advisory, and public finance. Other Other includes various corporate treasury activities such as management of our investment securities portfolio, long-term debt, short-term liquidity and funding activities, and balance sheet risk management, our principal investing unit, and various exit portfolios as well as reconciling items, which primarily represent the unallocated portion of nonearning assets of corporate support functions. Charges related to the funding of these assets are part of net interest income and are allocated to the business segments through noninterest expense. Reconciling items also include intercompany eliminations and certain items that are not allocated to the business segments because they do not reflect their normal operations. The table on the following page shows selected financial data for our major business segments for the years ended December 31, 2020, 2019, and 2018. The information was derived from the internal financial reporting system that we use to monitor and manage our financial performance. GAAP guides financial accounting, but there is no authoritative guidance for “management accounting” — the way we use our judgment and experience to make reporting decisions. Consequently, the line of business results we report may not be comparable to line of business results presented by other companies. The selected financial data is based on internal accounting policies designed to compile results on a consistent basis and in a manner that reflects the underlying economics of the businesses. In accordance with our policies: • Net interest income is determined by assigning a standard cost for funds used or a standard credit for funds provided based on their assumed maturity, prepayment, and/or repricing characteristics. • Indirect expenses, such as computer servicing costs and corporate overhead, are allocated based on assumptions regarding the extent that each line of business actually uses the services. • The consolidated provision for credit losses is allocated among the lines of business primarily based on their actual net loan charge-offs, adjusted periodically for loan growth and changes in risk profile. The amount of the consolidated provision is based on the methodology that we use to estimate our consolidated ALLL. This methodology is described in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Allowance for Loan and Lease Losses.” • Capital is assigned to each line of business based on economic equity. Developing and applying the methodologies that we use to allocate items among our lines of business is a dynamic process. Accordingly, financial results may be revised periodically to reflect enhanced alignment of expense base allocation drivers, changes in the risk profile of a particular business, or changes in our organizational structure. Year ended December 31, Consumer Bank Commercial Bank dollars in millions 2020 2019 2018 2020 2019 2018 SUMMARY OF OPERATIONS Net interest income (TE) $ 2,434 $ 2,366 $ 2,306 $ 1,698 $ 1,621 $ 1,657 Noninterest income 1,003 922 915 1,507 1,390 1,328 Total revenue (TE) (a) 3,437 3,288 3,221 3,205 3,011 2,985 Provision for credit losses 288 188 147 738 118 102 Depreciation and amortization expense 77 97 103 144 135 139 Other noninterest expense 2,200 2,078 2,143 1,589 1,408 1,430 Income (loss) from continuing operations before income taxes (TE) 872 925 828 734 1,350 1,314 Allocated income taxes (benefit) and TE adjustments 207 219 196 101 219 207 Income (loss) from continuing operations 665 706 632 633 1,131 1,107 Income (loss) from discontinued operations, net of taxes — — — — — — Net income (loss) 665 706 632 633 1,131 1,107 Less: Net income (loss) attributable to noncontrolling interests — — — — — — Net income (loss) attributable to Key $ 665 $ 706 $ 632 $ 633 $ 1,131 $ 1,107 AVERAGE BALANCES (b) Loans and leases $ 38,906 $ 32,536 $ 31,307 $ 63,108 $ 57,988 $ 55,828 Total assets (a) 42,953 36,096 34,523 72,056 66,122 63,684 Deposits 79,811 72,544 68,821 46,862 36,212 33,675 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 40 $ 150 $ (38) $ 1 $ (8) $ (17) Net loan charge-offs (b) 134 157 149 309 128 85 Return on average allocated equity (b) 18.92 % 21.30 % 19.24 % 12.86 % 24.99 % 24.94 % Return on average allocated equity 18.92 21.30 19.24 12.86 24.99 24.94 Average full-time equivalent employees (c) 8,213 9,292 9,957 2,093 2,232 2,449 Year ended December 31, Other Key dollars in millions 2020 2019 2018 2020 2019 2018 SUMMARY OF OPERATIONS Net interest income (TE) $ (69) $ (46) $ (23) $ 4,063 $ 3,941 $ 3,940 Noninterest income 142 147 272 2,652 2,459 2,515 Total revenue (TE) (a) 73 101 249 6,715 6,400 6,455 Provision for credit losses (5) 139 (3) 1,021 445 246 Depreciation and amortization expense 140 142 158 361 374 400 Other noninterest expense (41) 61 2 3,748 3,527 3,575 Income (loss) from continuing operations before income taxes (TE) (21) (241) 92 1,585 2,054 2,234 Allocated income taxes (benefit) and TE adjustments (52) (96) (28) 256 346 375 Income (loss) from continuing operations 31 (145) 120 1,329 1,708 1,859 Income (loss) from discontinued operations, net of taxes 14 9 7 14 9 7 Net income (loss) 45 (136) 127 1,343 1,717 1,866 Less: Net income (loss) attributable to noncontrolling interests — — — — — — Net income (loss) attributable to Key $ 45 $ (136) (d) $ 127 $ 1,343 $ 1,717 $ 1,866 AVERAGE BALANCES (b) Loans and leases $ 675 $ 987 $ 1,203 $ 102,689 $ 91,511 $ 88,338 Total assets (a) 47,046 40,961 38,605 162,055 143,179 136,812 Deposits 613 1,274 2,555 127,286 110,030 105,051 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 120 $ 103 $ 103 $ 161 $ 245 $ 48 Net loan charge-offs (b) — 139 — 443 424 234 Return on average allocated equity (b) .34 % (1.66) % 1.62 % 7.54 % 10.27 % 12.29 % Return on average allocated equity .49 (1.56) 1.71 7.62 10.32 12.33 Average full-time equivalent employees (c) 6,520 5,521 5,774 16,826 17,045 18,180 (a) Substantially all revenue generated by our major business segments is derived from clients that reside in the United States. Substantially all long-lived assets, including premises and equipment, capitalized software, and goodwill held by our major business segments, are located in the United States. (b) From continuing operations. (c) The number of average full-time equivalent employees was not adjusted for discontinued operations. (d) Other segments included $106 million provision for credit loss, net of tax, related to a previously disclosed fraud incident.

Condensed Financial Information

Condensed Financial Information of the Parent Company	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of the Parent Company	26. Condensed Financial Information of the Parent Company CONDENSED BALANCE SHEETS December 31, in millions 2020 2019 ASSETS Cash and due from banks $ 3,799 $ 3,813 Short-term investments 21 20 Securities available for sale 12 10 Other investments 43 36 Loans to: Banks 50 50 Nonbank subsidiaries 16 16 Total loans 66 66 Investment in subsidiaries: Banks 17,645 16,969 Nonbank subsidiaries 900 823 Total investment in subsidiaries 18,545 17,792 Goodwill 167 167 Corporate-owned life insurance 207 205 Derivative assets 100 44 Accrued income and other assets 299 295 Total assets $ 23,259 $ 22,448 LIABILITIES Accrued expense and other liabilities $ 505 $ 492 Long-term debt due to: Subsidiaries 500 483 Unaffiliated companies 4,273 4,435 Total long-term debt 4,773 4,918 Total liabilities 5,278 5,410 SHAREHOLDERS’ EQUITY (a) 17,981 17,038 Total liabilities and shareholders’ equity $ 23,259 $ 22,448 (a) See Key’s Consolidated Statements of Changes in Equity. CONDENSED STATEMENTS OF INCOME Year ended December 31, in millions 2020 2019 2018 INCOME Dividends from subsidiaries: Bank subsidiaries $ 1,250 $ 1,204 $ 1,675 Nonbank subsidiaries — 70 — Interest income from subsidiaries 4 9 11 Other income 8 11 11 Total income 1,262 1,294 1,697 EXPENSE Interest on long-term debt with subsidiary trusts 18 22 20 Interest on other borrowed funds 114 151 137 Personnel and other expense 63 87 69 Total expense 195 260 226 Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries 1,067 1,034 1,471 Income tax (expense) benefit 38 57 55 Income (loss) before equity in net income (loss) less dividends from subsidiaries 1,105 1,091 1,526 Equity in net income (loss) less dividends from subsidiaries 238 626 340 NET INCOME (LOSS) 1,343 1,717 1,866 Less: Net income attributable to noncontrolling interests — — — NET INCOME (LOSS) ATTRIBUTABLE TO KEY $ 1,343 $ 1,717 $ 1,866 . CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, in millions 2020 2019 2018 OPERATING ACTIVITIES Net income (loss) attributable to Key $ 1,343 $ 1,717 $ 1,866 Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Deferred income taxes (benefit) 2 (43) 109 Stock-based compensation expense 11 8 8 Equity in net (income) loss less dividends from subsidiaries (238) (626) (340) Net (increase) decrease in other assets (66) 39 (58) Net increase (decrease) in other liabilities 12 11 8 Other operating activities, net 131 244 79 NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 1,195 1,350 1,672 INVESTING ACTIVITIES Net (increase) decrease in securities available for sale and in short-term and other investments (7) (6) 1 Cash infusion from purchase of Cain Brothers — — — Proceeds from sales, prepayments and maturities of securities available for sale — — — Net (increase) decrease in loans to subsidiaries — 15 200 NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES (7) 9 201 FINANCING ACTIVITIES Net proceeds from issuance of long-term debt 800 750 1,250 Payments on long-term debt (1,003) (300) (750) Repurchase of Treasury Shares (170) (868) (1,145) Net cash from the issuance (redemption) of Common Shares and preferred stock — 435 412 Cash dividends paid (829) (804) (656) NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (1,202) (787) (889) NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS (14) 572 984 CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 3,813 3,241 2,257 CASH AND DUE FROM BANKS AT END OF YEAR $ 3,799 $ 3,813 $ 3,241 KeyCorp paid interest on borrowed funds totaling $204 million in 2020, $151 million in 2019, and $131 million in 2018.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	27. Revenue from Contracts with Customers The following table represents a disaggregation of revenue from contracts with customers, by line of business, for the twelve months ended December 31, 2020, and December 31, 2019: Year ended December 31, 2020 2019 dollars in millions Consumer Bank Commercial Bank Total Contract Revenue Consumer Bank Commercial Bank Total Contract Revenue NONINTEREST INCOME Trust and investment services income $ 374 $ 67 $ 441 $ 355 $ 64 $ 419 Investment banking and debt placement fees — 305 305 — 263 263 Services charges on deposit accounts 189 122 311 228 109 337 Cards and payments income 160 201 361 164 106 270 Other noninterest income 10 — 10 13 — 13 Total revenue from contracts with customers $ 733 $ 695 $ 1,428 $ 760 $ 542 $ 1,302 Other noninterest income (a) 1,082 1,010 Noninterest income from other segments (b) 142 147 Total noninterest income $ 2,652 $ 2,459 (a) Noninterest income considered earned outside the scope of contracts with customers. (b) Other includes other segments that consists of corporate treasury, our principal investing unit, and various exit portfolios as well as reconciling items which primarily represents the unallocated portion of nonearning assets of corporate support functions. Charges related to the funding of these assets are part of net interest income and are allocated to the business segments through noninterest expense. Reconciling items also includes intercompany eliminations and certain items that are not allocated to the business segments because they do not reflect their normal operations. Refer to Note 25 (“Business Segment Reporting”) for more information. We had no material contract assets or contract liabilities for the twelve months ended December 31, 2020, and December 31, 2019.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates Our accounting policies conform to GAAP and prevailing practices within the financial services industry. We must make certain estimates and judgments when determining the amounts presented in our consolidated financial statements and the related notes. If these estimates prove to be inaccurate, actual results could differ from those reported.
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of KeyCorp and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Some previously reported amounts have been reclassified to conform to current reporting practices. The consolidated financial statements also include the accounts of any voting rights entities in which we have a controlling financial interest and certain VIEs. In accordance with the applicable accounting guidance for consolidations, we consolidate a VIE if we have the power to direct activities of the VIE that most significantly impact the entity’s economic performance and the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. See Note 13 (“Variable Interest Entities”) for information on our involvement with VIEs. We use the equity method to account for unconsolidated investments in voting rights entities or VIEs if we have significant influence over the entity’s operating and financing decisions (usually defined as a voting or economic interest of 20% to 50%, but not controlling). Unconsolidated investments in voting rights entities or VIEs in which we have a voting or economic interest of less than 20% generally are carried at fair value or a cost measurement alternative. In preparing these financial statements, subsequent events were evaluated through the time the financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users or filed with the SEC.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and due from banks are considered “cash and cash equivalents” for financial reporting purposes. We do not consider cash on deposit with the Federal Reserve to be restricted.
Loans	Loans Loans held in portfolio, which management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are carried at the principal amount outstanding, net of unearned income, including net deferred loan fees and costs and unamortized premiums and discounts. We defer certain nonrefundable loan origination and commitment fees, and the direct costs of originating or acquiring loans. The net deferred amount is amortized over the estimated lives of the related loans as an adjustment to the yield. Accrued interest on loans is included in "other assets" on the balance sheet and is excluded from the calculation of the allowance for credit losses due to our charge-off policy to reverse accrued interest on nonperforming loans against interest income in a timely manner. Certain loans that received a payment deferral or forbearance under a COVID-19 hardship relief program have not been classified as nonperforming loans and continue to accrue and recognize interest income during the period of the deferral. We, therefore, recognize an allowance for credit losses for accrued interest receivable amounts that result from deferred payments under a COVID-19 hardship relief program because those amounts would not be considered to be written off in a timely manner. As of December 31, 2020, the allowance for credit losses on accrued interest receivable was immaterial. Sales-type leases are carried at the aggregate of the lease receivable, estimated unguaranteed residual values, and deferred initial direct fees and costs if certain criteria are met. Direct financing leases are carried at the aggregate of the lease receivable, estimated unguaranteed residual values, and deferred initial direct fees and costs, less unearned income. Unearned income on direct financing leases is amortized over the lease terms using a method approximating the interest method that produces a constant rate of return. Deferred initial direct fees and costs for both sales-type and direct financing leases are amortized over the lease terms as an adjustment to the yield.
Loans Held for Sale	Loans Held for Sale Loans held for sale generally include certain residential and commercial mortgage loans, other commercial loans, and student loans. Loans are initially classified as held for sale when they are individually identified as being available for immediate sale and a formal plan exists to sell them. Loans held for sale are recorded at either fair value, if elected, or the lower of cost or fair value. Fair value is determined based on available market data for similar assets. When a loan is originated as held-for-sale, origination fees and costs are deferred but not amortized. Upon sale of the loans, deferred origination fees and costs are recognized as part of the calculated gain or loss on sale. Our commercial loans (including commercial mortgage and non-mortgage loans) and student loans, which we originated and intend to sell, are carried at the lower of aggregate cost or fair value. Subsequent declines in fair value for loans held for sale are recognized as a charge to “other income” on the income statement. Consumer real estate - residential mortgages loans have been elected to be carried at fair value. Subsequent increases and decreases in fair value for loans elected to be measured at fair value are recorded to “consumer mortgage income” on the income statement. Additional information regarding fair value measurements associated with our loans held for sale is provided in Note 6 (“Fair Value Measurements”).
Nonperforming Loans	Nonperforming Loans Nonperforming loans are loans for which we do not accrue interest income, and include commercial and consumer loans and leases, as well as current year TDRs and nonaccruing TDR loans from prior years. Nonperforming loans do not include loans held for sale. Once a loan is designated nonaccrual, the interest accrued but not collected is reversed against interest income, and payments subsequently received are applied to principal until qualifying for return to accrual. We generally classify commercial loans as nonperforming and stop accruing interest (i.e., designate the loan “nonaccrual”) when the borrower’s principal or interest payment is 90 days past due unless the loan is well-secured and in the process of collection. Commercial loans are also placed on nonaccrual status when payment is not past due but we have serious doubts about the borrower’s ability to comply with existing repayment terms. Once a loan is designated nonaccrual (and as a result assessed for impairment), the interest accrued but not collected is generally charged against the ALLL, and payments subsequently received are applied to principal. Commercial loans are typically charged off in full or charged down to the fair value of the underlying collateral when the borrower’s payment is 180 days past due. We classify consumer loans as nonperforming and stop accruing interest when the borrower’s payment is 120 days past due, unless the loan is well-secured and in the process of collection. Any second lien home equity loan with an associated first lien that is 120 days or more past due or in foreclosure, or for which the first mortgage delinquency timeframe is unknown, is reported as a nonperforming loan. Secured loans that are discharged through Chapter 7 bankruptcy and not formally re-affirmed are designated as nonperforming and TDRs. Our charge-off policy for most consumer loans takes effect when payments are 120 days past due. Home equity and residential mortgage loans generally are charged down to net realizable value when payment is 180 days past due. Credit card loans and similar unsecured products continue to accrue interest until the account is charged off at 180 days past due. Commercial and consumer loans may be returned to accrual status if we are reasonably assured that all contractually due principal and interest are collectible and the borrower has demonstrated a sustained period (generally six months) of repayment performance under the contracted terms of the loan and applicable regulation.
Purchased Loans	Purchased Loans Purchased performing loans that do not have evidence of deterioration in credit quality at acquisition are recorded at fair value at the acquisition date. Any premium or discount associated with purchased performing loans is recognized as interest income based on the effective yield method of amortization for term loans or the straight-line method of amortization for revolving loans. The methods utilized to estimate the required ALLL for purchased performing loans is similar to originated loans. Purchased loans that have experienced a more-than-insignificant deterioration in credit quality since origination are deemed PCD loans. PCD loans are initially recorded at fair value along with an allowance for credit losses determined using the same methodology as originated loans. The sum of the loan's purchase price and allowance for credit losses becomes its initial amortized cost basis. The difference between the initial amortized cost basis and the par value of the loan is a noncredit discount or premium, which is amortized into interest income over the life of the loan. Subsequent changes to the allowance for credit losses are recorded through provision for credit losses.
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses We estimate the ALLL using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. The ALLL is measured on a collective (pool) basis when similar risk characteristics exist. Our portfolio segments include commercial and consumer. Each of these two segments comprises multiple loan classes. Classes are characterized by similarities in initial measurement, risk attributes, and the manner in which we monitor and assess credit risk. The commercial segment is composed of commercial and industrial, commercial real estate, and commercial lease financing loan classes. The consumer lending segment is composed of residential mortgage, home equity, consumer direct, credit card, student lending and consumer indirect loan classes. The ALLL represents our current estimate of lifetime credit losses inherent in our loan portfolio at the balance sheet date. In determining the ALLL, we estimate expected future losses for the loan's entire contractual term adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications. The ALLL is the sum of three components: (i) asset specific/ individual loan reserves; (ii) quantitative (formulaic or pooled) reserves; and (iii) qualitative (judgmental) reserves. Asset Specific / Individual Component Loans that do not share risk characteristics are evaluated on an individual basis. Loans evaluated individually are not included in the collective evaluation. We have elected to apply the practical expedient to measure expected credit losses of a collateral dependent asset using the fair value of the collateral, less any costs to sell, when foreclosure is not probable, when repayment of the loan is expected to be provided substantially through the operation or sale of the collateral, and the borrower is experiencing financial difficulty. Individual reserves are determined as follows: • For commercial non-accruing loans greater than or equal to a defined dollar threshold, individual reserves are determined based on an analysis of the present value of the loan's expected future cash flows or the fair value of the collateral less costs to sell. • For commercial non-accruing loans below the defined dollar threshold, an established LGD percentage is multiplied by the loan balance and the results are aggregated for purposes of measuring specific reserve impairment. • The population of individually assessed consumer loans includes loans deemed collateral dependent, in addition to all TDRs. The expected loss for these loans is estimated based on the present value of the loan's expected future cash flows, except in instances where the loan is collateral dependent, in which case the loan is written down based on the collateral's fair market value less costs to sell. Quantitative Component We use a non-DCF factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller loan portfolios. • PD: This component model is used to estimate the likelihood that a borrower will cease making payments as agreed. The major contributors to this are the borrower credit attributes and macro-economic trends. The objective of the PD model is to produce default likelihood forecasts based on the observed loan-level information and projected paths of macroeconomic variables. • LGD: This component model is used to estimate the loss on a loan once a loan is in default. • EAD: Estimates the loan balance at the time the borrower stops making payments. For all term loans, an amortization based formulaic approach is used for account level EAD estimates. We calculate EAD using a portfolio specific method in each of our revolving product portfolios. For line products that are unconditionally cancellable, the balances will either use a paydown curve or be held flat through the life of the loan. Qualitative Component The ALLL also includes identified qualitative factors related to idiosyncratic risk factors, changes in current economic conditions that may not be reflected in quantitatively derived results, and other relevant factors to ensure the ALLL reflects our best estimate of current expected credit losses. While our reserve methodologies strive to reflect all relevant risk factors, there continues to be uncertainty associated with, but not limited to, potential imprecision in the estimation process due to the inherent time lag of obtaining information and normal variations between estimates and actual outcomes. We provide additional reserves that are designed to provide coverage for losses attributable to such risks. The ALLL also includes factors that may not be directly measured in the determination of individual or collective reserves. Such qualitative factors may include: • The nature and volume of the institution’s financial assets; • The existence, growth, and effect of any concentrations of credit; • The volume and severity of past due financial assets, the volume of nonaccrual assets, and the volume and severity of adversely classified or graded assets; • The value of the underlying collateral for loans that are not collateral dependent; • The institution’s lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries; • The quality of the institution’s credit review function; • The experience, ability, and depth of the institution’s lending, investment, collection, and other relevant management and staff; • The effect of other external factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters; and • Actual and expected changes in international, national, regional, and local economic and business conditions and developments in which the institution operates that affect the collectability of financial assets.
Liability for Credit Losses on Lending-Related Commitments	Liability for Credit Losses on Lending-Related Commitments The liability for credit losses on lending-related commitments, such as letters of credit and unfunded loan commitments, is included in “accrued expense and other liabilities” on the balance sheet. Expected credit losses are estimated over the contractual period in which we are exposed to credit risk via a contractual obligation unless that obligation is unconditionally cancellable by us. The liability for credit losses on lending-related commitments is adjusted as a provision for credit losses. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated useful life. Consistent with our estimation process on our loan and lease portfolio, we use a non-DCF factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller portfolios. Allowance for Credit Losses on Other Financial Assets The allowance for credit losses on other financial assets, such as other receivables and servicing advances, is determined based on historical loss information and other available indicators. If such information does not indicate any expected credit losses, Key may estimate the allowance for credit losses on other financial assets to be zero or close to zero. As of December 31, 2020, the allowance for credit losses on other financial assets was immaterial.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market. Therefore, fair value represents an exit price at the measurement date. We value our assets and liabilities based on the principal or most advantageous market where each would be sold (in the case of assets) or transferred (in the case of liabilities). In the absence of observable market transactions, we consider liquidity valuation adjustments to reflect the uncertainty in pricing the instruments. Valuation inputs can be observable or unobservable. Observable inputs are assumptions based on market data obtained from an independent source. Unobservable inputs are assumptions based on our own information or assessment of assumptions used by other market participants in pricing the asset or liability. Our unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy that gives the highest ranking to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for Level 2 assets and liabilities are based on one or a combination of the following factors: (i) quoted market prices for similar assets or liabilities; (ii) observable inputs, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy ascribed to a fair value measurement in its entirety is based on the lowest level input that is significant to the measurement. Assets and liabilities may transfer between levels based on the observable and unobservable inputs used at the valuation date.
Short-Term Investments	Short-Term Investments Short-term investments consist of segregated, interest-bearing deposits due from banks, the Federal Reserve, and certain non-U.S. banks as well as reverse repurchase agreements and United States Treasury Bills with an original maturity of three months or less.
Trading Account Assets	Trading Account Assets Trading account assets are debt and equity securities, as well as commercial loans, that we purchase and hold but intend to sell in the near term. These assets are reported at fair value. Realized and unrealized gains and losses on trading account assets are reported in “other income” on the income statement.
Securities and Other Investments	Securities Securities available for sale. Debt securities that we intend to hold for an indefinite period of time but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs, or other factors are classified as available-for-sale and reported at fair value. Realized gains and losses resulting from sales of securities using the specific identification method, are included in “other income” on the income statement. Unrealized holding gains are recorded through other comprehensive income. Unrealized losses in fair value below the amortized cost basis are assessed to determine whether the impairment gets recorded through other comprehensive income or through earnings using a valuation allowance. For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either of these criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value in “other income” on the income statement. For debt securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized costs, the nature of the security, the underlying collateral, and the financial condition of the issuers, among other factors. If this assessment indicates a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for available-for-sale securities is recorded for the credit loss, limited by the amount that the fair value is less than the amortized costs basis. Any impairment that has not been recorded through an allowance for available-for-sale securities is recognized in other comprehensive income. Changes in the allowance available-for-sale are recorded as provision for (or reversal of) credit loss. Losses are charged against the allowance for available-for-sale securities when management believes the uncollectibility of an available-for-sale security is confirmed or when either criteria regarding intent or requirement to sell is met. “Other securities” held in the available-for-sale portfolio consist of convertible preferred stock of privately held companies. For additional information, refer to Note 7 (“Securities”). Held-to-maturity securities. Debt securities that we have the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost and adjusted for amortization of premiums and accretion of discounts using the interest method. This method produces a constant rate of return on the adjusted carrying amount. The held-to-maturity portfolio is classified by the following major security types: agency residential collateralized mortgage obligations, agency residential mortgage-backed securities, agency commercial mortgage-backed securities, asset backed securities, and other. “Other securities” held in the held-to-maturity portfolio consist of foreign bonds and capital securities. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type. The estimate of expected losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. We do not measure expected credit losses on held-to-maturity securities in which historical credit loss information adjusted for current conditions and reasonable and supportable forecasts results in an expectation that nonpayment of the amortized cost basis is zero. All of our mortgage-backed securities are issued by U.S. government-sponsored enterprises or GNMA, are highly rated by major rating agencies and have a long history of no credit losses. Other securities are comprised of State of Israel bonds denominated and paid in U.S. dollars. Israel bonds have a long history of no credit losses. Additionally, as of December 31, 2020, the State of Israel's credit rating remains "stable" among Fitch, Moody's, and S&P (A+, A1, AA-). Other Investments Other investments include equity and mezzanine instruments as well as other types of investments that generally are carried at the alternative cost method. The alternative cost method results in these investments being recorded at cost, less any impairment, plus or minus changes resulting from observable market transactions. Adjustments are included in “other income” on the income statement.
Derivatives and Hedging	Derivatives and Hedging All derivatives are recognized on the balance sheet at fair value in “accrued income and other assets” or “accrued expense and other liabilities.” The net increase or decrease in derivatives is included in “other operating activities, net” within the statement of cash flows. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedge relationship, and on the type of hedge relationship. For derivatives that are not in a hedge relationship, any gain or loss, as well as any premium paid or received, is recognized immediately in earnings in “corporate services income” or “other income” on the income statement, depending whether the derivative is for customer accommodation or risk management, respectively. A derivative that is designated and qualifies as a hedging instrument must be designated as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Changes in the fair value of a hedging instrument are reflected in the same income statement line as the earnings effect of the change in fair value of the hedged item attributable to the hedged risk. A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities, and commitments caused by changes in interest rates or other economic factors. The change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time as a change in fair value of the hedged item attributable to the hedged risk. A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The gain or loss on a cash flow hedge is recorded as a component of AOCI on the balance sheet and reclassified to earnings in the same period in which the hedged transaction affects earnings (e.g., when we incur variable-rate interest on debt, earn variable-rate interest on loans, or sell commercial real estate loans). A net investment hedge is used to hedge the exposure of changes in the carrying value of investments as a result of changes in the related foreign exchange rates. The gain or loss on a net investment hedge is recorded as a component of AOCI on the balance sheet when the terms of the derivative match the notional and currency risk being hedged. The amount in AOCI is reclassified into income when the hedged transaction affects earnings (e.g., when we dispose or liquidate a foreign subsidiary). Hedge “effectiveness” is determined by the extent to which changes in the fair value of a derivative instrument offset changes in the fair value, cash flows, or carrying value attributable to the risk being hedged. If the relationship between the change in the fair value of the derivative instrument and the change in the hedged item falls within a range considered to be the industry norm, the hedge is considered “highly effective” and qualifies for hedge accounting. A hedge is “ineffective” if the relationship between the changes falls outside the acceptable range. In that case, hedge accounting is discontinued on a prospective basis. Hedge effectiveness is tested at least quarterly.
Offsetting Derivative Positions	We take into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets on the balance sheet and contracts with positive fair values included in derivative liabilities. Derivative assets and derivative liabilities are recorded within “accrued income and other assets” and “accrued expense and other liabilities,” respectively.
Loan Sales And Securitizations	Loan Sales and Securitizations We sell and at times may securitize loans and other financial assets. We recognize the sale and securitization of loans or other financial assets when the transferred assets are legally isolated from our creditors and the appropriate accounting criteria are met. When we securitize loans or other financial assets, we may retain a portion of the securities issued, including senior interests, subordinated interests, interest-only strips, servicing rights, and other interests, all of which are considered retained interests in the transferred assets. The interests are initially measured at fair value which is based on independent third party market prices or market prices for similar assets. If market prices are not available, fair value is estimated based on the present value of expected future cash flows using assumptions as to discount rates, interest rates, prepayment speeds, and credit losses. Loans sold or securitized are removed from the balance sheet and a net gain or loss is recognized in “other income” at the time of
Servicing Assets	Servicing Assets We service commercial real estate and residential mortgage loans. Servicing assets and liabilities purchased or retained are initially measured at fair value and are recorded as a component of “accrued income and other assets” on the balance sheet. When no ready market value (such as quoted market prices, or prices based on sales or purchases of similar assets) is available to determine the fair value of servicing assets, fair value is determined by calculating the present value of future cash flows associated with servicing the loans. This calculation is based on a number of assumptions, including the market cost of servicing, the discount rate, the prepayment rate, and the default rate. We account for our servicing assets using the amortization method. The amortization of servicing assets is determined in proportion to, and over the period of, the estimated net servicing income and recorded in “mortgage servicing fees” on the income statement.
Leases	LeasesFor leases where Key is the lessee that have initial terms greater than one year, right-of-use assets and corresponding lease liabilities are reported on the balance sheet. Leases with an initial term of less than one year are not recorded on the balance sheet. Our leases where Key is the lessee are primarily classified as operating leases. Operating lease expense is recognized in "net occupancy" and "equipment"on a straight-line basis over the lease term.
Premises and Equipment	Premises and EquipmentPremises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation and amortization. We determine depreciation of premises and equipment using the straight-line method over the estimated useful lives of the particular assets. Leasehold improvements are amortized using the straight-line method over the shorter of their useful lives or terms of the leases. Premises and equipment are evaluated for impairment whenever events or circumstances indicate that the carrying value of the asset may not be recoverable.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the amount by which the cost of net assets acquired in a business combination exceeds their f air value. Goodwill is assigned to reporting units as of the acquisition date based on the expected benefit to such reporting unit from the synergies of the business combination. Goodwill is not amortized. Goodwill is tested at the reporting unit level for impairment, at least annually as of October 1, or when indicators of impairment exist. We may elect to perform a qualitative analysis to determine whether or not it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount. If we elect to bypass this qualitative analysis, or conclude via qualitative analysis that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value, a quantitative goodwill impairment test is performed. If the fair value is less than the carrying value, an impairment charge is recorded for the difference. The amount of capital being allocated to our reporting units as a proxy for the carrying value is based on risk-based regulatory capital requirements. Fair values are estimated using a combination of market and income approaches. The market approach incorporates comparable public company multiples along with data related to recent merger and acquisition activity. The income approach consists of discounted cash flow modeling that utilizes internal
Business Combinations	Business Combinations We account for our business combinations using the acquisition method of accounting. Under this accounting method, the acquired company’s assets and liabilities are recorded at fair value at the date of acquisition, except as provided for by the applicable accounting guidance, and the results of operations of the acquired company are combined with Key’s results from the date of acquisition forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identifiable intangible assets) is recorded as goodwill. Our accounting policy for intangible assets is summarized in this note under the heading “Goodwill and Other Intangible Assets.”
Securities Financing Activities	Securities Financing Activities We enter into repurchase agreements to finance overnight customer sweep deposits. We also enter into repurchase and reverse repurchase agreements to settle other securities obligations. We account for these securities financing agreements as collateralized financing transactions. Repurchase and reverse repurchase agreements are recorded on the balance sheet at the amounts that the securities will be subsequently sold or repurchased. Securities borrowed transactions are recorded on the balance sheet at the amounts of cash collateral advanced. While our securities financing agreements incorporate a right of set off, the assets and liabilities are reported on a gross basis. Reverse repurchase agreements and securities borrowed transactions are included in “short-term investments” on the balance sheet; repurchase agreements are included in “federal funds purchased and securities sold under repurchase agreements.” Fees received in connection with these transactions are recorded in interest income; fees paid are recorded in interest expense.
Contingencies and Guarantees	Contingencies and Guarantees We recognize liabilities for the fair value of our obligations under certain guarantees issued. These liabilities are included in “accrued expense and other liabilities” on the balance sheet. If we receive a fee for a guarantee requiring liability recognition, the amount of the fee represents the initial fair value of the “stand ready” obligation. If there is no fee, the fair value of the stand ready obligation is determined using expected present value measurement techniques, unless observable transactions for comparable guarantees are available. The subsequent accounting for these stand ready obligations depends on the nature of the underlying guarantees. We account for our release from risk under a particular guarantee when the guarantee expires or is settled, or by a systematic and rational amortization method, depending on the risk profile of the guarantee. Contingent aspects of guarantees within the scope of ASC 326 are assessed a reserve under CECL. Contingent liabilities may result from litigation, claims and assessments, loss or damage to Key. We recognize liabilities from contingencies when a loss is probable and can be reasonably estimated.
Revenue Recognition	Revenue Recognition We recognize revenues as they are earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. Our principal source of revenue is interest income from loans and investments. We also earn noninterest income from various banking and financial services offered through both the Commercial and Consumer banks. Interest Income. The largest source of revenue for us is interest income. Interest income is primarily recognized on an accrual basis according to nondiscretionary formulas in written contracts, such as loan agreements or securities contracts. Noninterest Income. We earn noninterest income through a variety of financial and transaction services provided to commercial and consumer clients. Revenue is recorded for noninterest income based on the contractual terms for the service or transaction performed. In certain circumstances, noninterest income is reported net of associated expenses. Trust and Investment Services Income. Trust and investment services revenues include brokerage commissions trust and asset management commissions. Revenue from trade execution and brokerage services is earned through commissions from trade execution on behalf of clients. Revenue from these transactions is recognized at the trade date. Any ongoing service fees are recognized on a monthly basis as services are performed. Trust and asset management services include asset custody and investment management services provided to individual and institutional customers. Revenue is recognized monthly based on a minimum annual fee, and the market value of assets in custody. Additional fees are recognized for transactional activity at a point in time. Investment Banking and Debt Placement Fees. Investment banking and debt placement fees primarily represent revenues earned by KeyBanc Capital Markets for various corporate services including advisory, debt placement and underwriting. Revenues for these services are recorded at a point in time, upon completion of a contractually identified transaction, or when an advisory opinion is provided. Investment banking and debt placement costs are reported on a gross basis within other expense on the income statement. Service Charges on Deposit Accounts. Revenue from service charges on deposit accounts is earned through cash management, wire transfer, and other deposit-related services as well as overdraft, non-sufficient funds, account management and other deposit-related fees. Revenue is recognized for these services either over time, corresponding with deposit accounts’ monthly cycle, or at a point in time for transactional related services and fees. Certain reward costs are netted within revenues from service charges on deposits. Corporate Services Income. Corporate services income includes various ancillary service revenue including letter of credit fees, loan fees, and certain capital market fees. Revenue from these fees is recorded in a manner that reflects the timing of when transactions occur, and as services are provided. Cards and Payments income. Cards and payments income includes interchange fees from consumer credit and debit cards processed through card association networks, merchant services, and other card related services. Interchange rates are generally set by the credit card associations and based on purchase volumes and other factors. Interchange fees are recognized as transactions occur. Certain card network costs and reward costs are netted within interchange revenues. Merchant services income represents account management fees and transaction fees charged to merchants for the processing of card association network transactions. Merchant services revenue is recognized as transactions occur, or as services are performed.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation is measured using the fair value method of accounting on the grant date. The measured cost is recognized over the period during which the recipient is required to provide service in exchange for the award. We estimate expected forfeitures when stock-based awards are granted and record compensation expense only for awards that are expected to vest. Compensation expense related to awards granted to employees is recorded in “personnel expense” on the Consolidated Statements of Income while compensation expense related to awards granted to directors is recorded in “other expense.” We recognize compensation expense for stock-based, mandatory deferred incentive compensation awards using the accelerated method of amortization over a period of approximately 5 years (the current year performance period and a four We estimate the fair value of options granted using the Black-Scholes option-pricing model, as further described in Note 17 (“Stock-Based Compensation”). Employee stock options typically become exercisable at the rate of 25% per year, beginning one year after the grant date. Options expire no later than 10 years after their grant date. We recognize stock-based compensation expense for stock options with graded vesting using an accelerated method of amortization. We use shares repurchased under our annual capital plan submitted to our regulators (treasury shares) for share issuances under all stock-based compensation programs.
Income Taxes	Income Taxes Deferred tax assets and liabilities are determined based on temporary differences between financial statement asset and liability amounts and their respective tax bases, and are measured using enacted tax laws and rates that are expected to apply in the periods in which the deferred tax assets or liabilities are expected to be realized. Deferred tax assets are also recorded for any tax attributes, such as tax credit and net operating loss carryforwards. The net balance of deferred tax assets and liabilities is reported in “Accrued income and other assets” or “Accrued expense and other liabilities” in the consolidated balance sheets, as appropriate. Subsequent changes in the tax laws require adjustment to these assets and liabilities with the cumulative effect included in the provision for income taxes for the period in which the change is enacted. A valuation allowance is recognized for a deferred tax asset if, based on the weight of available evidence, it is more-likely-than-not that some portion or all of the deferred tax asset will not be realized.
Earnings Per Share	Earnings Per Share Basic net income per common share is calculated using the two-class method. The two-class method is an earnings allocation formula that determines earnings per share for each share of common stock and participating securities according to dividends declared (distributed earnings) and participation rights in undistributed earnings. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights to receive dividends. Nonvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are considered participating securities (e.g., nonvested service-based restricted stock units). Undistributed net losses are not allocated to nonvested restricted shareholders, as these shareholders do not have a contractual obligation to fund the incurred losses. Net income attributable to common shares is then divided by the weighted-average number of common shares outstanding during the period. Diluted net income per common share is calculated using the more dilutive of either the treasury method or the two-class method. The dilutive calculation considers the potential dilutive effect of common stock equivalents determined under the treasury stock method. Common stock equivalents include stock options and service- and performance-based restricted stock and stock units granted under our stock plans. Net income attributable to common shares is then divided by the total of weighted-average number of common shares and common stock equivalents outstanding during the period.
Accounting Guidance Adopted and Pending Adoption	Accounting Guidance Adopted in 2020 Measurement of Credit Losses on Financial Instruments (ASU 2016-13, ASU 2018-19, ASU 2019-04, ASU 2019-05, ASU 2019-11, ASU 2020-02, ASU 2020-03) On January 1, 2020, we adopted ASU 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments, which replaces the incurred-loss methodology that recognized losses when a probable threshold was met with an expected-loss methodology, specifically, recognizing current expected credit losses (CECL) for the remaining life of the asset at the time of origination or acquisition. The CECL methodology applies to loans, debt securities, and other financial assets and net investment in leases measured at amortized cost. It also applies to off-balance sheet credit exposures (loan commitments, standby letters of credit, financial guarantees, and other similar instruments). Assets in the scope of ASC 326 are presented at the net amount expected to be collected after deducting the allowance for credit losses from the amortized cost basis of the assets. ASC 326 also requires credit losses relating to available-for-sale debt securities that management does not intend to sell or believes that it is more likely than not they will be required to sell to be recorded through an allowance rather than a reduction of the carrying amount. In accordance with ASC 326, we did not reassess whether recognized purchased credit impaired loans met the criteria of a PCD loan and whether modifications to individual acquired loans accounted for in pools were TDRs as of the date of adoption. At adoption, we elected to not maintain the pools of loans previously accounted for under Subtopic 310-30. The prospective application resulted in a $4 million adjustment to the amortized cost basis of PCD loans to reflect the addition to the allowance for loans and leases as of January 1, 2020. After the adjustment for the allowance for the loans and leases, the noncredit discount of $15 million is being accreted to interest income using the interest method based on the effective interest rate determined after the adjustment from credit losses as of January 1, 2020. Simplifying the Test for Goodwill Impairment (ASU 2017-04) On January 1, 2020, we adopted ASU 2017-04. The ASU amends ASC Topic 350, Intangibles - Goodwill and Other and eliminates the second step of the test for goodwill impairment. Under the new accounting guidance, the quantitative analysis requires the estimated fair value of each reporting unit to be compared to its carrying amount, including goodwill. If the estimated fair value of the reporting unit is less than its carrying value, an impairment charge would be recorded for the excess, not to exceed the amount of goodwill allocated to the reporting unit. The adoption of this accounting guidance was applied prospectively and did not affect our financial condition or results of operations. See Note 12 (“Goodwill and Other Intangible Assets”) for additional information. Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting (ASU 2020-04) We adopted ASU 2020-04 on April 1, 2020. The amendments provide optional expedients and exceptions for certain contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of rate reform. The guidance is effective from the date of issuance until December 31, 2022. The guidance permits Key not to apply modification accounting or remeasure lease payments in lease contracts if the changes to the contract are related to the discontinuation of the reference rate. If certain criteria are met, the amendments also allow exceptions to the dedesignation criteria of the hedging relationship and the assessment of hedge effectiveness during the transition period. It also allows Key to make a one time election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. This one time election may be made at any time after March 12, 2020, but no later than December 31, 2022. Key has not made a determination on whether it will make this election. At the time of adoption, the guidance did not have a significant impact on Key’s financial condition and results of operations. In January 2021, ASU 2021-01 was issued by the FASB and clarifies that certain exceptions in reference rate reform apply to derivatives that are affected by the discounting transition. We will continue to assess the impact as the reference rate transition occurs over the next two years. Accounting Guidance Adopted in 2021 Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2019-12, Simplifying the January 1, 2021 This ASU simplifies the accounting for income taxes by removing certain exceptions to the existing guidance, such as exceptions related to the incremental approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period when a Key adopted this guidance on January 1, 2021 using the transition guidance prescribed by amendment. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2020-01, January 1, 2021 This guidance clarifies that when applying the measurement alternative in Topic 321, companies should consider certain observable transactions that require the application or discontinuance of the equity method under Topic 323. Key adopted this guidance on January 1, 2021 on a prospective basis. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2020-08, January 1, 2021 This ASU clarifies that at each reporting period an entity should reevaluate whether a callable debt security is within the scope of ASC 310, which says that to the extent the amortized cost basis of an individual callable debt security exceeds the amount repayable by the Key adopted this guidance on January 1, 2021 on a prospective basis. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2021-01, Reference Rate Reform (Topic 848) January 1, 2021 The ASU clarifies that certain optional expedients and exceptions related to contracts modified as a result of reference rate reform and hedge accounting apply to derivatives affected by the discounting transition, such as those that use an interest rate for margining, discounting, or contract price alignment. Key adopted this guidance on January 1, 2021 on a prospective basis and will assess the impact in conjunction with the reference rate transition as it occurs over the next two years.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The main drivers of the adjustment to retained earnings are summarized in the following table. Pre-ASC 326 Adoption Impact of ASC 326 Adoption As Reported Under ASC 326 in millions December 31, 2019 January 1, 2020 Allowance for credit losses Commercial Commercial and industrial $ 551 $ (141) $ 410 Real estate — commercial mortgage 143 16 159 Real estate — construction 22 (7) 15 Commercial lease financing 35 8 43 Total commercial loans 751 (124) 627 Consumer Real estate — residential mortgage 7 77 84 Home equity loans 31 147 178 Consumer direct loans 34 63 97 Credit cards 47 35 82 Consumer indirect loans 30 6 36 Total consumer loans 149 328 477 Total ALLL — continuing operations 900 204 1,104 Discontinued operations 10 31 41 Total ALLL 910 235 1,145 Accrued expense and other liabilities 75 70 145 Total allowance for credit losses $ 985 $ 305 $ 1,290 Accounting Guidance Adopted in 2021 Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2019-12, Simplifying the January 1, 2021 This ASU simplifies the accounting for income taxes by removing certain exceptions to the existing guidance, such as exceptions related to the incremental approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period when a Key adopted this guidance on January 1, 2021 using the transition guidance prescribed by amendment. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2020-01, January 1, 2021 This guidance clarifies that when applying the measurement alternative in Topic 321, companies should consider certain observable transactions that require the application or discontinuance of the equity method under Topic 323. Key adopted this guidance on January 1, 2021 on a prospective basis. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2020-08, January 1, 2021 This ASU clarifies that at each reporting period an entity should reevaluate whether a callable debt security is within the scope of ASC 310, which says that to the extent the amortized cost basis of an individual callable debt security exceeds the amount repayable by the Key adopted this guidance on January 1, 2021 on a prospective basis. The adoption of this accounting guidance is not expected to have a material effect on our financial condition or results of operations. ASU 2021-01, Reference Rate Reform (Topic 848) January 1, 2021 The ASU clarifies that certain optional expedients and exceptions related to contracts modified as a result of reference rate reform and hedge accounting apply to derivatives affected by the discounting transition, such as those that use an interest rate for margining, discounting, or contract price alignment. Key adopted this guidance on January 1, 2021 on a prospective basis and will assess the impact in conjunction with the reference rate transition as it occurs over the next two years.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share	Our basic and diluted earnings per Common Share are calculated as follows: Year ended December 31, dollars in millions, except per share amounts 2020 2019 2018 EARNINGS Income (loss) from continuing operations $ 1,329 $ 1,708 $ 1,859 Less: Net income (loss) attributable to noncontrolling interests — — — Income (loss) from continuing operations attributable to Key 1,329 1,708 1,859 Less: Dividends on preferred stock 106 97 66 Income (loss) from continuing operations attributable to Key common shareholders 1,223 1,611 1,793 Income (loss) from discontinued operations, net of taxes 14 9 7 Net income (loss) attributable to Key common shareholders $ 1,237 $ 1,620 $ 1,800 WEIGHTED-AVERAGE COMMON SHARES Weighted-average Common Shares outstanding (000) 967,783 992,091 1,040,890 Effect of common share options and other stock awards 7,024 10,163 13,792 Weighted-average common shares and potential Common Shares outstanding (000) (a) 974,807 1,002,254 1,054,682 EARNINGS PER COMMON SHARE Income (loss) from continuing operations attributable to Key common shareholders $ 1.26 $ 1.62 $ 1.72 Income (loss) from discontinued operations, net of taxes .01 .01 .01 Net income (loss) attributable to Key common shareholders (b) 1.28 1.63 1.73 Income (loss) from continuing operations attributable to Key common shareholders — assuming dilution 1.26 1.61 1.70 Income (loss) from discontinued operations, net of taxes .01 .01 .01 Net income (loss) attributable to Key common shareholders — assuming dilution (b) 1.27 1.62 1.71 (a) Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable. (b) EPS may not foot due to rounding.

Loan Portfolio (Tables)

Loan Portfolio (Tables)	12 Months Ended
	Dec. 31, 2020
Financing Receivable, before Allowance for Credit Loss [Abstract]
Loans by Category	December 31, in millions 2020 2019 Commercial and industrial (a) $ 52,907 $ 48,295 Commercial real estate: Commercial mortgage 12,687 13,491 Construction 1,987 1,558 Total commercial real estate loans 14,674 15,049 Commercial lease financing (b) 4,399 4,688 Total commercial loans 71,980 68,032 Residential — prime loans: Real estate — residential mortgage 9,298 7,023 Home equity loans 9,360 10,274 Total residential — prime loans 18,658 17,297 Consumer direct loans 4,714 3,513 Credit cards 989 1,130 Consumer indirect loans 4,844 4,674 Total consumer loans 29,205 26,614 Total loans (c) $ 101,185 $ 94,646 (a) Accrued interest of $241 million and $244 million at December 31, 2020, and December 31, 2019, respectively, is presented in "Accrued income and other assets" on the Consolidated Balance Sheets and is excluded from the amortized cost basis disclosed in this table. (b) Loan balances include $127 million and $144 million of commercial credit card balances at December 31, 2020, and December 31, 2019, respectively. (c) Commercial lease financing includes receivables of $23 million and $15 million held as collateral for a secured borrowing at December 31, 2020, and December 31, 2019, respectively. Principal reductions are based on the cash payments received from these related receivables. Additional information pertaining to this secured borrowing is included in Note 20 (“Long-Term Debt”). (d) Total loans exclude loans in the amount of $710 million at December 31, 2020, and $865 million at December 31, 2019, related to the discontinued operations of the education lending business.

Asset Quality (Tables)

Asset Quality (Tables)	12 Months Ended
	Dec. 31, 2020
Credit Loss [Abstract]
Allowance for Loan and Lease Losses and Corresponding Loan Balances	The changes in the ALLL by loan category for the periods indicated are as follows: Twelve months ended December 31, 2020: in millions December 31, 2019 Impact of ASC 326 Adoption January 1, 2020 Provision Charge-offs Recoveries December 31, 2020 Commercial and Industrial $ 551 $ (141) $ 410 $ 585 $ (351) $ 34 $ 678 Commercial real estate: Real estate — commercial mortgage 143 16 159 184 (19) 3 327 Real estate — construction 22 (7) 15 32 — — 47 Total commercial real estate loans 165 9 174 216 (19) 3 374 Commercial lease financing 35 8 43 38 (35) 1 47 Total commercial loans 751 (124) 627 839 (405) 38 1,099 Real estate — residential mortgage 7 77 84 19 (2) 1 102 Home equity loans 31 147 178 (3) (11) 7 171 Consumer direct loans 34 63 97 61 (37) 7 128 Credit cards 47 35 82 36 (39) 8 87 Consumer indirect loans 30 6 36 13 (28) 18 39 Total consumer loans 149 328 477 126 (117) 41 527 Total ALLL — continuing operations 900 204 1,104 965 (a) (522) 79 1,626 Discontinued operations 10 31 41 (5) (5) 5 36 Total ALLL — including discontinued operations $ 910 $ 235 $ 1,145 $ 960 $ (527) $ 84 $ 1,662 (a) Excludes a provision for losses on lending-related commitments of $56 million. Twelve months ended December 31, 2019 : in millions December 31, 2018 Provision Charge-offs Recoveries December 31, 2019 Commercial and Industrial $ 532 $ 311 $ (319) $ 27 $ 551 Commercial real estate: Real estate — commercial mortgage 142 7 (8) 2 143 Real estate — construction 33 (6) (5) — 22 Total commercial real estate loans 175 1 (13) 2 165 Commercial lease financing 36 20 (26) 5 35 Total commercial loans 743 332 (358) 34 751 Real estate — residential mortgage 7 1 (3) 2 7 Home equity loans 35 7 (19) 8 31 Consumer direct loans 30 38 (41) 7 34 Credit cards 48 36 (44) 7 47 Consumer indirect loans 20 27 (34) 17 30 Total consumer loans 140 109 (141) 41 149 Total ALLL — continuing operations 883 441 (a) (b) (499) (b) 75 900 Discontinued operations 14 3 (12) 5 10 Total ALLL — including discontinued operations $ 897 $ 444 $ (511) $ 80 $ 910 (a) Excludes a provision for losses on lending-related commitments of $4 million. (b) Includes the realization of a $139 million loss related to a previously disclosed fraud incident. Twelve months ended December 31, 2018 in millions December 31, 2017 Provision Charge-offs Recoveries December 31, 2018 Commercial and industrial $ 529 $ 125 $ (159) $ 37 $ 532 Real estate — commercial mortgage 133 27 (21) 3 142 Real estate — construction 30 1 — 2 33 Commercial lease financing 43 (2) (10) 5 36 Total commercial loans 735 151 (190) 47 743 Real estate — residential mortgage 7 1 (3) 2 7 Home equity loans 43 2 (21) 11 35 Consumer direct loans 28 31 (36) 7 30 Credit cards 44 41 (44) 7 48 Consumer indirect loans 20 14 (30) 16 20 Total consumer loans 142 89 (134) 43 140 Total ALLL — continuing operations 877 240 (a) (324) 90 883 Discontinued operations 16 8 (15) 5 14 Total ALLL — including discontinued operations $ 893 $ 248 $ (339) $ 95 $ 897 (a) Excludes a provision for losses on lending-related commitments of $6 million.
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table discloses key macroeconomic variables for each loan portfolio. Segment Portfolio Key Macroeconomic Variables (a) Commercial Commercial and industrial BBB corporate bond rate (spread), GDP, industrial production, and unemployment rate Commercial real estate BBB corporate bond rate (spread), property and real estate price indices, and unemployment rate Commercial lease financing BBB corporate bond rate (spread), GDP, and unemployment rate Consumer Real estate — residential mortgage GDP, home price index, unemployment rate, and 30 year mortgage rate Home equity Home price index, unemployment rate, and 30 year mortgage rate Consumer direct Unemployment rate and U.S. household income Consumer indirect New vehicle sales, Manheim used vehicle value index, and unemployment rate Credit cards Unemployment rate and U.S. household income Discontinued operations Unemployment rate (a) Variables include all transformations and interactions with other risk drivers. Additionally, variables may have varying impacts at different points in the economic cycle.
Financing Receivable Credit Quality Indicators	Credit Risk Profile by Creditworthiness Category and Vintage (a) As of December 31, 2020 Term Loans Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Amortized Cost Basis by Origination Year and Internal Risk Rating in millions 2020 2019 2018 2017 2016 Prior Total Commercial and Industrial Risk Rating: Pass $ 13,100 $ 5,487 $ 4,040 $ 2,617 $ 1,967 $ 2,709 $ 19,832 $ 118 $ 49,870 Criticized (Accruing) 66 198 174 236 150 279 1,527 22 2,652 Criticized (Nonaccruing) 8 27 71 28 17 7 226 1 385 Total commercial and industrial 13,174 5,712 4,285 2,881 2,134 2,995 21,585 141 52,907 Real estate — commercial mortgage Risk Rating: Pass 1,591 2,937 1,737 867 765 3,027 885 43 11,852 Criticized (Accruing) 12 142 81 145 72 255 22 2 731 Criticized (Nonaccruing) — 1 4 4 2 88 5 — 104 Total real estate — commercial mortgage 1,603 3,080 1,822 1,016 839 3,370 912 45 12,687 Real estate — construction Risk Rating: Pass 367 764 510 188 27 22 31 5 1,914 Criticized (Accruing) — 14 38 18 — 2 1 — 73 Criticized (Nonaccruing) — — — — — — — — Total real estate — construction 367 778 548 206 27 24 32 5 1,987 Commercial lease financing Risk Rating: Pass 1,076 1,050 534 504 228 901 — — 4,293 Criticized (Accruing) 10 35 15 26 7 4 — — 97 Criticized (Nonaccruing) — 2 2 2 2 1 — — 9 Total commercial lease financing 1,086 1,087 551 532 237 906 — 4,399 Total commercial loans $ 16,230 $ 10,657 $ 7,206 $ 4,635 $ 3,237 $ 7,295 $ 22,529 $ 191 $ 71,980 (a) Accrued interest of $140 million, presented in Other Assets on the Consolidated Balance Sheets, was excluded from the amortized cost basis disclosed in this table. Consumer Credit Exposure Credit Risk Profile by FICO Score and Vintage (a) As of December 31, 2020 Term Loans Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Amortized Cost Basis by Origination Year and FICO Score in millions 2020 2019 2018 2017 2016 Prior Total Real estate — residential mortgage FICO Score: 750 and above $ 3,595 $ 1,620 $ 194 $ 254 $ 537 $ 1,211 — — $ 7,411 660 to 749 710 284 76 48 100 332 — — 1,550 Less than 660 16 28 21 10 26 170 — — 271 No Score 1 2 2 7 2 52 — — 66 Total real estate — residential mortgage 4,322 1,934 293 319 665 1,765 — — 9,298 Home equity loans FICO Score: 750 and above 1,043 404 168 202 190 839 $ 2,689 $ 590 6,125 660 to 749 385 198 82 77 69 253 1,237 206 2,507 Less than 660 27 30 18 20 20 113 426 61 715 No Score 2 2 1 — — 2 5 1 13 Total home equity loans 1,457 634 269 299 279 1,207 4,357 858 9,360 Consumer direct loans FICO Score: 750 and above 1,840 883 115 32 16 57 119 — 3,062 660 to 749 479 268 80 22 14 33 254 1 1,151 Less than 660 23 37 21 8 5 10 81 — 185 No Score 65 35 21 21 10 11 153 — 316 Total consumer direct loans 2,407 1,223 237 83 45 111 607 1 4,714 Credit cards FICO Score: 750 and above — — — — — — 488 — 488 660 to 749 — — — — — — 407 — 407 Less than 660 — — — — — — 93 — 93 No Score — — — — — — 1 — 1 Total credit cards — — — — — — 989 — 989 Consumer indirect loans FICO Score: 750 and above 1,092 924 369 188 69 66 — — 2,708 660 to 749 653 558 232 97 36 47 — — 1,623 Less than 660 143 163 99 54 25 28 — — 512 No Score 1 — — — — — — — 1 Total consumer indirect loans 1,889 1,645 700 339 130 141 — — 4,844 Total consumer loans $ 10,075 $ 5,436 $ 1,499 $ 1,040 $ 1,119 $ 3,224 $ 5,953 $ 859 $ 29,205 (a) Accrued interest of $101 million, presented in Other Assets on the Consolidated Balance Sheets, was excluded from the amortized cost basis disclosed in this table.
Past Due Loans Including Current Loans	The following aging analysis of past due and current loans as of December 31, 2020, and December 31, 2019, provides further information regarding Key’s credit exposure. Aging Analysis of Loan Portfolio (a) December 31, 2020 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans (c) Total Past Due and Non-performing Loans (c) Total Loans (d) in millions LOAN TYPE Commercial and industrial $ 52,396 $ 36 $ 50 $ 40 $ 385 $ 511 $ 52,907 Commercial real estate: Commercial mortgage 12,548 9 5 21 104 139 12,687 Construction 1,986 — — 1 — 1 1,987 Total commercial real estate loans 14,534 9 5 22 104 140 14,674 Commercial lease financing 4,369 21 1 — 8 30 4,399 Total commercial loans $ 71,299 $ 66 $ 56 $ 62 $ 497 $ 681 $ 71,980 Real estate — residential mortgage $ 9,173 $ 11 $ 3 $ 1 $ 110 $ 125 $ 9,298 Home equity loans 9,143 34 20 9 154 217 9,360 Consumer direct loans 4,694 7 4 4 5 20 4,714 Credit cards 972 5 3 7 2 17 989 Consumer indirect loans 4,792 25 7 3 17 52 4,844 Total consumer loans $ 28,774 $ 82 $ 37 $ 24 $ 288 $ 431 $ 29,205 Total loans $ 100,073 $ 148 $ 93 $ 86 $ 785 $ 1,112 $ 101,185 (a) Amounts in table represent amortized cost and exclude loans held for sale. (b) Accrued interest of $241 million presented in “other assets” on the Consolidated Balance Sheets is excluded from the amortized cost basis disclosed in this table. (c) PCI loans meeting nonperforming criteria were historically excluded from Key's nonperforming disclosures. As a result of CECL implementation on January 1, 2020, PCI loans became PCD loans. PCD loans that met the definition of nonperforming are now included in nonperforming disclosures. (d) Net of unearned income, net of deferred fees and costs, and unamortized discounts and premiums. December 31, 2019 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans in millions LOAN TYPE Commercial and industrial $ 47,768 $ 110 $ 52 $ 53 $ 264 $ 479 48 $ 48,295 Commercial real estate: Commercial mortgage 13,258 8 5 13 83 109 124 13,491 Construction 1,551 3 — 1 2 6 1 1,558 Total commercial real estate loans 14,809 11 5 14 85 115 125 15,049 Commercial lease financing 4,647 22 11 2 6 41 — 4,688 Total commercial loans $ 67,224 $ 143 $ 68 $ 69 $ 355 $ 635 173 $ 68,032 Real estate — residential mortgage $ 6,705 $ 7 $ 5 $ 1 $ 48 $ 61 $ 257 $ 7,023 Home equity loans 10,071 30 10 5 145 190 13 10,274 Consumer direct loans 3,484 10 5 7 4 26 3 3,513 Credit cards 1,104 6 5 12 3 26 — 1,130 Consumer indirect loans 4,609 32 8 3 22 65 — 4,674 Total consumer loans $ 25,973 $ 85 $ 33 $ 28 $ 222 $ 368 $ 273 $ 26,614 Total loans $ 93,197 $ 228 $ 101 $ 97 $ 577 $ 1,003 $ 446 $ 94,646 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the principal amount of the loan increased or decreased by net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude PCI, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans.
Post-Modification Outstanding Recorded Investment by Concession Type for Our Commercial Accruing and Nonaccruing TDRs	December 31, in millions 2020 2019 Commercial loans: Extension of Maturity Date $ 5 $ 11 Payment or Covenant Modification/Deferment 59 11 Bankruptcy Plan Modification — — Increase in new commitment or new money — 8 Total $ 64 $ 30 Consumer loans: Interest rate reduction $ 41 $ 14 Other 21 29 Total $ 62 $ 43 Total TDRs $ 126 $ 73
Summary Of Post-Modification Outstanding Recorded Investment, Accruing And Nonaccruing TDRs	The following table summarizes the change in the post-modification outstanding recorded investment of our accruing and nonaccruing TDRs during the periods indicated: December 31, in millions 2020 2019 Balance at beginning of the period $ 347 $ 399 Additions 173 112 Payments (95) (145) Charge-offs (62) (19) Balance at end of period $ 363 $ 347
Breakdown of Nonperforming TDRs by Loans Category	A further breakdown of TDRs included in nonperforming loans by loan category for the periods indicated are as follows: December 31, 2020 December 31, 2019 Number of Loans Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number Pre-modification Post-modification dollars in millions LOAN TYPE Nonperforming: Commercial and industrial 66 $ 136 $ 92 51 $ 72 $ 53 Commercial real estate: Real estate — commercial mortgage 7 62 50 6 64 58 Total commercial real estate loans 7 62 50 6 64 58 Total commercial loans 73 198 142 57 136 111 Real estate — residential mortgage 258 35 34 181 13 11 Home equity loans 630 41 37 713 42 41 Consumer direct loans 212 3 3 172 2 2 Credit cards 356 2 2 368 2 2 Consumer indirect loans 861 15 11 1,131 19 16 Total consumer loans 2,317 96 87 2,565 78 72 Total nonperforming TDRs 2,390 294 229 2,622 214 183 Prior-year accruing: (a) Commercial and industrial 3 5 — 6 30 25 Commercial real estate: Real estate — commercial mortgage — — — 1 — — Total commercial loans 3 5 — 7 30 25 Real estate — residential mortgage 485 37 31 493 37 31 Home equity loans 1,781 106 83 1,751 104 84 Consumer direct loans 163 4 3 139 4 3 Credit cards 536 3 1 486 3 1 Consumer indirect loans 775 29 16 714 33 20 Total consumer loans 3,740 179 134 3,583 181 139 Total prior-year accruing TDRs 3,743 184 134 3,590 211 164 Total TDRs 6,133 $ 478 $ 363 6,212 $ 425 $ 347 (a) All TDRs that were restructured prior to January 1, 2020, and January 1, 2019, are fully accruing.
Financing Receivables, Off-Balance Sheet, Liabilities	Changes in the liability for credit losses on off balance sheet exposures are summarized as follows: Twelve Months Ended December 31, in millions 2020 2019 Balance at the end of the prior period $ 68 $ 64 Liability for credit losses on contingent guarantees at the end of the prior period 7 — Cumulative effect from change in accounting principle (a), (b) 66 — Balance at beginning of period 141 64 Provision (credit) for losses on off balance sheet exposures 56 4 Balance at end of period $ 197 $ 68 (a) The cumulative effect from change in accounting principle relates to the January 1, 2020, adoption of ASU 2016-13. (b) Excludes $4 million related to the provision for other financial assets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities Measured on Recurring Basis	The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2020, and December 31, 2019. December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total in millions ASSETS MEASURED ON A RECURRING BASIS Trading account assets: U.S. Treasury, agencies and corporations — $ 633 — $ 633 — $ 843 — $ 843 States and political subdivisions — 24 — 24 — 30 — 30 Other mortgage-backed securities — 47 — 47 — 78 — 78 Other securities — 13 — 13 — 44 — 44 Total trading account securities — 717 — 717 — 995 — 995 Commercial loans — 18 — 18 — 45 — 45 Total trading account assets — 735 — 735 — 1,040 — 1,040 Securities available for sale: U.S. Treasury, agencies and corporations — 1,000 — 1,000 — 334 — 334 States and political subdivisions — — — — — 4 — 4 Agency residential collateralized mortgage obligations — 14,273 — 14,273 — 12,783 — 12,783 Agency residential mortgage-backed securities — 2,164 — 2,164 — 1,714 — 1,714 Agency commercial mortgage-backed securities — 10,106 — 10,106 — 6,997 — 6,997 Other securities — — $ 13 13 — — $ 11 11 Total securities available for sale — 27,543 13 27,556 — 21,832 11 21,843 Other investments: Principal investments: Direct — — 1 1 — — 1 1 Indirect (measured at NAV) (a) — — — 53 — — — 68 Total principal investments — — 1 54 — — 1 69 Equity investments: Direct — — 13 13 — — 12 12 Direct (measured at NAV) (a) — — — 7 — — — 1 Indirect (measured at NAV) (a) — — — 7 — — — 8 Total equity investments — — 13 27 — — 12 21 Total other investments — — 14 81 — — 13 90 Loans, net of unearned income (residential) — — 11 11 — — 4 4 Loans held for sale (residential) — 264 — 264 — 140 — 140 Derivative assets: Interest rate — 1,528 56 1,584 — 941 22 963 Foreign exchange $ 78 31 — 109 $ 49 $ 18 $ — $ 67 Commodity — 424 2 426 — 208 — 208 Credit — — 1 1 — — 1 1 Other — 26 32 58 — 9 5 14 Derivative assets 78 2,009 91 2,178 49 1,176 28 1,253 Netting adjustments (b) — — — (380) — — — (473) Total derivative assets 78 2,009 91 1,798 49 1,176 28 780 Total assets on a recurring basis at fair value $ 78 $ 30,551 $ 129 $ 30,445 $ 49 $ 24,188 $ 56 $ 23,897 LIABILITIES MEASURED ON A RECURRING BASIS Bank notes and other short-term borrowings: Short positions $ 256 $ 503 — $ 759 $ 19 $ 686 — $ 705 Derivative liabilities: Interest rate — 288 — 288 — 253 — 253 Foreign exchange 72 31 — 103 43 17 — 60 Commodity — 408 — 408 — 200 — 200 Credit — — $ 11 11 — 1 $ 9 10 Other — 16 — 16 — 10 — 10 Derivative liabilities 72 743 11 826 43 481 9 533 Netting adjustments (b) — — — (675) — — — (335) Total derivative liabilities 72 743 11 151 43 481 9 198 Total liabilities on a recurring basis at fair value $ 328 $ 1,246 $ 11 $ 910 $ 62 $ 1,167 $ 9 $ 903 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (b) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The net basis takes into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Total derivative assets and liabilities include these netting adjustments.
Fair Value Measurement Inputs and Valuation Techniques	The following table describes the valuation techniques and significant inputs used to measure the classes of assets and liabilities reported at fair value on a recurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Securities (includes trading account assets securities available for sale, and U.S. Treasury Bills classified as short-term investments) Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities. This includes exchange-traded equity securities. Fair value of level 2 securities is determined by: • Pricing models (either by a third party pricing service or internally). Inputs include: yields, benchmark securities, bids, offers, actual trade data (i.e., spreads, credit ratings, and interest rates) for comparable assets, spread tables, matrices, high-grade scales, and option-adjusted spreads. • Observable market prices of similar securities. Fair value of level 3 securities is determined by: • Internally developed valuation techniques, principally discounted cash flow methods (income approach). • Revenue multiples of comparable public companies (market approach). For level 3 securities, increases (decreases) in the discount rate and marketability discount used in the discounted cash flow models would have resulted in lower (higher) fair value measurements. Higher volatility factors would have further magnified changes in fair value. The valuations provided by the third-party pricing service are based on observable market inputs, which include benchmark yields, reported trades, issuer spreads, benchmark securities, bids, offers, and reference data obtained from market research publications. Inputs used by the third-party pricing service in valuing CMOs and other mortgage-backed securities also include new issue data, monthly payment information, whole loan collateral performance, and “To Be Announced” prices. In valuations of securities issued by state and political subdivisions, inputs used by the third-party pricing service also include material event notices. We regularly validate the pricing methodologies of valuations derived from a third-party pricing service to ensure the fair value determination is consistent with applicable accounting guidance and that our assets are properly classified in the fair value hierarchy. To perform this validation, we: • review documentation received from our third-party pricing service regarding the inputs used in its valuations and determine a level assessment for each category of securities; • substantiate actual inputs used for a sample of securities by comparing the actual inputs used by our third-party pricing service to comparable inputs for similar securities; and • substantiate the fair values determined for a sample of securities by comparing the fair values provided by our third-party pricing service to prices from other independent sources for the same and similar securities. We analyze variances and conduct additional research with our third-party pricing service and take appropriate steps based on our findings. Level 1, 2, and 3 (primarily Level 2) Commercial loans (trading account assets) Fair value is based on: • Observable market price spreads for similar loans. Valuations reflect prices within the bid-ask spread that are most representative of fair value. Level 2 Principal investments (direct) Direct principal investments consist of equity and debt instruments of private companies made by our principal investing entities. Fair value is determined using: • Operating performance and market multiples of comparable businesses • Other unique facts and circumstances related to each individual investment Direct principal investments are accounted for as investment companies in accordance with the applicable accounting guidance, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. We are in the process of winding down our direct principal investment portfolio. As of December 31, 2020, the balance is less than $1 million. Level 3 Asset/liability class Valuation technique Valuation hierarchy classification(s) Principal investments (indirect) Indirect principal investments include primary and secondary investments in private equity funds engaged mainly in venture- and growth-oriented investing. These investments do not have readily determinable fair values and qualify for the practical expedient to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership interest in partners’ capital to which a proportionate share of net assets is attributed). Indirect principal investments are also accounted for as investment companies, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. Under the provisions of the Volcker Rule, we are required to dispose or conform our indirect investments to the requirements of the statute by no later than July 21, 2022. As of December 31, 2020, we have not committed to a plan to sell these investments. Therefore, these investments continue to be valued using the net asset value per share methodology. NAV Asset/liability class Valuation technique Valuation hierarchy classification(s) Other direct equity investments Fair value is determined using: • Discounted cash flows • Operating performance and market/exit multiples of comparable businesses • Other unique facts and circumstances related to each individual investment For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. Level 2 investments reflect the price of recent investments, which is deemed representative of fair value. Level 2 and 3 Other direct and indirect equity investments (NAV) Certain direct investments do not have readily determinable fair values and qualify for the practical expedient in the accounting guidance that allows us to estimate fair value based upon net asset value per share. NAV Asset/liability class Valuation technique Valuation hierarchy classification(s) Loans held for sale and held for investment (residential) Residential mortgage loans held for sale are accounted for at fair value. Fair values are based on: • Quoted market prices, where available • Prices for other traded mortgage loans with similar characteristics • Purchase commitments and bid information received from market participants Prices are adjusted as necessary to include: • The embedded servicing value in the loans • The specific characteristics of certain loans that are priced based on the pricing of similar loans. (These adjustments represent unobservable inputs to the valuation but are not considered significant given the relative insensitivity of the value to changes in these inputs to the fair value of the loans.) Residential loans held for investment: Certain residential loans held for sale contain salability exceptions that make them unable to be sold into the performing loan sales market. Loans in this category are transferred to the held to maturity loan portfolio and are included in “Loans, net of unearned income” on the balance sheet. This type of loan is classified as level 3 in the valuation hierarchy as transaction details regarding sales of this type of loan are often unavailable. Fair value is based upon: • Unobservable bid information from brokers and investors Higher (lower) unobservable bid information would have resulted in higher (lower) fair value measurements. Level 1, 2 and 3 (primarily level 2) Derivatives Exchange-traded derivatives are valued using quoted prices in active markets and, therefore, are classified as Level 1 instruments. The majority of our derivative positions are Level 2 and are valued using internally developed models based on market convention and observable market inputs. These derivative contracts include interest rate swaps, certain options, floors, cross currency swaps, credit default swaps, and forward mortgage loan sale commitments. Significant inputs used in the valuation models include: • LIBOR, SOFR and OIS curves, index pricing curves, foreign currency curves • Volatility surfaces (a three-dimensional graph of implied volatility against strike price and maturity) We have customized derivative instruments and risk participations that are classified as Level 3 instruments. These derivative positions are valued using internally developed models, with inputs consisting of available market data, including: • Credit spreads and interest rates The unobservable internally derived assumptions include: • Loss given default • Internal risk assessments of customers The fair value represents an estimate of the amount that the risk participation counterparty would need to pay/receive as of the measurement date based on the probability of customer default on the swap transaction and the fair value of the underlying customer swap. Therefore, for sold risk participation agreements, a higher loss probability and a lower credit rating would negatively affect the fair value of the risk participations and a lower loss probability and higher credit rating would positively affect the fair value of the risk participations. (For purchased risk participation agreements, higher loss probabilities and lower credit ratings would positively affect the fair value.) Level 1, 2, and 3 (primarily level 2) Asset/liability class Valuation technique Valuation hierarchy classification(s) Derivatives (continued) We use interest rate lock commitments for our residential mortgage business, which are classified as Level 3 instruments. The significant components of the valuation model include: • Interest rates observable in the market • Investor supplied prices for similar securities • The probability of the loan closing (i.e. the "pull-through" amount, a significant unobservable input). Increases (decreases) in the probability of the loan closing would have resulted in higher (lower) fair value measurements. Valuation of residential mortgage forward sale commitments utilizes observable market prices of comparable commitments and mortgage securities (Level 2). The fair values of our derivatives include a credit valuation adjustment related to both counterparty and our own creditworthiness. The credit component considers master netting and collateral agreements and is determined by the individual counterparty based on potential future exposures, expected recovery rates, and market-implied probabilities of default. Level 1, 2, and 3 (primarily level 2) Liability for short positions This includes fixed income securities held by our broker dealer in its trading inventory. Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities Fair value of level 2 securities is determined by: • Observable market prices of similar securities • Market activity, spreads, credit ratings and interest rates for each security type Level 1 and 2 Asset/liability class Valuation technique Valuation hierarchy classification(s) Collateral-dependent loans When a loan is collateral-dependent, the fair value of the loan is determined based on the fair value of the underlying collateral. Level 3 Commercial loans and student loans held for sale Through a quarterly analysis of our loan portfolios held for sale, which include both performing and nonperforming commercial loans and student loans, we determine any adjustments necessary to record the portfolios at the lower of cost or fair value in accordance with GAAP. Valuation inputs include: • Non-binding bids for the respective loans or similar loans • Recent sales transactions • Internal models that emulate recent securitizations Level 2 and 3 Direct financing leases and operating lease assets held for sale Valuations of direct financing leases and operating lease assets held for sale are performed using an internal model that relies on market data, including: • Swap rates and bond ratings • Our own assumptions about the exit market for the leases • Details about the individual leases in the portfolio Leases for which we receive a current nonbinding bid, and for which the sale is considered probable, may be classified as Level 2. Valuations of lease and operating lease assets held for sale that employ our own assumptions are classified as Level 3 assets. The inputs based on our own assumptions include changes in the value of leased items and internal credit ratings. Level 2 and 3 OREO, other repossessed personal properties, and right-of-use assets (a) OREO, other repossessed properties, and right-of-use assets are valued based on: • Appraisals and third-party price opinions, less estimated selling costs Generally, we classify these assets as Level 3, but OREO and other repossessed properties for which we receive binding purchase agreements are classified as Level 2. Returned lease inventory is valued based on market data for similar assets and is classified as Level 2. Level 2 and 3 LIHTC, HTC, and NMTC investments (a) Valuation of LIHTC, HTC and NMTC involves measuring the present value of future tax benefits and comparing that value against the current carrying value of the investment. Expected future tax benefits are discounted to their present value using discounted cash flow modeling that incorporates an appropriate risk premium. LIHTC and HTC investments are impaired when it is more likely than not that the carrying amount of the investment will not be realized. Level 3 Other equity investments We have other investments in equity securities that do not have readily determinable fair values and do not qualify for the practical expedient to measure the investment using a net asset value per share. We have elected to measure these securities at cost less impairment plus or minus adjustments due to observable orderly transactions. Impairment is recorded when there is evidence that the expected fair value of the investment has declined to below the recorded cost. At each reporting period, we assess if these investments continue to qualify for this measurement alternative. At December 31, 2020, and December 31, 2019, the carrying amount of equity investments recorded under this method was $171 million and $134 million, respectively. No impairment was recorded for the year ended December 31, 2020. Level 3 Mortgage Servicing Rights (a) Refer to Note 9. Mortgage Servicing Assets Level 3 (a) Asset classes included in “Accrued income and other assets” on the Consolidated Balance Sheets The range and weighted-average of the significant unobservable inputs used to fair value our material Level 3 recurring and nonrecurring assets at December 31, 2020, and December 31, 2019, along with the valuation techniques used, are shown in the following table: Level 3 Asset (Liability) Valuation Technique Significant Range (Weighted-Average) (b), (c) dollars in millions December 31, 2020 December 31, 2019 December 31, 2020 December 31, 2019 Recurring Securities available-for-sale: Other securities $ 13 $ 11 Discounted cash flows Discount rate N/A (15.09%) N/A (16.10%) Marketability discount N/A (30.00%) N/A (30.00%) Volatility factor N/A (44.00%) N/A (43.00%) Other investments: (a) Equity investments Direct 13 12 Discounted cash flows Discount rate 13.90 - 17.04% (15.47%) 13.91 - 17.24% (15.61%) Marketability discount N/A (30.00%) N/A (30.00%) Volatility factor N/A (52.00%) N/A (47.00%) Loans, net of unearned income (residential) 11 4 Market comparable pricing Comparability factor 64.50%-99.04% (94.17%) 79.00 - 98.00% (91.05%) Derivative instruments: Interest rate 56 22 Discounted cash flows Probability of default .02 - 100% (7.90%) .02 - 100% (5.40%) Internal risk rating 1 - 19 (9.675) 1 - 19 (9.168) Loss given default 0 - 1 (.483) 0 - 1 (.492) Credit (assets) 1 1 Discounted cash flows Probability of default .02 - 100% (4.70%) .02 - 100% (4.2%) Internal risk rating 1 - 19 (10.478) 1 - 19 (10.13) Loss given default 0 - 1 (.490) 0 - 1 (.498) Credit (liabilities) (11) (9) Discounted cash flows Probability of default .02 - 100% (15.45%) .02 - 100% (12.24%) Internal risk rating 1 - 19 (8.555) 1 - 19 (8.058) Loss given default 0 - 1 (.431) 0 - 1 (.411) Other (d) 32 5 Discounted cash flows Loan closing rates 36.95 - 99.68% (77.51%) 37.71 - 99.69% (79.33%) Nonrecurring Impaired loans 108 76 Fair value of underlying collateral Discount rate 0 - 100.00% (36.00%) 0 - 60.00% (10.00%) Accrued income and other assets: (e) OREO 16 5 Appraised value Appraised value N/M N/M (a) Principal investments, direct is excluded from this table as the balance at December 31, 2020, is insignificant (less than $1 million). (a) The weighted average of significant unobservable inputs is calculated using a weighting relative to fair value. (b) For significant unobservable inputs with no range, a single figure is reported to denote the single quantitative factor used. (c) Amounts represent interest rate lock commitments. (d) Excludes $40 million and $46 million pertaining to mortgage servicing assets measured at fair value as of December 31, 2020, and December 31, 2019, respectively. Refer to Note 9 (“Mortgage Servicing Assets”) for significant unobservable inputs pertaining to these assets.
Fair Values of Funds and Unfunded Commitments	The following table presents the fair value of our direct and indirect principal investments and related unfunded commitments at December 31, 2020, as well as financial support provided for the years ended December 31, 2020, and December 31, 2019. Financial support provided Year ended December 31, December 31, 2020 2020 2019 in millions Fair Value Unfunded Commitments Funded Commitments Funded Other Funded Commitments Funded Other INVESTMENT TYPE Direct investments $ 1 — — — — $ — Indirect investments (a) 53 $ 16 $ 2 — $ 2 — Total $ 54 $ 16 $ 2 — $ 2 $ — (a) Our indirect investments consist of buyout funds, venture capital funds, and fund of funds. These investments are generally not redeemable. Instead, distributions are received through the liquidation of the underlying investments of the fund. An investment in any one of these funds typically can be sold only with the approval of the fund’s general partners. At December 31, 2020, no significant liquidation of the underlying investments has been communicated to Key. The purpose of funding our capital commitments to these investments is to allow the funds to make additional follow-on investments and pay fund expenses until the fund dissolves. We, and all other investors in the fund, are obligated to fund the full amount of our respective capital commitments to the fund based on our and their respective ownership percentages, as noted in the applicable Limited Partnership Agreement.
Change in Fair Values of Level 3 Financial Instruments	The following table shows the change in the fair values of our Level 3 financial instruments measured at fair value on a recurring basis for the years ended December 31, 2020, and December 31, 2019. in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 Transfers out of Level 3 End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2020 Securities available for sale Other securities $ 11 $ 2 — — — — — — — $ 13 — Other investments Principal investments Direct 1 — — — — — — — — 1 — Equity investments Direct 12 — $ 1 (c) — — — — — — 13 $ 1 Loans held for sale (residential) — — — — $ (10) — $ 10 — — — — Loans held for investment (residential) 4 — — — (2) — 9 — — 11 — Derivative instruments (b) Interest rate 22 — 19 (d) $ 17 (10) — — $ 99 (e) $ (91) (e) 56 — Credit (8) — (2) (d) 1 (1) — — — — (10) — Other (a) 5 — 7 — — — 20 — — 32 — in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 Transfers out of Level 3 End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2019 Securities available for sale Other securities $ 20 15 — — — — — — $ (24) $ 11 — Other investments Principal investments Direct 1 — — — — — — — — 1 — Equity investments Direct 7 — $ 4 (c) — — — — $ 1 — 12 $ 4 Loans held for sale (residential) — — — — $ (1) — $ 1 — — — — Loans held for investment (residential) 3 — — — — — 1 — — 4 — Derivative instruments (b) Interest rate 5 — 3 (d) $ 2 (1) — — 21 (e) (8) (e) 22 — Credit — — (8) (d) — — $ — — — — (8) — Other (a) 3 — — — — — $ 2 — — 5 — (a) Amounts represent Level 3 interest rate lock commitments. (b) Amounts represent Level 3 derivative assets less Level 3 derivative liabilities. (c) Realized and unrealized gains and losses on principal investments are reported in “other income” on the income statement. Realized and unrealized losses on equity investments are reported in “other income” on the income statement. (d) Realized and unrealized gains and losses on derivative instruments are reported in “corporate services income” and “other income” on the income statement. (e) Certain derivatives previously classified as Level 2 were transferred to Level 3 because Level 3 unobservable inputs became significant. Certain derivatives previously classified as Level 3 were transferred to Level 2 because Level 3 unobservable inputs became less significant.
Assets and Liabilities Measured at Fair Value on Nonrecurring Basis	The following table presents our assets measured at fair value on a nonrecurring basis at December 31, 2020, and December 31, 2019: December 31, 2020 December 31, 2019 in millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS MEASURED ON A NONRECURRING BASIS Impaired loans and leases — — $ 108 $ 108 — — $ 76 $ 76 Accrued income and other assets — $ — 56 56 — 118 51 169 Total assets on a nonrecurring basis at fair value — $ — $ 164 $ 164 — 118 $ 127 $ 245
Fair Value Disclosures of Financial Instruments	The levels in the fair value hierarchy ascribed to our financial instruments and the related carrying amounts at December 31, 2020, and December 31, 2019, are shown in the following table. December 31, 2020 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 735 — $ 735 — — — $ 735 Other investments (b) 621 — — $ 555 $ 66 — 621 Loans, net of unearned income (residential) (d) 11 — — 11 — — 11 Loans held for sale (residential) (b) 264 — 264 — — — 264 Derivative assets - trading (b) 1,676 $ 78 1,939 91 — $ (433) (f) 1,675 Fair value - OCI Securities available for sale (b) 27,556 — 27,543 13 — — 27,556 Derivative assets - hedging (b) (g) 123 — 70 — — 53 (f) 123 Amortized cost Held-to-maturity securities (c) 7,595 — 8,023 — — — 8,023 Loans, net of unearned income (d) 99,548 — — 98,946 — — 98,946 Loans held for sale (b) 1,319 — — 1,319 — — 1,319 Other Cash and short-term investments (a) 17,285 17,285 — — — — 17,285 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) 154 72 746 11 — (675) (f) 154 Fair value - OCI Derivative liabilities - hedging (b) (g) (3) — (3) — — — (f) (3) Amortized cost Time deposits (e) 5,743 — 5,765 — — — 5,765 Short-term borrowings (a) 979 256 723 — — — 979 Long-term debt (e) 13,709 13,925 734 — — — 14,659 Other Deposits with no stated maturity (a) 129,539 — 129,539 — — — 129,539 December 31, 2019 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 1,040 — $ 1,040 — — — $ 1,040 Other investments (b) 605 — — $ 528 $ 77 — 605 Loans, net of unearned income (residential) (d) 4 — — 4 — — 4 Loans held for sale (residential) (b) 140 — 140 — — — 140 Derivative assets - trading (b) 715 $ 49 985 28 — $ (347) (f) 715 Fair value - OCI Securities available for sale (b) 21,843 — 21,832 11 — — 21,843 Derivative assets - hedging (b) (g) 65 — 191 — — (126) (f) 65 Amortized cost Held-to-maturity securities (c) 10,067 — 10,116 — — — 10,116 Loans, net of unearned income (d) 93,742 — — 92,641 — — 92,641 Loans held for sale (b) 1,194 — — 1,194 — — 1,194 Other Cash and short-term investments (a) 2,004 2,004 — — — — 2,004 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) 194 43 461 9 — (319) (f) 194 Fair value - OCI Derivative liabilities - hedging (b) (g) 4 — 20 — — (16) (f) 4 Amortized cost Time deposits (e) 11,652 — 11,752 — — — 11,752 Short-term borrowings (a) 1,092 19 1,073 — — — 1,092 Long-term debt (e) 12,448 12,694 $ 249 — — — 12,943 Other Deposits with no stated maturity (a) 100,218 — 100,218 — — — 100,218 Valuation Methods and Assumptions (a) Fair value equals or approximates carrying amount. The fair value of deposits with no stated maturity does not take into consideration the value ascribed to core deposit intangibles. (b) Information pertaining to our methodology for measuring the fair values of these assets and liabilities is included in the sections entitled “Qualitative Disclosures of Valuation Techniques” and “Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis” in this Note. Investments accounted for under the cost method (or cost less impairment adjusted for observable price changes for certain equity investments) are classified as Level 3 assets. These investments are not actively traded in an open market as sales for these types of investments are rare. The carrying amount of the investments carried at cost are adjusted for declines in value if they are considered to be other-than-temporary (or due to observable orderly transactions of the same issuer for equity investments eligible for the cost less impairment measurement alternative). These adjustments are included in “other income” on the income statement. (c) Fair values of held-to-maturity securities are determined by using models that are based on security-specific details, as well as relevant industry and economic factors. The most significant of these inputs are quoted market prices, interest rate spreads on relevant benchmark securities, and certain prepayment assumptions. We review the valuations derived from the models to ensure that they are reasonable and consistent with the values placed on similar securities traded in the secondary markets. (d) The fair value of loans is based on the present value of the expected cash flows. The projected cash flows are based on the contractual terms of the loans, adjusted for prepayments and use of a discount rate based on the relative risk of the cash flows, taking into account the loan type, maturity of the loan, liquidity risk, servicing costs, and a required return on debt and capital. In addition, an incremental liquidity discount is applied to certain loans, using historical sales of loans during periods of similar economic conditions as a benchmark. The fair value of loans includes lease financing receivables at their aggregate carrying amount, which is equivalent to their fair value. (e) Fair values of time deposits and long-term debt are based on discounted cash flows utilizing relevant market inputs. (f) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The net basis takes into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Total derivative assets and liabilities include these netting adjustments. (g) Derivative assets-hedging and derivative liabilities-hedging includes both cash flow and fair value hedges. Additional information regarding our accounting policies for cash flow and fair value hedges is provided in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Derivatives and Hedging.”

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Details of Securities	The amortized cost, unrealized gains and losses, and approximate fair value of our securities available for sale and held-to-maturity securities are presented in the following tables. Gross unrealized gains and losses represent the difference between the amortized cost and the fair value of securities on the balance sheet as of the dates indicated. Accordingly, the amount of these gains and losses may change in the future as market conditions change. 2020 2019 December 31, in millions Amortized Cost (a) Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE U.S. Treasury, Agencies, and Corporations $ 1,000 — — $ 1,000 $ 334 — $ — $ 334 States and political subdivisions — — — — 4 — — 4 Agency residential collateralized mortgage obligations 14,001 $ 297 $ 25 14,273 12,772 $ 82 71 12,783 Agency residential mortgage-backed securities 2,094 70 — 2,164 1,677 41 4 1,714 Agency commercial mortgage-backed securities 9,707 432 33 10,106 6,898 139 40 6,997 Other securities 8 5 — 13 7 4 — 11 Total securities available for sale $ 26,810 $ 804 $ 58 $ 27,556 $ 21,692 $ 266 $ 115 $ 21,843 HELD-TO-MATURITY SECURITIES Agency residential collateralized mortgage obligations $ 3,775 $ 124 $ — $ 3,899 $ 5,692 $ 23 $ 49 $ 5,666 Agency residential mortgage-backed securities 271 14 — 285 409 6 — 415 Agency commercial mortgage-backed securities 3,515 290 — 3,805 3,940 78 9 4,009 Asset-backed securities 19 — — 19 11 — — 11 Other securities 15 — — 15 15 — — 15 Total held-to-maturity securities $ 7,595 $ 428 $ — $ 8,023 $ 10,067 $ 107 $ 58 $ 10,116
Schedule of Unrealized Loss on Investments	The following table summarizes available for sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of December 31, 2020, and December 31, 2019: Duration of Unrealized Loss Position Less than 12 Months 12 Months or Longer Total in millions Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses December 31, 2020 Securities available for sale: Agency residential collateralized mortgage obligations $ 2,110 $ 25 $ — $ — $ 2,110 $ 25 Agency residential mortgage-backed securities 6 — (a) $ 5 — (a) 11 — Agency commercial mortgage-backed securities 2,709 33 — — 2,709 33 Held-to-maturity securities: Agency residential collateralized mortgage obligations — — 24 — (a) 24 — Other securities 5 — (a) — — 5 — Total securities in an unrealized loss position $ 4,830 $ 58 $ 29 $ — $ 4,859 $ 58 December 31, 2019 Securities available for sale: U.S. Treasury, agencies, and corporations $ 30 — (b) $ 30 — (b) $ 60 — Agency residential collateralized mortgage obligations 3,432 $ 20 3,221 $ 51 6,653 $ 71 Agency residential mortgage-backed securities 33 — (b) 629 4 662 4 Agency commercial mortgage-backed securities 1,541 17 1,213 23 2,754 40 Held-to-maturity securities: Agency residential collateralized mortgage obligations 1,626 14 2,289 35 3,915 49 Agency residential mortgage-backed securities 56 — (b) — — 56 — Agency commercial mortgage-backed securities 518 9 — — 518 9 Asset-backed securities 11 — (b) — — 11 — Other securities 3 — (b) — — 3 — Total securities in an unrealized loss position $ 7,250 $ 60 $ 7,382 $ 113 $ 14,632 $ 173 (a) At December 31, 2020, gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for other securities held-to-maturity with a loss duration of less than 12 months. At December 31, 2020, gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration greater than 12 months or longer and less than $1 million. for agency residential mortgage-backed securities held to maturity. (b) At December 31, 2019, gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations and agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for agency residential mortgage-backed securities, asset-backed securities, and other securities held-to-maturity with a loss duration of less than 12 months. At December 31, 2019, gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations securities available for sale with a loss duration greater than 12 months or longer.
Securities by Maturity	The following table shows securities by remaining maturity. CMOs and other mortgage-backed securities in the available-for-sale and held-to-maturity portfolios are presented based on their expected average lives. The remaining securities, in both the available-for-sale and held-to-maturity portfolios, are presented based on their remaining contractual maturity. Actual maturities may differ from expected or contractual maturities since borrowers have the right to prepay obligations with or without prepayment penalties. Securities Held-to-Maturity December 31, 2020 Amortized Cost Fair Value Amortized Cost Fair Value in millions Due in one year or less $ 1,889 $ 1,896 $ 77 $ 78 Due after one through five years 15,410 15,891 4,941 5,150 Due after five through ten years 6,686 6,964 2,577 2,795 Due after ten years 2,825 2,805 — — Total $ 26,810 $ 27,556 $ 7,595 $ 8,023

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments	The following table summarizes the fair values of our derivative instruments on a gross and net basis as of December 31, 2020, and December 31, 2019. The change in the notional amounts of these derivatives by type from December 31, 2019, to December 31, 2020, indicates the volume of our derivative transaction activity during 2020. The notional amounts are not affected by bilateral collateral and master netting agreements. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Where master netting agreements are not in effect or are not enforceable under bankruptcy laws, we do not adjust those derivative assets and liabilities with counterparties. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. Our derivative instruments are included in “accrued income and other assets” or “accrued expenses and other liabilities” on the balance sheet, as indicated in the following table: December 31, 2020 December 31, 2019 Fair Value (a) Fair Value in millions Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate $ 36,135 $ 70 $ (3) $ 39,208 $ 191 $ 20 Total 36,135 70 (3) 39,208 191 20 Derivatives not designated as hedging instruments: Interest rate 78,424 1,514 291 71,209 772 233 Foreign exchange 6,385 109 103 6,572 67 60 Commodity 9,702 426 408 5,324 208 200 Credit 423 1 11 427 1 10 Other (b) 4,951 58 16 3,337 14 10 Total 99,885 2,108 829 86,869 1,062 513 Netting adjustments (c) — (380) (675) — (473) (335) Net derivatives in the balance sheet 136,020 1,798 151 126,077 780 198 Other collateral (d) — (2) (11) — (2) (42) Net derivative amounts $ 136,020 $ 1,796 $ 140 $ 126,077 $ 778 $ 156 (a) We take into account bilateral collateral and master netting agreement that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets and contracts with positive fair values included in derivative liabilities. (b) Other derivatives include interest rate lock commitments and forward sale commitments related to our residential mortgage banking activities, forward purchase and sales contracts consisting of contractual commitments associated with “to be announced” securities and when issued securities. (c) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. (d) Other collateral represents the amount that cannot be used to offset our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The other collateral consists of securities and is exchanged under bilateral collateral and master netting agreements that allow us to offset the net derivative position with the related collateral. The application of the other collateral cannot reduce the net derivative position below zero. Therefore, excess other collateral, if any, is not reflected above.
Pre-Tax Net Gains (Losses) on Fair Value Hedges	The following tables summarize the amounts that were recorded on the balance sheet as of December 31, 2020 and December 31, 2019, related to cumulative basis adjustments for fair value hedges. December 31, 2020 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment Interest rate contracts Long-term debt (b) $ 8,182 $ 416 Interest rate contracts Securities available for sale (c) 2,080 (21) December 31, 2019 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment Interest rate contracts Long-term debt (b) $ 8,408 $ 240 (a) The carrying amount represents the portion of the asset or liability designated as the hedged item. (b) Basis adjustments related to de-designated hedges that no longer qualify as fair value hedges reduced the hedge accounting basis adjustment by $8 million and $9 million at December 31, 2020 and December 31, 2019, respectively. (c) These amounts are designated as fair value hedges under the last-of-layer method. The carrying amount represents the amortized costs basis of the prepayable financial assets used to designate hedging relationships in which the hedged item is the last layer expected to be remaining at the end of the hedging relationship. At December 31, 2020, the amortized cost of the closed portfolios used in these hedging relationships was $2.5 billion
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location	The following tables summarize the effect of fair value and cash flow hedge accounting on the income statement for the years ended December 31, 2020, December 31, 2019, and December 31, 2018. Location and amount of net gains (losses) recognized in income on fair value and cash flow hedging relationships (a) in millions Interest expense – long-term debt Interest income – loans Investment banking and debt placement fees Interest expense – deposits Other income Twelve months ended December 31, 2020 Total amounts presented in the consolidated statement of income $ (286) $ 3,866 $ 661 $ (347) $ 15 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (177) — — — — Recognized on derivatives designated as hedging instruments 305 — — — — Net income (expense) recognized on fair value hedges 128 — — — — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (4) 319 — — — Net income (expense) recognized on cash flow hedges $ (4) $ 319 $ — — — Twelve months ended December 31, 2019 Total amounts presented in the consolidated statement of income $ (454) $ 4,267 $ 630 $ (853) $ 68 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (247) — — (1) — Recognized on derivatives designated as hedging instruments 231 — — — — Net income (expense) recognized on fair value hedges (16) — — $ (1) $ — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (1) 15 — — — Foreign exchange contracts — — — — 32 Net income (expense) recognized on cash flow hedges $ (1) $ 15 $ — — $ 32 Twelve months ended December 31, 2018 Total amounts presented in the consolidated statement of income $ (420) $ 4,023 $ 650 $ (517) $ 176 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (5) — — 1 — Recognized on derivatives designated as hedging instruments (12) — — — — Net income (expense) recognized on fair value hedges (17) — — 1 $ — Net gain (loss) on cash flow hedging relationships Realized gains (losses) (pre-tax) reclassified from AOCI into net income Interest contracts (2) (68) 2 — 31 Net income (expense) recognized on cash flow hedges $ (2) $ (68) $ 2 — 31
Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location	The following table summarizes the pre-tax net gains (losses) on our cash flow and net investment hedges for the years ended December 31, 2020, December 31, 2019, and December 31, 2018, and where they are recorded on the income statement. The table includes net gains (losses) recognized in OCI during the period and net gains (losses) reclassified from AOCI into income during the current period. in millions Net Gains (Losses) Income Statement Location of Net Gains (Losses) Net Gains (Losses) Reclassified From OCI Into Income (a) Net Gains (Losses) Recognized in Other Income (a) Twelve months ended December 31, 2020 Cash Flow Hedges Interest rate $ 628 Interest income — Loans $ 319 $ — Interest rate (5) Interest expense — Long-term debt (4) — Interest rate (9) Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts — Other Income — — Total $ 614 $ 315 $ — Twelve months ended December 31, 2019 Cash Flow Hedges Interest rate $ 442 Interest income — Loans $ 15 $ — Interest rate (1) Interest expense — Long-term debt (1) — Interest rate 3 Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (4) Other Income 32 — Total $ 440 $ 46 $ — Twelve months ended December 31, 2018 Cash Flow Hedges Interest rate $ (13) Interest income — Loans $ (68) $ — Interest rate 2 Interest expense — Long-term debt (2) — Interest rate 1 Investment banking and debt placement fees 2 — Net Investment Hedges Foreign exchange contracts 19 Other Income 31 — Total $ 9 $ (37) $ —
Pre-Tax Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments	The following table summarizes the pre-tax net gains (losses) on our derivatives that are not designated as hedging instruments for the years ended December 31, 2020, December 31, 2019, and December 31, 2018, and where they are recorded on the income statement. 2020 2019 2018 Year ended December 31, in millions Corporate Consumer Mortgage Income Other Total Corporate Consumer Mortgage Income Other Total Corporate Consumer Mortgage Income Other Total NET GAINS (LOSSES) Interest rate $ 32 — $ (10) $ 22 $ 46 — $ (2) $ 44 $ 38 — $ (1) $ 37 Foreign exchange 41 — — 41 45 — — 45 42 — — 42 Commodity 19 — — 19 6 — — 6 8 — — 8 Credit (4) — (29) (33) (6) — (36) (42) 2 — (30) (28) Other — $ 19 19 38 — $ 2 — 2 — $ (1) 12 11 Total net gains (losses) $ 88 $ 19 $ (20) $ 87 $ 91 $ 2 $ (38) $ 55 $ 90 $ (1) $ (19) $ 70
Fair Value of Derivative Assets by Type	The following table summarizes the fair value of our derivative assets by type at the dates indicated. These assets represent our gross exposure to potential loss after taking into account the effects of bilateral collateral and master netting agreements and other means used to mitigate risk. December 31, in millions 2020 2019 Interest rate $ 1,448 $ 848 Foreign exchange 52 30 Commodity 178 95 Credit (1) — Other 58 14 Derivative assets before collateral 1,735 987 Add (Less): Related collateral 63 (207) Total derivative assets $ 1,798 $ 780
Credit Derivatives Sold and Held	The following table provides information on the types of credit derivatives sold by us and held on the balance sheet at December 31, 2020, and December 31, 2019. The notional amount represents the amount that the seller could be required to pay. The payment/performance risk shown in the table represents a weighted average of the default probabilities for all reference entities in the respective portfolios. These default probabilities are implied from observed credit indices in the credit default swap market, which are mapped to reference entities based on Key’s internal risk rating. 2020 2019 December 31, dollars in millions Notional Average Payment / Notional Average Payment / Other $ 227 12.76 19.53 % $ 134 14.30 14.56 % Total credit derivatives sold $ 227 — — $ 134 — —
Credit Risk Contingent Feature	The following table summarizes the additional cash and securities collateral that KeyBank would have been required to deliver under the ISDA Master Agreements had the credit risk contingent features been triggered for the derivative contracts in a net liability position as of December 31, 2020, and December 31, 2019. The additional collateral amounts were calculated based on scenarios under which KeyBank’s ratings are downgraded one, two, or three ratings as of December 31, 2020, and December 31, 2019, and take into account all collateral already posted. A similar calculation was performed for KeyCorp, and no additional collateral would have been required at December 31, 2020, or December 31, 2019. December 31, in millions 2020 2019 Moody’s S&P Moody’s S&P KeyBank’s long-term senior unsecured credit ratings A3 A- A3 A- One rating downgrade $ 1 $ 1 $ 1 $ 1 Two rating downgrades 1 1 1 1 Three rating downgrades 1 1 1 1

Mortgage Servicing Assets (Tabl

Mortgage Servicing Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Servicing Asset [Abstract]
Changes in Carrying Amount of Mortgage Servicing Assets	Changes in the carrying amount of commercial mortgage servicing assets are summarized as follows: Year ended December 31, in millions 2020 2019 Balance at beginning of period $ 539 $ 502 Servicing retained from loan sales 138 108 Purchases 33 47 Amortization (117) (115) Temporary impairments (15) (3) Balance at end of period $ 578 $ 539 Fair value at end of period $ 668 $ 665 Changes in the carrying amount of residential mortgage servicing assets are summarized as follows: in millions 2020 2019 Balance at beginning of period $ 46 37 Servicing retained from loan sales 36 $ 15 Purchases — — Amortization (14) (6) Temporary impairments $ (10) $ — Balance at end of period $ 58 $ 46 Fair value at end of period $ 60 $ 50
Schedule of Range and Weighted-Average of Significant Unobservable Inputs	The range and weighted-average of the significant unobservable inputs used to fair value our commercial mortgage servicing assets at December 31, 2020, and December 31, 2019, along with the valuation techniques, are shown in the following table: dollars in millions December 31, 2020 December 31, 2019 Valuation Technique Significant Unobservable Input Range Weighted-Average Range Weighted-Average Discounted cash flow Expected defaults 1.01 2.00 % 1.18 % 1.00 2.00 % 1.13 % Residual cash flows discount rate 7.48 10.62 % 9.22 % 7.00 11.44 % 9.32 % Escrow earn rate 0.92 1.14 % 1.04 % 1.44 2.32 % 2.03 % Loan assumption rate 0.00 1.77 % 1.43 % 0.01 3.37 % 1.37 % December 31, 2020 December 31, 2019 Valuation Technique Significant Unobservable Input Range Weighted-Average Range Weighted-Average Discounted cash flow Prepayment speed 12.39 54.27 % 17.09 % 10.38 61.51 % 12.95 % Discount rate 7.51 8.63 % 7.55 % 7.5 8.50 % 7.52 % Servicing cost $62.00 $5,125 $75.37 $62 $4,375 $68.73

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Components of Lease Expense	The components of lease expense are summarized as follows: in millions December 31, 2020 December 31, 2019 Operating lease cost $ 135 $ 136 Finance lease cost: Amortization of right-of-use assets 2 2 Interest on lease liabilities 1 1 Variable lease cost 20 24 Total lease cost (a) $ 158 $ 163 (a) Short-term lease cost was less than $1 million for both the twelve months ended December 31, 2020.and the twelve months ended December 31, 2019 December 31, 2020 December 31, 2019 Weighted-average remaining lease term: Operating leases 7.09 7.50 Finance leases 5.03 6.06 Weighted-average discount rate: Operating leases 3.01 % 3.26 % Finance leases 3.94 % 3.94 %
Summary of Cash Flows Related to Leases	Cash flows related to leases are summarized as follows: in millions December 31, 2020 December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 1 $ 1 Operating cash flows from operating leases 143 146 Financing cash flows from finance leases 2 2 Right-of-use assets obtained in exchange for lease obligations: (a) Operating leases $ 86 $ 81 Net gain recognized from sale leaseback transaction (b) $ — $ 14 Finance leases — (a) There were no right-of-use assets obtained in exchange for finance lease obligations for either the twelve months ended December 31, 2020 or the Twelve months ended December 31, 2019.
Summary of Additional Balance Sheet Information Related to Leases	Additional balance sheet information related to leases is summarized as follows: in millions Balance sheet classification December 31, 2020 December 31, 2019 Operating lease assets Accrued income and other assets $ 630 $ 654 Operating lease liabilities Accrued expense and other liabilities 711 748 Finance leases: Property and equipment, gross Premises and equipment 28 28 Accumulated depreciation Premises and equipment (19) (17) Property and equipment, net 9 11 Finance lease liabilities Long-term debt 11 13
Finance Lease, Maturities of Lease Liabilities	Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722
Lessee, Operating Lease, Maturities of Lease Liabilities	Maturities of lease liabilities are summarized as follows: in millions Operating Leases Finance Leases Total 2021 $ 140 $ 3 $ 143 2022 131 3 134 2023 116 2 118 2024 97 1 98 2025 79 1 80 Thereafter 233 3 236 Total lease payments 796 13 809 Less imputed interest 85 2 87 Total $ 711 $ 11 $ 722
Operating Lease, Lease Income	The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295
Sales-type Lease, Lease Income	The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295
Direct Financing Lease, Lease Income	The components of equipment leasing income are summarized in the table below: in millions December 31, 2020 December 31, 2019 Sales-type and direct financing leases Interest income on lease receivable $ 119 $ 121 Interest income related to accretion of unguaranteed residual asset (3) 13 Interest income on deferred fees and costs — — Total sales-type and direct financing lease income 116 134 Operating leases Operating lease income related to lease payments 136 133 Other operating leasing gains 31 28 Total operating lease income and other leasing gains 167 161 Total lease income $ 283 $ 295
Composition of Net Investment in Sales-Type and Direct Financing Leases	The composition of the net investment in sales-type and direct financing leases is as follows: in millions December 31, 2020 December 31, 2019 Lease receivables $ 3,570 $ 3,792 Unearned income (257) (329) Unguaranteed residual value 478 490 Deferred fees and costs 8 16 Net investment in sales-type and direct financing leases $ 3,799 $ 3,969
Minimum Future Lease Payments to be Received for Sales-Type and Direct Financing Leases	At December 31, 2020, minimum future lease payments to be received for sales-type and direct financing leases are as follows: in millions Sales-type and direct financing lease payments 2021 $ 1,085 2022 838 2023 573 2024 371 2025 226 Thereafter 477 Total lease payments $ 3,570
Minimum Future Lease Payments to be Received for Operating Leases	At December 31, 2020 , minimum future lease payments to be received for operating leases are as follows: in millions Operating lease payments 2021 $ 122 2022 106 2023 88 2024 76 2025 63 Thereafter 126 Total lease payments $ 581

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Premises and Equipment	Premises and equipment at December 31, 2020, and December 31, 2019, consisted of the following: December 31, dollars in millions Useful life (in years) 2020 2019 Land Indefinite $ 126 $ 128 Buildings and improvements 15-40 722 729 Leasehold improvements 1-15 631 620 Furniture and equipment 2-15 843 872 Capitalized building leases 1-14 (a) 28 28 Construction in process N/A 44 48 Total premises and equipment 2,394 2,425 Less: Accumulated depreciation and amortization (1,641) (1,611) Premises and equipment, net $ 753 $ 814 (a) Capitalized building and equipment leases are amortized over the lesser of the useful life of asset or lease term.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill by reporting segment are presented in the following table: in millions Consumer Bank Commercial Bank Total BALANCE AT DECEMBER 31, 2018 $ 2,102 $ 414 $ 2,516 Reallocation of goodwill (498) 498 — Laurel Road acquisition 148 — 148 BALANCE AT DECEMBER 31, 2019 1,752 912 2,664 BALANCE AT DECEMBER 31, 2020 $ 1,752 $ 912 $ 2,664
Gross Carrying Amount and Accumulated Amortization of Intangible Assets	The following table shows the gross carrying amount and the accumulated amortization of intangible assets subject to amortization: 2020 2019 December 31, in millions Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible assets subject to amortization: Core deposit intangibles $ 355 $ 236 $ 355 $ 193 PCCR intangibles 16 12 152 145 Other intangible assets 105 40 115 31 Total $ 476 $ 288 $ 622 $ 369
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table presents estimated intangible asset amortization expense for the next five years. Estimated in millions 2021 2022 2023 2024 2025 Intangible asset amortization expense $ 62 $ 57 $ 51 $ 28 $ 19

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities Information	The assets and liabilities presented in the table below convey the size of KCDC’s direct and indirect investments at December 31, 2020, and December 31, 2019. As these investments represent unconsolidated VIEs, the assets and liabilities of the investments themselves are not recorded on our balance sheet. Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2020 LIHTC investments $ 6,914 $ 2,765 $ 1,823 December 31, 2019 LIHTC investments $ 6,405 $ 2,526 $ 1,846 Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2020 Indirect investments $ 10,899 $ 168 $ 69 December 31, 2019 Indirect investments $ 12,954 $ 205 $ 89

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes Included in Income Statement	Income taxes included in the income statement are summarized below. We file a consolidated federal income tax return. Year ended December 31, in millions 2020 2019 2018 Currently payable: Federal $ 336 $ 241 $ 184 State 83 20 62 Total currently payable 419 261 246 Deferred: Federal (156) 34 117 State (36) 19 (19) Total deferred (192) 53 98 Total income tax (benefit) expense (a) $ 227 $ 314 $ 344 (a) There was income tax (benefit) expense on securities transactions of $1 million in 2020, a $5 million in 2019 and no income tax (benefit) expense on securities transactions 2018. Income tax expense excludes equity- and gross receipts-based taxes, which are assessed in lieu of an income tax in certain states in which we operate. These non-income taxes, which are recorded in “noninterest expense” on the income statement, totaled $30 million in 2020, $23 million in 2019, and $15 million in 2018.
Significant Components of Deferred Tax Assets and Liabilities Included in "Accrued Income and Other Assets" and "Accrued Expense and Other Liabilities"	Significant components of our deferred tax assets and liabilities included in “accrued expense and other liabilities” on the balance sheet, are as follows: December 31, in millions 2020 2019 Allowance for loan and lease losses $ 443 $ 236 Employee benefits 166 164 Federal net operating losses and credits 7 81 Fair value adjustments — 21 Non-tax accruals 76 61 Operating lease liabilities (a) 174 178 State net operating losses and credits 1 1 Other 297 245 Gross deferred tax assets 1,164 987 Less: Valuation Allowance — — Total deferred tax assets 1,164 987 Leasing transactions 556 628 Net unrealized securities gains 340 117 Operating lease right-of-use assets (a) 153 156 Other 215 175 Total deferred tax liabilities 1,264 1,076 Net deferred tax assets (liabilities) (b) $ (100) $ (89) (a) A separate deferred tax asset and liability is recognized for each operating lease item resulting from the adoption of ASC 842 in 2019. (b) From continuing operations.
Total Income Tax Expense (Benefit) and Resulting Effective Tax Rate	The following table shows how our total income tax expense (benefit) and the resulting effective tax rate were derived: Year ended December 31, dollars in millions 2020 2019 2018 Amount Rate Amount Rate Amount Rate Income (loss) before income taxes times 21% statutory federal tax rate $ 327 21.0 % $ 425 21.0 % $ 463 21.0 % Amortization of tax-advantaged investments 150 9.7 132 6.5 127 5.8 Foreign tax adjustments — — — — 2 .1 Tax-exempt interest income (28) (1.8) (30) (1.5) (30) (1.4) Corporate-owned life insurance income (29) (1.9) (29) (1.4) (29) (1.3) State income tax, net of federal tax benefit 37 2.4 31 1.5 34 1.5 Tax credits (218) (14.0) (231) (11.4) (234) (10.6) Tax Cuts and Jobs Act — — — — 7 .3 Other (12) (.8) 16 .9 4 .2 Total income tax expense (benefit) $ 227 14.6 % $ 314 15.6 % $ 344 15.6 %
Change in Liability for Unrecognized Tax Benefits	The change in our liability for unrecognized tax benefits is as follows: Year ended December 31, 2020 2019 Balance at beginning of year $ 19 $ 35 Increase for other tax positions of prior years 40 2 Decrease for payments and settlements — — Decrease related to tax positions taken in prior years (1) (18) Balance at end of year $ 58 $ 19

Securities Financing Activiti_2

Securities Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2020
Brokers and Dealers [Abstract]
Summarized Securities Financing Agreements	The following table summarizes our securities financing agreements at December 31, 2020, and December 31, 2019: December 31, 2020 December 31, 2019 in millions Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Offsetting of financial assets: Reverse repurchase agreements $ 6 $ (6) — — $ 5 $ (5) — — Securities borrowed 500 — $ (500) — — — — — Total $ 506 $ (6) $ (500) — $ 5 $ (5) — — Offsetting of financial liabilities: Repurchase agreements (c) $ 220 $ (6) $ (214) — $ 187 $ (7) $ (180) — Total $ 220 $ (6) $ (214) — $ 187 $ (7) $ (180) — (a) Netting adjustments take into account the impact of master netting agreements that allow us to settle with a single counterparty on a net basis. (b) These adjustments take into account the impact of bilateral collateral agreements that allow us to offset the net positions with the related collateral. The application of collateral cannot reduce the net position below zero. Therefore, excess collateral, if any, is not reflected above.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Assumptions Used in Options Pricing Model	The assumptions pertaining to options issued during 2020, 2019, and 2018 are shown in the following table. Year ended December 31, 2020 2019 2018 Average option life 6.5 years 6.5 years 6.5 years Future dividend yield 3.90 % 3.88 % 2.28 % Historical share price volatility .267 .266 .282 Weighted-average risk-free interest rate 1.3 % 2.5 % 2.8 %
Activity, Pricing and Other Information for Stock Options	The following table summarizes activity, pricing and other information for our stock options for the year ended December 31, 2020: Number of Options Weighted-Average Exercise Price Per Option Weighted-Average Remaining Life Aggregate Intrinsic Value (a) Outstanding at December 31, 2019 6,685,808 $ 13.32 5.2 years $ 47 Granted 549,170 19.03 Exercised (821,916) 10.37 Lapsed or canceled (40,378) 15.25 Outstanding at December 31, 2020 6,372,684 $ 14.18 4.6 21 Expected to vest 1,426,063 18.75 7.1 — Exercisable at December 31, 2020 4,867,838 $ 12.77 3.8 $ 21 (a) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of the option.
Activity and Pricing Information for Nonvested Shares in Long-Term Incentive Compensation Program	The following table summarizes activity and pricing information for the nonvested shares in the Program for the year ended December 31, 2020. Vesting Contingent on Service Conditions Vesting Contingent on Performance and Service Conditions - Payable in Stock Vesting Contingent on Performance and Service Conditions - Payable in Cash Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Weighted- Outstanding at December 31, 2019 10,296,394 $ 17.73 491,189 $ 18.87 $ 3,899,884 $ 20.37 Granted 5,796,992 19.40 (10,666) 18.98 1,651,519 16.16 Vested (4,203,663) 16.33 (421,352) 18.96 (654,108) 19.46 Forfeited (373,353) 19.16 — — (117,256) 13.16 Outstanding at December 31, 2020 11,516,370 $ 19.01 59,171 $ 18.20 $ 4,780,039 $ 16.23
Activity and Pricing Information for Nonvested Shares Granted Under Deferred Compensation Plans and Other Restricted Stock Awards	The following table summarizes activity and pricing information for the nonvested shares granted under our deferred compensation plans and these other restricted stock or unit award programs for the year ended December 31, 2020. Number of Nonvested Shares Weighted-Average Grant-Date Fair Value Outstanding at December 31, 2019 3,037,964 $ 17.67 Granted 691,377 16.22 Dividend equivalents 11 13.91 Vested (1,048,864) 17.18 Forfeited (108,401) 18.20 Outstanding at December 31, 2020 2,572,087 $ 17.46

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Net Pension Cost and Amount Recognized in OCI for All Funded and Unfunded Plans	The components of net pension cost and the amount recognized in OCI for all funded and unfunded plans are as follows: Year ended December 31, in millions 2020 2019 2018 Interest cost on PBO $ 34 $ 46 $ 41 Expected return on plan assets (38) (48) (53) Amortization of losses 17 13 17 Settlement loss 9 18 17 Net pension cost $ 22 $ 29 $ 22 Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ (18) $ (8) $ 20 Amortization of gains (26) (31) (33) Total recognized in comprehensive income $ (44) $ (39) $ (13) Total recognized in net pension cost and comprehensive income $ (22) $ (10) $ 9
Changes in PBO Related to Pension Plans	The following table summarizes changes in the PBO related to our pension plans. Actuarial losses in 2020 were primarily a result of the decrease in discount rate, offset by a gain from the decrease in interest crediting rates. Year ended December 31, in millions 2020 2019 PBO at beginning of year $ 1,233 $ 1,201 Interest cost 34 46 Actuarial losses (gains) 66 91 Benefit payments (85) (105) PBO at end of year $ 1,248 $ 1,233
Changes in FVA	The following table summarizes changes in the FVA. Year ended December 31, in millions 2020 2019 FVA at beginning of year $ 1,102 $ 1,046 Actual return on plan assets 123 147 Employer contributions 13 14 Benefit payments (85) (105) FVA at end of year $ 1,153 $ 1,102
Funded Status of Pension Plans Recognized in Balance Sheets	The following table summarizes the funded status of the pension plans, which equals the amounts recognized in the balance sheets at December 31, 2020, and December 31, 2019. December 31, in millions 2020 2019 Funded status (a) $ (95) $ (131) Net prepaid pension cost recognized consists of: Noncurrent assets $ 81 48 Current liabilities (14) $ (14) Noncurrent liabilities (162) (165) Net prepaid pension cost recognized (b) $ (95) $ (131) (a) The shortage of the FVA under the PBO. (b) Represents the accrued benefit liability of the pension plans.
Plans ABO in Excess of Plan Assets	As indicated in the table below, collectively our plans had an ABO in excess of plan assets as follows: December 31, 2020 2019 in millions Cash Balance Pension Plan Other Defined Benefit Plans Cash Balance Pension Plan Other Defined Benefit Plans PBO $ 1,072 $ 176 $ 1,054 $ 179 ABO 1,072 176 1,054 179 Fair value of plan assets 1,153 — 1,102 —
Weighted-Average Rates to Determine Actuarial Present Value of Benefit Obligations	To determine the actuarial present value of benefit obligations, we assumed the following weighted-average rates. December 31, 2020 2019 Discount rate 2.05 % 2.89 % Compensation increase rate N/A N/A Weighted-average interest crediting rate 1.65 % 2.39 %
Weighted-Average Rates to Determine Net Pension Cost	To determine net pension cost, we assumed the following weighted-average rates. Year ended December 31, 2020 2019 2018 Discount rate 2.89 % 4.00 % 3.25 % Compensation increase rate N/A N/A N/A Expected return on plan assets 3.75 4.50 4.75
Asset Target Allocations Prescribed by Pension Funds' Investment Policies	The following table shows the asset target allocations prescribed by the pension fund’s investment policies based on the plan’s funded status at December 31, 2020. Target Allocation Asset Class 2020 Equity securities: U.S. 4 % International 2 Fixed income securities 87 Real assets 4 Other assets 3 Total 100 %
Fair Values of Pension Plan Assets by Asset Category	The following tables show the fair values of our pension plan assets by asset class at December 31, 2020, and December 31, 2019. December 31, 2020 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. $ 9 — — $ 9 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 171 — 171 Corporate bonds — International — 79 — 79 Government and agency bonds — U.S. — 165 — 165 Government bonds — International — 2 — 2 State and municipal bonds — 27 — 27 Mutual funds: Equity — International 2 — — 2 Collective investment funds (measured at NAV) (a) — — — 636 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 17 Other assets (measured at NAV) (a) — — — 42 Total net assets at fair value $ 14 $ 444 — $ 1,153 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2019 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. 8 — — 8 Common — International — — — — Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 155 — 155 Corporate bonds — International — 72 — 72 Government and agency bonds — U.S. — 190 — 190 Government bonds — International — 2 — 2 State and municipal bonds — 27 — 27 Mutual funds: Equity — International 2 — — 2 Collective investment funds (measured at NAV) (a) — — — 584 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 16 Other assets (measured at NAV) (a) — — — 43 Total net assets at fair value $ 13 $ 446 — $ 1,102
Pre-tax AOCI Not Yet Recognized as Net Postretirement Benefit Cost	The components of pre-tax AOCI not yet recognized as net postretirement benefit cost are shown below. December 31, in millions 2020 2019 Net unrecognized losses (gains) $ (10) $ (10) Net unrecognized prior service credit (15) (17) Total unrecognized AOCI $ (25) $ (27)
Net Postretirement Benefit Cost and Amount Recognized in OCI for All Funded and Unfunded Plans	The components of net postretirement benefit cost and the amount recognized in OCI for all funded and unfunded plans are as follows: December 31, in millions 2020 2019 2018 Service cost of benefits earned $ — $ 1 $ 1 Interest cost on APBO 2 2 2 Expected return on plan assets (2) (2) (2) Amortization of prior service credit (1) — (1) Amortization of gains — (1) (1) Net postretirement benefit (1) — (1) Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 1 $ 1 $ 1 Amortization of prior service credit — 1 1 Amortization of losses — — — Total recognized in comprehensive income $ 1 $ 2 $ 2 Total recognized in net postretirement benefit cost and comprehensive income $ — $ 2 $ 1
Changes in APBO	The following table summarizes changes in the APBO. Actuarial losses are a result of asset performance. Year ended December 31, in millions 2020 2019 APBO at beginning of year $ 52 $ 63 Service cost — 1 Interest cost 2 2 Plan participants’ contributions 1 1 Actuarial losses (gains) 8 10 Benefit payments (11) (8) Plan amendments — (17) APBO at end of year $ 52 $ 52
Change in FVA (Other Post Retirement Benefit Plan Assets)	The following table summarizes changes in FVA. Year ended December 31, in millions 2020 2019 FVA at beginning of year $ 52 $ 47 Employer contributions — — Plan participants’ contributions 1 1 Benefit payments (11) (8) Actual return on plan assets 10 12 FVA at end of year $ 52 $ 52
Weighted-Average Rates to Determine Net Postretirement Benefit Cost	To determine net postretirement benefit cost, we assumed the following weighted-average rates. Year ended December 31, 2020 2019 2018 Discount rate 4.50 % 4.50 % 3.50 % Expected return on plan assets 4.50 4.50 4.50
Asset Target Allocations Prescribed by Trusts' Investment Policies	The following table shows the asset target allocations prescribed by the trust’s investment policy. Target Allocation Asset Class 2020 Equity securities 80 % Fixed income securities 20 Cash equivalents — Total 100 %
Fair Values of Pension Plan Assets by Asset Category	The following tables show the fair values of our postretirement plan assets by asset class at December 31, 2020, and December 31, 2019. December 31, 2020 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 21 — — $ 21 Equity — International 9 — — 9 Fixed income — U.S. 7 — — 7 Collective investment funds: Equity — U.S. (a) — — — 14 Other assets (measured at NAV) (a) — — — 1 Total net assets at fair value $ 37 — — $ 52 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2019 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 22 — — $ 22 Equity — International 9 — — 9 Fixed income — U.S. 7 — — 7 Fixed income — International — — — — Collective investment funds: Equity — U.S. (a) — $ — — 12 Other assets (measured at NAV) — — — 2 Total net assets at fair value $ 38 $ — — $ 52

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Components of Short-Term Borrowings	Selected financial information pertaining to the components of our short-term borrowings is as follows: December 31, dollars in millions 2020 2019 2018 FEDERAL FUNDS PURCHASED Balance at year end $ — 200 $ — Average during the year 455 $ 61 537 Maximum month-end balance 2,285 1,000 3,197 Weighted-average rate during the year (a) 1.24 % 2.12 % 1.68 % Weighted-average rate at December 31 (a) — 1.56 — SECURITIES SOLD UNDER REPURCHASE AGREEMENTS Balance at year end $ 220 $ 187 $ 319 Average during the year 215 203 391 Maximum month-end balance 267 283 614 Weighted-average rate during the year (a) .11 % .22 % .09 % Weighted-average rate at December 31 (a) .04 .09 .09 OTHER SHORT-TERM BORROWINGS Balance at year end $ 759 $ 705 $ 544 Average during the year 1,452 730 915 Maximum month-end balance 4,606 847 1,133 Weighted-average rate during the year (a) 0.85 % 2.31 % 2.34 % Weighted-average rate at December 31 (a) .60 1.99 2.92 (a) Rates exclude the effects of interest rate swaps and caps, which modify the repricing characteristics of certain short-term borrowings. For more information about such financial instruments, see Note 8 (“Derivatives and Hedging Activities”).

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Components of Long-Term Debt	The following table presents the components of our long-term debt, net of unamortized discounts and adjustments related to hedging with derivative financial instruments. We use interest rate swaps and caps, which modify the repricing characteristics of certain long-term debt, to manage interest rate risk. For more information about such financial instruments, see Note 8 (“Derivatives and Hedging Activities”). December 31, dollars in millions 2020 2019 Senior medium-term notes due through 2021 (a) $ 3,962 $ 4,111 3.136% Subordinated notes due 2028 (b) 162 162 6.875% Subordinated notes due 2029 (b) 115 109 7.75% Subordinated notes due 2029 (b) 149 141 7.25% Subordinated notes due 2021 (c) 311 324 Other subordinated notes (b)(d) 74 71 Total parent company 4,773 4,918 Senior medium-term notes due through 2039 (e) 6,718 5,874 3.18% Senior remarketable notes due 2027 (f) 232 222 3.40% Subordinated notes due 2026 (g) 625 589 6.95% Subordinated notes due 2028 (g) 299 299 3.90% Subordinated notes due 2029 (g) 398 371 Secured borrowing due through 2025 (h) 19 15 Federal Home Loan Bank advances due through 2038 (i) 608 121 Investment Fund Financing due through 2052 (j) 21 26 Key Govt Finance, Inc. Other Long Term Debt-ASR 4 — Obligations under Capital Leases due through 2032 (k) 12 13 Total subsidiaries 8,936 7,530 Total long-term debt $ 13,709 $ 12,448 (a) Senior medium-term notes had a weighted-average interest rate of 3.7025% at December 31, 2020, and 3.7815% at December 31, 2019. These notes had fixed interest rates at December 31, 2020, and December 31, 2019. These notes may not be redeemed prior to their maturity dates. (b) See Note 21 (“Trust Preferred Securities Issued by Unconsolidated Subsidiaries”) for a description of these notes. (c) The First Niagara subordinated debt had a weighted-average interest rate of 7.25% at December 31, 2020, and a weighted-average interest rate of 7.25% at December 31, 2019. These notes may not be redeemed prior to their maturity dates. (d) The First Niagara variable rate trust preferred securities had a weighted-average interest rate of 1.72% at December 31, 2020, and 3.42% at December 31, 2019. These notes may be redeemed prior to their maturity dates. (e) Senior medium-term notes had weighted-average interest rates of 2.516% at December 31, 2020, and 2.595% at December 31, 2019. These notes are a combination of fixed and floating rates. These notes may not be redeemed prior to their maturity dates. (f) The remarketable senior medium-term notes had a weighted-average interest rate of 3.18% at December 31, 2020, and 3.18% at December 31, 2019. These notes had fixed interest rates at December 31, 2017, and December 31, 2018. These notes may not be redeemed prior to their maturity dates. (g) These notes are all obligations of KeyBank and may not be redeemed prior to their maturity dates. (h) The secured borrowing had weighted-average interest rates of 4.445% at December 31, 2020, and 4.445% at December 31, 2019. This borrowing is collateralized by commercial lease financing receivables, and principal reductions are based on the cash payments received from the related receivables. Additional information pertaining to these commercial lease financing receivables is included in Note 4 (“Loan Portfolio”). (i) Long-term advances from the Federal Home Loan Bank had a weighted-average interest rate of 1.15% at December 31, 2020, and 3.506% at December 31, 2019. These advances, which had fixed interest rates, were secured by real estate loans and securities totaling $607 million at December 31, 2020, and $121 million at December 31, 2019. (j) Investment Fund Financing had a weighted-average interest rate of 1.77% at December 31, 2020, and 1.63% at December 31, 2019. (k) These are capital leases acquired in the First Niagara merger with a maturity range from March 2021 through October 2032
Scheduled Principal Payments on Long-Term Debt	At December 31, 2020, scheduled principal payments on long-term debt were as follows: in millions Parent Subsidiaries Total 2021 $ 1,315 $ 1,272 $ 2,587 2022 — 2,403 2,403 2023 — 1,231 1,231 2024 — 1,101 1,101 2025 562 772 1,334 All subsequent years 2,896 2,157 5,053

Trust Preferred Securities Is_2

Trust Preferred Securities Issued by Unconsolidated Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2020
Banking and Thrift, Other Disclosures [Abstract]
Schedule Of Capital Securities Issued By Unconsolidated Subsidiaries	The trust preferred securities, common stock, and related debentures are summarized as follows: dollars in millions Trust Preferred Securities, Net of Discount (a) Common Stock Principal Amount of Debentures, Net of Discount (b) Interest Rate of Trust Preferred Securities and (c) Maturity of Trust Preferred Securities and Debentures December 31, 2020 KeyCorp Capital I $ 156 $ 6 $ 162 0.965 % 2028 KeyCorp Capital II 110 4 114 6.875 2029 KeyCorp Capital III 145 4 149 7.750 2029 HNC Statutory Trust III 20 1 21 1.605 2035 Willow Grove Statutory Trust I 19 1 20 1.527 2036 HNC Statutory Trust IV 17 1 18 1.494 2037 Westbank Capital Trust II 8 — 8 2.429 2034 Westbank Capital Trust III 8 — 8 2.429 2034 Total $ 483 $ 17 $ 500 4.464 % — December 31, 2019 $ 466 $ 17 $ 483 5.214 % — (a) The trust preferred securities must be redeemed when the related debentures mature, or earlier if provided in the governing indenture. Each issue of trust preferred securities carries an interest rate identical to that of the related debenture. Certain trust preferred securities include debt issuance costs and basis adjustments related to fair value hedges totaling $70 million at December 31, 2020, and $57 million at December 31, 2019. See Note 8 (“Derivatives and Hedging Activities”) for an explanation of fair value hedges. (b) We have the right to redeem these debentures. If the debentures purchased by KeyCorp Capital I, HNC Statutory Trust III, Willow Grove Statutory Trust I, HNC Statutory Trust IV, Westbank Capital Trust II, or Westbank Capital Trust III are redeemed before they mature, the redemption price will be the principal amount, plus any accrued but unpaid interest. If the debentures purchased by KeyCorp Capital II or KeyCorp Capital III are redeemed before they mature, the redemption price will be the greater of: (i) the principal amount, plus any accrued but unpaid interest, or (ii) the sum of the present values of principal and interest payments discounted at the Treasury Rate (as defined in the applicable indenture), plus 20 basis points for KeyCorp Capital II or 25 basis points for KeyCorp Capital III or 50 basis points in the case of redemption upon either a tax or a capital treatment event for either KeyCorp Capital II or KeyCorp Capital III, plus any accrued but unpaid interest. The principal amount of certain debentures includes debt issuance costs and basis adjustments related to fair value hedges totaling $70 million at December 31, 2020, and $57 million at December 31, 2019. See Note 8 for an explanation of fair value hedges. The principal amount of debentures, net of discounts, is included in “long-term debt” on the balance sheet. (c) The interest rates for the trust preferred securities issued by KeyCorp Capital II and KeyCorp Capital III are fixed. The trust preferred securities issued by KeyCorp Capital I have a floating interest rate, equal to three-month LIBOR plus 74 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust III have a floating interest rate, equal to three-month LIBOR plus 140 basis points, that reprices quarterly. The trust preferred securities issued by Willow Grove Statutory Trust I have a floating interest rate, equal to three-month LIBOR plus 131 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust IV have a floating interest rate, equal to three-month LIBOR plus 128 basis points, that reprices quarterly. The trust preferred securities issued by Westbank Capital Trust II and Westbank Capital Trust III each have a floating interest rate, equal to three-month LIBOR plus 219 basis points, that reprices quarterly. The total interest rates are weighted-average rates.

Commitments, Contingent Liabi_2

Commitments, Contingent Liabilities and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments to Extend Credit or Funding	The following table shows the remaining contractual amount of each class of commitment related to extending credit or funding principal investments as of December 31, 2020, and December 31, 2019. For loan commitments and commercial letters of credit, this amount represents our maximum possible accounting loss on the unused commitment if the borrower were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan. December 31, in millions 2020 2019 Loan commitments: Commercial and other $ 47,792 $ 45,323 Commercial real estate and construction 2,365 2,961 Home equity 9,299 9,945 Credit cards 6,685 6,560 Total loan commitments 66,141 64,789 Commercial letters of credit 74 91 Purchase card commitments 708 729 Principal investing commitments 16 21 Tax credit investment commitments 487 547 Total loan and other commitments $ 67,426 $ 66,177
Guarantees	The following table shows the types of guarantees that we had outstanding at December 31, 2020. Information pertaining to the basis for determining the liabilities recorded in connection with these guarantees is included in Note 1 (“Summary of Significant Accounting Policies”) under the heading “Contingencies and Guarantees.” December 31, 2020 Maximum Potential Undiscounted Future Payments Liability Recorded in millions Financial guarantees: Standby letters of credit $ 3,231 $ 71 Recourse agreement with FNMA 5,811 23 Residential mortgage reserve 2,471 10 Written put options (a) 3,631 54 Total $ 15,144 $ 158 (a) The maximum potential undiscounted future payments represent notional amounts of derivatives qualifying as guarantees.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Changes in AOCI	Our changes in AOCI for the years ended December 31, 2020, and December 31, 2019, are as follows: in millions Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on derivative financial instruments Foreign currency translation adjustment Net pension and postretirement benefit costs Total Balance at December 31, 2018 $ (373) $ (50) $ (14) $ (381) $ (818) Other comprehensive income before reclassification, net of income taxes 503 335 3 19 860 Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (15) (35) 11 23 (16) Net current-period other comprehensive income, net of income taxes 488 300 14 42 844 Balance at December 31, 2019 $ 115 $ 250 $ — $ (339) $ 26 Other comprehensive income before reclassification, net of income taxes 455 466 — 15 936 Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (3) (240) — 19 (224) Net current-period other comprehensive income, net of income taxes 452 226 — 34 712 Balance at December 31, 2020 $ 567 $ 476 $ — $ (305) $ 738 (a) See table below for details about these reclassifications.
Reclassifications Out of AOCI	Our reclassifications out of AOCI for the years ended December 31, 2020, and December 31, 2019, are as follows: Twelve months ended December 31, Affected Line Item in the Statement Where Net Income is Presented in millions 2020 2019 Unrealized gains (losses) on available for sale securities Realized gains $ 4 20 Other income 4 20 Income (loss) from continuing operations before income taxes 1 5 Income taxes $ 3 15 Income (loss) from continuing operations Unrealized gains (losses) on derivative financial instruments Interest rate $ 319 $ 15 Interest income — Loans Interest rate (4) (1) Interest expense — Long-term debt Foreign exchange contracts — 32 Other income 315 46 Income (loss) from continuing operations before income taxes 75 11 Income taxes $ 240 $ 35 Income (loss) from continuing operations Foreign currency translation adjustment — (14) Other income — (14) Income (loss) from continuing operations before income taxes — (3) Income taxes — (11) Income (loss) from continuing operations Net pension and postretirement benefit costs Amortization of losses $ (17) $ (13) Other expense Settlement loss (9) (18) Other expense Amortization of prior service credit 1 — Other expense (25) (31) Income (loss) from continuing operations before income taxes (6) (8) Income taxes $ (19) $ (23) Income (loss) from continuing operations

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Stockholders Equity	The following table summarizes our preferred stock at December 31, 2020: Preferred stock series Amount outstanding (in millions) Shares authorized and outstanding Par value Liquidation preference Ownership interest per depositary share Liquidation preference per depositary share 2020 dividends paid per depositary share Fixed-to-Floating Rate Perpetual Noncumulative Series D $ 525 21,000 $ 1 $ 25,000 1/25th $ 1,000 $ 12.50 Fixed-to-Floating Rate Perpetual Noncumulative Series E 500 500,000 1 1,000 1/40th 25 .382813 Fixed Rate Perpetual Noncumulative Series F 425 425,000 1 1,000 1/40th 25 .353125 Fixed Rate Perpetual Noncumulative Series G 450 450,000 1 1,000 1/40th 25 .351563
Key's and KeyBank's Actual Capital Amounts and Ratios, Minimum Capital Amounts and Ratios	At December 31, 2020, Key and KeyBank (consolidated) had regulatory capital in excess of all current minimum risk-based capital (including all adjustments for market risk) and leverage ratio requirements as shown in the following table. Actual To Meet Minimum To Qualify as Well dollars in millions Amount Ratio Amount Ratio Amount Ratio December 31, 2020 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 17,976 13.40 % $ 10,736 8.00 % N/A N/A KeyBank (consolidated) 17,195 13.09 10,511 8.00 $ 13,139 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 14,907 11.11 % $ 8,052 6.00 % N/A N/A KeyBank (consolidated) 14,539 11.07 7,884 6.00 $ 10,511 8.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 14,907 8.94 % $ 6,671 4.00 % N/A N/A KeyBank (consolidated) 14,539 8.80 6,605 4.00 $ 8,256 5.00 % December 31, 2019 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 16,731 12.79 % $ 10,469 8.00 % N/A N/A KeyBank (consolidated) 16,313 12.69 10,287 8.00 $ 12,858 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 14,207 10.86 % $ 7,852 6.00 % N/A N/A KeyBank (consolidated) 14,091 10.96 7,715 6.00 $ 7,715 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 14,207 9.87 % $ 5,756 4.00 % N/A N/A KeyBank (consolidated) 14,091 9.91 5,688 4.00 $ 7,110 5.00 %

Business Segment Reporting (Tab

Business Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Financial Information of Business Groups	Year ended December 31, Consumer Bank Commercial Bank dollars in millions 2020 2019 2018 2020 2019 2018 SUMMARY OF OPERATIONS Net interest income (TE) $ 2,434 $ 2,366 $ 2,306 $ 1,698 $ 1,621 $ 1,657 Noninterest income 1,003 922 915 1,507 1,390 1,328 Total revenue (TE) (a) 3,437 3,288 3,221 3,205 3,011 2,985 Provision for credit losses 288 188 147 738 118 102 Depreciation and amortization expense 77 97 103 144 135 139 Other noninterest expense 2,200 2,078 2,143 1,589 1,408 1,430 Income (loss) from continuing operations before income taxes (TE) 872 925 828 734 1,350 1,314 Allocated income taxes (benefit) and TE adjustments 207 219 196 101 219 207 Income (loss) from continuing operations 665 706 632 633 1,131 1,107 Income (loss) from discontinued operations, net of taxes — — — — — — Net income (loss) 665 706 632 633 1,131 1,107 Less: Net income (loss) attributable to noncontrolling interests — — — — — — Net income (loss) attributable to Key $ 665 $ 706 $ 632 $ 633 $ 1,131 $ 1,107 AVERAGE BALANCES (b) Loans and leases $ 38,906 $ 32,536 $ 31,307 $ 63,108 $ 57,988 $ 55,828 Total assets (a) 42,953 36,096 34,523 72,056 66,122 63,684 Deposits 79,811 72,544 68,821 46,862 36,212 33,675 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 40 $ 150 $ (38) $ 1 $ (8) $ (17) Net loan charge-offs (b) 134 157 149 309 128 85 Return on average allocated equity (b) 18.92 % 21.30 % 19.24 % 12.86 % 24.99 % 24.94 % Return on average allocated equity 18.92 21.30 19.24 12.86 24.99 24.94 Average full-time equivalent employees (c) 8,213 9,292 9,957 2,093 2,232 2,449 Year ended December 31, Other Key dollars in millions 2020 2019 2018 2020 2019 2018 SUMMARY OF OPERATIONS Net interest income (TE) $ (69) $ (46) $ (23) $ 4,063 $ 3,941 $ 3,940 Noninterest income 142 147 272 2,652 2,459 2,515 Total revenue (TE) (a) 73 101 249 6,715 6,400 6,455 Provision for credit losses (5) 139 (3) 1,021 445 246 Depreciation and amortization expense 140 142 158 361 374 400 Other noninterest expense (41) 61 2 3,748 3,527 3,575 Income (loss) from continuing operations before income taxes (TE) (21) (241) 92 1,585 2,054 2,234 Allocated income taxes (benefit) and TE adjustments (52) (96) (28) 256 346 375 Income (loss) from continuing operations 31 (145) 120 1,329 1,708 1,859 Income (loss) from discontinued operations, net of taxes 14 9 7 14 9 7 Net income (loss) 45 (136) 127 1,343 1,717 1,866 Less: Net income (loss) attributable to noncontrolling interests — — — — — — Net income (loss) attributable to Key $ 45 $ (136) (d) $ 127 $ 1,343 $ 1,717 $ 1,866 AVERAGE BALANCES (b) Loans and leases $ 675 $ 987 $ 1,203 $ 102,689 $ 91,511 $ 88,338 Total assets (a) 47,046 40,961 38,605 162,055 143,179 136,812 Deposits 613 1,274 2,555 127,286 110,030 105,051 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 120 $ 103 $ 103 $ 161 $ 245 $ 48 Net loan charge-offs (b) — 139 — 443 424 234 Return on average allocated equity (b) .34 % (1.66) % 1.62 % 7.54 % 10.27 % 12.29 % Return on average allocated equity .49 (1.56) 1.71 7.62 10.32 12.33 Average full-time equivalent employees (c) 6,520 5,521 5,774 16,826 17,045 18,180 (a) Substantially all revenue generated by our major business segments is derived from clients that reside in the United States. Substantially all long-lived assets, including premises and equipment, capitalized software, and goodwill held by our major business segments, are located in the United States. (b) From continuing operations. (c) The number of average full-time equivalent employees was not adjusted for discontinued operations. (d) Other segments included $106 million provision for credit loss, net of tax, related to a previously disclosed fraud incident.

Condensed Financial Informati_2

Condensed Financial Information of the Parent Company (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	CONDENSED BALANCE SHEETS December 31, in millions 2020 2019 ASSETS Cash and due from banks $ 3,799 $ 3,813 Short-term investments 21 20 Securities available for sale 12 10 Other investments 43 36 Loans to: Banks 50 50 Nonbank subsidiaries 16 16 Total loans 66 66 Investment in subsidiaries: Banks 17,645 16,969 Nonbank subsidiaries 900 823 Total investment in subsidiaries 18,545 17,792 Goodwill 167 167 Corporate-owned life insurance 207 205 Derivative assets 100 44 Accrued income and other assets 299 295 Total assets $ 23,259 $ 22,448 LIABILITIES Accrued expense and other liabilities $ 505 $ 492 Long-term debt due to: Subsidiaries 500 483 Unaffiliated companies 4,273 4,435 Total long-term debt 4,773 4,918 Total liabilities 5,278 5,410 SHAREHOLDERS’ EQUITY (a) 17,981 17,038 Total liabilities and shareholders’ equity $ 23,259 $ 22,448 (a) See Key’s Consolidated Statements of Changes in Equity.
Condensed Statements of Income	CONDENSED STATEMENTS OF INCOME Year ended December 31, in millions 2020 2019 2018 INCOME Dividends from subsidiaries: Bank subsidiaries $ 1,250 $ 1,204 $ 1,675 Nonbank subsidiaries — 70 — Interest income from subsidiaries 4 9 11 Other income 8 11 11 Total income 1,262 1,294 1,697 EXPENSE Interest on long-term debt with subsidiary trusts 18 22 20 Interest on other borrowed funds 114 151 137 Personnel and other expense 63 87 69 Total expense 195 260 226 Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries 1,067 1,034 1,471 Income tax (expense) benefit 38 57 55 Income (loss) before equity in net income (loss) less dividends from subsidiaries 1,105 1,091 1,526 Equity in net income (loss) less dividends from subsidiaries 238 626 340 NET INCOME (LOSS) 1,343 1,717 1,866 Less: Net income attributable to noncontrolling interests — — — NET INCOME (LOSS) ATTRIBUTABLE TO KEY $ 1,343 $ 1,717 $ 1,866 .
Condensed Statements of Cash Flows	CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, in millions 2020 2019 2018 OPERATING ACTIVITIES Net income (loss) attributable to Key $ 1,343 $ 1,717 $ 1,866 Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Deferred income taxes (benefit) 2 (43) 109 Stock-based compensation expense 11 8 8 Equity in net (income) loss less dividends from subsidiaries (238) (626) (340) Net (increase) decrease in other assets (66) 39 (58) Net increase (decrease) in other liabilities 12 11 8 Other operating activities, net 131 244 79 NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 1,195 1,350 1,672 INVESTING ACTIVITIES Net (increase) decrease in securities available for sale and in short-term and other investments (7) (6) 1 Cash infusion from purchase of Cain Brothers — — — Proceeds from sales, prepayments and maturities of securities available for sale — — — Net (increase) decrease in loans to subsidiaries — 15 200 NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES (7) 9 201 FINANCING ACTIVITIES Net proceeds from issuance of long-term debt 800 750 1,250 Payments on long-term debt (1,003) (300) (750) Repurchase of Treasury Shares (170) (868) (1,145) Net cash from the issuance (redemption) of Common Shares and preferred stock — 435 412 Cash dividends paid (829) (804) (656) NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (1,202) (787) (889) NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS (14) 572 984 CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 3,813 3,241 2,257 CASH AND DUE FROM BANKS AT END OF YEAR $ 3,799 $ 3,813 $ 3,241

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table represents a disaggregation of revenue from contracts with customers, by line of business, for the twelve months ended December 31, 2020, and December 31, 2019: Year ended December 31, 2020 2019 dollars in millions Consumer Bank Commercial Bank Total Contract Revenue Consumer Bank Commercial Bank Total Contract Revenue NONINTEREST INCOME Trust and investment services income $ 374 $ 67 $ 441 $ 355 $ 64 $ 419 Investment banking and debt placement fees — 305 305 — 263 263 Services charges on deposit accounts 189 122 311 228 109 337 Cards and payments income 160 201 361 164 106 270 Other noninterest income 10 — 10 13 — 13 Total revenue from contracts with customers $ 733 $ 695 $ 1,428 $ 760 $ 542 $ 1,302 Other noninterest income (a) 1,082 1,010 Noninterest income from other segments (b) 142 147 Total noninterest income $ 2,652 $ 2,459 (a) Noninterest income considered earned outside the scope of contracts with customers. (b) Other includes other segments that consists of corporate treasury, our principal investing unit, and various exit portfolios as well as reconciling items which primarily represents the unallocated portion of nonearning assets of corporate support functions. Charges related to the funding of these assets are part of net interest income and are allocated to the business segments through noninterest expense. Reconciling items also includes intercompany eliminations and certain items that are not allocated to the business segments because they do not reflect their normal operations. Refer to Note 25 (“Business Segment Reporting”) for more information.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)branchstateATMsegment	Dec. 31, 2019USD ($)		Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Accounting Policies [Line Items]
Number of retail branches | branch	1,073
Number of automated teller machines | ATM	1,386
Number of states with automated teller machines | state	15
Number of business segments | segment	2
Number of days to designate the loan as nonaccrual for commercial loan payment due period	90 days
Number of days to designate commercial loans will be charged off in full or charged down to the fair value of the underlying collateral payment due period	180 days
Number of days to designate the loan as nonaccrual for consumer payment due period	120 days
Second lien home equity loan with associated first lien due period	120 days
Number of days to designate the charge-off policy for most consumer loans taking effect, payment due period	120 days
Number of days to designate home equity and residential mortgage loans to get charged down to the fair value of the underlying collateral payment due period	180 days
Number of days to designate charge-off policy for credit card loans and similar unsecured products taking effect, payment due period	180 days
Threshold period by which amortized cost is greater than fair value to be considered as other-than-temporary	6 months
Amortization period of stock-based compensation awards	5 years
Vesting period for compensation cost	4 years
Cumulative effect from adoption	$ (17,981)	$ (17,038)
Retained Earnings [Member]
Accounting Policies [Line Items]
Cumulative effect from adoption	$ (12,751)	(12,469)		$ (11,556)	$ (10,335)
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounting Policies [Line Items]
Adjustment to amortized cost basis of PCD loans		4
Noncredit discount		15
Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings [Member]
Accounting Policies [Line Items]
Cumulative effect from adoption		230	[1]		$ 2	[2]
Deferred taxes		$ 71
Stock Options [Member]
Accounting Policies [Line Items]
Options expiration years	10 years
Stock Options [Member] | One year after the grant date [Member]
Accounting Policies [Line Items]
Rate at which employee stock options granted to be exercisable	25.00%
[1]	Includes the impact of implementing ASU 2016-13. See Notes to Consolidated Financial Statements.
[2]	Includes the impact of implementing ASU 2014-09, ASU 2016-01, and ASU 2017-12.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Adjustment to Retained Earnings (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	$ 1,626	$ 900	$ 883	$ 877
Total ALLL, including discontinued operations	1,662	910	897	893
Accrued expense and other liabilities		75
Total allowance for credit losses		985
Discontinued Operations [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	36	10	14	16
Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		204
Total ALLL, including discontinued operations		235
Accrued expense and other liabilities		70
Total allowance for credit losses		305
Cumulative Effect, Period of Adoption, Adjustment [Member] | Discontinued Operations [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		31
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		1,104
Total ALLL, including discontinued operations		1,145
Accrued expense and other liabilities		145
Total allowance for credit losses		1,290
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Discontinued Operations [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		41
Commercial Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	1,099	751	743	735
Commercial Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		(124)
Commercial Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		627
Commercial Loans [Member] | Commercial And Industrial [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	678	551	532	529
Commercial Loans [Member] | Commercial And Industrial [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		(141)
Commercial Loans [Member] | Commercial And Industrial [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		410
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	327	143	142	133
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		16
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		159
Commercial Loans [Member] | Construction Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	47	22	33	30
Commercial Loans [Member] | Construction Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		(7)
Commercial Loans [Member] | Construction Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		15
Commercial Loans [Member] | Commercial Lease Financing [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	47	35	36	43
Commercial Loans [Member] | Commercial Lease Financing [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		8
Commercial Loans [Member] | Commercial Lease Financing [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		43
Consumer Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	527	149	140	142
Consumer Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		328
Consumer Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		477
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	102	7	7	7
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		77
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		84
Consumer Loans [Member] | Home Equity Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	171	31	35	43
Consumer Loans [Member] | Home Equity Loan [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		147
Consumer Loans [Member] | Home Equity Loan [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		178
Consumer Loans [Member] | Consumer Direct Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	128	34	30	28
Consumer Loans [Member] | Consumer Direct Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		63
Consumer Loans [Member] | Consumer Direct Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		97
Consumer Loans [Member] | Consumer Credit Card [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	87	47	48	44
Consumer Loans [Member] | Consumer Credit Card [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		35
Consumer Loans [Member] | Consumer Credit Card [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		82
Consumer Loans [Member] | Consumer Indirect Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables	$ 39	30	$ 20	$ 20
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		6
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance related to lease financing receivables		$ 36

Earnings Per Common Share - Bas

Earnings Per Common Share - Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
EARNINGS
Income (loss) from continuing operations		$ 1,329	$ 1,708	$ 1,859
Less: Net income (loss) attributable to noncontrolling interests		0	0	0
Income (loss) from continuing operations attributable to Key		1,329	1,708	1,859
Less: Dividends on preferred stock		106	97	66
Income (loss) from continuing operations attributable to Key common shareholders		1,223	1,611	1,793
Income (loss) from discontinued operations, net of taxes		14	9	7
Net income (loss) attributable to Key common shareholders		$ 1,237	$ 1,620	$ 1,800
WEIGHTED-AVERAGE COMMON SHARES
Weighted-average common shares outstanding (in shares)		967,783	992,091	1,040,890
Effect of common share options and other stock awards (in shares)		7,024	10,163	13,792
Weighted-average common shares and potential common shares outstanding (in shares)	[1]	974,807	1,002,254	1,054,682
EARNINGS PER COMMON SHARE
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		$ 1.26	$ 1.62	$ 1.72
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0.01
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.28	1.63	1.73
Income (loss) from continuing operations attributable to Key common shareholders - assuming dilution (in dollars per share)		1.26	1.61	1.70
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0.01
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	$ 1.27	$ 1.62	$ 1.71
[1]	Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable.
[2]	EPS may not foot due to rounding.

Restrictions on Cash, Dividen_2

Restrictions on Cash, Dividends and Lending Activities - Narrative (Details) - USD ($) $ in Millions	Jan. 01, 2021	Dec. 31, 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Average reserve balance maintained		$ 97
Short-term investments held for discharge of obligations		3,800
KeyBank (consolidated) [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Dividends paid by non banking subsidiaries		$ 1,300
KeyBank (consolidated) [Member] | Subsequent Event [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Capacity to pay dividends	$ 720

Loan Portfolio - Loans by Categ

Loan Portfolio - Loans by Category (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	$ 101,185	$ 94,646
Discontinued Operations [Member] | Education Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	710	865
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	71,980	68,032
Accrued interest	140
Commercial Loans [Member] | Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	52,907	48,295
Accrued interest	241	244
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	12,687	13,491
Commercial Loans [Member] | Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	1,987	1,558
Commercial Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	14,674	15,049
Commercial Loans [Member] | Commercial Lease Financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	4,399	4,688
Commercial Loans [Member] | Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	127	144
Commercial Loans [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	23	15
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	29,205	26,614
Accrued interest	101
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	9,298	7,023
Consumer Loans [Member] | Home Equity Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	9,360	10,274
Consumer Loans [Member] | Residential Prime Financing Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	18,658	17,297
Consumer Loans [Member] | Consumer Direct Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	4,714	3,513
Consumer Loans [Member] | Consumer Credit Card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	989	1,130
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	4,844	4,674
Consumer Loans [Member] | Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)	$ 989	$ 1,130

Asset Quality - Changes in Allo

Asset Quality - Changes in Allowance for Loan and Lease Losses by Loan Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 900	$ 883	$ 877
Provision	965	441	240
Charge-offs	(522)	(499)	(324)
Recoveries	79	75	90
Ending balance	1,626	900	883
Total ALLL, including discontinued operations	1,662	910	897	$ 893
Total provision, including discontinued operations	960	444	248
Total charge-offs, including discontinued operations	(527)	(511)	(339)
Total recoveries, including discontinued operations	84	80	95
Provision (credit) for losses on off balance sheet exposures	56	4	6
Provision for credit loss, net of tax, related to previously disclosed fraud incident		(139)
Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	204
Ending balance		204
Total ALLL, including discontinued operations		235
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,104
Ending balance		1,104
Total ALLL, including discontinued operations		1,145
Discontinued Operations [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10	14	16
Provision	(5)	3	8
Charge-offs	(5)	(12)	(15)
Recoveries	5	5	5
Ending balance	36	10	14
Discontinued Operations [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	31
Ending balance		31
Discontinued Operations [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	41
Ending balance		41
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	751	743	735
Provision	839	332	151
Charge-offs	(405)	(358)	(190)
Recoveries	38	34	47
Ending balance	1,099	751	743
Commercial Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(124)
Ending balance		(124)
Commercial Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	627
Ending balance		627
Commercial Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	551	532	529
Provision	585	311	125
Charge-offs	(351)	(319)	(159)
Recoveries	34	27	37
Ending balance	678	551	532
Commercial Loans [Member] | Commercial And Industrial [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(141)
Ending balance		(141)
Commercial Loans [Member] | Commercial And Industrial [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	410
Ending balance		410
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	143	142	133
Provision	184	7	27
Charge-offs	(19)	(8)	(21)
Recoveries	3	2	3
Ending balance	327	143	142
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	16
Ending balance		16
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	159
Ending balance		159
Commercial Loans [Member] | Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	22	33	30
Provision	32	(6)	1
Charge-offs	0	(5)	0
Recoveries	0	0	2
Ending balance	47	22	33
Commercial Loans [Member] | Construction Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(7)
Ending balance		(7)
Commercial Loans [Member] | Construction Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	15
Ending balance		15
Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	165	175
Provision	216	1
Charge-offs	(19)	(13)
Recoveries	3	2
Ending balance	374	165	175
Commercial Loans [Member] | Commercial Real Estate [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9
Ending balance		9
Commercial Loans [Member] | Commercial Real Estate [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	174
Ending balance		174
Commercial Loans [Member] | Commercial Lease Financing [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	35	36	43
Provision	38	20	(2)
Charge-offs	(35)	(26)	(10)
Recoveries	1	5	5
Ending balance	47	35	36
Commercial Loans [Member] | Commercial Lease Financing [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8
Ending balance		8
Commercial Loans [Member] | Commercial Lease Financing [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	43
Ending balance		43
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	149	140	142
Provision	126	109	89
Charge-offs	(117)	(141)	(134)
Recoveries	41	41	43
Ending balance	527	149	140
Consumer Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	328
Ending balance		328
Consumer Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	477
Ending balance		477
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	7	7	7
Provision	19	1	1
Charge-offs	(2)	(3)	(3)
Recoveries	1	2	2
Ending balance	102	7	7
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	77
Ending balance		77
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	84
Ending balance		84
Consumer Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	31	35	43
Provision	(3)	7	2
Charge-offs	(11)	(19)	(21)
Recoveries	7	8	11
Ending balance	171	31	35
Consumer Loans [Member] | Home Equity Loan [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	147
Ending balance		147
Consumer Loans [Member] | Home Equity Loan [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	178
Ending balance		178
Consumer Loans [Member] | Consumer Direct Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	34	30	28
Provision	61	38	31
Charge-offs	(37)	(41)	(36)
Recoveries	7	7	7
Ending balance	128	34	30
Consumer Loans [Member] | Consumer Direct Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	63
Ending balance		63
Consumer Loans [Member] | Consumer Direct Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	97
Ending balance		97
Consumer Loans [Member] | Consumer Credit Card [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	47	48	44
Provision	36	36	41
Charge-offs	(39)	(44)	(44)
Recoveries	8	7	7
Ending balance	87	47	48
Consumer Loans [Member] | Consumer Credit Card [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	35
Ending balance		35
Consumer Loans [Member] | Consumer Credit Card [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	82
Ending balance		82
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	30	20	20
Provision	13	27	14
Charge-offs	(28)	(34)	(30)
Recoveries	18	17	16
Ending balance	39	30	$ 20
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	6
Ending balance		6
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 36
Ending balance		$ 36

Asset Quality - Additional Info

Asset Quality - Additional Information (Details) $ in Millions	Jan. 01, 2020USD ($)	Dec. 31, 2020USD ($)SecurityLoan	Dec. 31, 2019USD ($)SecurityLoan	Dec. 31, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)		$ 101,185	$ 94,646
Portfolio loans that have received payment, CARES Act		575
Loan modifications and forbearance, CARES Act		$ 506
Percentage of carrying amount of our commercial nonperforming loans outstanding		70.00%
Percentage of nonperforming loans outstanding face value		76.00%
Percentage of loans held for sale and other nonperforming assets		83.00%
Net reduction to interest income		$ 27	31	$ 30
Commitments outstanding to lend additional funds to borrowers		1	4
Financial receivable, modifications, subsequent default, recorded investment		10	8
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)		71,980	68,032
Accrued interest		140
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)		29,205	$ 26,614
Accrued interest		101
Continuing Operations [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in ALLL	$ (124)	$ 472
Increase (decrease) in ALLL, percent	(16.50%)	75.30%
Continuing Operations [Member] | Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in ALLL	$ 328	$ 50
Increase (decrease) in ALLL, percent	220.00%	10.50%
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan		7	0
PPP
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)		$ 6,700
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan		212	356
Real Estate - Residential Mortgage [Member] | Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income (residential)		$ 9,298	$ 7,023
Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonperforming loans on nonaccrual status with no allowance		379
Real Estate - Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		$ 92	$ 97

Asset Quality - Commercial Cred

Asset Quality - Commercial Credit Exposure (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 101,185	$ 94,646
Commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	16,230
2019	10,657
2018	7,206
2017	4,635
2016	3,237
Prior	7,295
Revolving Loans Amortized Cost Basis	22,529
Revolving Loans Converted to Term Loans Amortized Cost Basis	191
Total	71,980	68,032
Accrued interest	140
Commercial Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	13,174
2019	5,712
2018	4,285
2017	2,881
2016	2,134
Prior	2,995
Revolving Loans Amortized Cost Basis	21,585
Revolving Loans Converted to Term Loans Amortized Cost Basis	141
Total	52,907	48,295
Accrued interest	241	244
Commercial Loans [Member] | Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	13,100
2019	5,487
2018	4,040
2017	2,617
2016	1,967
Prior	2,709
Revolving Loans Amortized Cost Basis	19,832
Revolving Loans Converted to Term Loans Amortized Cost Basis	118
Total	49,870
Commercial Loans [Member] | Commercial And Industrial [Member] | Criticized Accruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	66
2019	198
2018	174
2017	236
2016	150
Prior	279
Revolving Loans Amortized Cost Basis	1,527
Revolving Loans Converted to Term Loans Amortized Cost Basis	22
Total	2,652
Commercial Loans [Member] | Commercial And Industrial [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	8
2019	27
2018	71
2017	28
2016	17
Prior	7
Revolving Loans Amortized Cost Basis	226
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	385
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,603
2019	3,080
2018	1,822
2017	1,016
2016	839
Prior	3,370
Revolving Loans Amortized Cost Basis	912
Revolving Loans Converted to Term Loans Amortized Cost Basis	45
Total	12,687	13,491
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,591
2019	2,937
2018	1,737
2017	867
2016	765
Prior	3,027
Revolving Loans Amortized Cost Basis	885
Revolving Loans Converted to Term Loans Amortized Cost Basis	43
Total	11,852
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Criticized Accruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	12
2019	142
2018	81
2017	145
2016	72
Prior	255
Revolving Loans Amortized Cost Basis	22
Revolving Loans Converted to Term Loans Amortized Cost Basis	2
Total	731
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	1
2018	4
2017	4
2016	2
Prior	88
Revolving Loans Amortized Cost Basis	5
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	104
Commercial Loans [Member] | Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	367
2019	778
2018	548
2017	206
2016	27
Prior	24
Revolving Loans Amortized Cost Basis	32
Revolving Loans Converted to Term Loans Amortized Cost Basis	5
Total	1,987	1,558
Commercial Loans [Member] | Construction Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	367
2019	764
2018	510
2017	188
2016	27
Prior	22
Revolving Loans Amortized Cost Basis	31
Revolving Loans Converted to Term Loans Amortized Cost Basis	5
Total	1,914
Commercial Loans [Member] | Construction Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	14
2018	38
2017	18
2016	0
Prior	2
Revolving Loans Amortized Cost Basis	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	73
Commercial Loans [Member] | Construction Loans [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	0
Commercial Loans [Member] | Commercial Lease Financing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,086
2019	1,087
2018	551
2017	532
2016	237
Prior	906
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	4,399	$ 4,688
Commercial Loans [Member] | Commercial Lease Financing [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,076
2019	1,050
2018	534
2017	504
2016	228
Prior	901
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	4,293
Commercial Loans [Member] | Commercial Lease Financing [Member] | Criticized Accruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	10
2019	35
2018	15
2017	26
2016	7
Prior	4
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	97
Commercial Loans [Member] | Commercial Lease Financing [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	2
2018	2
2017	2
2016	2
Prior	1
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	$ 9

Asset Quality - Consumer Credit

Asset Quality - Consumer Credit Exposure (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 101,185	$ 94,646
Consumer Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	10,075
2019	5,436
2018	1,499
2017	1,040
2016	1,119
Prior	3,224
Revolving Loans Amortized Cost Basis	5,953
Revolving Loans Converted to Term Loans Amortized Cost Basis	859
Total	29,205	26,614
Accrued interest	101
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,322
2019	1,934
2018	293
2017	319
2016	665
Prior	1,765
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	9,298	7,023
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | FICO Score, 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,595
2019	1,620
2018	194
2017	254
2016	537
Prior	1,211
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	7,411
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	710
2019	284
2018	76
2017	48
2016	100
Prior	332
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	1,550
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	16
2019	28
2018	21
2017	10
2016	26
Prior	170
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	271
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | FICO Score, No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1
2019	2
2018	2
2017	7
2016	2
Prior	52
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	66
Consumer Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,457
2019	634
2018	269
2017	299
2016	279
Prior	1,207
Revolving Loans Amortized Cost Basis	4,357
Revolving Loans Converted to Term Loans Amortized Cost Basis	858
Total	9,360	10,274
Consumer Loans [Member] | Home Equity Loan [Member] | FICO Score, 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,043
2019	404
2018	168
2017	202
2016	190
Prior	839
Revolving Loans Amortized Cost Basis	2,689
Revolving Loans Converted to Term Loans Amortized Cost Basis	590
Total	6,125
Consumer Loans [Member] | Home Equity Loan [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	385
2019	198
2018	82
2017	77
2016	69
Prior	253
Revolving Loans Amortized Cost Basis	1,237
Revolving Loans Converted to Term Loans Amortized Cost Basis	206
Total	2,507
Consumer Loans [Member] | Home Equity Loan [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27
2019	30
2018	18
2017	20
2016	20
Prior	113
Revolving Loans Amortized Cost Basis	426
Revolving Loans Converted to Term Loans Amortized Cost Basis	61
Total	715
Consumer Loans [Member] | Home Equity Loan [Member] | FICO Score, No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2
2019	2
2018	1
2017	0
2016	0
Prior	2
Revolving Loans Amortized Cost Basis	5
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	13
Consumer Loans [Member] | Consumer Direct Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,407
2019	1,223
2018	237
2017	83
2016	45
Prior	111
Revolving Loans Amortized Cost Basis	607
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	4,714	3,513
Consumer Loans [Member] | Consumer Direct Loans [Member] | FICO Score, 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,840
2019	883
2018	115
2017	32
2016	16
Prior	57
Revolving Loans Amortized Cost Basis	119
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	3,062
Consumer Loans [Member] | Consumer Direct Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	479
2019	268
2018	80
2017	22
2016	14
Prior	33
Revolving Loans Amortized Cost Basis	254
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	1,151
Consumer Loans [Member] | Consumer Direct Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	23
2019	37
2018	21
2017	8
2016	5
Prior	10
Revolving Loans Amortized Cost Basis	81
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	185
Consumer Loans [Member] | Consumer Direct Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	65
2019	35
2018	21
2017	21
2016	10
Prior	11
Revolving Loans Amortized Cost Basis	153
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	316
Consumer Loans [Member] | Credit Card Receivable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	989
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	989	1,130
Consumer Loans [Member] | Credit Card Receivable [Member] | FICO Score, 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	488
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	488
Consumer Loans [Member] | Credit Card Receivable [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	407
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	407
Consumer Loans [Member] | Credit Card Receivable [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	93
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	93
Consumer Loans [Member] | Credit Card Receivable [Member] | FICO Score, No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	1
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,889
2019	1,645
2018	700
2017	339
2016	130
Prior	141
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	4,844	$ 4,674
Consumer Loans [Member] | Consumer Indirect Loans [Member] | FICO Score, 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,092
2019	924
2018	369
2017	188
2016	69
Prior	66
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	2,708
Consumer Loans [Member] | Consumer Indirect Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	653
2019	558
2018	232
2017	97
2016	36
Prior	47
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	1,623
Consumer Loans [Member] | Consumer Indirect Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	143
2019	163
2018	99
2017	54
2016	25
Prior	28
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	512
Consumer Loans [Member] | Consumer Indirect Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	$ 1

Asset Quality - Aging Analysis

Asset Quality - Aging Analysis of Past Due and Current Loans (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Current	$ 100,073	$ 93,197
Days Past Due	1,112	1,003
Purchased Credit Impaired		446
Total	101,185	94,646
Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	785	577
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	148	228
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	93	101
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	86	97
Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	71,299	67,224
Days Past Due	681	635
Purchased Credit Impaired		173
Total	71,980	68,032
Accrued interest	140
Commercial Loans [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	497	355
Commercial Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Current	52,396	47,768
Days Past Due	511	479
Purchased Credit Impaired		48
Total	52,907	48,295
Accrued interest	241	244
Commercial Loans [Member] | Commercial And Industrial [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	385	264
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Current	12,548	13,258
Days Past Due	139	109
Purchased Credit Impaired		124
Total	12,687	13,491
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	104	83
Commercial Loans [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Past Due [Line Items]
Current	1,986	1,551
Days Past Due	1	6
Purchased Credit Impaired		1
Total	1,987	1,558
Commercial Loans [Member] | Commercial Real Estate Construction [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	0	2
Commercial Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	14,534	14,809
Days Past Due	140	115
Purchased Credit Impaired		125
Total	14,674	15,049
Commercial Loans [Member] | Commercial Real Estate Loans [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	104	85
Commercial Loans [Member] | Commercial Lease Financing [Member]
Financing Receivable, Past Due [Line Items]
Current	4,369	4,647
Days Past Due	30	41
Purchased Credit Impaired		0
Total	4,399	4,688
Commercial Loans [Member] | Commercial Lease Financing [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	8	6
Commercial Loans [Member] | Credit Card Receivable [Member]
Financing Receivable, Past Due [Line Items]
Total	127	144
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	66	143
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	36	110
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	9	8
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	0	3
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	9	11
Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	21	22
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	56	68
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	50	52
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	5	5
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	0	0
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	5	5
Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	1	11
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	62	69
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	40	53
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	21	13
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	1	1
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	22	14
Commercial Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	0	2
Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	28,774	25,973
Days Past Due	431	368
Purchased Credit Impaired		273
Total	29,205	26,614
Accrued interest	101
Consumer Loans [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	288	222
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Current	9,173	6,705
Days Past Due	125	61
Purchased Credit Impaired		257
Total	9,298	7,023
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	110	48
Consumer Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Current	9,143	10,071
Days Past Due	217	190
Purchased Credit Impaired		13
Total	9,360	10,274
Consumer Loans [Member] | Home Equity Loan [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	154	145
Consumer Loans [Member] | Consumer Direct Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	4,694	3,484
Days Past Due	20	26
Purchased Credit Impaired		3
Total	4,714	3,513
Consumer Loans [Member] | Consumer Direct Loans [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	5	4
Consumer Loans [Member] | Credit Card Receivable [Member]
Financing Receivable, Past Due [Line Items]
Current	972	1,104
Days Past Due	17	26
Purchased Credit Impaired		0
Total	989	1,130
Consumer Loans [Member] | Credit Card Receivable [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	2	3
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	4,792	4,609
Days Past Due	52	65
Purchased Credit Impaired		0
Total	4,844	4,674
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Nonperforming [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	17	22
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	82	85
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	11	7
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	34	30
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	7	10
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	5	6
Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	25	32
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	37	33
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	3	5
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	20	10
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	4	5
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	3	5
Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	7	8
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	24	28
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	1	1
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	9	5
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	4	7
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	7	12
Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Past Due [Line Items]
Days Past Due	$ 3	$ 3

Asset Quality - Post-Modificati

Asset Quality - Post-Modification Outstanding Recorded Investment by Concession Type for Our Commercial Accruing and Nonaccruing TDRs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total commercial and consumer TDRs	$ 126	$ 73
Commercial Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Extension of Maturity Date	5	11
Payment or Covenant Modification/Deferment	59	11
Bankruptcy Plan Modification	0	0
Increase in new commitment or new money	0	8
Total	64	30
Consumer Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest rate reduction	41	14
Other	21	29
Total	$ 62	$ 43

Asset Quality - Summary of Post

Asset Quality - Summary of Post-Modification Outstanding Recorded Investment TDRs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Financing Receivables, Modifications, Rollforward [Roll Forward]
Balance at beginning of the period	$ 347	$ 399
Additions	173	112
Payments	(95)	(145)
Charge-offs	(62)	(19)
Balance at end of period	$ 363	$ 347

Asset Quality - Breakdown of No

Asset Quality - Breakdown of Nonperforming TDRs by Loans Category (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)SecurityLoan	Dec. 31, 2019USD ($)SecurityLoan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	6,133	6,212
Pre-modification Outstanding Recorded Investment	$ 478	$ 425
Post-modification Outstanding Recorded Investment	$ 363	$ 347
Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	3,743	3,590
Pre-modification Outstanding Recorded Investment	$ 184	$ 211
Post-modification Outstanding Recorded Investment	$ 134	$ 164
Nonperforming [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	2,390	2,622
Pre-modification Outstanding Recorded Investment	$ 294	$ 214
Post-modification Outstanding Recorded Investment	$ 229	$ 183
Commercial Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	3	7
Pre-modification Outstanding Recorded Investment	$ 5	$ 30
Post-modification Outstanding Recorded Investment	$ 0	$ 25
Commercial Loans [Member] | Commercial And Industrial [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	3	6
Pre-modification Outstanding Recorded Investment	$ 5	$ 30
Post-modification Outstanding Recorded Investment	$ 0	$ 25
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	0	1
Pre-modification Outstanding Recorded Investment	$ 0	$ 0
Post-modification Outstanding Recorded Investment	$ 0	$ 0
Commercial Loans [Member] | Nonperforming [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	73	57
Pre-modification Outstanding Recorded Investment	$ 198	$ 136
Post-modification Outstanding Recorded Investment	$ 142	$ 111
Commercial Loans [Member] | Nonperforming [Member] | Commercial And Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	66	51
Pre-modification Outstanding Recorded Investment	$ 136	$ 72
Post-modification Outstanding Recorded Investment	$ 92	$ 53
Commercial Real Estate Portfolio Segment [Member] | Nonperforming [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	7	6
Pre-modification Outstanding Recorded Investment	$ 62	$ 64
Post-modification Outstanding Recorded Investment	$ 50	$ 58
Commercial Real Estate Portfolio Segment [Member] | Nonperforming [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	7	6
Pre-modification Outstanding Recorded Investment	$ 62	$ 64
Post-modification Outstanding Recorded Investment	$ 50	$ 58
Consumer Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	3,740	3,583
Pre-modification Outstanding Recorded Investment	$ 179	$ 181
Post-modification Outstanding Recorded Investment	$ 134	$ 139
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	485	493
Pre-modification Outstanding Recorded Investment	$ 37	$ 37
Post-modification Outstanding Recorded Investment	$ 31	$ 31
Consumer Loans [Member] | Home Equity Loan [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	1,781	1,751
Pre-modification Outstanding Recorded Investment	$ 106	$ 104
Post-modification Outstanding Recorded Investment	$ 83	$ 84
Consumer Loans [Member] | Consumer Direct Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	163	139
Pre-modification Outstanding Recorded Investment	$ 4	$ 4
Post-modification Outstanding Recorded Investment	$ 3	$ 3
Consumer Loans [Member] | Consumer Credit Card [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	536	486
Pre-modification Outstanding Recorded Investment	$ 3	$ 3
Post-modification Outstanding Recorded Investment	$ 1	$ 1
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	775	714
Pre-modification Outstanding Recorded Investment	$ 29	$ 33
Post-modification Outstanding Recorded Investment	$ 16	$ 20
Consumer Loans [Member] | Nonperforming [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	2,317	2,565
Pre-modification Outstanding Recorded Investment	$ 96	$ 78
Post-modification Outstanding Recorded Investment	$ 87	$ 72
Consumer Loans [Member] | Nonperforming [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	258	181
Pre-modification Outstanding Recorded Investment	$ 35	$ 13
Post-modification Outstanding Recorded Investment	$ 34	$ 11
Consumer Loans [Member] | Nonperforming [Member] | Home Equity Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	630	713
Pre-modification Outstanding Recorded Investment	$ 41	$ 42
Post-modification Outstanding Recorded Investment	$ 37	$ 41
Consumer Loans [Member] | Nonperforming [Member] | Consumer Direct Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	212	172
Pre-modification Outstanding Recorded Investment	$ 3	$ 2
Post-modification Outstanding Recorded Investment	$ 3	$ 2
Consumer Loans [Member] | Nonperforming [Member] | Consumer Credit Card [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	356	368
Pre-modification Outstanding Recorded Investment	$ 2	$ 2
Post-modification Outstanding Recorded Investment	$ 2	$ 2
Consumer Loans [Member] | Nonperforming [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | SecurityLoan	861	1,131
Pre-modification Outstanding Recorded Investment	$ 15	$ 19
Post-modification Outstanding Recorded Investment	$ 11	$ 16

Asset Quality - Changes in Liab

Asset Quality - Changes in Liability for Credit Losses on Lending Related Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the end of the prior period	$ 68	$ 64
Liability for credit losses on contingent guarantees at the end of the prior period		7	$ 0
Provision (credit) for losses on off balance sheet exposures	56	4	6
Balance at end of period	197	68	64
Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Cumulative effect from change in accounting principle		66	0
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the end of the prior period	$ 141	64
Balance at end of period		$ 141	$ 64

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	$ 735	$ 1,040
Securities available for sale	27,556	21,843
Loans, net of unearned income (residential)	101,185	94,646
Netting adjustments	(380)	(473)
Total derivative assets	1,798	780
LIABILITIES MEASURED ON A RECURRING BASIS
Netting adjustments	(675)	(335)
U.S. Treasury, Agencies, and Corporations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	1,000	334
State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	4
Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	13	11
Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,164	1,714
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	10,106	6,997
Fair Value, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	717	995
Commercial loans	18	45
Total trading account assets	735	1,040
Securities available for sale	27,556	21,843
Total other investments	81	90
Loans, net of unearned income (residential)	11	4
Loans held for sale	264	140
Derivative assets	2,178	1,253
Netting adjustments	(380)	(473)
Total derivative assets	1,798	780
Total assets on a recurring basis at fair value	30,445	23,897
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	910	903
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	14,273	12,783
Fair Value, Recurring [Member] | U.S. Treasury, Agencies, and Corporations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	633	843
Securities available for sale	1,000	334
Fair Value, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	24	30
Securities available for sale	0	4
Fair Value, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	13	44
Securities available for sale	13	11
Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	10,106	6,997
Fair Value, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	1
Fair Value, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	54	69
Fair Value, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	13	12
Fair Value, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	27	21
Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	47	78
Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,164	1,714
Fair Value, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	759	705
Fair Value, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	826	533
Netting adjustments	(675)	(335)
Total derivative liabilities	151	198
Fair Value, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1,584	963
Fair Value, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	288	253
Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	109	67
Fair Value, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	103	60
Fair Value, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	426	208
Fair Value, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	408	200
Fair Value, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1	1
Fair Value, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	11	10
Fair Value, Recurring [Member] | Other [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	58	14
Fair Value, Recurring [Member] | Other [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	16	10
Level 1 [Member] | Fair Value, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Commercial loans	0	0
Total trading account assets	0	0
Securities available for sale	0	0
Total other investments	0	0
Loans, net of unearned income (residential)	0	0
Loans held for sale	0	0
Derivative assets	78	49
Netting adjustments	0	0
Total derivative assets	78	49
Total assets on a recurring basis at fair value	78	49
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	328	62
Level 1 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | U.S. Treasury, Agencies, and Corporations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	256	19
Level 1 [Member] | Fair Value, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	72	43
Netting adjustments	0	0
Total derivative liabilities	72	43
Level 1 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	78	49
Level 1 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	72	43
Level 1 [Member] | Fair Value, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Other [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Recurring [Member] | Other [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 2 [Member] | Fair Value, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	717	995
Commercial loans	18	45
Total trading account assets	735	1,040
Securities available for sale	27,543	21,832
Total other investments	0	0
Loans, net of unearned income (residential)	0	0
Loans held for sale	264	140
Derivative assets	2,009	1,176
Netting adjustments	0	0
Total derivative assets	2,009	1,176
Total assets on a recurring basis at fair value	30,551	24,188
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	1,246	1,167
Level 2 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	14,273	12,783
Level 2 [Member] | Fair Value, Recurring [Member] | U.S. Treasury, Agencies, and Corporations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	633	843
Securities available for sale	1,000	334
Level 2 [Member] | Fair Value, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	24	30
Securities available for sale	0	4
Level 2 [Member] | Fair Value, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	13	44
Securities available for sale	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	10,106	6,997
Level 2 [Member] | Fair Value, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	47	78
Level 2 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,164	1,714
Level 2 [Member] | Fair Value, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	503	686
Level 2 [Member] | Fair Value, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	743	481
Netting adjustments	0	0
Total derivative liabilities	743	481
Level 2 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1,528	941
Level 2 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	288	253
Level 2 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	31	18
Level 2 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	31	17
Level 2 [Member] | Fair Value, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	424	208
Level 2 [Member] | Fair Value, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	408	200
Level 2 [Member] | Fair Value, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 2 [Member] | Fair Value, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	1
Level 2 [Member] | Fair Value, Recurring [Member] | Other [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	26	9
Level 2 [Member] | Fair Value, Recurring [Member] | Other [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	16	10
Level 3 [Member] | Fair Value, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Commercial loans	0	0
Total trading account assets	0	0
Securities available for sale	13	11
Total other investments	14	13
Loans, net of unearned income (residential)	11	4
Loans held for sale	0	0
Derivative assets	91	28
Netting adjustments	0	0
Total derivative assets	91	28
Total assets on a recurring basis at fair value	129	56
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	11	9
Level 3 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | U.S. Treasury, Agencies, and Corporations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	13	11
Level 3 [Member] | Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	1
Level 3 [Member] | Fair Value, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	1
Level 3 [Member] | Fair Value, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	13	12
Level 3 [Member] | Fair Value, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	13	12
Level 3 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	11	9
Netting adjustments	0	0
Total derivative liabilities	11	9
Level 3 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	56	22
Level 3 [Member] | Fair Value, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	2	0
Level 3 [Member] | Fair Value, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1	1
Level 3 [Member] | Fair Value, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	11	9
Level 3 [Member] | Fair Value, Recurring [Member] | Other [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	32	5
Level 3 [Member] | Fair Value, Recurring [Member] | Other [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Recurring [Member] | Equity Investments Direct, NAV [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	7	1
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Recurring [Member] | Equity Investments Indirect, NAV [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	$ 7	$ 8

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value of Direct and Indirect Investments, Related Unfunded Commitments and Financial Support Provided (Details) - Principal Investments [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 54
Unfunded Commitments	16
Funded Commitments	2	$ 2
Funded Other	0	0
Direct Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1
Unfunded Commitments	0
Funded Commitments	0	0
Funded Other	0	0
Indirect Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	53
Unfunded Commitments	16
Funded Commitments	2	2
Funded Other	$ 0	$ 0

Fair Value Measurements - Chang

Fair Value Measurements - Change in Fair Values of Level 3 Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Investments [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	$ 12	$ 7
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	1	4
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	1
Transfers out of Level 3	0	0
End of Period Balance	13	12
Unrealized Gains (Losses) Included in Earnings	1	4
Other Investments [Member] | Principal Direct Investments [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	1	1
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	1	1
Unrealized Gains (Losses) Included in Earnings	0	0
Available-for-sale Securities [Member] | Other Securities [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	11	20
Gains (Losses) included in comprehensive income	2	15
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(24)
End of Period Balance	13	11
Unrealized Gains (Losses) Included in Earnings	0	0
Interest Rate [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	22	5
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	19	3
Purchases	17	2
Sales	(10)	(1)
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	99	21
Transfers out of Level 3	(91)	(8)
End of Period Balance	56	22
Unrealized Gains (Losses) Included in Earnings	0	0
Credit [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	(8)	0
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	(2)	(8)
Purchases	1	0
Sales	(1)	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	(10)	(8)
Unrealized Gains (Losses) Included in Earnings	0	0
Other [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	5	3
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	7	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	20	2
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	32	5
Unrealized Gains (Losses) Included in Earnings	0	0
Loans Held For Sale Fair Value [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	0	0
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	(10)	(1)
Settlements	0	0
Transfers Other	10	1
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	0	0
Unrealized Gains (Losses) Included in Earnings	0	0
Loans Held For Investment Fair Value [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	4	3
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	(2)	0
Settlements	0	0
Transfers Other	9	1
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	11	4
Unrealized Gains (Losses) Included in Earnings	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities without readily determinable fair value	$ 171,000,000	$ 134,000,000
Impairment on equity securities without readily determinable fair value	0
Financing receivable, net of allowance	99,559,000,000	93,746,000,000
Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans carried at fair value	2,000,000	2,000,000
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	621,000,000	605,000,000
Loans carried at fair value	11,000,000	4,000,000
Carrying Amount [Member] | Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing receivable, net of allowance	674,000,000	855,000,000
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	621,000,000	605,000,000
Loans carried at fair value	11,000,000	4,000,000
Estimate of Fair Value Measurement [Member] | Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing receivable, net of allowance	567,000,000	729,000,000
Fair Value, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	81,000,000	90,000,000
Liabilities measured at fair value on non recurring basis	910,000,000	903,000,000
Fair Value, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value on non recurring basis	0	0
Principal Direct Investments [Member] | Fair Value, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	$ 1,000,000	$ 1,000,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	$ 108	$ 76
Accrued income and other assets	56	169
Total assets on a recurring basis at fair value	164	245
Level 1 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	0	0
Accrued income and other assets	0	0
Total assets on a recurring basis at fair value	0	0
Level 2 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	0	0
Accrued income and other assets	0	118
Total assets on a recurring basis at fair value	0	118
Level 3 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	108	76
Accrued income and other assets	56	51
Total assets on a recurring basis at fair value	$ 164	$ 127

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Details) $ in Millions	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	$ 27,556	$ 21,843
Derivative assets	1,798	780
Mortgage servicing assets excluded from OREO	40	46
Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	27,556	21,843
Other investments	81	90
Derivative assets	1,798	780
Fair Value, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans	108	76
Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	13	11
Other investments	14	13
Derivative assets	91	28
Level 3 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans	108	76
Other Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	13	11
Other Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	13	11
Other Securities [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	13	11
Principal Direct Investments [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments	1	1
Principal Direct Investments [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments	1	1
Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments	13	12
Valuation Technique, Discounted Cash Flow [Member] | Other Securities [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available for sale	13	11
Valuation, Fair Value Of Underlying Collateral [Member] | Level 3 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans	108	76
Valuation, Market Approach [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, net of unearned income (residential)	11	4
Valuation, Appraised Value [Member] | Level 3 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
OREO	16	5
Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets	56	22
Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets	1	1
Derivative liabilities	11	9
Other Contract [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets	$ 32	$ 5
Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available-for-sale, measurement input	0.1509	0.1610
Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments, measurement input	0.1390	0.1391
Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments, measurement input	0.1704	0.1724
Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments, measurement input	0.1547	0.1561
Measurement Input, Discount Rate [Member] | Valuation, Fair Value Of Underlying Collateral [Member] | Level 3 [Member] | Fair Value, Nonrecurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans, measurement input	0	0
Measurement Input, Discount Rate [Member] | Valuation, Fair Value Of Underlying Collateral [Member] | Level 3 [Member] | Fair Value, Nonrecurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans, measurement input	1	0.6000
Measurement Input, Discount Rate [Member] | Valuation, Fair Value Of Underlying Collateral [Member] | Level 3 [Member] | Fair Value, Nonrecurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans, measurement input	0.3600	0.1000
Measurement Input, Discount for Lack of Marketability [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available-for-sale, measurement input	0.3000	0.3000
Measurement Input, Discount for Lack of Marketability [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments, measurement input	0.3000	0.3000
Measurement Input, Price Volatility [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Securities available-for-sale, measurement input	0.4400	0.4300
Measurement Input, Price Volatility [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments, measurement input	0.5200	0.4700
Measurement Input, Comparability Adjustment [Member] | Valuation, Market Approach [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, net of unearned income (residential), measurement input	0.6450	0.7900
Measurement Input, Comparability Adjustment [Member] | Valuation, Market Approach [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, net of unearned income (residential), measurement input	0.9904	0.9800
Measurement Input, Comparability Adjustment [Member] | Valuation, Market Approach [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, net of unearned income (residential), measurement input	0.9417	0.9105
Measurement Input, Default Rate [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.0002	0.0002
Measurement Input, Default Rate [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Measurement Input, Default Rate [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.0790	0.0540
Measurement Input, Default Rate [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.0002	0.0002
Derivative liabilities, measurement input	0.0002	0.0002
Measurement Input, Default Rate [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Derivative liabilities, measurement input	1	1
Measurement Input, Default Rate [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.0470	0.042
Derivative liabilities, measurement input	0.1545	0.1224
Measurement Input, Internal Risk Rating [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Measurement Input, Internal Risk Rating [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	19	19
Measurement Input, Internal Risk Rating [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	9.675	9.168
Measurement Input, Internal Risk Rating [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Derivative liabilities, measurement input	1	1
Measurement Input, Internal Risk Rating [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	19	19
Derivative liabilities, measurement input	19	19
Measurement Input, Internal Risk Rating [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	10.478	10.13
Derivative liabilities, measurement input	8.555	8.058
Measurement Input, Loss Given Default [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0	0
Measurement Input, Loss Given Default [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Measurement Input, Loss Given Default [Member] | Interest Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.483	0.492
Measurement Input, Loss Given Default [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0	0
Derivative liabilities, measurement input	0	0
Measurement Input, Loss Given Default [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	1	1
Derivative liabilities, measurement input	1	1
Measurement Input, Loss Given Default [Member] | Credit [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.490	0.498
Derivative liabilities, measurement input	0.431	0.411
Measurement Input, Loan Closing Rates [Member] | Other Contract [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.3695	0.3771
Measurement Input, Loan Closing Rates [Member] | Other Contract [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.9968	0.9969
Measurement Input, Loan Closing Rates [Member] | Other Contract [Member] | Valuation Technique, Discounted Cash Flow [Member] | Level 3 [Member] | Fair Value, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative assets, measurement input	0.7751	0.7933

Fair Value Measurements - Fai_3

Fair Value Measurements - Fair Value Disclosures of Financial Instruments (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
ASSETS
Trading account assets		$ 735	$ 1,040
Held-to-maturity securities		7,595	10,067
Held-to-maturity securities		8,023	10,116
Loans, net of unearned income (residential)		101,185	94,646
Loans held for sale, Carrying Amount	[1]	1,583	1,334
Derivative assets		1,798	780
Fair Value		27,556	21,843
LIABILITIES
Long-term debt, Carrying Amount		13,709	12,448
Carrying Amount [Member]
ASSETS
Trading account assets		735	1,040
Other investments		621	605
Loans, net of allowance		11	4
Held-to-maturity securities		7,595	10,067
Loans, net of unearned income (residential)		99,548	93,742
Loans held for sale, Carrying Amount		1,319	1,194
Loans held for sale		264	140
Fair Value		27,556	21,843
Cash and short-term investments		17,285	2,004
LIABILITIES
Time deposits, Carrying Amount		5,743	11,652
Short-term borrowings, Carrying Amount		979	1,092
Long-term debt, Carrying Amount		13,709	12,448
Deposits with no stated maturity		129,539	100,218
Estimate of Fair Value Measurement [Member]
ASSETS
Trading account assets		735	1,040
Other investments		621	605
Loans, net of allowance		11	4
Held-to-maturity securities		8,023	10,116
Loans, net of unearned income (residential)		98,946	92,641
Loans held for sale, Carrying Amount		1,319	1,194
Loans held for sale		264	140
Fair Value		27,556	21,843
Cash and short-term investments		17,285	2,004
LIABILITIES
Time deposits		5,765	11,752
Short-term borrowings		979	1,092
Long-term debt		14,659	12,943
Deposits with no stated maturity		129,539	100,218
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Trading account assets		0	0
Other investments		0	0
Loans, net of allowance		0	0
Held-to-maturity securities		0	0
Loans, net of unearned income (residential)		0	0
Loans held for sale, Carrying Amount		0	0
Loans held for sale		0	0
Fair Value		0	0
Cash and short-term investments		17,285	2,004
LIABILITIES
Time deposits		0	0
Short-term borrowings		256	19
Long-term debt		13,925	12,694
Deposits with no stated maturity		0	0
Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Trading account assets		735	1,040
Other investments		0	0
Loans, net of allowance		0	0
Held-to-maturity securities		8,023	10,116
Loans, net of unearned income (residential)		0	0
Loans held for sale, Carrying Amount		0	0
Loans held for sale		264	140
Fair Value		27,543	21,832
Cash and short-term investments		0	0
LIABILITIES
Time deposits		5,765	11,752
Short-term borrowings		723	1,073
Long-term debt		734	249
Deposits with no stated maturity		129,539	100,218
Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Trading account assets		0	0
Other investments		555	528
Loans, net of allowance		11	4
Held-to-maturity securities		0	0
Loans, net of unearned income (residential)		98,946	92,641
Loans held for sale, Carrying Amount		1,319	1,194
Loans held for sale		0	0
Fair Value		13	11
Cash and short-term investments		0	0
LIABILITIES
Time deposits		0	0
Short-term borrowings		0	0
Long-term debt		0	0
Deposits with no stated maturity		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
ASSETS
Other investments		66	77
Not Designated as Hedging Instrument [Member] | Carrying Amount [Member]
ASSETS
Derivative assets		1,676	715
LIABILITIES
Derivative liabilities		154	194
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member]
ASSETS
Derivative assets		1,675	715
Derivative assets, netting adjustment		(433)	(347)
LIABILITIES
Derivative liabilities		154	194
Derivative liabilities, netting adjustment		(675)	(319)
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Derivative assets		78	49
LIABILITIES
Derivative liabilities		72	43
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Derivative assets		1,939	985
LIABILITIES
Derivative liabilities		746	461
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Derivative assets		91	28
LIABILITIES
Derivative liabilities		11	9
Designated as Hedging Instrument [Member] | Carrying Amount [Member]
ASSETS
Derivative assets		123	65
LIABILITIES
Derivative liabilities		(3)	4
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member]
ASSETS
Derivative assets		123	65
Derivative assets, netting adjustment		53	(126)
LIABILITIES
Derivative liabilities		(3)	4
Derivative liabilities, netting adjustment		0	(16)
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Derivative assets		0	0
LIABILITIES
Derivative liabilities		0	0
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Derivative assets		70	191
LIABILITIES
Derivative liabilities		(3)	20
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Derivative assets		0	0
LIABILITIES
Derivative liabilities		$ 0	$ 0
[1]	Total loans held for sale include Real estate — residential mortgage loans held for sale at fair value of $264 million at December 31, 2020, and $140 million at December 31, 2019

Securities - Details of Securit

Securities - Details of Securities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 26,810	$ 21,692
Gross Unrealized Gains	804	266
Gross Unrealized Losses	58	115
Fair Value	27,556	21,843
HELD-TO-MATURITY SECURITIES
Amortized Cost	7,595	10,067
Gross Unrealized Gains	428	107
Gross Unrealized Losses	0	58
Fair Value	8,023	10,116
Available-for-sale Securities [Member]
HELD-TO-MATURITY SECURITIES
Accrued interest	42
Held-to-maturity Securities [Member]
HELD-TO-MATURITY SECURITIES
Accrued interest	15
U.S. Treasury, Agencies, and Corporations [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	1,000	334
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	1,000	334
State and municpal bonds [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	0	4
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	4
Collateralized Mortgage Obligations [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	14,001	12,772
Gross Unrealized Gains	297	82
Gross Unrealized Losses	25	71
Fair Value	14,273	12,783
HELD-TO-MATURITY SECURITIES
Amortized Cost	3,775	5,692
Gross Unrealized Gains	124	23
Gross Unrealized Losses	0	49
Fair Value	3,899	5,666
Residential Mortgage Backed Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	2,094	1,677
Gross Unrealized Gains	70	41
Gross Unrealized Losses	0	4
Fair Value	2,164	1,714
HELD-TO-MATURITY SECURITIES
Amortized Cost	271	409
Gross Unrealized Gains	14	6
Gross Unrealized Losses	0	0
Fair Value	285	415
Asset-backed Securities [Member]
HELD-TO-MATURITY SECURITIES
Amortized Cost	19	11
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	19	11
Other Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	8	7
Gross Unrealized Gains	5	4
Gross Unrealized Losses	0	0
Fair Value	13	11
HELD-TO-MATURITY SECURITIES
Amortized Cost	15	15
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	15	15
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	9,707	6,898
Gross Unrealized Gains	432	139
Gross Unrealized Losses	33	40
Fair Value	10,106	6,997
HELD-TO-MATURITY SECURITIES
Amortized Cost	3,515	3,940
Gross Unrealized Gains	290	78
Gross Unrealized Losses	0	9
Fair Value	$ 3,805	$ 4,009

Securities - Summary of Securit

Securities - Summary of Securities in Unrealized Loss Position (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Held-to-maturity securities:
Temporarily impaired securities, fair value, less than 12 months	$ 4,830	$ 7,250
Temporarily impaired securities, gross unrealized losses, less than 12 months	58	60
Temporarily impaired securities, fair value, 12 months or longer	29	7,382
Temporarily impaired securities, gross unrealized losses, 12 months or longer	0	113
Temporarily impaired securities, fair value	4,859	14,632
Temporarily impaired securities, gross unrealized losses	58	173
Loans pledged as collateral	13,600
U.S. Treasury, Agencies, and Corporations [Member]
Securities available for sale:
Fair value, less than 12 months		30
Gross unrealized losses, less than 12 months		0
Fair value, 12 months or longer		30
Gross unrealized losses, 12 months or longer		0
Fair value		60
Gross unrealized losses		0
Collateralized Mortgage Obligations [Member]
Securities available for sale:
Fair value, less than 12 months	2,110	3,432
Gross unrealized losses, less than 12 months	25	20
Fair value, 12 months or longer	0	3,221
Gross unrealized losses, 12 months or longer	0	51
Fair value	2,110	6,653
Gross unrealized losses	25	71
Held-to-maturity securities:
Fair value, less than 12 months	0	1,626
Gross unrealized losses, less than 12 months	0	14
Fair value, 12 months or longer	24	2,289
Gross unrealized losses, 12 months or longer	0	35
Fair value	24	3,915
Gross unrealized losses	0	49
Commercial Mortgage Backed Securities [Member]
Securities available for sale:
Fair value, less than 12 months	2,709	1,541
Gross unrealized losses, less than 12 months	33	17
Fair value, 12 months or longer	0	1,213
Gross unrealized losses, 12 months or longer	0	23
Fair value	2,709	2,754
Gross unrealized losses		40
Held-to-maturity securities:
Fair value, less than 12 months		518
Gross unrealized losses, less than 12 months		9
Fair value, 12 months or longer		0
Gross unrealized losses, 12 months or longer		0
Fair value		518
Gross unrealized losses		9
Asset-backed Securities [Member]
Held-to-maturity securities:
Fair value, less than 12 months		11
Gross unrealized losses, less than 12 months		0
Fair value, 12 months or longer		0
Gross unrealized losses, 12 months or longer		0
Fair value		11
Gross unrealized losses		0
Other Securities [Member]
Held-to-maturity securities:
Fair value, less than 12 months	5	3
Gross unrealized losses, less than 12 months	0	0
Fair value, 12 months or longer	0	0
Gross unrealized losses, 12 months or longer	0	0
Fair value	5	3
Gross unrealized losses	0	0
Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
Securities available for sale:
Fair value, less than 12 months	6	33
Gross unrealized losses, less than 12 months	0	0
Fair value, 12 months or longer	5	629
Gross unrealized losses, 12 months or longer	0	4
Fair value	11	662
Gross unrealized losses	0	4
Held-to-maturity securities:
Fair value, less than 12 months		56
Gross unrealized losses, less than 12 months		0
Fair value, 12 months or longer		0
Gross unrealized losses, 12 months or longer		0
Fair value		56
Gross unrealized losses		$ 0
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
Securities available for sale:
Gross unrealized losses	$ 33

Securities - Securities by Matu

Securities - Securities by Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Amortized Cost of Securities Available for sale, Due in one year or less	$ 1,889
Amortized Cost of Securities Available for sale, Due after one through five years	15,410
Amortized Cost of Securities Available for sale, Due after five through ten years	6,686
Amortized Cost of Securities Available for sale, Due after ten years	2,825
Amortized Cost	26,810	$ 21,692
Fair Value of Securities Available for sale, Due in one year or less	1,896
Fair Value of Securities Available for sale, Due after one through five years	15,891
Fair Value of Securities Available for sale, Due after five through ten years	6,964
Fair Value of Securities Available for sale, Due after ten years	2,805
Total Fair Value of Securities Available-for-sale	27,556	21,843
Amortized Cost of Held-to-Maturity Securities, Due in one year or less	77
Amortized Cost of Held-to-Maturity Securities, Due after one through five years	4,941
Amortized Cost of Held-to-Maturity Securities, Due after five through ten years	2,577
Amortized Cost of Held-to-Maturity Securities, Due after ten years	0
Amortized Cost	7,595	10,067
Fair Value of Held-to-Maturity Securities, Due in one year or less	78
Fair Value of Held-to-Maturity Securities, Due after one through five years	5,150
Fair Value of Held-to-Maturity Securities, Due after five through ten years	2,795
Fair Value of Held-to-Maturity Securities, Due after ten years	0
Total Fair Value of Held-to-Maturity Securities	$ 8,023	$ 10,116

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities - Additional Information (Details)		1 Months Ended	12 Months Ended
		Dec. 31, 2019USD ($)rating	Dec. 31, 2020USD ($)derivativerating	Dec. 31, 2019USD ($)rating	Dec. 31, 2018USD ($)
Credit Derivatives [Line Items]
Derivative assets after effects of bilateral collateral and master netting agreements			$ 123,000,000
Derivative liabilities after effects of bilateral collateral and master netting agreements			3,000,000
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses			1,700,000,000
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses			153,000,000
Reclassify of after-tax net losses on derivative instruments from AOCI			$ 232,000,000
Length of time hedge in cash flow hedge			12 months
Reclassification of net losses related to terminated cash flow hedges from AOCI to income			$ 73,000,000
Maximum length of time over which forecasted transactions are hedged, years			11 years
Other Comprehensive income unrealized gain on derivatives arising during period net of tax		$ 25,000,000		$ 25,000,000
Other income	[1]		$ (15,000,000)	(68,000,000)	$ (176,000,000)
Cash collateral netted against derivative assets		(207,000,000)	63,000,000	(207,000,000)
Collateral netted against derivative liabilities		69,000,000	232,000,000	69,000,000
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements			250,000,000
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements			245,000,000
Over-collateralization on derivatives to broker-dealers and banks, after the application of master netting agreements and collateral			243,000,000
Additional collateral held in the form of securities			3,000,000
Default reserve associated with uncollateralized contracts			49,000,000
Gross exposure on derivatives after taking into account effects of master netting agreements			1,700,000,000
Net exposure on derivatives with clients after application of master netting agreements collateral and related reserve			1,600,000,000
Net liability position totaled		$ 9,000,000	$ 9,000,000	$ 9,000,000
Number of credit risk derivatives held | derivative			0
KeyBank (consolidated) [Member]
Credit Derivatives [Line Items]
Net liability position totaled			$ 44,000,000
Derivative assets included in net liability position			111,000,000
Derivative liabilities included in net liability position			156,000,000
Cash and securities collateral posted			$ 30,000,000
KeyBank (consolidated) [Member] | Unsecured Debt [Member]
Credit Derivatives [Line Items]
Number of ratings above noninvestment | rating		4	4	4
KeyBank (consolidated) [Member] | Maximum [Member] | Unsecured Debt [Member]
Credit Derivatives [Line Items]
Payments to terminate contracts		$ 3,000,000	$ 2,000,000	$ 3,000,000
Key Corp [Member]
Credit Derivatives [Line Items]
Additional collateral held in the form of securities			0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustment [Member]
Credit Derivatives [Line Items]
Other income		$ 11,000,000	$ 0	$ 14,000,000
[1]	Net securities gains (losses) totaled $4 million for the year ended December 31, 2020, $20 million for the year ended December 31, 2019, and less than $1 million for the year ended December 31, 2018. For 2020, 2019, and 2018, we did not have any impairment losses related to securities.

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities - Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Notional Amount	$ 136,020	$ 126,077
Derivative assets, Netting adjustments	(380)	(473)
Derivative assets, Fair Value	1,796	778
Derivative liabilities, Netting adjustments	(675)	(335)
Derivative liabilities, Fair Value	140	156
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	36,135	39,208
Derivative assets, Fair Value	70	191
Derivative liabilities, Fair Value	(3)	20
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	99,885	86,869
Derivative assets, Fair Value	2,108	1,062
Derivative liabilities, Fair Value	829	513
Interest Rate [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	36,135	39,208
Derivative assets, Fair Value	70	191
Derivative liabilities, Fair Value	(3)	20
Interest Rate [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	78,424	71,209
Derivative assets, Fair Value	1,514	772
Derivative liabilities, Fair Value	291	233
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	6,385	6,572
Derivative assets, Fair Value	109	67
Derivative liabilities, Fair Value	103	60
Commodity [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	9,702	5,324
Derivative assets, Fair Value	426	208
Derivative liabilities, Fair Value	408	200
Credit [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	423	427
Derivative assets, Fair Value	1	1
Derivative liabilities, Fair Value	11	10
Other [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	4,951	3,337
Derivative assets, Fair Value	58	14
Derivative liabilities, Fair Value	16	10
Net Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	136,020	126,077
Derivative assets, Fair Value	1,798	780
Derivative liabilities, Fair Value	151	198
Counterparty And Cash Collateral Netting [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Fair Value	(2)	(2)
Derivative liabilities, Fair Value	$ (11)	$ (42)

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities - Cumulative Basis Adjustments on Fair Value Hedges (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Certificate of deposit ($100,000 or more)	$ 100,000	$ 100,000
Securities available for sale	27,556,000,000	21,843,000,000
Long-term Debt [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	8,182,000,000	8,408,000,000
Hedge accounting basis adjustment	416,000,000	240,000,000
Available-for-sale Securities [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	2,080,000,000
Hedge accounting basis adjustment	(21,000,000)
Securities available for sale	2,500,000,000
Not Designated as Hedging Instrument [Member] | Long-term Debt [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Hedge accounting basis adjustment	$ (8,000,000)	$ (9,000,000)

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities - Effect of Fair Value and Cash Flow Hedges on Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense — Long-term debt		$ (286)	$ (454)	$ (420)
Interest income — Loans		3,866	4,267	4,023
Investment banking and debt placement fees		661	630	650
Deposits		(347)	(853)	(517)
Other income	[1]	15	68	176
Interest Expense, Long-Term Debt [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Net income (expense) recognized on cash flow hedges			(1)	(2)
Interest Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Net income (expense) recognized on cash flow hedges			15	(68)
Investment Banking And Debt Placement [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Net income (expense) recognized on fair value hedges			0
Investment Banking And Debt Placement [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Net income (expense) recognized on cash flow hedges		0	0	2
Interest Expense, Deposits [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Net income (expense) recognized on cash flow hedges			0	0
Other Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Net income (expense) recognized on cash flow hedges			32	31
Interest Rate [Member] | Interest Expense, Long-Term Debt [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		(177)	(247)	(5)
Recognized on derivatives designated as hedging instruments		305	231	(12)
Net income (expense) recognized on fair value hedges		128	(16)	(17)
Interest Rate [Member] | Interest Expense, Long-Term Debt [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		(4)	(1)	(2)
Net income (expense) recognized on cash flow hedges		(4)
Interest Rate [Member] | Interest Income [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0	0	0
Interest Rate [Member] | Interest Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		319	15	(68)
Net income (expense) recognized on cash flow hedges		319
Interest Rate [Member] | Investment Banking And Debt Placement [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0		0
Interest Rate [Member] | Investment Banking And Debt Placement [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		0	0	2
Interest Rate [Member] | Interest Expense, Deposits [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	(1)	1
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0	(1)	1
Interest Rate [Member] | Interest Expense, Deposits [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		0	0	0
Net income (expense) recognized on cash flow hedges		0
Interest Rate [Member] | Other Income [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0	0	0
Interest Rate [Member] | Other Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		0	0	$ 31
Net income (expense) recognized on cash flow hedges		$ 0
Foreign Exchange Contract [Member] | Interest Expense, Long-Term Debt [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income			0
Foreign Exchange Contract [Member] | Interest Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income			0
Foreign Exchange Contract [Member] | Investment Banking And Debt Placement [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income			0
Foreign Exchange Contract [Member] | Interest Expense, Deposits [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income			0
Foreign Exchange Contract [Member] | Other Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income			$ 32
[1]	Net securities gains (losses) totaled $4 million for the year ended December 31, 2020, $20 million for the year ended December 31, 2019, and less than $1 million for the year ended December 31, 2018. For 2020, 2019, and 2018, we did not have any impairment losses related to securities.

Derivatives and Hedging Activ_7

Derivatives and Hedging Activities - Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	$ 614	$ 440	$ 9
Net Gains (Losses) Reclassified From OCI Into Income	315	46	(37)
Net Gains (Losses) Recognized in Other Income	0	0	0
Interest Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	628	442	(13)
Net Gains (Losses) Reclassified From OCI Into Income	319	15	(68)
Net Gains (Losses) Recognized in Other Income	0	0	0
Interest Expense [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	(5)	(1)	2
Net Gains (Losses) Reclassified From OCI Into Income	(4)	(1)	(2)
Net Gains (Losses) Recognized in Other Income	0	0	0
Investment Banking and Debt Placement Fees [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	(9)	3	1
Net Gains (Losses) Reclassified From OCI Into Income	0	0	2
Net Gains (Losses) Recognized in Other Income	0	0	0
Other Income [Member] | Foreign Exchange Contract [Member] | Net Investment Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	0	(4)	19
Net Gains (Losses) Reclassified From OCI Into Income	0	32	31
Net Gains (Losses) Recognized in Other Income	$ 0	$ 0	$ 0

Derivatives and Hedging Activ_8

Derivatives and Hedging Activities - Pre-Tax Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 87	$ 55	$ 70
Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	22	44	37
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	41	45	42
Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	19	6	8
Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(33)	(42)	(28)
Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	38	2	11
Corporate Services Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	88	91	90
Corporate Services Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	32	46	38
Corporate Services Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	41	45	42
Corporate Services Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	19	6	8
Corporate Services Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(4)	(6)	2
Corporate Services Income [Member] | Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	19	2	(1)
Consumer Mortgage Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	19	2	(1)
Other Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(20)	(38)	(19)
Other Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(10)	(2)	(1)
Other Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Other Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Other Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(29)	(36)	(30)
Other Income [Member] | Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 19	$ 0	$ 12

Derivatives and Hedging Activ_9

Derivatives and Hedging Activities - Fair Value of Derivative Assets by Type (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 1,735	$ 987
Add (Less): Related collateral	63	(207)
Total derivative assets	1,798	780
Interest Rate [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	1,448	848
Foreign Exchange Contract [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	52	30
Commodity [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	178	95
Credit [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	(1)	0
Other [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 58	$ 14

Derivatives and Hedging Acti_10

Derivatives and Hedging Activities - Credit Derivatives Sold and Held (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Credit Derivatives [Line Items]
Notional Amount	$ 227	$ 134
Payment / Performance Risk	0.00%	0.00%
Other [Member]
Credit Derivatives [Line Items]
Notional Amount	$ 227	$ 134
Average Term	12 years 9 months 3 days	14 years 3 months 18 days
Payment / Performance Risk	19.53%	14.56%

Derivatives and Hedging Acti_11

Derivatives and Hedging Activities - Credit Risk Contingent Feature (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	$ 3
One Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	1	$ 1
One Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	1	1
Two Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	1	1
Two Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	1	1
Three Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	1	1
Three Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	$ 1	$ 1

Mortgage Servicing Assets - Cha

Mortgage Servicing Assets - Changes in Carrying Amount of Mortgage Servicing Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commercial Mortgage Backed Securities [Member]
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	$ 539	$ 502
Servicing retained from loan sales	138	108
Purchases	33	47
Amortization	(117)	(115)
Temporary impairments	(15)	(3)
Balance at end of period	578	539
Fair value at end of period	668	665
Residential Mortgage Backed Securities [Member]
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	46	37
Servicing retained from loan sales	36	15
Purchases	0	0
Amortization	(14)	(6)
Temporary impairments	(10)	0
Balance at end of period	58	46
Fair value at end of period	$ 60	$ 50

Mortgage Servicing Assets - Sch

Mortgage Servicing Assets - Schedule of Range and Weighted-Average of Significant Unobservable Inputs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commercial Mortgage Backed Securities [Member] | Minimum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults	101.00%	100.00%
Discount rate	748.00%	700.00%
Escrow earn rate	92.00%	144.00%
Loan assumption rate	0.00%	1.00%
Commercial Mortgage Backed Securities [Member] | Maximum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults	2.00%	2.00%
Discount rate	10.62%	11.44%
Escrow earn rate	1.14%	2.32%
Loan assumption rate	1.77%	3.37%
Commercial Mortgage Backed Securities [Member] | Weighted Average [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults	1.18%	1.13%
Discount rate	9.22%	9.32%
Escrow earn rate	1.04%	2.03%
Loan assumption rate	1.43%	1.37%
Residential Mortgage Backed Securities [Member] | Minimum [Member]
Servicing Assets at Fair Value [Line Items]
Discount rate	7.51%	7.50%
Prepayment speed	12.39%	10.38%
Servicing cost	$ 62	$ 62
Residential Mortgage Backed Securities [Member] | Maximum [Member]
Servicing Assets at Fair Value [Line Items]
Discount rate	8.63%	8.50%
Prepayment speed	54.27%	61.51%
Servicing cost	$ 5,125	$ 4,375
Residential Mortgage Backed Securities [Member] | Weighted Average [Member]
Servicing Assets at Fair Value [Line Items]
Discount rate	7.55%	7.52%
Prepayment speed	17.09%	12.95%
Servicing cost	$ 75.37	$ 68.73

Mortgage Servicing Assets - Nar

Mortgage Servicing Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commercial Mortgage Backed Securities [Member]
Servicing Assets at Fair Value [Line Items]
Contractual fee income	$ 214	$ 196	$ 171
Amortization of mortgage servicing rights	117	115	102
Residential Mortgage Backed Securities [Member]
Servicing Assets at Fair Value [Line Items]
Contractual fee income	34	21	14
Amortization of mortgage servicing rights	$ 14	$ 6	$ 4

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lease renewal term	5 years
Carrying amount of residual assets covered by residual value guarantees	$ 269	$ 289
Carrying amount of operating lease assets	$ 859	$ 941
Leases, Excluding Ground Leases [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, lease term of operating or financing leases	1 year
Leases, Excluding Ground Leases [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, lease term of operating or financing leases	20 years
Ground Leases [Member]
Lessee, Lease, Description [Line Items]
Lessee, lease term of operating or financing leases	30 years

Leases - Components of Lease Ex

Leases - Components of Lease Expense and Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 135	$ 136
Finance lease cost:
Amortization of right-of-use assets	2	2
Interest on lease liabilities	1	1
Variable lease cost	20	24
Total lease cost	158	163
Short-term lease cost (less than $1 million)	$ 1	$ 1

Leases - Summary of Cash Flows

Leases - Summary of Cash Flows Related to Leases (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases		$ 1,000,000	$ 1,000,000
Operating cash flows from operating leases		143,000,000	146,000,000
Financing cash flows from finance leases		2,000,000	2,000,000
Right-of-use assets obtained in exchange for lease obligations: (b)
Operating leases		86,000,000	81,000,000
Net gain recognized from sale leaseback transaction		0	14,000,000
Finance leases		$ 0	$ 0
Proceeds from sale leaseback transaction	$ 16,000,000

Leases - Summary of Additional

Leases - Summary of Additional Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating lease assets	$ 630	$ 654
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Operating lease liabilities	$ 711	$ 748
Finance leases:
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Finance lease, right of use asset, before accumulated depreciation	$ 28	$ 28
Accumulated depreciation	(19)	(17)
Property and equipment, net	9	11
Finance lease liabilities	$ 11	$ 13

Leases - Summary of Information

Leases - Summary of Information Pertaining to Lease Term and Weighted-Average Discount Rate (Details)	Dec. 31, 2020	Dec. 31, 2019
Weighted-average remaining lease term:
Operating leases	7 years 1 month 2 days	7 years 6 months
Finance leases	5 years 10 days	6 years 21 days
Weighted-average discount rate:
Operating leases	3.01%	3.26%
Finance leases	3.94%	3.94%

Leases - Summary of Maturities

Leases - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
2021	$ 140
2022	131
2023	116
2024	97
2025	79
Thereafter	233
Total lease payments	796
Less imputed interest	85
Total	711	$ 748
Finance Leases
2021	3
2022	3
2023	2
2024	1
2025	1
Thereafter	3
Total lease payments	13
Less imputed interest	2
Total	11	$ 13
2021	143
2022	134
2023	118
2024	98
2025	80
Thereafter	236
Total lease payments	809
Less imputed interest	87
Total	$ 722

Leases - Components of Equipmen

Leases - Components of Equipment Leasing Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Sales-type and direct financing leases
Interest income on lease receivable	$ 119	$ 121
Interest income related to accretion of unguaranteed residual asset	(3)	13
Interest income on deferred fees and costs	0	0
Total sales-type and direct financing lease income	116	134
Operating leases
Operating lease income related to lease payments	136	133
Other operating leasing gains	31	28
Total operating lease income and other leasing gains	167	161
Total lease income	$ 283	$ 295

Leases - Composition of Net Inv

Leases - Composition of Net Investment in Sales-Type and Direct Financing Leases (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Lease receivables	$ 3,570	$ 3,792
Unearned income	(257)	(329)
Unguaranteed residual value	478	490
Deferred fees and costs	8	16
Net investment in sales-type and direct financing leases	$ 3,799	$ 3,969

Leases - Minimum Future Lease P

Leases - Minimum Future Lease Payments to be Received for Sales-Type and Direct Financing Leases (Details) $ in Millions	Dec. 31, 2020USD ($)
Sales-type and direct financing lease payments
2021	$ 1,085
2022	838
2023	573
2024	371
2025	226
Thereafter	477
Total lease payments	$ 3,570

Leases - Minimum Future Lease_2

Leases - Minimum Future Lease Payments to be Received for Operating Leases (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 122
2022	106
2023	88
2024	76
2025	63
Thereafter	126
Total lease payments	$ 581

Premises and Equipment - Schedu

Premises and Equipment - Schedule of Premises and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Leases	$ 28	$ 28
Total premises and equipment	2,394	2,425
Less: Accumulated depreciation and amortization	(1,641)	(1,611)
Premises and equipment, net	753	814
Land
Property, Plant and Equipment [Line Items]
Premises and equipment	126	128
Buildings and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 722	729
Buildings and improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Buildings and improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 631	620
Leasehold improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Leasehold improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Furniture and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 843	872
Furniture and equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	2 years
Furniture and equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Capitalized building leases
Property, Plant and Equipment [Line Items]
Leases	$ 28	28
Capitalized building leases | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Capitalized building leases | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	14 years
Construction in process
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 44	$ 48

Premises and Equipment - Narrat

Premises and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 115	$ 118	$ 131
Capitalized computer software	385	910
Capitalized computer software, accumulated amortization	183	756
In-process software amortization expense	$ 49	$ 46	$ 52

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Expected deductible goodwill for tax purpose	$ 517,000,000
Accumulated impairment loss	$ 0	$ 0	$ 0
Consumer Bank [Member]
Goodwill [Line Items]
Estimated fair value of the units greater than certain percent of carrying value	11.00%
Commercial Bank [Member]
Goodwill [Line Items]
Estimated fair value of the units greater than certain percent of carrying value	17.00%
Institutional Bank [Member]
Goodwill [Line Items]
Estimated fair value of the units greater than certain percent of carrying value	11.00%

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 2,516
Reallocation of goodwill	0
Laurel Road acquisition	148
Ending Balance	2,664
Consumer Bank [Member]
Goodwill [Roll Forward]
Beginning Balance	2,102
Reallocation of goodwill	(498)
Laurel Road acquisition	148
Ending Balance	1,752
Commercial Bank [Member]
Goodwill [Roll Forward]
Beginning Balance	414
Reallocation of goodwill	498
Laurel Road acquisition	$ 0

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Gross Carrying Amount	$ 476	$ 622
Accumulated Amortization	288	369
Core Deposit Intangibles [Member]
Goodwill [Line Items]
Gross Carrying Amount	355	355
Accumulated Amortization	236	193
Purchased Credit Card Relationship Intangible [Member]
Goodwill [Line Items]
Gross Carrying Amount	16	152
Accumulated Amortization	12	145
Other Intangible Assets [Member]
Goodwill [Line Items]
Gross Carrying Amount	105	115
Accumulated Amortization	$ 40	$ 31

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Future Amortization Expense of Finite-Lived Intangible Assets (Details) $ in Millions	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 62
2022	57
2023	51
2024	28
2025	$ 19

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 170,336,000,000	$ 144,988,000,000
Liabilities	152,355,000,000	127,950,000,000
Fair Value, Recurring [Member]
Variable Interest Entity [Line Items]
Other investments	81,000,000	90,000,000
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	351,000,000	282,000,000
Liabilities	1,000,000	1,000,000
Variable Interest Entity, Not Primary Beneficiary [Member] | Qualified affordable housing projects investment [Member]
Variable Interest Entity [Line Items]
Liabilities	484,000,000	546,000,000
Variable Interest Entity, Not Primary Beneficiary [Member] | Accrued Income And Other Assets [Member]
Variable Interest Entity [Line Items]
Assets	1,400,000,000	1,500,000,000
Variable Interest Entity, Not Primary Beneficiary [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Amortization of investment	195,000,000	187,000,000
Tax credit of investment	177,000,000	184,000,000
Variable Interest Entity, Not Primary Beneficiary [Member] | Principal Indirect Investments [Member]
Variable Interest Entity [Line Items]
Assets	10,899,000,000	12,954,000,000
Liabilities	168,000,000	205,000,000
Variable Interest Entity, Primary Beneficiary [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Liabilities	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Principal Indirect Investments [Member] | Fair Value, Recurring [Member]
Variable Interest Entity [Line Items]
Other investments	$ 53,000,000	$ 68,000,000

Variable Interest Entities - Va

Variable Interest Entities - Variable Interest Entities Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 170,336	$ 144,988
Liabilities	152,355	127,950
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	351	282
Liabilities	1	1
Variable Interest Entity, Not Primary Beneficiary [Member] | Principal Indirect Investments [Member]
Variable Interest Entity [Line Items]
Assets	10,899	12,954
Liabilities	168	205
Maximum Exposure to Loss	69	89
Variable Interest Entity, Not Primary Beneficiary [Member] | LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Assets	6,914	6,405
Liabilities	2,765	2,526
Maximum Exposure to Loss	$ 1,823	$ 1,846

Income Taxes - Income Taxes Inc

Income Taxes - Income Taxes Included in Income Statement (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Currently payable:
Federal	$ 336	$ 241	$ 184
State	83	20	62
Total currently payable	419	261	246
Deferred:
Federal	(156)	34	117
State	(36)	19	(19)
Total deferred	(192)	53	98
Total income tax expense (benefit)	227	314	344
Income tax (benefit) expense on securities transactions	1	5	0
Equity and gross receipts based taxes assessed in lieu of income tax recorded in noninterest expense	$ 30	$ 23	$ 15

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Tax reform, measurement period adjustment			$ 7,000,000
Valuation allowances	$ 0	$ 0
Credit carryforward	7,000,000	81,000,000
Deferred tax asset	1,164,000,000	987,000,000
Unrecognized tax benefits	58,000,000	19,000,000	35,000,000
Net interest expense (benefit)	200,000	900,000	700,000
Recovery of penalties related to unrecognized tax benefits in income tax expense	0	0	$ 0
Accrued interest payable	3,000,000	2,000,000
Accrued state tax penalties	0	0
Reduction in federal tax credit carryforward	0	$ 15,900,000
Maximum [Member]
Income Taxes [Line Items]
Valuation allowances	0
Federal [Member]
Income Taxes [Line Items]
Federal net operating loss carryforwards	26,000,000
Credit carryforward	1,000,000
State [Member]
Income Taxes [Line Items]
State net operating loss carryforwards	30,000,000
Deferred tax asset	1,000,000
First Niagara Bank, N.A. [Member]
Income Taxes [Line Items]
Allocated bad debt deductions for which no income taxes have been recorded	$ 92,000,000

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets and Liabilities Included in "Accrued Income and Other Assets" and "Accrued Expense and Other Liabilities" (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Allowance for loan and lease losses	$ 443	$ 236
Employee benefits	166	164
Federal net operating losses and credits	7	81
Fair value adjustments	0	21
Non-tax accruals	76	61
Operating lease liabilities	174	178
State net operating losses and credits	1	1
Other	297	245
Gross deferred tax assets	1,164	987
Less: Valuation Allowance	0	0
Total deferred tax assets	1,164	987
Leasing transactions	556	628
Net unrealized securities gains	340	117
Operating lease right-of-use assets	153	156
Other	215	175
Total deferred tax liabilities	1,264	1,076
Net deferred tax assets (liabilities)	$ (100)	$ (89)

Income Taxes - Total Income Tax

Income Taxes - Total Income Tax Expense (Benefit) and Resulting Effective Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amount
Income (loss) before income taxes times 21% statutory federal tax rate	$ 327	$ 425	$ 463
Amortization of tax-advantaged investments	150	132	127
Foreign tax adjustments	0	0	2
Tax-exempt interest income	(28)	(30)	(30)
Corporate-owned life insurance income	(29)	(29)	(29)
State income tax, net of federal tax benefit	37	31	34
Tax credits	(218)	(231)	(234)
Tax Cuts and Jobs Act	0	0	7
Other	(12)	16	4
Total income tax expense (benefit)	$ 227	$ 314	$ 344
Rate
Federal income tax rate (as a percent)	21.00%	21.00%	21.00%
Amortization of tax-advantaged investments (as a percent)	9.70%	6.50%	5.80%
Foreign tax adjustments (as a percent)	0.00%	0.00%	0.10%
Tax-exempt interest income (as a percent)	(1.80%)	(1.50%)	(1.40%)
Corporate-owned life insurance income (as a percent)	(1.90%)	(1.40%)	(1.30%)
State income tax, net of federal tax benefit (as a percent)	2.40%	1.50%	1.50%
Tax credits (as a percent)	(14.00%)	(11.40%)	(10.60%)
Tax Cuts and Jobs Act (as a percent)	0	0	0.003
Other (as a percent)	(0.80%)	0.90%	0.20%
Total income tax expense (benefit) (as a percent)	14.60%	15.60%	15.60%

Income Taxes - Change in Liabil

Income Taxes - Change in Liability for Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 19	$ 35
Increase for other tax positions of prior years	40	2
Decrease for payments and settlements	0	0
Decrease related to tax positions taken in prior years	(1)	(18)
Balance at end of year	$ 58	$ 19

Acquisitions, Divestiture, an_2

Acquisitions, Divestiture, and Discontinued Operations - Narrative (Details) $ in Millions	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Apr. 03, 2019USD ($)branch	Dec. 31, 2018USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill	$ 2,664	$ 2,664		$ 2,516
Discontinued Operations [Member] | Government Guaranteed Loans [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans included in divestiture	$ 710	$ 865
Laurel Road Bank [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of bank branches excluded from transaction | branch			3
Other intangible assets			$ 37
Goodwill			$ 148

Securities Financing Activiti_3

Securities Financing Activities - Summarized Securities Financing Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	$ 0	$ 0
Securities borrowed	0	0
Total offsetting of financial assets	0	0
Repurchase agreements	0	0
Total offsetting of financial liabilities	0	0
Counterparty And Cash Collateral Netting [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	0	0
Securities borrowed	(500)	0
Total offsetting of financial assets	(500)	0
Repurchase agreements	(214)	(180)
Total offsetting of financial liabilities	(214)	(180)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities Financing Transaction [Line Items]
Carrying amount of assets pledged as collateral against repurchase agreements	232
Liabilities associated with collateral pledged	214
Gross Amount Presented in Balance Sheet [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	6	5
Securities borrowed	500	0
Total offsetting of financial assets	506	5
Repurchase agreements	220	187
Total offsetting of financial liabilities	220	187
Netting Adjustments [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	(6)	(5)
Securities borrowed	0	0
Total offsetting of financial assets	(6)	(5)
Repurchase agreements	(6)	(7)
Total offsetting of financial liabilities	$ (6)	$ (7)

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense for stock-based compensation plans	$ 101,000,000	$ 96,000,000	$ 99,000,000
Total income tax benefit recognized for stock-based compensation plans	$ 24,000,000	$ 23,000,000	$ 23,000,000
Common Shares available for future grant under compensation plans (in shares)	47,287,594
Maximum percentage of outstanding common stock that may be granted as options	6.00%
Rolling period in which a certain percentage of common stock cannot be granted as options	3 years
Exercise rate of stock options granted to employees	25.00%
Vesting period for compensation cost	4 years
Authorized number of shares that may be issued as equity awards (in shares)	71,600,000
Common shares, shares issued (in shares)	1,256,702,081	1,256,702,081
Weighted-average grant-date fair value of options (in dollars per share)	$ 2.96	$ 3.07	$ 5.12
Number of options, exercised (in shares)	821,916
Total intrinsic value of exercised options	$ 5,000,000	$ 18,000,000	$ 21,000,000
Cash received from options exercised	8,000,000	18,000,000	20,000,000
Actual tax benefit realized for tax deductions from options exercised	$ 1,000,000	$ 1,000,000	$ 1,000,000
Mandatory deferred incentive awards, vesting rate (as a percent)	25.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares, shares issued (in shares)	3,000,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration years	10 years
Number of options, exercised (in shares)	821,916	2,039,208	1,960,444
Unrecognized compensation cost related to nonvested options expected to vest	$ 1,000,000
Weighted-average period	2 years 6 months
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for compensation cost	1 year
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration years	10 years
Deferred Cash Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Equity Based Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	three-year
Cash Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	three-year
Deferred Compensation Plans and Other Restricted Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value granted (in dollars per share)	$ 16.22	$ 17.57	$ 20.77
Deferred Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested options expected to vest	$ 13,000,000
Weighted-average period	3 years 10 months 24 days
Fair value of units/shares vested	$ 18,000,000	$ 19,000,000	$ 22,000,000
Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested options expected to vest	$ 88,000,000
Weighted-average period	2 years 3 months 18 days
Fair value of units/shares vested	$ 89,000,000	$ 89,000,000	$ 93,000,000
Weighted-average grant-date fair value granted (in dollars per share)	$ 18.68	$ 18.25	$ 19.28
Discounted Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee discount on the purchase of stock through Discounted Stock Purchase Plan	10.00%
Purchases are limited to any month	$ 10,000
Purchases are limited to any calendar year	$ 50,000
Issuance of common shares (in shares)	500,508	327,243	327,435
Weighted-average cost of common shares issued under the plan (in dollars per share)	11.76	15.73	17.48
Vesting Contingent On Performance And Service Conditions, Payable In Stock [Member] | Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance units vested (in shares)	421,352
Weighted-average grant-date fair value granted (in dollars per share)	$ 18.98
Vesting Contingent On Performance And Service Conditions, Payable In Stock [Member] | Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance units vested (in shares)		855,233
Vesting Contingent On Performance And Service Conditions, Payable In Stock [Member] | Long-Term Incentive Compensation Program [Member] | Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of units/shares vested	$ 8,000,000	$ 9,000,000
Vesting Contingent On Performance And Service Conditions, Payable In Cash [Member] | Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance units vested (in shares)	654,108
Weighted-average grant-date fair value granted (in dollars per share)	$ 16.16
Vesting Contingent On Performance And Service Conditions, Payable In Cash [Member] | Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance units vested (in shares)		1,139,582
Vesting Contingent On Performance And Service Conditions, Payable In Cash [Member] | Long-Term Incentive Compensation Program [Member] | Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of units/shares vested	$ 13,000,000	$ 20,000,000

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used in Options Pricing Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Average option life	6 years 6 months	6 years 6 months	6 years 6 months
Future dividend yield (as a percentage)	3.90%	3.88%	2.28%
Historical share price volatility (as a percentage)	0.267%	0.266%	0.282%
Weighted-average risk-free interest rate (as a percentage)	1.30%	2.50%	2.80%

Stock-Based Compensation - Acti

Stock-Based Compensation - Activity, Pricing and Other Information for Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Number of Options
Number of Options Outstanding, Beginning Balance (in shares)	6,685,808
Granted, Number of Options (in shares)	549,170
Exercised, Number of Options (in shares)	(821,916)
Lapsed or canceled, Number of Options (in shares)	(40,378)
Number of Options Outstanding, Ending Balance (in shares)	6,372,684	6,685,808
Expected to vest, Number of Options (in shares)	1,426,063
Number of Options Exercisable, Ending Balance (in shares)	4,867,838
Weighted-Average Exercise Price Per Option
Weighted-Average Exercise Price Per Option Outstanding, Beginning Balance (in dollars per share)	$ 13.32
Granted, Weighted-Average Exercise Price Per Option (in dollars per share)	19.03
Exercised, Weighted-Average Exercise Price Per Option (in dollars per share)	10.37
Lapsed or canceled, Weighted-Average Exercise Price Per Option (in dollars per share)	15.25
Weighted-Average Exercise Price Per Option Outstanding, Ending Balance (in dollars per share)	14.18	$ 13.32
Expected to vest, Weighted-Average Exercise Price Per Option (in dollars per share)	18.75
Weighted-Average Exercise Price Per Option Exercisable, Ending Balance (in dollars per share)	$ 12.77
Weighted-Average Remaining Life (Years) Outstanding	4 years 7 months 6 days	5 years 2 months 12 days
Expected to vest, Weighted-Average Remaining Life (Years)	7 years 1 month 6 days
Weighted-Average Remaining Life (Years) Exercisable	3 years 9 months 18 days
Aggregate Intrinsic Value Outstanding	$ 21	$ 47
Expected to vest, Aggregate Intrinsic Value	0
Aggregate Intrinsic Value Exercisable	$ 21

Stock-Based Compensation - Ac_2

Stock-Based Compensation - Activity and Pricing Information for Nonvested Shares in Long-Term Incentive Compensation Program (Details) - Long-Term Incentive Compensation Program [Member]	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Vesting Contingent on Service Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares) | shares	10,296,394
Number of Nonvested Shares, Granted (in shares) | shares	5,796,992
Number of Nonvested Shares, Vested (in shares) | shares	(4,203,663)
Number of Nonvested Shares, Forfeited (in shares) | shares	(373,353)
Number of Nonvested Shares Outstanding, Ending Balance (in shares) | shares	11,516,370
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 17.73
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	19.40
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share) | $ / shares	16.33
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share) | $ / shares	19.16
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 19.01
Vesting Contingent On Performance And Service Conditions, Payable In Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares) | shares	491,189
Number of Nonvested Shares, Granted (in shares) | shares	(10,666)
Number of Nonvested Shares, Vested (in shares) | shares	(421,352)
Number of Nonvested Shares, Forfeited (in shares) | shares	0
Number of Nonvested Shares Outstanding, Ending Balance (in shares) | shares	59,171
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 18.87
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	18.98
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share) | $ / shares	18.96
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share) | $ / shares	0
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 18.20
Vesting Contingent On Performance And Service Conditions, Payable In Cash [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares) | shares	3,899,884
Number of Nonvested Shares, Granted (in shares) | shares	1,651,519
Number of Nonvested Shares, Vested (in shares) | shares	(654,108)
Number of Nonvested Shares, Forfeited (in shares) | shares	(117,256)
Number of Nonvested Shares Outstanding, Ending Balance (in shares) | shares	4,780,039
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 20.37
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	16.16
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share) | $ / shares	19.46
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share) | $ / shares	13.16
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 16.23

Stock-Based Compensation - Ac_3

Stock-Based Compensation - Activity and Pricing Information for Nonvested Shares Granted Under Deferred Compensation Plans and Other Restricted Stock Awards (Details) - Deferred Compensation Plans and Other Restricted Stock Award [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares)	3,037,964
Number of Nonvested Shares, Granted (in shares)	691,377
Number of Nonvested Shares, Dividend Equivalents (in shares)	11
Number of Nonvested Shares, Vested (in shares)	(1,048,864)
Number of Nonvested Shares, Forfeited (in shares)	(108,401)
Number of Nonvested Shares Outstanding, Ending Balance (in shares)	2,572,087	3,037,964
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share)	$ 17.67
Weighted-Average Grant Date Fair Value, Granted (in dollars per share)	16.22	$ 17.57	$ 20.77
Weighted-Average Grant Date Fair Value, Dividend Equivalents (in dollars per share)	13.91
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share)	17.18
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share)	18.20
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share)	$ 17.46	$ 17.67

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Pre-tax AOCI not yet recognized as net pension cost			$ 427,000,000	$ 471,000,000
Accumulated benefit obligation for all pension plans			$ 1,200,000,000	$ 1,200,000,000
Percentage increase or decrease in expected return on plan assets			0.25%
Estimated increase or decrease in net pension cost			$ 3,000,000
Percentage increase or decrease in assumed discount rate			0.25%
Estimated change in net pension cost due to discount rate			$ 2,000,000
Expected return on plan assets (as a percent)			3.75%	4.50%	4.75%
Expected return on plan assets on estimating 2020 pension cost (as a percent)			2.75%
Employer contribution to saving plan			6.00%
Employer discretionary contribution, required service period			1 year
Employer discretionary contribution percentage			1.00%	1.00%	2.00%
Total expenses associated with saving plan			$ 103,000,000	$ 98,000,000	$ 106,000,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2021			92,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2022			91,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2023			89,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2024			87,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2025			84,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2026 through 2030			371,000,000
Accumulated benefit obligation for all pension plans			1,072,000,000	1,054,000,000
Net pension cost (benefit)			$ 22,000,000	$ 29,000,000	$ 22,000,000
Expected return on plan assets (as a percent)			3.75%	4.50%	4.75%
Discount rate			2.05%	2.89%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Pre-tax AOCI not yet recognized as net pension cost			$ (25,000,000)	$ (27,000,000)
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2021			6,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2022			6,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2023			5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2024			5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2025			5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2026 through 2030			23,000,000
Net pension cost (benefit)			$ (1,000,000)	$ 0	$ (1,000,000)
Expected return on plan assets (as a percent)			4.50%	4.50%	4.50%
Age of employees under condition one			55 years
Period of service under condition one			5 years
Age of employees under condition two			50 years
Period of service under condition two			15 years
Minimum period of service at the time of termination hired before 2001			15 years
Discount rate			4.00%	4.50%
Forecast [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension cost (benefit)	$ 15,000,000
Forecast [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension cost (benefit)		$ 0
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employees contribution to saving plan			1.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employees contribution to saving plan			100.00%

Employee Benefits - Net Pension

Employee Benefits - Net Pension Cost and Amount Recognized in OCI for All Funded and Unfunded Plans (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 34	$ 46	$ 41
Expected return on plan assets	(38)	(48)	(53)
Amortization of losses	17	13	17
Settlement loss	9	18	17
Net pension cost (benefit)	22	29	22
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	(18)	(8)	20
Amortization of gains	(26)	(31)	(33)
Total recognized in comprehensive income	(44)	(39)	(13)
Total recognized in net pension cost and comprehensive income	$ (22)	$ (10)	$ 9

Employee Benefits - Changes in

Employee Benefits - Changes in PBO Related to Pension Plans (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
PBO/APBO at beginning of year	$ 1,233	$ 1,201
Interest cost	34	46	$ 41
Actuarial losses (gains)	66	91
Benefit payments	(85)	(105)
PBO/APBO at end of year	$ 1,248	$ 1,233	$ 1,201

Employee Benefits - Changes i_2

Employee Benefits - Changes in FVA (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
FVA at beginning of year	$ 1,102	$ 1,046
Actual return on plan assets	123	147
Employer contributions	13	14
Benefit payments	(85)	(105)
FVA at end of year	$ 1,153	$ 1,102

Employee Benefits - Funded Stat

Employee Benefits - Funded Status of Pension Plans Recognized in Balance Sheets (Details) - Pension Plan [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ (95)	$ (131)
Net prepaid pension cost recognized consists of:
Noncurrent assets	81	48
Current liabilities	(14)	(14)
Noncurrent liabilities	(162)	(165)
Net prepaid pension cost recognized	$ (95)	$ (131)

Employee Benefits - Plans ABO i

Employee Benefits - Plans ABO in Excess of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
ABO	$ 1,200	$ 1,200
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
PBO	1,072	1,054
ABO	1,072	1,054
Fair value of plan assets	1,153	1,102
Other Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
PBO	176	179
ABO	176	179
Fair value of plan assets	$ 0	$ 0

Employee Benefits - Weighted-Av

Employee Benefits - Weighted-Average Rates to Determine Actuarial Present Value of Benefit Obligations (Details) - Pension Plan [Member]	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	2.05%	2.89%
Weighted-average interest crediting rate	1.65%	2.39%

Employee Benefits - Weighted-_2

Employee Benefits - Weighted-Average Rates to Determine Net Pension Cost (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Discount rate	2.89%	4.00%	3.25%
Expected return on plan assets	3.75%	4.50%	4.75%

Employee Benefits - Asset Targe

Employee Benefits - Asset Target Allocations Prescribed by Pension Funds' Investment Policies (Details)	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	100.00%
Equity Securities, United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	4.00%
Equity Securities, International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	2.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	87.00%
Defined Benefit Plan, Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	4.00%
Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	3.00%

Employee Benefits - Fair Values

Employee Benefits - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 1,153	$ 1,102	$ 1,046
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	9	8
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3	3
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	171	155
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	79	72
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | U.S. Treasury, Agencies, and Corporations [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	165	190
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	27	27
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Level 1 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	14	13
Level 1 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	9	8
Level 1 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 1 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3	3
Level 1 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | U.S. Treasury, Agencies, and Corporations [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Level 2 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Level 2 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	444	446
Level 2 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 2 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	171	155
Level 2 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	79	72
Level 2 [Member] | Pension Plan [Member] | U.S. Treasury, Agencies, and Corporations [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	165	190
Level 2 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	27	27
Level 2 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 3 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | U.S. Treasury, Agencies, and Corporations [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Collective Investment Funds (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	636	584
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Insurance investment contracts and pooled separate accounts (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	17	16
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 42	$ 43

Employee Benefits - Pre-tax AOC

Employee Benefits - Pre-tax AOCI Not Yet Recognized as Net Postretirement Benefit Cost (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Total unrecognized AOCI	$ 427	$ 471
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized losses (gains)	(10)	(10)
Net unrecognized prior service credit	(15)	(17)
Total unrecognized AOCI	$ (25)	$ (27)

Employee Benefits - Net Postret

Employee Benefits - Net Postretirement Benefit Cost and the Amount Recognized in OCI for All Funded and Unfunded Plans (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost of benefits earned	$ 0	$ (1)	$ (1)
Interest cost on APBO	(2)	(2)	(2)
Expected return on plan assets	(2)	(2)	(2)
Amortization of prior service credit	(1)	0	(1)
Amortization of gains	0	(1)	(1)
Net pension cost (benefit)	(1)	0	(1)
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	1	1	1
Amortization of prior service credit	0	1	1
Amortization of losses	0	0	0
Total recognized in comprehensive income	1	2	2
Total recognized in net postretirement benefit cost and comprehensive income	$ 0	$ 2	$ 1

Employee Benefits - Changes i_3

Employee Benefits - Changes in APBO (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
PBO/APBO at beginning of year	$ 52	$ 63
Service cost	0	1	$ 1
Interest cost	2	2	2
Plan participants’ contributions	1	1
Actuarial losses (gains)	8	10
Benefit payments	(11)	(8)
Plan amendments	0	(17)
PBO/APBO at end of year	$ 52	$ 52	$ 63

Employee Benefits - Change in F

Employee Benefits - Change in FVA (Other Post Retirement Benefit Plan Assets) (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
FVA at beginning of year	$ 52	$ 47
Employer contributions	0	0
Plan participants’ contributions	1	1
Benefit payments	(11)	(8)
Actual return on plan assets	10	12
FVA at end of year	$ 52	$ 52

Employee Benefits - Weighted-_3

Employee Benefits - Weighted-Average Rates to Determine Net Postretirement Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.89%	4.00%	3.25%
Expected return on plan assets	3.75%	4.50%	4.75%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.50%	4.50%	3.50%
Expected return on plan assets	4.50%	4.50%	4.50%

Employee Benefits - Asset Tar_2

Employee Benefits - Asset Target Allocations Prescribed by Trusts' Investment Policies (Details)	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Equity Securities [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	80.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	87.00%
Fixed Income Securities [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	20.00%
Defined Benefit Plan, Cash and Cash Equivalents [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%

Employee Benefits - Fair Valu_2

Employee Benefits - Fair Values of Postretirement Plan Assets by Asset Category (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 52	$ 52	$ 47
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	21	22
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	9	9
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	7	7
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	14	12
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	37	38
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	21	22
Level 1 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	9	9
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	7	7
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 1 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 2 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 3 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 1	$ 2

Short-Term Borrowings - Compone

Short-Term Borrowings - Components of Short-Term Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Balance at year end, Securities Sold Under Repurchase Agreements	$ 0	$ 0
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Balance at year end, Federal Funds Purchase	0	200	$ 0
Average during the year	455	61	537
Maximum month-end balance	$ 2,285	$ 1,000	$ 3,197
Weighted-average rate during the year	1.24%	2.12%	1.68%
Weighted-average rate at December 31	0.00%	1.56%	0.00%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Balance at year end, Securities Sold Under Repurchase Agreements	$ 220	$ 187	$ 319
Average during the year	215	203	391
Maximum month-end balance	$ 267	$ 283	$ 614
Weighted-average rate during the year	0.11%	0.22%	0.09%
Weighted-average rate at December 31	0.04%	0.09%	0.09%
Other Short Term Borrowings [Member]
Short-term Debt [Line Items]
Balance at year end, Other Short-Term Borrowings	$ 759	$ 705	$ 544
Average during the year	1,452	730	915
Maximum month-end balance	$ 4,606	$ 847	$ 1,133
Weighted-average rate during the year	0.85%	2.31%	2.34%
Weighted-average rate at December 31	0.60%	1.99%	2.92%

Short-Term Borrowings - Narrati

Short-Term Borrowings - Narrative (Details) $ in Billions	Dec. 31, 2020USD ($)
Short-term Debt [Line Items]
Deposits with the Federal Reserve	$ 15.4
Federal Reserve Bank of Cleveland [Member]
Short-term Debt [Line Items]
Unused Secured borrowing capacity	22.6
Federal Home Loan Bank of Cincinnati [Member]
Short-term Debt [Line Items]
Unused Secured borrowing capacity	$ 8.4

Long-Term Debt - Components of

Long-Term Debt - Components of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Finance lease liabilities	$ 11	$ 13
Total long-term debt	13,709	12,448
Real Estate Loans and securities pledged	607	121
Senior Medium-Term Notes Due Through 2021 [Member]
Debt Instrument [Line Items]
Senior medium-term notes	$ 3,962	$ 4,111
Long-term debt weighted average interest rate	3.7025%	3.7815%
3.136% Subordinated notes due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	3.136%
Subordinated long-term notes	$ 162	$ 162
6.875% Subordinated Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	6.875%
Subordinated long-term notes	$ 115	109
7.750% Subordinated Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	7.75%
Subordinated long-term notes	$ 149	141
7.25% Subordinated notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	7.25%
Subordinated long-term notes	$ 311	$ 324
Long-term debt weighted average interest rate	7.25%	7.25%
Other Subordinated Notes [Member]
Debt Instrument [Line Items]
Subordinated long-term notes	$ 74	$ 71
Long-term debt weighted average interest rate	1.72%	3.42%
Senior Medium-Term Notes Due Through 2039 [Member]
Debt Instrument [Line Items]
Senior medium-term notes	$ 6,718	$ 5,874
Long-term debt weighted average interest rate	2.516%	2.595%
3.18% Senior Remarketable Notes Due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	3.18%
Subordinated long-term notes	$ 232	$ 222
Long-term debt weighted average interest rate	3.18%	3.18%
3.40% Subordinated notes due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	3.40%
Subordinated long-term notes	$ 625	$ 589
6.95% Subordinated notes due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	6.95%
Subordinated long-term notes	$ 299	299
3.90% Subordinated notes due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	3.90%
Subordinated long-term notes	$ 398	371
Secured Borrowing Due Through 2025 [Member]
Debt Instrument [Line Items]
Secured borrowing due through 2025	$ 19	$ 15
Long-term debt weighted average interest rate	4.445%	4.445%
Federal Home Loan Bank Advances Due Through 2038 [Member]
Debt Instrument [Line Items]
Federal Home Loan Bank advances due through 2038	$ 608	$ 121
Long-term debt weighted average interest rate	1.15%	3.506%
Investment Fund Financing Due Through 2052 [Member]
Debt Instrument [Line Items]
Investment Fund Financing due through 2052	$ 21	$ 26
Long-term debt weighted average interest rate	1.77%	1.63%
Key Government Finance Incorporated Other Long Term Debt ASR
Debt Instrument [Line Items]
Key Govt Finance, Inc. Other Long Term Debt-ASR	$ 4	$ 0
Obligations Under Capital Lease Due Through 2032 [Member]
Debt Instrument [Line Items]
Finance lease liabilities	12	13
Key [Member]
Debt Instrument [Line Items]
Total long-term debt	4,773	4,918
Subsidiaries [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 8,936	$ 7,530

Long-Term Debt - Scheduled Prin

Long-Term Debt - Scheduled Principal Payments on Long-Term Debt (Details) $ in Millions	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
2021	$ 2,587
2022	2,403
2023	1,231
2024	1,101
2025	1,334
All subsequent years	5,053
Key [Member]
Debt Instrument [Line Items]
2021	1,315
2022	0
2023	0
2024	0
2025	562
All subsequent years	2,896
Subsidiaries [Member]
Debt Instrument [Line Items]
2021	1,272
2022	2,403
2023	1,231
2024	1,101
2025	772
All subsequent years	$ 2,157

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($)	Sep. 28, 2018	Dec. 31, 2020	Dec. 16, 2020	Mar. 10, 2020	Feb. 06, 2020	Sep. 11, 2019	Mar. 13, 2019	Feb. 01, 2019
Debt Instrument [Line Items]
Bank note, maximum issuable amount	$ 20,000,000,000
Senior notes available for future issuance		$ 16,800,000,000
Senior Notes [Member]
Debt Instrument [Line Items]
Original maturity of bank note	7 days
Issuance of senior notes		$ 3,200,000,000
Subordinated Notes [Member]
Debt Instrument [Line Items]
Original maturity of bank note	5 years
3.300% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Issuance of senior notes								$ 600,000,000
Debt instrument interest rate (as a percent)								3.30%
Floating Rate Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Issuance of senior notes								$ 400,000,000
3.900% Subordinated Notes Due 2029 [Member]
Debt Instrument [Line Items]
Issuance of senior notes							$ 350,000,000
Debt instrument interest rate (as a percent)							3.90%
1.25% Senior Bank Notes Due 2023 [Member]
Debt Instrument [Line Items]
Issuance of senior notes				$ 700,000,000
Debt instrument interest rate (as a percent)				1.25%
Fixed-to-Floating Rate Senior Bank Notes due 2024 [Member]
Debt Instrument [Line Items]
Issuance of senior notes			$ 750,000,000
Floating Rate Senior Bank Notes Due 2024 [Member]
Debt Instrument [Line Items]
Issuance of senior notes			$ 350,000,000
Medium-Term Notes [Member]
Debt Instrument [Line Items]
Debt term		9 months
Additional debt securities authorized and available for issuance under note program		$ 5,000,000,000
2.550% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Issuance of senior notes						$ 750,000,000
Debt instrument interest rate (as a percent)						2.55%
2.250% Senior Notes Due 2027 [Member]
Debt Instrument [Line Items]
Issuance of senior notes					$ 800,000,000
Debt instrument interest rate (as a percent)					2.25%

Trust Preferred Securities Is_3

Trust Preferred Securities Issued by Unconsolidated Subsidiaries - Summary of Trust Preferred Securities, Common Stock and Related Debentures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Stock	$ 1,257	$ 1,257
Debentures adjustments related to financial instrument hedging	70	57
KeyCorp Capital I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	156
Common Stock	6
Principal Amount of of Debentures, Net of Discount	$ 162
Interest Rate of Trust Preferred Securities and Debentures	0.965%
KeyCorp Capital II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 110
Common Stock	4
Principal Amount of of Debentures, Net of Discount	$ 114
Interest Rate of Trust Preferred Securities and Debentures	6.875%
KeyCorp Capital III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 145
Common Stock	4
Principal Amount of of Debentures, Net of Discount	$ 149
Interest Rate of Trust Preferred Securities and Debentures	7.75%
HNC Statutory Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 20
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 21
Interest Rate of Trust Preferred Securities and Debentures	1.605%
Willow Grove Statutory Trust I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 19
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 20
Interest Rate of Trust Preferred Securities and Debentures	1.527%
HNC Statutory Trust IV [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 17
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 18
Interest Rate of Trust Preferred Securities and Debentures	1.494%
Westbank Capital Trust II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 8
Common Stock	0
Principal Amount of of Debentures, Net of Discount	$ 8
Interest Rate of Trust Preferred Securities and Debentures	2.429%
Westbank Capital Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 8
Common Stock	0
Principal Amount of of Debentures, Net of Discount	$ 8
Interest Rate of Trust Preferred Securities and Debentures	2.429%
Business Trusts [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 483	466
Common Stock	17	17
Principal Amount of of Debentures, Net of Discount	$ 500	$ 483
Interest Rate of Trust Preferred Securities and Debentures	4.464%	5.214%
Treasury Rate [Member] | KeyCorp Capital II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	20.00%
Treasury Rate [Member] | KeyCorp Capital III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	25.00%
London Interbank Offered Rate (LIBOR) [Member] | KeyCorp Capital I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	74.00%
London Interbank Offered Rate (LIBOR) [Member] | HNC Statutory Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	140.00%
London Interbank Offered Rate (LIBOR) [Member] | Willow Grove Statutory Trust I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	131.00%
London Interbank Offered Rate (LIBOR) [Member] | HNC Statutory Trust IV [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	128.00%
London Interbank Offered Rate (LIBOR) [Member] | Westbank Capital Trust II and III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	219.00%
Debt Instrument, Redemption, Period Five [Member] | Treasury Rate [Member] | Keycorp Capital II and III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	50.00%

Commitments, Contingent Liabi_3

Commitments, Contingent Liabilities and Guarantees - Commitments to Extend Credit or Funding (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Guarantor Obligations [Line Items]
Total loan commitments	$ 66,141	$ 64,789
Commercial letters of credit	74	91
Purchase card commitments	708	729
Principal investing commitments	16	21
Tax credit investment commitments	487	547
Total loan and other commitments	67,426	66,177
Commercial and Other [Member]
Guarantor Obligations [Line Items]
Total loan commitments	47,792	45,323
Commercial Real Estate and Construction [Member]
Guarantor Obligations [Line Items]
Total loan commitments	2,365	2,961
Home Equity [Member]
Guarantor Obligations [Line Items]
Total loan commitments	9,299	9,945
Credit Cards [Member]
Guarantor Obligations [Line Items]
Total loan commitments	$ 6,685	$ 6,560

Commitments, Contingent Liabi_4

Commitments, Contingent Liabilities and Guarantees - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Written Put Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Weighted average life of written put options	3 years
Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining weighted-average life of standby letters of credit in years	1 year 8 months 12 days
Underwriting And Servicing Program [Member]
Commitments Contingencies And Guarantees [Line Items]
Weighted-average remaining term for outstanding commercial mortgage loans in years	7 years 10 months 24 days
Unpaid principal balance outstanding of loans sold	$ 19,300
Maximum potential amount of undiscounted future payments that could be required, percentage of principal balance of loans outstanding	30.00%
Residential Mortgage Reserve [Member]
Commitments Contingencies And Guarantees [Line Items]
Unpaid principal balance outstanding of loans sold	$ 8,200
Liability for estimated repurchase obligations on loans sold	$ 10
Minimum [Member] | Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining actual life letters of credit in years	1 year
Minimum [Member] | Low [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment	0.00%
Minimum [Member] | Moderate [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment	30.00%
Minimum [Member] | High [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment	70.00%
Maximum [Member] | Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining actual life letters of credit in years	13 years 10 months 24 days
Maximum [Member] | Low [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment	30.00%
Maximum [Member] | Moderate [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment	70.00%

Commitments, Contingent Liabi_5

Commitments, Contingent Liabilities and Guarantees - Guarantees (Details) $ in Millions	Dec. 31, 2020USD ($)
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	$ 15,144
Liability Recorded	158
Written Put Options [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	3,631
Liability Recorded	54
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	3,231
Liability Recorded	71
Recourse Agreement with FNMA [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	5,811
Liability Recorded	23
Residential Mortgage Reserve [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	2,471
Liability Recorded	$ 10

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income - Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 17,038
Other comprehensive income before reclassification, net of income taxes	936	$ 860
Amounts reclassified from accumulated other comprehensive income, net of income taxes	(224)	(16)
Total other comprehensive income (loss), net of tax	712	844	$ (39)
Ending Balance	17,981	17,038
Unrealized Gains (Losses) on Securities Available for Sale [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	115	(373)
Other comprehensive income before reclassification, net of income taxes	455	503
Amounts reclassified from accumulated other comprehensive income, net of income taxes	(3)	(15)
Total other comprehensive income (loss), net of tax	452	488
Ending Balance	567	115	(373)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	250	(50)
Other comprehensive income before reclassification, net of income taxes	466	335
Amounts reclassified from accumulated other comprehensive income, net of income taxes	(240)	(35)
Total other comprehensive income (loss), net of tax	226	300
Ending Balance	476	250	(50)
Foreign Currency Translation Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	0	(14)
Other comprehensive income before reclassification, net of income taxes	0	3
Amounts reclassified from accumulated other comprehensive income, net of income taxes	0	11
Total other comprehensive income (loss), net of tax	0	14
Ending Balance	0	0	(14)
Net Pension and Postretirement Benefit Costs [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(339)	(381)
Other comprehensive income before reclassification, net of income taxes	15	19
Amounts reclassified from accumulated other comprehensive income, net of income taxes	19	23
Total other comprehensive income (loss), net of tax	34	42
Ending Balance	(305)	(339)	(381)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	26	(818)	(779)
Total other comprehensive income (loss), net of tax	712	844	(39)
Ending Balance	$ 738	$ 26	$ (818)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
		Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income	[1]		$ 15	$ 68	$ 176
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries			1,585	2,054	2,234
Income taxes			227	314	344
Interest income — Loans			3,866	4,267	4,023
Interest expense — Long-term debt			(286)	(454)	(420)
Other expense			2,336	2,250	2,309
Income (loss) from continuing operations			1,329	1,708	$ 1,859
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income			4	20
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries			4	20
Income taxes			1	5
Income (loss) from continuing operations			3	15
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries			315	46
Income taxes			75	11
Income (loss) from continuing operations			240	35
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Interest Rate [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income — Loans			319	15
Interest expense — Long-term debt			(4)	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Foreign Exchange Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income			0	32
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income		$ (11)	0	(14)
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries			0	(14)
Income taxes			0	(3)
Income (loss) from continuing operations			0	(11)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries			(25)	(31)
Income taxes			(6)	(8)
Income (loss) from continuing operations			(19)	(23)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Amortization of Losses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense			(17)	(13)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Settlement Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense			(9)	(18)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Amortization Of Prior Service Credit [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense			$ 1	$ 0
[1]	Net securities gains (losses) totaled $4 million for the year ended December 31, 2020, $20 million for the year ended December 31, 2019, and less than $1 million for the year ended December 31, 2018. For 2020, 2019, and 2018, we did not have any impairment losses related to securities.

Shareholders' Equity - Comprehe

Shareholders' Equity - Comprehensive Capital Plan (Details) - USD ($)	3 Months Ended				12 Months Ended			24 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Jan. 31, 2021
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.185	$ 0.185	$ 0.185	$ 0.185	$ 0.74	$ 0.710	$ 0.565
2021 Repurchase Authorization [Member] | Subsequent Event [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Authorized amount of share repurchases									$ 900,000,000
2019 Capital Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common shares repurchased, value				$ 152,000,000				$ 489,000,000
Open Market Share Repurchases [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common shares repurchased, value				117,000,000
Employee Equity Compensation Programs [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common shares repurchased, value				$ 35,000,000

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Preferred Stock (Details)	Dec. 31, 2020USD ($)$ / sharesshares
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 525,000,000
Preferred stock, shares authorized (in shares) | shares	21,000
Preferred stock, shares outstanding (in shares) | shares	21,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 25,000
Depository Shares, Series D [Member]
Class of Stock [Line Items]
Depository receipt ratio	0.04
Preferred stock, liquidation preference (in usd per share)	$ 1,000
Dividend payable per share (in usd per share)	$ 12.50
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 500,000,000
Preferred stock, shares authorized (in shares) | shares	500,000
Preferred stock, shares outstanding (in shares) | shares	500,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 1,000
Depository Shares, Series E [Member]
Class of Stock [Line Items]
Depository receipt ratio	25,000
Preferred stock, liquidation preference (in usd per share)	$ 25
Dividend payable per share (in usd per share)	$ 0.382813
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 425,000,000
Preferred stock, shares authorized (in shares) | shares	425,000
Preferred stock, shares outstanding (in shares) | shares	425,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 1,000
Depository Shares, Series F [Member]
Class of Stock [Line Items]
Depository receipt ratio	25,000
Preferred stock, liquidation preference (in usd per share)	$ 25
Dividend payable per share (in usd per share)	$ 0.353125
Series G Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 450,000,000
Preferred stock, shares authorized (in shares) | shares	450,000
Preferred stock, shares outstanding (in shares) | shares	450,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 1,000
Depository Shares, Series G [Member]
Class of Stock [Line Items]
Depository receipt ratio	25,000
Dividend payable per share (in usd per share)	$ 0.351563

Shareholders' Equity - Key's an

Shareholders' Equity - Key's and KeyBank's Actual Capital Amounts and Ratios, Minimum Capital Amounts and Ratios (Details) $ in Millions	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Key [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Net Risk-Weighted Assets, Actual Amount	$ 17,976	$ 16,731
Tier 1 Capital to Average Quarterly Tangible Assets, Amount	14,907	14,207
Tier 1 Capital to Net Risk-Weighted Assets, Actual Amount	$ 14,907	$ 14,207
Total Capital to Net Risk-Weighted Assets, Actual Ratio	0.1340	0.1279
Tier 1 Capital to Net Risk-Weighted Assets, Actual Ratio	0.1111	0.1086
Tier 1 Capital to Average Quarterly Tangible Assets, Actual Ratio	0.0894	0.0987
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	$ 10,736	$ 10,469
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	8,052	7,852
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Amount	$ 6,671	$ 5,756
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	0.0800	0.0800
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	0.0600	0.0600
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Ratio	0.0400	0.0400
KeyBank (consolidated) [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Net Risk-Weighted Assets, Actual Amount	$ 17,195	$ 16,313
Tier 1 Capital to Average Quarterly Tangible Assets, Amount	14,539	14,091
Tier 1 Capital to Net Risk-Weighted Assets, Actual Amount	$ 14,539	$ 14,091
Total Capital to Net Risk-Weighted Assets, Actual Ratio	0.1309	0.1269
Tier 1 Capital to Net Risk-Weighted Assets, Actual Ratio	0.1107	0.1096
Tier 1 Capital to Average Quarterly Tangible Assets, Actual Ratio	0.0880	0.0991
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	$ 10,511	$ 10,287
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	7,884	7,715
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Amount	$ 6,605	$ 5,688
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	0.0800	0.0800
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	0.0600	0.0600
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Ratio	0.0400	0.0400
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	$ 13,139	$ 12,858
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	10,511	7,715
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	$ 8,256	$ 7,110
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	0.1000	0.1000
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	0.0800	0.0600
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	5.00%	5.00%

Business Segment Reporting - Na

Business Segment Reporting - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019USD ($)segment	Dec. 31, 2020USD ($)segmentbranchsector	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2	2
Goodwill		$ 2,664	$ 2,664	$ 2,516
Consumer Bank [Member]
Segment Reporting Information [Line Items]
Goodwill	$ 1,600	$ 1,752	$ 1,752	2,102
Number of state branch network | branch		15
Commercial Bank [Member]
Segment Reporting Information [Line Items]
Goodwill	$ 912	$ 912		$ 414
Number of business units | sector		7

Business Segment Reporting - Fi

Business Segment Reporting - Financial Information of Business Groups (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)employee	Dec. 31, 2019USD ($)employee	Dec. 31, 2018USD ($)employee
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 4,063	$ 3,941	$ 3,940
Noninterest income	2,652	2,459	2,515
Total revenue (TE)	6,715	6,400	6,455
Provision for credit losses	1,021	445	246
Depreciation and amortization expense	361	374	400
Other noninterest expense	3,748	3,527	3,575
Income (loss) from continuing operations before income taxes (TE)	1,585	2,054	2,234
Allocated income taxes (benefit) and TE adjustments	256	346	375
INCOME (LOSS) FROM CONTINUING OPERATIONS	1,329	1,708	1,859
Income (loss) from discontinued operations, net of taxes	14	9	7
NET INCOME (LOSS)	1,343	1,717	1,866
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	1,343	1,717	1,866
AVERAGE BALANCES
Loans and leases	102,689	91,511	88,338
Total assets	162,055	143,179	136,812
Deposits	127,286	110,030	105,051
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	161	245	48
Net loan charge-offs	$ 443	$ 424	$ 234
Return on average allocated equity, continuing operations (as a percentage)	7.54%	10.27%	12.29%
Return on average allocated equity (as a percentage)	7.62%	10.32%	12.33%
Average full-time equivalent employees | employee	16,826	17,045	18,180
Provision for credit loss, net of tax, related to previously disclosed fraud incident		$ (139)
Operating Segments [Member] | Consumer Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 2,434	2,366	$ 2,306
Noninterest income	1,003	922	915
Total revenue (TE)	3,437	3,288	3,221
Provision for credit losses	288	188	147
Depreciation and amortization expense	77	97	103
Other noninterest expense	2,200	2,078	2,143
Income (loss) from continuing operations before income taxes (TE)	872	925	828
Allocated income taxes (benefit) and TE adjustments	207	219	196
INCOME (LOSS) FROM CONTINUING OPERATIONS	665	706	632
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	665	706	632
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	665	706	632
AVERAGE BALANCES
Loans and leases	38,906	32,536	31,307
Total assets	42,953	36,096	34,523
Deposits	79,811	72,544	68,821
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	40	150	(38)
Net loan charge-offs	$ 134	$ 157	$ 149
Return on average allocated equity, continuing operations (as a percentage)	18.92%	21.30%	19.24%
Return on average allocated equity (as a percentage)	18.92%	21.30%	19.24%
Average full-time equivalent employees | employee	8,213	9,292	9,957
Operating Segments [Member] | Commercial Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 1,698	$ 1,621	$ 1,657
Noninterest income	1,507	1,390	1,328
Total revenue (TE)	3,205	3,011	2,985
Provision for credit losses	738	118	102
Depreciation and amortization expense	144	135	139
Other noninterest expense	1,589	1,408	1,430
Income (loss) from continuing operations before income taxes (TE)	734	1,350	1,314
Allocated income taxes (benefit) and TE adjustments	101	219	207
INCOME (LOSS) FROM CONTINUING OPERATIONS	633	1,131	1,107
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	633	1,131	1,107
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	633	1,131	1,107
AVERAGE BALANCES
Loans and leases	63,108	57,988	55,828
Total assets	72,056	66,122	63,684
Deposits	46,862	36,212	33,675
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	1	(8)	(17)
Net loan charge-offs	$ 309	$ 128	$ 85
Return on average allocated equity, continuing operations (as a percentage)	12.86%	24.99%	24.94%
Return on average allocated equity (as a percentage)	12.86%	24.99%	24.94%
Average full-time equivalent employees | employee	2,093	2,232	2,449
Corporate And Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ (69)	$ (46)	$ (23)
Noninterest income	142	147	272
Total revenue (TE)	73	101	249
Provision for credit losses	(5)	139	(3)
Depreciation and amortization expense	140	142	158
Other noninterest expense	(41)	61	2
Income (loss) from continuing operations before income taxes (TE)	(21)	(241)	92
Allocated income taxes (benefit) and TE adjustments	(52)	(96)	(28)
INCOME (LOSS) FROM CONTINUING OPERATIONS	31	(145)	120
Income (loss) from discontinued operations, net of taxes	14	9	7
NET INCOME (LOSS)	45	(136)	127
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	45	(136)	127
AVERAGE BALANCES
Loans and leases	675	987	1,203
Total assets	47,046	40,961	38,605
Deposits	613	1,274	2,555
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	120	103	103
Net loan charge-offs	$ 0	$ 139	$ 0
Return on average allocated equity, continuing operations (as a percentage)	0.34%	(1.66%)	1.62%
Return on average allocated equity (as a percentage)	0.49%	(1.56%)	1.71%
Average full-time equivalent employees | employee	6,520	5,521	5,774
Provision for credit loss, net of tax, related to previously disclosed fraud incident	$ 106

Condensed Financial Informati_3

Condensed Financial Information of the Parent Company - Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Cash and due from banks	$ 1,091	$ 732
Short-term investments	16,194	1,272
Securities available for sale	27,556	21,843
Goodwill	2,664	2,664	$ 2,516
Corporate-owned life insurance	4,286	4,233
Derivative assets	1,798	780
Accrued income and other assets	6,812	5,494
Total assets	170,336	144,988
Accrued expense and other liabilities	2,385	2,540
Total long-term debt	13,709	12,448
Total liabilities	152,355	127,950
SHAREHOLDERS' EQUITY	17,981	17,038
Total liabilities and equity	170,336	144,988
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and due from banks	3,799	3,813
Short-term investments	21	20
Securities available for sale	12	10
Other investments	43	36
Total loans	66	66
Total investment in subsidiaries	18,545	17,792
Goodwill	167	167
Corporate-owned life insurance	207	205
Derivative assets	100	44
Accrued income and other assets	299	295
Total assets	23,259	22,448
Accrued expense and other liabilities	505	492
Long term debt due to Subsidiaries	500	483
Total long-term debt	4,773	4,918
Total liabilities	5,278	5,410
SHAREHOLDERS' EQUITY	17,981	17,038
Total liabilities and equity	23,259	22,448
Key [Member] | Banks [Member]
Condensed Financial Statements, Captions [Line Items]
Total loans	50	50
Investment in subsidiaries	17,645	16,969
Key [Member] | Nonbank Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Total loans	16	16
Investment in subsidiaries	900	823
Key [Member] | Unaffiliated Companies [Member]
Condensed Financial Statements, Captions [Line Items]
Total long-term debt	$ 4,273	$ 4,435

Condensed Financial Informati_4

Condensed Financial Information of the Parent Company - Condensed Statements of Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Other income	[1]	$ 15	$ 68	$ 176
Total interest income		4,685	5,235	4,878
Interest on long-term debt with subsidiary trusts		286	454	420
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		1,585	2,054	2,234
Income tax (expense) benefit		(227)	(314)	(344)
NET INCOME (LOSS)		1,343	1,717	1,866
Less: Net income attributable to noncontrolling interests		0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,343	1,717	1,866
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Interest income from subsidiaries		4	9	11
Other income		8	11	11
Total interest income		1,262	1,294	1,697
Interest on long-term debt with subsidiary trusts		18	22	20
Interest on other borrowed funds		114	151	137
Personnel and other expense		63	87	69
Total expense		195	260	226
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		1,067	1,034	1,471
Income tax (expense) benefit		38	57	55
Income (loss) before equity in net income (loss) less dividends from subsidiaries		1,105	1,091	1,526
Equity in net income (loss) less dividends from subsidiaries		238	626	340
NET INCOME (LOSS)		1,343	1,717	1,866
Less: Net income attributable to noncontrolling interests		0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,343	1,717	1,866
Key [Member] | Banks [Member]
Condensed Financial Statements, Captions [Line Items]
Bank/Nonbank subsidiaries		1,250	1,204	1,675
Key [Member] | Nonbank Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Bank/Nonbank subsidiaries		$ 0	$ 70	$ 0
[1]	Net securities gains (losses) totaled $4 million for the year ended December 31, 2020, $20 million for the year ended December 31, 2019, and less than $1 million for the year ended December 31, 2018. For 2020, 2019, and 2018, we did not have any impairment losses related to securities.

Condensed Financial Informati_5

Condensed Financial Information of the Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net income (loss) attributable to Key	$ 1,343	$ 1,717	$ 1,866
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income taxes (benefit)	(191)	53	98
Stock-based compensation expense	101	96	99
Other operating activities, net	(893)	560	14
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	1,673	2,906	2,506
INVESTING ACTIVITIES
Net decrease (increase) in short-term investments, excluding acquisitions	(14,922)	1,290	1,885
Proceeds from sales, prepayments and maturities of securities available for sale	9,923	3,586	3,197
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(24,721)	(4,918)	(2,482)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	3,607	2,129	2,306
Payments on long-term debt	(2,508)	(3,634)	(2,880)
Repurchase of Treasury Shares	(134)	(835)	(1,098)
Cash dividends paid	(829)	(804)	(656)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	23,407	2,066	(17)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	359	54	7
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	732	678	671
CASH AND DUE FROM BANKS AT END OF YEAR	1,091	732	678
Key [Member]
OPERATING ACTIVITIES
Net income (loss) attributable to Key	1,343	1,717	1,866
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income taxes (benefit)	2	(43)	109
Stock-based compensation expense	11	8	8
Equity in net (income) loss less dividends from subsidiaries	(238)	(626)	(340)
Net (increase) decrease in other assets	(66)	39	(58)
Net increase (decrease) in other liabilities	12	11	8
Other operating activities, net	131	244	79
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	1,195	1,350	1,672
INVESTING ACTIVITIES
Net decrease (increase) in short-term investments, excluding acquisitions	(7)	(6)	1
Cash infusion from purchase of Cain Brothers	0	0	0
Proceeds from sales, prepayments and maturities of securities available for sale	0	0	0
Net (increase) decrease in loans to subsidiaries	0	15	200
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(7)	9	201
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	800	750	1,250
Payments on long-term debt	(1,003)	(300)	(750)
Repurchase of Treasury Shares	(170)	(868)	(1,145)
Net cash from the issuance (redemption) of Common Shares and preferred stock	0	435	412
Cash dividends paid	(829)	(804)	(656)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(1,202)	(787)	(889)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	(14)	572	984
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	3,813	3,241	2,257
CASH AND DUE FROM BANKS AT END OF YEAR	$ 3,799	$ 3,813	$ 3,241

Condensed Financial Informati_6

Condensed Financial Information of the Parent Company - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Interest paid	$ 731	$ 1,251	$ 892
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Interest paid	$ 204	$ 151	$ 131

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Other noninterest income	$ 1,082	$ 1,010
Noninterest income	2,652	2,459	$ 2,515
Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,428	1,302
Operating Segments [Member] | Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	441	419
Operating Segments [Member] | Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	305	263
Operating Segments [Member] | Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	311	337
Operating Segments [Member] | Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	361	270
Operating Segments [Member] | Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10	13
Operating Segments [Member] | Consumer Bank [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	733	760
Noninterest income	1,003	922	915
Operating Segments [Member] | Consumer Bank [Member] | Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	374	355
Operating Segments [Member] | Consumer Bank [Member] | Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
Operating Segments [Member] | Consumer Bank [Member] | Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	189	228
Operating Segments [Member] | Consumer Bank [Member] | Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	160	164
Operating Segments [Member] | Consumer Bank [Member] | Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10	13
Operating Segments [Member] | Commercial Bank [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	695	542
Noninterest income	1,507	1,390	1,328
Operating Segments [Member] | Commercial Bank [Member] | Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	67	64
Operating Segments [Member] | Commercial Bank [Member] | Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	305	263
Operating Segments [Member] | Commercial Bank [Member] | Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	122	109
Operating Segments [Member] | Commercial Bank [Member] | Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	201	106
Operating Segments [Member] | Commercial Bank [Member] | Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
Corporate And Reconciling Items [Member]
Disaggregation of Revenue [Line Items]
Noninterest income	142	147	$ 272
Segment Reconciling Items [Member]
Disaggregation of Revenue [Line Items]
Noninterest income	$ 2,652	$ 2,459