Cover Page
Jul. 08, 2020
Entity Information [Line Items]  
Document Type 8-K
Document Period End Date Jul. 08, 2020
Entity Registrant Name KeyCorp
Entity Incorporation, State or Country Code OH
Entity File Number 001-11302
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
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Amendment Flag false
Entity Central Index Key 0000091576
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 Depositary Shares (each representing a 1/40th interest in a share of Fixed-to-Floating Rate 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 Depositary Shares (each representing a 1/40th interest in a share of Fixed Rate Perpetual Non-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 Depositary Shares (each representing a 1/40th interest in a share of Fixed Rate Perpetual Non-Cumulative Preferred Stock, Series G)
Trading Symbol KEY PrK
Security Exchange Name NYSE