Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 12, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Entity File Number	001-06351
Entity Registrant Name	ELI LILLY AND COMPANY
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-0470950
Entity Address, Address Line One	Lilly Corporate Center
Entity Address, City or Town	Indianapolis
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46285
City Area Code	317
Local Phone Number	276-2000
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			$ 138,907
Entity Common Stock, Shares Outstanding (in shares)		958,425,693
Document Transition Report	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000059478
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement for the 2021 Annual Meeting of Shareholders have been incorporated by reference into Part III of this report.
Common Stock (no par value)
Document Information [Line Items]
Title of 12(b) Security	Common Stock (no par value)
Trading Symbol	LLY
Security Exchange Name	NYSE
1.000% Notes due 2022
Document Information [Line Items]
Title of 12(b) Security	1.000% Notes due 2022
Trading Symbol	LLY22
Security Exchange Name	NYSE
7 1/8% Notes due 2025
Document Information [Line Items]
Title of 12(b) Security	7 1/8% Notes due 2025
Trading Symbol	LLY25
Security Exchange Name	NYSE
1.625% Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	1.625% Notes due 2026
Trading Symbol	LLY26
Security Exchange Name	NYSE
2.125% Notes due 2030
Document Information [Line Items]
Title of 12(b) Security	2.125% Notes due 2030
Trading Symbol	LLY30
Security Exchange Name	NYSE
0.625% Notes due 2031
Document Information [Line Items]
Title of 12(b) Security	0.625% Notes due 2031
Trading Symbol	LLY31
Security Exchange Name	NYSE
6.77% Notes due 2036
Document Information [Line Items]
Title of 12(b) Security	6.77% Notes due 2036
Trading Symbol	LLY36
Security Exchange Name	NYSE
1.700% Notes due 2049
Document Information [Line Items]
Title of 12(b) Security	1.700% Notes due 2049
Trading Symbol	LLY49A
Security Exchange Name	NYSE