| Document and Entity Information | Oct. 29, 2019 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | ELI LILLY & Co |
| Amendment Flag | false |
| Entity Central Index Key | 0000059478 |
| Document Type | 8-K |
| Document Period End Date | Oct. 29, 2019 |
| Entity Incorporation State Country Code | IN |
| Entity File Number | 001-06351 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Class A [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock (no par value) |
| Trading Symbol | LLY |
| Security Exchange Name | NYSE |
| A 1.000 Notes Due June 22022 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.000% Notes Due June 2, 2022 |
| Trading Symbol | LLY22 |
| Security Exchange Name | NYSE |
| A 718 Notes Due June 12025 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 7 1/8% Notes Due June 1, 2025 |
| Trading Symbol | LLY25 |
| Security Exchange Name | NYSE |
| A 1.625 Notes Due June 22026 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.625% Notes Due June 2, 2026 |
| Trading Symbol | LLY26 |
| Security Exchange Name | NYSE |
| A 2.125 Notes Due June 32030 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 2.125% Notes Due June 3, 2030 |
| Trading Symbol | LLY30 |
| Security Exchange Name | NYSE |
| A 6.77 Notes Due January 12036 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 6.77% Notes Due January 1, 2036 |
| Trading Symbol | LLY36 |
| Security Exchange Name | NYSE |
