| Document and Entity Information | Feb. 25, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 25, 2021 |
| Entity Registrant Name | ERIE INDEMNITY COMPANY |
| Entity Incorporation, State or Country Code | PA |
| Entity File Number | 0-24000 |
| Entity Tax Identification Number | 25-0466020 |
| Entity Address, Address Line One | 100 Erie Insurance Place, |
| Entity Address, City or Town | Erie, |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 16530 |
| City Area Code | 814 |
| Local Phone Number | 870-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A common stock, |
| Trading Symbol | ERIE |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000922621 |
| Amendment Flag | false |
