Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 22, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	0-24000
Entry Registrant Name	ERIE INDEMNITY COMPANY
Entity Incorporation, State or Country Code	PA
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
Title of 12(b) Security	Class A common stock,
Trading Symbol	ERIE
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Central Index Key	0000922621
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		46,189,068
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,542