Investments - Impairments on Available-For-Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Available-for-sale securities:
Intent to sell	$ (149)	$ (31)	$ (1,581)	$ (101)
Credit impaired	(22)	(7)	(223)	(153)
Net impairment losses recognized in earnings	$ (171)	$ (38)	$ (1,804)	$ (254)

Amount of impairment recognized in earnings on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from intent to sell or more likely than not will be required to sell before recovery of amortized cost basis.

No definition available.

Name:	erie_DebtSecuritiesAvailableforsaleSellbeforeRecovery
Namespace Prefix:	erie_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration