Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cost of pension plans:
Service cost for benefits earned	$ 7,191	$ 12,560
Interest cost on benefit obligation	12,548	9,941
Expected return on plan assets	(17,218)	(13,639)
Prior service cost amortization	362	361
Net actuarial (gain) loss amortization	(3,833)	1,830
Pension plan (income) cost	$ (950)	$ 11,053
Defined benefit plan, net periodic benefit cost (credit) excluding service cost, statement of income or comprehensive income	Other income
Employee pension plan | Funded Plan | Qualified Plan
Postretirement Benefits
Funding target (as a percentage of the funding target liability)	100.00%
Expected future employer contributions	$ 95,000
Erie Insurance Exchange | Employee pension plan | Funded Plan | Qualified Plan
Postretirement Benefits
Postretirement annual benefit income and expense reimbursed to and from, respectively, the Exchange and its subsidiaries (as a percent)	60.00%
Erie Insurance Exchange | Supplemental employee retirement plan (SERP) | Unfunded Plan | Nonqualified Plan
Postretirement Benefits
Postretirement annual benefit income and expense reimbursed to and from, respectively, the Exchange and its subsidiaries (as a percent)	36.00%