Postretirement Benefits - Cost of Pension Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cost of pension plans:
Service cost for benefits earned	$ 50,242	$ 53,041	$ 43,492
Interest cost on benefit obligation	39,764	36,824	37,578
Expected return on plan assets	(54,557)	(50,275)	(49,411)
Prior service cost amortization	1,443	1,428	1,343
Net actuarial loss amortization	7,320	16,106	12,125
Pension plan cost	$ 44,212	$ 57,124	$ 45,127
Defined benefit plan, net periodic benefit cost (credit) excluding service cost, statement of income or comprehensive income	Other income (expense)
Erie Insurance Exchange (EIE)
Postretirement benefits
Postretirement annual benefit expense reimbursed to Indemnity from the Exchange and its subsidiaries	58.00%