Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Postretirement Benefits
Defined benefit plan, funded percentage		100.00%		100.00%
Cost of pension plans:
Service cost for benefits earned		$ 12,561	$ 13,260	$ 25,121	$ 26,520
Interest cost on benefits obligation		9,941	9,206	19,882	18,412
Expected return on plan assets		(13,639)	(12,568)	(27,278)	(25,137)
Prior service cost amortization		360	357	721	714
Net actuarial loss amortization		1,830	4,026	3,660	8,053
Pension plan cost		$ 11,053	$ 14,281	$ 22,106	$ 28,562
Forecast
Postretirement Benefits
Defined benefit plan, plan assets, contributions by employer	$ 25,000
Erie Insurance Exchange
Postretirement Benefits
Postretirement annual benefit expense reimbursed to Indemnity from the Exchange and its subsidiaries (as a percent)				58.00%