Incentive and Deferred Compensation Plans - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) plan performance shares	Dec. 31, 2024	Dec. 31, 2023
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Number of incentive plans for executives, senior vice presidents and other selected officers | plan	2
Number of deferred compensation plans for executives, senior vice presidents and other selected officers | plan	2
Number of deferred compensation plans for outside directors | plan	2
Annual Incentive Plan
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Maximum percentage of employee compensation that can be deferred (as a percent)	100.00%
Long-Term Incentive Plan
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Maximum percentage of employee compensation that can be deferred (as a percent)	100.00%
Vesting period of performance and/or service condition(s)	3 years
Number of performance periods | performance	3
Total unrecognized compensation cost related to share-based compensation plan awards pertaining to open performance periods | $	$ 7.9
Expected period of recognition related to unrecognized compensation cost (in years)	2 years
Long-Term Incentive Plan | Erie Insurance Exchange (EIE)
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Compensation cost reimbursed to Indemnity from the Exchange and its subsidiaries (as a percent)	36.00%	39.00%	35.00%
Long-Term Incentive Plan | Class A common stock
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Maximum number of shares authorized for grant (in shares)	1,500,000
Long-Term Incentive Plan | Performance-Vesting Award
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Vesting percent of the grant (as a percent)	75.00%
Long-Term Incentive Plan | Time-Vesting Award
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Vesting percent of the grant (as a percent)	25.00%
Incentive Compensation Deferral Plan | Class A common stock
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Vesting percent of the grant (as a percent)	100.00%
Payment period for vested share credits (in years)	3 years
Stock Compensation Plan Outside Directors | Class A common stock
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Maximum number of shares authorized for grant (in shares)	250,000
Maximum period shares may be credited	10 years
Stock Compensation Plan Outside Directors | Three Month Vesting Period | Class A common stock
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Vesting period of performance and/or service condition(s)	3 months
Vesting percent of the grant (as a percent)	25.00%
Equity Compensation Plan
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Total unrecognized compensation cost related to share-based compensation plan awards pertaining to open performance periods | $	$ 0.5
Equity Compensation Plan | Erie Insurance Exchange (EIE)
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Compensation cost reimbursed to Indemnity from the Exchange and its subsidiaries (as a percent)	32.00%	35.00%	35.00%
Equity Compensation Plan | Class A common stock
Schedule of Incentive Plans and Deferred Compensation [Line Items]
Maximum number of shares authorized for grant (in shares)	250,000
Maximum number of shares which may be received by any single participant during any specified period (in shares)	10,000